The smell arising during the fermentation process is called. Fermentation of food products and its significance. What is fermentation anyway?

Biopolymers

General information
There are two main types of biopolymers: polymers that come from living organisms, and polymers that come from renewable resources but require polymerization. Both types are used to produce bioplastics. Biopolymers, present in or created by living organisms, contain hydrocarbons and proteins (proteins). They can be used in the production of plastics for commercial purposes. Examples include:

Biopolymers existing/created in living organisms

Molecules from renewable natural resources can be polymerized for use in the production of biodegradable plastics.

Eating Natural sources polymerizable into plastics

Two methods are used to produce plastic materials from plants. The first method is based on fermentation, and the second uses the plant itself to produce plastic.

Fermentation
The fermentation process uses microorganisms to break down organic matter in the absence of oxygen. Today's conventional processes use genetically engineered microorganisms specifically designed for the conditions under which fermentation occurs and a substance degraded by the microorganism. Currently, there are two approaches to creating biopolymers and bioplastics:
- Bacterial polyester fermentation: Fermentation involves the bacteria ralstonia eutropha, which uses the sugars of harvested plants, such as grains, to fuel its own cellular processes. A by-product of such processes is a polyester biopolymer, which is subsequently extracted from bacterial cells.
- Lactic acid fermentation: Lactic acid is produced by fermentation from sugar, much like the process used to directly produce polyester polymers using bacteria. However, in this fermentation process, the by-product is lactic acid, which is then processed through traditional polymerization to produce polylactic acid (PLA).

Plastics from plants
Plants have great potential to become plastic factories. This potential can be maximized through genomics. The resulting genes can be introduced into grain, using technologies that allow the development of new plastic materials with unique properties. This genetic engineering gave scientists the opportunity to create the Arabidopsis thaliana plant. It contains enzymes that bacteria use to make plastics. The bacterium creates plastic by converting sunlight into energy. Scientists transferred the gene encoding this enzyme into a plant, allowing the plant's cellular processes to produce plastic. After harvesting, the plastic is released from the plant using a solvent. The resulting liquid from this process is distilled to separate the solvent from the resulting plastic.

Biopolymer market

Bridging the gap between synthetic polymers and biopolymers
About 99% of all plastics are produced or derived from major non-renewable energy sources, including natural gas, naphtha, crude oil, and coal, which are used in the production of plastics both as feedstocks and as an energy source. At one time, agricultural materials were considered an alternative feedstock for plastics production, but for more than a decade they have not met the expectations of developers. The main obstacle to the use of plastics made from agricultural raw materials has been their cost and limited functionality (sensitivity of starch products to moisture, fragility of polyhydroxybutyrate), as well as lack of flexibility in the production of specialized plastic materials.

Projected CO2 emissions

A combination of factors, soaring oil prices, increased worldwide interest in renewable resources, rising concerns about greenhouse gas emissions, and increased focus on waste management have renewed interest in biopolymers and efficient ways to produce them. New technologies for growing and processing plants are reducing the cost difference between bioplastics and synthetic plastics, as well as improving material properties (for example, Biomer is developing PHB (polyhydroxybutyrate) grades with increased melt strength for extrusion films). Growing environmental concerns and legislative incentives, particularly in the European Union, have stimulated interest in biodegradable plastics. The implementation of the principles of the Kyoto Protocol also forces us to pay special attention to the comparative effectiveness of biopolymers and synthetic materials in terms of energy consumption and CO2 emissions. (In accordance with the Kyoto Protocol, the European Community undertakes to reduce greenhouse gas emissions into the atmosphere by 8% over the period 2008-2012 compared to 1990 levels, and Japan undertakes to reduce such emissions by 6%).
It is estimated that starch-based plastics can save between 0.8 and 3.2 tonnes of CO2 per tonne compared to a tonne of fossil fuel-derived plastics, with this range reflecting the proportion of petroleum-based copolymers used in plastics. For alternative oil grain-based plastics, CO2 equivalent greenhouse gas savings are estimated at 1.5 tonnes per tonne of polyol made from rapeseed oil.

World market of biopolymers
Over the next ten years, the rapid growth in the global plastics market experienced over the past fifty years is expected to continue. According to forecasts, today's per capita consumption of plastics in the world will increase from 24.5 kg to 37 kg in 2010. This growth is driven primarily by the United States, Western European countries and Japan, however, active participation is expected from countries in Southeast and Eastern Europe. Asia and India, which should account for about 40% of the global plastics consumption market during this period. Global plastic consumption is also expected to increase from 180 million tons today to 258 million tons in 2010, with significant growth in all categories of polymers as plastics continue to displace traditional materials including steel, wood and glass. According to some expert estimates, during this period bioplastics will be able to firmly occupy from 1.5% to 4.8% of the total plastics market, which in quantitative terms will range from 4 to 12.5 million tons, depending on the technological level of development and research in the field of new bioplastics polymers. According to Toyota management, by 2020, a fifth of the global plastics market will be occupied by bioplastics, which is equivalent to 30 million tons.

Marketing Strategies for Biopolymers
Developing, refining and executing an effective marketing strategy is the most critical step for any company planning to invest heavily in biopolymers. Despite the guaranteed development and growth of the biopolymer industry, there are certain factors that cannot be ignored. The following questions determine marketing strategies for biopolymers, their production and research activities in this area:
- Selection of market segment (packaging, agriculture, automotive, construction, target markets). Improved biopolymer processing technologies provide more efficient control of macromolecular structures, allowing new generations of “consumer” polymers to compete with more expensive “specialty” polymers. In addition, with the availability of new catalysts and improved polymerization control, a new generation of specialized polymers is emerging, created for functional and structural purposes and generating new markets. Examples include biomedical applications of implants in dentistry and surgery, which are rapidly increasing their pace of development.
- Basic technologies: fermentation technologies, crop production, molecular science, production of feedstocks, energy sources or both, use of genetically modified or unmodified organisms in the process of fermentation and biomass production.
- Level of support from government policy and the legislative environment in general: recycled plastics compete to some extent with biodegradable polymers. Government regulations and legislation related to the environment and recycling can have a positive impact on increasing plastics sales for a variety of polymers. Meeting Kyoto Protocol commitments is likely to increase demand for certain bio-based materials.
- Supply chain developments in the fragmented biopolymers industry and the commercial impact of economies of scale versus product enhancements that can be sold at higher prices.

Biodegradable and petroleum-free polymers

Plastics with low environmental impact
There are three groups of biodegradable polymers on the market. These are PHA (phytohemagglutinin) or PHB, polylactides (PLA) and starch-based polymers. Other materials that have commercial applications in the field of biodegradable plastics are lignin, cellulose, polyvinyl alcohol, poly-e-caprolactone. There are many manufacturers producing blends of biodegradable materials, either to improve the properties of these materials or to reduce production costs.
To improve process parameters and increase toughness, PHB and its copolymers are mixed with a range of polymers with different characteristics: biodegradable or non-degradable, amorphous or crystalline with different melt and glass transition temperatures. Blends are also used to improve the properties of PLA. Conventional PLA behaves much like polystyrene, exhibiting brittleness and low elongation at break. But, for example, the addition of 10-15% Eastar Bio, a biodegradable polyester-based petroleum product produced by Novamont (formerly Eastman Chemical), significantly increases viscosity and, accordingly, flexural modulus, as well as impact strength. To improve biodegradability while reducing costs and conserving resources, it is possible to mix polymeric materials with natural products, such as starches. Starch is a semi-crystalline polymer consisting of amylase and amylopectin with different ratios depending on the plant material. Starch is water soluble, and the use of compatibilizers can be critical to successfully blending this material with otherwise incompatible hydrophobic polymers.

Comparing the properties of bioplastics with traditional plastics

Properties of PHB compared to traditional plastics

In terms of comparative cost, existing petroleum-based plastics are less expensive than bioplastics. For example, industrial and medical grades of high-density polyethylene (HDPE), also used in packaging and consumer products, range from $0.65 to $0.75 per pound. The price of low density polyethylene (LDPE) is $0.75-$0.85 per pound. Polystyrenes (PS) average $0.65 to $0.85 per pound, polypropylenes (PP) average $0.75 to $0.95 per pound, and polyethylene terephthalates (PET) average $0.90 to $1. $25 per pound. In comparison, polylactide plastics (PLA) cost between $1.75 and $3.75 per pound, starch-derived polycaprolactones (PCL) cost $2.75 to $3.50 per pound, and polyhydroxybutyrates (PHB) $4.75 - $7.50 per pound. Currently, taking into account comparative overall prices, bioplastics are 2.5 to 7.5 times more expensive than traditional common petroleum-based plastics. However, just five years ago, their cost was 35 to 100 times higher than existing non-renewable fossil fuel equivalents.

Polylactides (PLA)
PLA is a biodegradable thermoplastic made from lactic acid. It is water resistant but cannot withstand high temperatures (>55°C). Because it is insoluble in water, microbes in the marine environment can also break it down into CO2 and water. The plastic is similar to pure polystyrene, has good aesthetic qualities (gloss and transparency), but is too rigid and brittle and needs to be modified for most practical applications (i.e. its elasticity is increased by plasticizers). Like most thermoplastics, it can be processed into fibers, films, thermoformed or injection molded.

Structure of polylactide

During the production process, grains are usually first ground to produce starch. The starch is then processed to produce crude dextrose, which is converted to lactic acid by fermentation. Lactic acid is condensed to produce lactide, a cyclic intermediate dimer that is used as a monomer for biopolymers. Lactide is purified by vacuum distillation. A solvent-free melt process then opens the ring structure for polymerization, thus producing a polylactic acid polymer.

Tensile modulus

Notched Izod strength

Flexural modulus

Tensile elongation

NatureWorks, a subsidiary of Cargill, the largest privately held company in the United States, produces polylactide polymer (PLA) from renewable resources using proprietary technology. As a result of 10 years of research and development at NatureWorks and a $750 million investment, the Cargill Dow joint venture (now a wholly owned subsidiary of NatureWorks LLC) was formed in 2002 with an annual production capacity of 140,000 tons. Grain-derived polylactides, marketed under the NatureWorks PLA and Ingeo brands, primarily find their applications in thermal packaging, extruded films and fibers. The company is also developing technical capabilities for the production of injection molded products.

PLA compost bin

PLA, like PET, requires drying. The processing technology is similar to LDPE. Recyclates can be re-polymerized or ground and reused. The material is completely biochemically degradable. Originally used in thermoplastic sheet molding, film and fiber production, today this material is also used for blow molding. Like PET, grain-based plastics produce a range of varied and complex bottle shapes in all sizes and are used by Biota to stretch blow mold bottles for premium spring water bottling. NatureWorks PLA single-layer bottles are molded on the same injection/orientation blow molding equipment used for PET without sacrificing productivity. Although the barrier effectiveness of NatureWorks PLA is lower than PET, it can compete with polypropylene. Moreover, SIG Corpoplast is currently developing the use of its "Plasmax" coating technology for such alternative materials in order to improve its barrier effectiveness and therefore expand its range of applications. NatureWorks materials lack the heat resistance of standard plastics. They begin to lose their shape at temperatures around 40°C, but the supplier is making significant progress in creating new grades that have the heat resistance of petroleum-based plastics, thereby opening up new applications in hot food packaging and beverages sold on take-out, or microwaveable foods.

Plastics that reduce oil dependence
Increased interest in reducing polymer production's dependence on petroleum resources is also driving the development of new polymers or formulations. Given the growing need to reduce dependence on petroleum products, special attention is being paid to the importance of maximizing the use of renewable resources as a source of raw materials. A case in point is the use of soybeans to produce bio-based polyol Soyol as the main feedstock for polyurethane.
The plastics industry uses several billion pounds of fillers and enhancers each year. Improved formulation technology and new coupling agents that allow higher loading levels of fibers and fillers are helping to expand the use of such additives. Fiber loading levels of 75 ppm may become common practice in the near future. This will have a tremendous impact on reducing the use of petroleum-based plastics. The new technology of highly filled composites demonstrates some very interesting properties. Studies of the 85% kenaf-thermoplastic composite have shown that its properties, such as flexural modulus and strength, are superior to most types of wood particles, low- and medium-density chipboards, and can even compete with oriented strand board in some applications.

The author of the book is “a rock star of the American culinary scene” - according to the New York Times, self-taught, anti-globalist, downshifter and openly gay - Sandor Elix Katz. This book, as you probably already guessed, falls out of the range of elegant culinary “coffee table books” (as in the Anglo-Saxon world they usually call weighty and colorful volumes, the purpose of which is to lie on the table in the living room and be more of a decorative element than a source of knowledge) .

The photographs in this book are worthy of special mention: looking at them, one gets the impression that they happened completely by accident. But this book is really full of unique information: how cassava is fermented, national Ethiopian flatbreads made from teff flour are baked, kvass is made in Russia (yes, even that!) and much more. The theoretical part contains data from the fields of anthropology, history, medicine, nutrition and microbiology. The book includes a large number of recipes: they are divided into several thematic parts (cooking fermented vegetables, bread, wine, dairy products).

We present here a very free translation of the chapter devoted to the beneficial properties of fermentation.

Numerous Benefits of Fermented Foods

Fermented foods literally have living flavors and contain living nutrients. Their taste is usually pronounced. Remember fragrant mature cheeses, sour sauerkraut, thick tart miso paste, rich noble wines. Of course, we can say that the taste of some fermented foods is not for everyone. However, people have always appreciated the unique flavors and appetizing aromas that products acquire thanks to the work of bacteria and fungi.

From a practical point of view, the main advantage of fermented foods is that they last longer. Microorganisms involved in the fermentation process produce alcohol, lactic and acetic acids. All these “biopreservatives” help preserve nutrients and suppress the growth of pathogenic bacteria and thus prevent spoilage of food supplies.

Vegetables, fruits, milk, fish and meat spoil quickly. And when they managed to obtain a surplus, our ancestors used all available means to preserve food supplies for as long as possible. Throughout human history, fermentation has been used for this purpose everywhere: from the tropics to the Arctic.

Captain James Cook was a famous 18th century English explorer. Thanks to his active work, the borders of the British Empire expanded significantly. In addition, Cook received recognition from the Royal Society of London - Britain's leading scientific society - for curing members of his team from scurvy (a disease caused by acute deficiency of vitamin C).Cook was able to defeat the disease thanks to the fact that during his expeditions he took on board a large supply of sauerkraut(which contains significant amounts of vitamin C).

Thanks to his discovery, Cook was able to discover many new lands, which then came under the rule of the British crown and strengthened its power, including the Hawaiian Islands, where he was subsequently killed.

The native inhabitants of the islands, the Polynesians, crossed the Pacific Ocean and settled in the Hawaiian Islands more than 1,000 years before Captain Cook's visit. Another interesting fact is that fermented foods helped them survive long journeys, just like Cook’s team! In this case, poi, a porridge made from the dense, starchy root of taro, which is still popular in Hawaii and the South Pacific region.

Fermentation not only preserves the beneficial properties of nutrients, but also helps the body absorb them. Many nutrients are complex chemical compounds, but fermentation breaks down complex molecules into simpler elements.

As an example of such a transformation of properties during fermentation, soybeans have. This is a unique protein-rich product. However, without fermentation, soy is practically indigestible by the human body (some even claim that it is toxic). During the fermentation process, complex protein molecules in soybeans are broken down, resulting in the formation of amino acids that the body can already absorb. At the same time, plant toxins contained in soybeans are broken down and neutralized. The result is traditional fermented soy products such assoy sauce, miso paste and tempeh.

These days, many people have difficulty digesting milk. The cause is lactose intolerance - milk sugar. Lactic acid bacteria in fermented milk products convert lactose into lactic acid, which is much easier to digest.

The same thing happens with gluten, a protein found in cereal plants. In the process of bacterial fermentation using sourdough starters (as opposed to yeast fermentation, which is now most often used in baking), gluten molecules are broken down, andFermented gluten is easier to digest than unfermented gluten.

According to experts from the United Nations Food and Agriculture Organization, fermented foods are a source of vital nutrients. The organization is actively working to increase the popularity of fermented foods around the world. According to the Fermentation Organizationincreases the bioavailability (i.e., the body’s ability to absorb a particular substance) of mineralspresent in products.

Bill Mollison, author of The Permaculture Book of Ferment and Human Nutrition, calls fermentation a “form of predigestion.” Pre-digestion also helps break down and neutralize certain toxic substances found in foods. We have already given soybeans as an example.

Another illustration of the process of neutralizing toxins iscassava fermentation(also known as yucca or cassava). It is a root vegetable native to South America that later became a staple food in equatorial Africa and Asia.

Cassava may contain high concentrations of cyanide. The level of this substance greatly depends on the type of soil in which the root crop grows. If the cyanide is not neutralized, then cassava cannot be eaten: it is simply poisonous. To remove the toxin, regular soaking is often used: for this, peeled and coarsely chopped tubers are placed in water for about 5 days. This allows the cyanide to be broken down and cassava to be made not only safe for consumption, but also to preserve the beneficial substances it contains.

Fermented miso soy paste of various types with additives:

But not all toxins found in foods are as dangerous as cyanide. For example, cereals and legumes (as well as nuts - editor's note) contain a compound calledphytic acid. This acid hasability to bind zinc, calcium, iron, magnesium and other minerals. As a result, these minerals will not be absorbed by the body. Fermenting grains by pre-soaking them breaks down phytic acid, thereby increasing the nutritional value of grains, legumes and nuts.

There are other potentially toxic substances that can be reduced or neutralized through fermentation. Among them are nitrites, hydrocyanic acid, oxalic acid, nitrosamines, lectins and glucosides.

Not only does fermentation break down plant toxins, but the process also produces new nutrients.
So, during its life cycle,Sourdough bacteria produce B vitamins, including folic acid (B9), riboflavin (B2), niacin (B3), thiamine (B1) and biotin (B7,H). Enzymes are also often credited with producing vitamin B12, which is missing in plant foods. However, not everyone agrees with this point of view. There is a version that the substance that is contained in fermented soybeans and vegetables is actually only similar in some respects to vitamin B12, but it does not have its active properties. This substance is called “pseudovitamin” B12.

Some enzymes produced during the fermentation processact like antioxidants, that is, they remove free radicals from the cells of the human body, which are considered to be the precursors of cancer cells.

Lactic acid bacteria (which are found in particular in sourdough bread, as well as in yoghurt, kefir and other fermented milk products - editor's note) help produce Omega-3 fatty acids, which are vital for the normal functioning of the cell membrane of human cells and the immune system.

Fermentation of vegetables produces isothiocyanates and indole-3-carbinol. Both of these substances are believed to have anti-oncological properties.

Sellers of “natural food supplements” often “proud” that “their cultivation process produces large amounts of beneficial natural substances.” Such as, for example, superoxide dismutase, or GTF-chromium (a type of chromium that is more easily absorbed by the human body and helps maintain normal blood glucose concentrations), or detoxifying compounds: glutathione, phospholipids, digestive enzymes and beta 1,3 glucans. Honestly, I just (the words of the author of the book) lose interest in the conversation when I hear such pseudoscientific facts. It is quite possible to understand how useful a product is without molecular analysis.

Trust your instincts and taste buds. Listen to your body: how you feel after consuming this or that product. Find out what science says about this. Research results confirm that fermentation increases the nutritional value of foods.

Perhaps,The greatest benefit of fermented foods lies precisely in the bacteria themselves that carry out the fermentation process. They are also called probiotics. Many fermented foods contain compact colonies of microorganisms: these colonies include many species of a wide variety of bacteria. Scientists are only now beginning to understand how bacterial colonies affect the functioning of our intestinal microflora.The interaction of microorganisms found in fermented foods with bacteria in our digestive system can improve the functioning of our digestive and immune systems, psychological aspects of health and general well-being.

However, not all fermented foods remain “alive” by the time they reach our table. Some of them, due to their nature, cannot contain live bacteria. Bread, for example, needs to be baked at high temperatures and cannot serve as a source of pribiotics (the benefits of bread are different; we do not consider them in this article). And this leads to the death of all living organisms contained in it.

Fermented products do not require such a method of preparation; they are recommended to be consumed when they still contain live bacteria, that is, without heat treatment (in our Russian reality - sauerkraut, cucumbers: pickled lingonberries, apples, plums; different types of live kvass; kombucha drink; unpasteurized live grape wines; dairy, unpasteurized fermented milk products with a short shelf life such as kefir, fermented baked milk, acidophilus, tan, matsoni, kumiss; farm cheeses, etc., editor's note). And it is in this form that fermented foods are most useful.

Sauerkraut, pickled apples:

Read food labels carefully. Remember, many fermented foods sold in stores undergo a pasteurization process or other heat treatment. This extends shelf life but kills microorganisms. You will often see the phrase “contains live cultures” on the label of fermented foods. This label indicates that live bacteria are still present in the final product.

Unfortunately, we live in a time when stores, for the most part, sell semi-finished products intended for the mass consumer, and live bacteria in such products are difficult to find. If you want to see truly “live” fermented foods on your table, you will have to look hard for them or prepare them yourself.

"Live" fermented foods are beneficial for the health of the digestive system. Therefore, they are effective in treating diarrhea and dysentery. Products containing live bacteria help fight infant mortality.

A study was conducted in Tanzania that looked at infant mortality rates. Scientists observed infants who were fed different formulas after weaning. Some children were fed porridge made from fermented cereals, others - from ordinary ones.

Infants fed fermented cereal had half the incidence of diarrhea compared to those fed unfermented cereal. The reason is that lactic acid fermentation inhibits the growth of bacteria that causes diarrhea.

According to another study published in the journal Nutrition ( Nutrition), rich intestinal microflora helps prevent the development of diseases of the digestive tract. Lactic acid bacteria “fight potential pathogens by attaching to receptors on cells in the intestinal mucosa.” Thus, diseases can be treated using “eco-immunonutrition”.

The word itself, of course, is not so easy to pronounce. But I still like the term “eco-immunonutrition”. It implies that the immune system and the bacterial microflora of the body function as a single whole.

The bacterial ecosystem consists of colonies of various microorganisms. And such a system can be created and maintained with the help of a certain diet. Eating foods high in live bacteria is one way to build a bacterial ecosystem in the body.

Tea mushroom:

The book mentioned was awarded several awards. Besides her in Katz's bibliography:

The Big Book of Kombucha

The Wild Wisdom of Weeds

Art Natural Cheese Making

Revolution Will Not Be Microvaved: inside America's underground Food movements.

Link to the book on Amazon: https://www.amazon.com/gp/product/B01KYI04CG/ref=kinw_myk_ro_title

________________________________________ _________

Fermented food product pace - useful properties and application

Tempe Tempeh is a fermented food product made from soybeans.

Preparation

Tempeh is popular in Indonesia and other Southeast Asian countries. The process of making tempeh is similar to the process of fermenting cheese. Tempeh is made from whole soybeans. The soybeans are softened, then opened or shelled and cooked, but not until cooked. Then an oxidizing agent (usually vinegar) and a starter containing beneficial bacteria are added. Under the influence of these bacteria, a fermented product is obtained that has a complex odor, which is compared to nutty, meat or mushroom, and tastes like chicken.

At low temperatures or increased ventilation, spores sometimes appear on the surface of tempeh in the form of harmless gray or black spots. This is a normal phenomenon and does not affect the taste or smell of the product. Cooked, quality tempeh has a slight ammonia smell, but the smell should not be very strong.

Tempeh is usually produced in briquettes about 1.5 cm thick. Tempeh is classified as a perishable product and cannot be stored for a long time, so it is difficult to find outside of Asia.

Usefulproperties and application

In Indonesia and Sri Lanka, tempeh is consumed as a staple food. Tempeh is rich in protein. Thanks to fermentation during the manufacturing process, the protein from tempeh is easier to digest and absorb into the body. Tempeh is a good source of dietary fiber because contains a large amount of dietary fiber, unlike tofu, which has no fiber.

Most often, tempeh cut into pieces is fried in vegetable oil with the addition of other products, sauces and spices. Tempeh is sometimes pre-soaked in a marinade or salty sauce. It's easy to prepare and only takes a few minutes to prepare. The meat-like texture allows tempeh to be used in place of meat in hamburgers or in place of chicken in salad.

Ready-made tempeh is served with a side dish, in soups, stewed or fried dishes, and also as an independent dish. Due to its low calorie content, tempeh is used as a dietary and vegetarian dish.

Compound

Tempeh contains a number of beneficial microorganisms typical of fermented foods that inhibit pathogenic bacteria. Moreover, it contains phytates, which bind with radioactive elements and remove them from the body. Tempeh, like all soy products, is very rich in protein and dietary fiber. The fungal culture used in the tempeh production process contains bacteria that produce vitamin B12, which inhibits the absorption of radioactive cobalt.

Interesting fact

Tempeh, like other soy products, does not go well with all animal protein products and animal fats, but goes well with fish and seafood. You should not eat soy products with other legumes either.

Tempeh calories

Calorie content of tempeh - from 90 to 150kcal per 100 g of product depending on the method of preparation.

Keywords

annotation scientific article on livestock and dairy farming, author of the scientific work - Babicheva Irina Andreevna, Mustafin Ramis Zufarovich

The effect of strains of probiotic preparations Bacell and Lactomicrotsikol on rumen contents was studied. The preparations include live lactobacilli, bifidobacteria, essential amino acids, organic acids, vitamins, microelements and biologically active substances. For the experiment with the microbiological preparation Bacell, bulls of the Kazakh white-headed breed were selected, and a probiotic was added to the main diet of the animals in the experimental groups in doses of 15, 25 and 35 g/animal. per day. The drug Laktomikrotsikol was introduced into the main diet of young animals of the red steppe breed in doses of 10 g/animal/day. within 3 months; 10 g in the first 7 days, then a week break and so on for 3 months; 10 g in the first 7 days, then 1 time per decade for 3 months. During the study, a shift in the indicator was noted hydrogen ion concentration in the forestomach of animals in the acidic direction by 3.2-3.6% when feeding Bacell, which, according to the authors, is explained by an increase in the concentration of VFAs in the rumen fluid of bulls by 26.7%. The use of the multienzyme drug Bacell in the diet contributed to a decrease in the concentration of ammonia in the rumen, and this decrease was noticeable only in animals receiving the probiotic at doses of 25 and 35 g/bird per day. Feeding the feed additive Laktomikrotsikol also had an effect on the rumen contents of experimental animals. Analysis of the data obtained as a result of the experiment revealed that the highest concentration of VFA in the rumen fluid was observed in bulls, to whose main diet 10 g of probiotic was added in the first 7 days, then a week break was taken and this was continued for 3 months. In the rumen contents of these animals, more volatile fatty acids before feeding (by 3.6-8.6%), as well as after feeding (by 2.8-13.4%). The results of the study are recommended to be used in farms of the Orenburg region and other regions that have similar conditions of keeping and growing young cattle Kazakh white-headed breed and red steppe breed.

Related topics scientific works on livestock and dairy farming, author of the scientific work - Babicheva Irina Andreevna, Mustafin Ramis Zufarovich

• Effect of a probiotic on the rumen contents of young red steppe breeds

  2014 / Nikulin Vladimir Nikolaevich, Mustafin Ramis Zufarovich, Biktimirov Rinat Aptlazhanovich
• 2016 / Khristianovsky Pavel Igorevich, Gontyurev Vladimir Anisimovich, Ivanov Sergey Anatolyevich

• Biochemical and microbiological indicators of rumen contents in bulls using lactoamilovorin and sodium selenite

  2014 / Biktimirov Rinat Aptlazhanovich

• Characteristics of rumen digestion in ruminants when organometallic complexes are introduced into the diet

  2017 / Kurilkina Marina Yakovlevna, Kholodilina Tatyana Nikolaevna, Muslyumova Dina Marselevna, Atlanderova Ksenia Nikolaevna, Poberukhin Mikhail Mikhailovich

• Peculiarities of ruminal digestion of bulls fed with different doses of quaterin

  2010 / Babicheva Irina Andreevna

• The influence of the fat-containing additive Palmatrix on the processes of rumen digestion in bull calves and the efficiency of their use of dietary nutrients

  2018 / Levakhin Yuri Ivanovich, Nurzhanov Baer Serekpaevich, Ryazanov Vitaly Alexandrovich, Poberukhin Mikhail Mikhailovich

• Rumen contents of young cattle fed microadditives of selenium and iodine

  2016 / Prokhorov O.N., Zubova T.V., Kolokoltsova E.A., Saparova E.I.

• The influence of various methods of feeding mixtures of sugar-containing components on the course of digestive processes in the rumen

  2011 / Kazachkova Nadezhda Mikhailovna

• Utilization of feed nutrients by bull calves when fed various doses of the probiotic Bacell

  2013 / Voroshilova Larisa Nikolaevna, Levakhin Vladimir Ivanovich

• The influence of Xylanit, Fospasim and motherwort tincture on metabolic and functional parameters in the body of female rabbits during long-term transportation

  2016 / Ibragimova Lyudmila Leonidovna, Ismagilova Elza Ravilievna

BACTERIAL FERMENTATION OF NUTRIENTS IN THE RUMEN OF CATTLE FED DIETS SUPPLEMENTED WITH PROBIOTIC PREPARATIONS

The effect of strains of the Bacell and Lactomicrotsikol probiotic preparations on the rumen contents of young cattle has been studied. The preparations include live lactobacteria, bifidobacteria, essential amino acids, organic acids, vitamins, minerals and biologically active substances. Kazakh White-Head steers were selected for the trials to test the microbiological Bacell preparation, which was added to the basic diet of animals of experimental groups in the doses of 15, 25 and 35 g/head a day. The Lactomicrotsikol supplement was introduced into the basic diet of the Red Steppe young animals in the doses of 10 g/head during 3 months; 10 g in the first 7 days, then a weekly interval, this mode of feeding being repeated during 3 months; then again 10 g in the first 7 days after the above three months, which was followed by once a decade feeding of the supplement for 3 months more. In the course of studies there was observed a shift of the hydrogen ions concentration index in the animals' gizzards to the acidic side at 3.2-3.6%, when the Bacell preparation was fed, which was believed to be due to the increase of volatile fatty acids (VFA) concentration in the rumen fluid of steers by 26.7%. The inclusion of the multi-enzyme Bacell preparation into the diet stimulated the decrease of ammonia concentration in the rumen, this reduction having been observed only in animals obtaining the probiotic in doses of 25 and 35 g/day per head. The Laktomicrotsikol supplement fed to the animals influenced the ammonia content in the rumen of animals under study. The analysis of findings obtained as a result of trials conducted revealed that the highest concentration of VFA in rumen fluid was observed in steers fed the basic diet supplemented with 10 g of the above probiotic in the first 7 days, followed with a week interval, with this mode of feeding having been repeated during the period of 3 months. In the rumen contents of these animals there was observed more volatile fatty acids before feeding (at 3.6-8.6%), and after feeding (at 2.8-13.4%) the probiotic. It is recommended to use the data, obtained in the course of studies, on the farms of Orenburg region and of other regions with similar conditions of Kazakh White-Head and Red Steppe young cattle management.

Text of scientific work on the topic “Bacterial fermentation of nutrients in the rumen when using probiotic preparations”

control group listened to harsh vesicular breathing accompanied by a cough. Combs have formed on the paws. Two rabbits had a strong, loud, short, superficial cough, the larynx area was swollen, and the body temperature increased (44.2°C), which indicated inflammation of the larynx and trachea. In III gr. Corresponding signs of rhinitis were noted in only two individuals, the rest were in a healthy condition. In female rabbits of groups IV and V, clinical signs of rhinitis did not appear.

Conclusion. Administration before transportation of the drug Xylanit in a dose of 0.45 ml per head or the homeopathic drug Fospasim, 0.4 ml per head, twice - before transportation and after unloading on the first day of adaptation, then orally 12-13 drops daily for 7 days. prevents disruption of metabolic and functional changes in the body and thereby reduces emotional stress, improves the adaptation process of Californian breed rabbits during long-term transportation.

Literature

1. Ismagilova E.R., Ibragimova L.L. The use of the homeopathic drug “Fospasim” to increase the adaptive capacity of rabbits during transportation // Fundamental Research. 2013. No. 8 (part 2). pp. 376-379.

2. Ibragimova L.L., Ismagilova E.R. Histostructure of the myocardium and adrenal glands of rabbits during transportation and use of the protector drug // Fundamental Research. 2013. No. 10 (part 3). pp. 164-167.

3. Mager S.N., Ekremov V.A., Smirnov P.N. The influence of stress factors on the reproductive ability of cattle // Bulletin of the Novosibirsk State Agrarian University. 2005. No. 2. P. 49.

4. Sapozhnikova O.G., Orobets V.A., Slavetskaya B.M. Homeopathic correction of stress // International Veterinary Bulletin. 2010. No. 2. P. 44-46.

5. Krylov V.N., Kosilov V.I. Blood parameters of young animals of the Kazakh white-headed breed and its crosses with the light Aquitaine // News of the Orenburg State Agrarian University. 2009. No. 2 (22). pp. 121-125.

6. Litvinov K.S., Kosilov V.I. Hematological parameters of young animals of the red steppe breed // Bulletin of beef cattle breeding. 2008. T. 1. No. 61. P. 148-154.

7. Traisov B.B. Hematological parameters of meat and wool sheep / B.B. Traisov, K.G. Yesengaliev, A.K. Bozymova, V.I. Kosilov // News of the Orenburg State Agrarian University. 2012. No. 3 (35). pp. 124-125.

8. Antonova V.S., Topuria G.M., Kosilov V.I. Methodology of scientific research in animal husbandry. Orenburg, 2011. 246 p.

Bacterial fermentation of nutrients in the rumen when using probiotic preparations

I.A. Babicheva, Doctor of Biological Sciences, R.Z. Mustafin, Ph.D., Orenburg State Agrarian University

Various transformations of nutrients in the forestomach of ruminants occur under the influence of various types of microorganisms. At the same time, going through a series of multi-stage transformations, many metabolites are formed in the rumen, some of which become plastic and energy material for the body, while others are converted into microbial complete protein, being the main source of necessary biologically active substances and essential amino acids.

Therefore, to provide polygastric animals with normal nutrition, it is first necessary to create optimal conditions for the development of microflora. The degree of intensity of its vital activity depends on many factors, the most important of which are the concentration of hydrogen ions in the environment, the condition of the walls of the rumen mucosa, as well as the amount of feed metabolites in the forestomach.

The purpose of the research was to study the effect of the strains of probiotic preparations Bacell and Lactomikrotsikol on the rumen contents of young cattle.

Material and research methods. For the experiment with the microbiological preparation Bacell, there were

bulls of the Kazakh white-headed breed were selected. The differences between the groups were that the bulls of the experimental groups, unlike the control peers, additionally received a probiotic in doses of 15, 25 and 35 g/head, respectively, to the main diet. per day.

The effect of the probiotic Laktomikrotsikol on the intensity of microbiological processes in the rumen of ruminants was assessed on young animals of the red steppe breed. The diet of calves in the experimental groups included a probiotic according to the developed scheme.

A study to study the effect of probiotic preparations Bacell and Lactomicrotsikol on the rumen contents of bulls was carried out on farms in the Orenburg region. The experiments used preparations including live lactobacilli, bifidobacteria, essential amino acids, organic acids, vitamins, microelements and biologically active substances.

The results of the study made it possible to establish that feeding various amounts of the Bacell feed additive as part of the diet, as a source of enzymes with proteolytic, amylolytic and cellulolytic action, influenced the degree of intensity of microbiological processes (Table 1).

In particular, the concentration of hydrogen ions in animals of the control and experimental group I. was practically at the same level, the difference was not significant

1. Concentration of the main metabolites of bacterial fermentation in the rumen of animals when consuming the Bacell feed additive after 3 hours. after feeding, (X±Sx)

Indicator Group

control I experimental II experimental III experimental

pH VFA, mmol/100 ml Ammonia, mmol/100 ml 6.89±0.13 7.80±0.10 23.70±0.74 6.87±0.17 8.03±0.13 22, 81±0.70 6.65±0.10 9.88±0.11 19.45±0.83 6.68±0.15 9.84±0.11 19.50±0.57

2. Scheme of the experiment when using the feed additive Laktomikrotsikol

Group Number of animals, heads. Factor under study

Control I experimental II experimental III experimental 10 10 10 10 basic diet OR +10 g probiotic per animal/day for 3 months. RR +10 g of probiotic in the first 7 days, then a week break and so on for 3 months. RR +10 g of probiotic in the first 7 days, then once a decade for 3 months.

3. Biochemical indicators of rumen contents when feeding Laktomikrotsikol (X±Sx)

Indicator Group

control I experimental II experimental III experimental

VFA, mmol/100ml

before feeding 3 hours later 6.4±0.98 8.24±0.27 6.63±1.18* 8.47±0.36 6.95±0.93* 9.35±0.26 6 .7±0.27* 8.94±0.23

Ammonia, mmol/l

before feeding 3 hours later 20.6±0.31 22.67±0.17 20.87±0.61 22.8±0.30 21.6±0.64 24.0±0.12 21.07 ±0.38* 22.9±0.26

pH before feeding after 3 hours 7.13±0.02 6.79±0.01 7.11±0.01* 6.75±0.01 7.1±0.01* 6.71±0.01 7.11±0.01* 6.73±0.01

Note: * - P< 0,05, разница с контролем достоверна

increased 0.2-0.4%, while in young animals II and III I

experienced gr. this indicator has shifted to acidic

side by 3.2-3.6% (P>0.05). Decrease in pH, b

probably due to an increase in the concentration of h

VFA in the rumen fluid of experimental bulls II and III

gr., which was 26.7 and 26.2% (P>0.05) higher, d

than among peers in the control group. The concentration of volatile fatty acids in their rumen was at

same level and averaged 9.86 mmol/l, I

which was higher by 1.83 mmol/l, or 22.8% in

(P>0.05) than in the first experimental group. G

Use of multien- r as part of the diet

winter drug contributed to a decrease in p

concentration of ammonia in the rumen, and this decrease was noticeable only in the II and III experimental

gr. Feeding 15 g/animal/day of this feed do-e

the supplement had no effect on proteolytic t

microflora activity, which is clearly visible from the ammonia content, which was almost

identical to the control indicators. Once

data on ammonia concentration in the rumen of steers

control and II experimental group. was 21.9% h

(R<0,05), а молодняка контрольной и III опытной п

gr. - 21.6% (R<0,05) в пользу контрольной гр. г

The amount formed 3 hours after

feeding ammonia in the rumen of animals I experimental I

gr. was higher, respectively, by 17.3 (P>0.05) and with

17.0% (R<0,05), чем у аналогов II и III опытных д

g., and 3.9% (P>0.05) lower than in the rumen of young

no control group The decrease in ammonia concentration in the rumen of animals of groups II and III was apparently associated with an increase in the work of amylolytic microflora, leading to a decrease in pH towards the acidic side and a slowdown in the activity of proteolytic microflora and their enzymes.

Feeding the feed additive Laktomikro-tsikol had an effect on the rumen contents of experimental animals. Control group bulls received a basic diet, the nutritional value of which met established standards, and a probiotic was included in the diet of calves in the experimental groups according to the scheme (Table 2).

Analyzing the data obtained as a result of the experiment, it was found that the highest concentration of VFA in the rumen fluid was observed in bulls of the II experimental group. (Table 3).

In animals of the experimental groups, the contents of the rumen contained more VFAs before feeding by 3.6-8.6%, and also after feeding - by 2.8-13.4%. We believe that the greater amount of VFA is due to the fact that the positive microflora of the rumen contents more actively participated in the process of fiber fermentation, which leads to the formation of VFA. VFA concentration influenced the rumen content environment. If the pH value of the ruminal contents before feeding in the control group bulls was slightly alkaline, then after

feeding, the rumen content environment became close to neutral.

The concentration of ammonia before feeding in the rumen of bull calves of the experimental groups when fed with Lactomikrotsikol was higher than in individuals of the control group: I experimental - by 1.3%, II experimental - by 4.85%, III experimental - by 2.85% . In 3 hours. after feeding, the concentration of ammonia in the rumen of bulls of the first experimental group. exceeded the indicator in the control group. by 0.57%, II experimental - by 5.87%, III experimental - by 1.01%.

It was found that the animals of the experimental groups were characterized by a slight decrease in pH levels. At the same time, the concentration of volatile fatty acids increased with a slight change in their ratio. The level of ammonia and the fractional composition of VFA in the rumen of bulls from the experimental groups varied within the physiological norm.

Conclusion. The preparations Bacell and Laktomikrotsikol have a positive effect on the microbial fermentation of nutrients in the rumen of ruminants.

Literature

1. Babicheva I.A., Nikulin V.N. Efficiency of using probiotic preparations in growing and fattening bulls // News of the Orenburg State Agrarian University. 2014. No. 1 (45). pp. 167-168.

2. Levakhin V.I., Babicheva I.A., Poberukhin M.M. and others. The use of probiotics in animal husbandry // Dairy and meat cattle breeding. 2011. No. 2. P. 13-14.

3. Antonova V.S., Topuria G.M., Kosilov V.I. Methodology of scientific research in animal husbandry. Orenburg: OSAU Publishing Center, 2011. 246 p.

4. Mironova I.V., Kosilov V.I. Cows’ digestibility of the main nutrients in the diets of black-and-white cows when using the probiotic additive Vetosporin-aktiv in feeding // Proceedings of the Orenburg State Agrarian University. 2015. No. 2 (52). pp. 143-146.

5. Mironova I.V. Efficiency of using the probiotic Biodarin in feeding heifers / I.V. Mironova, G.M. Dol-zhenkova, N.V. Gizatova, V.I. Kosilov // News of the Orenburg State Agrarian University. 2016. No. 3 (59). pp. 207-210.

6. Mustafin R.Z., Nikulin V.N. Biochemical rationale for the use of probiotics in raising young cattle // Collection of scientific papers of the All-Russian Institute of Sheep and Goat Breeding. 2014. T. 3. No. 7. P. 457-461.

7. Nikulin V.N., Mustafin R.Z., Biktimirov R.A. The effect of probiotic on the rumen contents of young animals of the red steppe breed // Bulletin of beef cattle breeding. 2014. No. 1 (84). pp. 96-100.

8. Kosilov V.I., Mironova I.V. Efficiency of energy use in diets by black-and-white cows when fed with the probiotic additive Vetosporin-active // ​​News of the Orenburg State Agrarian University. 2015. No. 2 (52). pp. 179-182.

9. Batanov S.D., Ushakova O.Yu. Probiotic Bacell and probiotic Lactacid in the diets of dairy cows // Feeding agricultural animals and feed production. 2013. No. 11. P. 26-34.

10. Mambetov M.M., Shevkhushev A.F., Sheikin P.A. Conversion of feed into cattle carcass growth // Veterinary Bulletin. 2002. No. 2 (23). pp. 60-64.

Efficiency of seasonal calving of beef cows productivity

P.I. Khristianovsky, Doctor of Biological Sciences, Professor, Orenburg State Agrarian University; V.A. Gontyurev, Ph.D., FGBNU VNIIMS; S.A. Ivanov, Chairman, APC (collective farm) “Anikhovsky”, Orenburg region

In recent years, interest in beef cattle breeding among Russian agricultural producers has increased significantly, and not only in areas that have always specialized in beef cattle breeding. Beef cattle began to be raised in many regions of the Non-Black Earth Region - in Bryansk, Tula, Kaluga, Tver and other regions, i.e. in the traditional dairy farming area.

In modern conditions, beef cattle breeding can become a profitable industry. Beef cattle can use scarce steppe pastures, tolerate high and low temperatures well, are less demanding on the composition of the diet, and the survival rate of young meat breeds is usually higher than that of dairy breeds. Facilities for beef cattle are simpler and cheaper. In addition, beef cattle farming can be combined with dairy farming or other livestock sectors that will complement each other.

In beef cattle breeding, the most technologically advanced are tour (seasonal) calvings. Seal-

Reducing the timing of calving of cows makes it possible to receive calves in a more favorable period and subsequently form uniform herds of young stock. In this regard, the purpose of the study was determined - to study the effectiveness of seasonal calving of beef cows.

Material and research methods. The material for the study was cows and heifers of the Kazakh white-headed breed from the herd of the Anikhovsky collective farm (collective farm) of the Adamovsky district of the Orenburg region. To achieve seasonal calving, bulls on the farm are kept in brood herds from January to July. Every year in September, a gynecological examination of cows is carried out to determine pregnancy and identify the causes of infertility. At the same time, the breeding stock is graded and cows are culled for unsuitability for reproduction and zootechnical indicators.

During the study, methods of rectal diagnosis of pregnancy and analysis of production indicators were used.

Research results. At the agricultural cooperative (collective farm) “Anikhovsky”, cows are raised from November to February, i.e. during the stall period. At the same time, the production of offspring is controlled, and the calves themselves are monitored. Calving is due in March

Tea making process is a sequence of interconnected steps, at the very beginning of which is a freshly picked leaf, and at the very end is what we in the trade call “finished” or “ready” tea. The six types of tea (green, yellow, white, oolong, black, and pu-erh) have several similar processing stages (such as picking, primary sorting, final processing, etc.), but also have nuances that are unique to one or another. several specifically prepared teas. Oxidation- this is one of the most recently described chemical processes that must occur during the production of some types of teas, and must be prevented during the production of others. We can say that all types of tea are divided into two large classes depending on whether oxidation is involved in obtaining the finished product or not.

Oxidation in tea

First let's define oxidation. Oxidation is a biochemical, enzymatic process during which oxygen is absorbed and (as a result) changes occur in the substances involved in the process. In the case of freshly picked tea leaves, tea - the substances contained in the tea leaves. Oxidation can be spontaneous or controlled and lead to both positive and negative changes. A familiar example of spontaneous negative oxidation is what happens when you cut an apple or a banana, or leave a cut piece of a leaf out in the open air. Unprotected cells absorb oxygen, soften, and turn brown. This is the simplest form of oxidation that most people are familiar with. If the oxidation process is not interfered with, the fruit may simply dry out or rot, depending on atmospheric conditions. By simply cutting an apple into pieces and drying them in a dehydrator, you can see an example of the controlled negative oxidation that occurs during the drying process. Darkening of the cut surface is not considered aesthetically attractive in the market, so color changes are sometimes corrected with sulfur compounds or citric acid, but even in this situation (without visible color changes) oxidation still occurs.

During tea production, both spontaneous and controlled oxidation occurs. Spontaneous oxidation occurs during the drying stage of the tea leaves during the production of white, oolong and black teas. The controlled oxidation stage, which requires special attention, is one of the most important stages in the production of both oolong and black teas. In green and yellow teas, oxidation is prevented by thorough steaming, drying and/or roasting, also often called “de-enzyming.”

Oxidation is a chemical process that requires an excess of moist, oxygen-rich air. In black tea production, oxidation rooms must undergo 15 to 20 exchanges of humidified air per hour to ensure complete oxidation. Polyphenols in the leaf (tea catechins) absorb significant amounts of oxygen, especially during the early stages of oxidation. Oxidation in tea production formally begins spontaneously from the moment the tea leaves dry, and is then gradually accelerated by subsequent steps necessary to transform the fresh leaf into finished black tea. After several preparatory steps, the pre-prepared leaf is ready for the controlled oxidation process, which is often erroneously referred to as “fermentation.” In traditional oxidation, the sorted sheet is spread in thin layers (maximum 5 to 8 cm) on the factory floor, on tables, on porous pallets - and this is similar to the drying that is done at the primary withering stage. Oxygenation of the polyphenols initiates a series of chemical reactions involving them, ultimately producing new aromatic components and providing a thicker infusion characteristic of black tea. During the first and most important period of enzymatic oxidation, the enzymes polyphenol oxidase and peroxidase (a group of redox enzymes that use hydrogen peroxide as an electron acceptor) act on other polyphenols, resulting in the formation of theaflavins. These red-orange compounds further act on polyphenols to produce thearubigins, which are chemically responsible for changing the color of the leaf from green to gold, copper, and chocolate brown. Thearubigins, meanwhile, interact with several amino acids and sugars in the leaf to create highly polymeric substances that develop into the diverse and distinctive aromatic components we expect to have in black tea.

Theaflavins primarily contribute freshness and brightness to the taste of black tea, while thearubigins contribute to its strength, richness and color.

During the oxidation process, carbon dioxide is released from the tea leaf and the temperature of the mass of oxidizing leaves increases. If leaf temperatures are allowed to rise too high, oxidation will get out of control; if the temperature drops too low, oxidation will stop.

An array of tea leaves undergoing a controlled oxidation process is called dhool. Oxidation requires 2 to 4 hours and can be controlled empirically rather than scientifically. Although there may be technical markers to determine the expected completion of a process, there are also many parameters that characterize the process and are observed “live”. Therefore, the best method for determining when a leaf has completely oxidized may be expert visual olfactory observation.

The tea master must control the thickness and uniformity of the leaf layer, ensure that the temperature is approximately 29 C, the relative humidity is 98%; and provide constant ventilation (15 or 20 complete changes of indoor air per hour). Also, the microclimate must be completely hygienic; bacteria can spoil the dhool.

During the oxidation process, the processed leaf (dhul) receives a predictable series of taste parameters, fresh, rich color and final strength. The tea master can control the oxidation of dhula in his own particular manner by adjusting the duration of oxidation, allowing oxidation in combination with changes in temperature/humidity in the oxidation room. Most teas produced provide a balanced brew in the cup with a vibrant infusion, a good intense aroma, and a thick, rich consistency. When the tea master determines that the dhool has oxidized to the desired level ("fully oxidized" is a degree, but not an absolute one), then the critical phase of controlled oxidation is stopped by the final process of black tea production: drying.

Fermentation in tea

Fermentation- This is an important component in the production of pu-erh and other aged teas, such as Luan, Liubao, some oolongs, etc. It is most convenient to talk about fermentation in tea production using the example of the production of pu-erh. Let's explore what fermentation is and why careful and skillful fermentation is inseparable from the production of traditional high-quality pu-erh. Despite the fact that the production of pu-erh is one of the oldest and simplest forms of tea production, the world of pu-erh is so complex and vast that it has become the subject of close attention of tea experts and requires special care in study. In any case, we will not explore the specific complexity of the production of different types of pu-erh here, since this article proposes to consider only a more basic description of fermentation and oxidation.

Fermentation is a microbial activity (activity) involving certain types of bacteria. By definition, fermentation occurs most easily in the absence of oxygen, although some exposure to the environment is ideal for aging unripe sheng pu'er. Although an abundance of oxygen is required for most steps in tea making, exposure to oxygen in pu-erh production is often reduced or eliminated after the tea leaf drying step. The leaf that is transformed into pu-erh must be exposed to bacteria (or has bacteria in nature) suitable for undergoing fermentation.

As in the case of the production of “fermented” apple cider or Roquefort cheese, the bacteria necessary for the activity of microorganisms begin to naturally reproduce in the open air and/or inside a special fermentation room (cider “house” or cheese ripening chamber). In the case of pu-erh, the bacteria required to both initiate and maintain fermentation are found in the following places.

1. On the surface of the leaf itself, from old trees in a primeval forest where large-leaf trees grow - most famously in the Xishuangbanna area in southwestern Yunnan Province in China.
2. Climate-controlled tea production facilities in which "raw (sheng) mao cha" is temporarily stored awaiting pressing; in heaps of “mao-cha” during artificial fermentation of finished (shu) pu-erh; or in a humid, steamy climate in which the pu-erh is pressed.
3. In cool, dry rooms where sheng pu-erh pancakes are stored for post-fermentation and aging under careful control.

During the fermentation phase of pu-erh production, several important factors must come together. During harvesting, the leaf itself, which meets the standards, must contain “wild” bacteria - there can be a lot of them or very few, and the quality of the tea will also depend on this. The leaf intended to become pu-erh (“maocha”, which has been dried-withered, fried until “killing the greens” (sa cheen, shaqing), crumpled (ro nien, rounyan), and then partially dried leaf), is put into bags and these bags are placed on top of each other, waiting to be pressed in bacteria-rich steam; or, in the case of ready-made shu pu-erh, it is dumped into heaps indoors, exposed to external influences. Unlike the low, porous piles of leaves collected for oxidation, the mao cha piles in which the artificial fermentation of shu pu'er is stimulated are stacked tightly, compactly, and with minimal exposed surface area. The maocha pile is stirred infrequently - to rest the leaves (and prevent fermentation from going too far), to provide the bacteria with the oxygen they need, and to provide the temperature desired for favorable microbial growth and desired leaf transformation. During the fermentation process of pu-erh, the piles are often covered in order to increase the temperature of the processes occurring in the leaves.

One can imagine the slight confusion that tea traders experience when observing the processes of drying, oxidation and fermentation. Observing the mixing of piles of leaves on the floor, piles of leaves in trenches or on floorings, novice tea traders may be dumbfounded by the rudimentary and artisanal processes involved in tea production (this artisanalism is exacerbated by the reluctance of the Chinese to explain their “secrets”). And, although a lot has been described over the past 75 years, it is still difficult to clearly separate the processes of drying, fermentation and oxidation (and, accordingly, clearly control them).

It is imperative that both consumers and tea traders understand the characteristic differences between oxidation and fermentation. These processes should be clear and should not get lost in the frills of tea terminology or marketing.

A good sign that distinguishes a good trader is his understanding of the production of white, oolong and black teas, which are very dependent on the drying and oxidation processes. The use of the terms "oxidation" and "fermentation" unduly contributes to confusion among tea drinkers. In addition, those who can correctly identify what type of pu'er is offered for purchase, and what conditions are necessary to complete the unripe sheng pu'er to its maximum development (long aging, aging, and aging), provide themselves with a reliable purchasing base. For tea enthusiasts, knowledge is power, the tea world is becoming more and more accessible, and knowledge guarantees us better and better tea, and many other joyful moments of real pleasure from drinking our favorite drink.

(For even more information on tea production and an explanation of the oxidative processes in different types of teas, see The Tea Story; A Cultural History and Drinking Guide by Mary Lou Heiss and Robert J. Heiss, Ten Speed ​​Press October 2007)

* The wording “No oxidation” should be understood as “Almost no oxidation.” This is a translators' note.

GENERAL INFORMATION ABOUT CULTIVATION OF MICROORGANISMS

In a general sense, fermentation is the biochemical processing of raw materials under the influence of enzymes contained in itself and in saprotrophs (tea leaves, tobacco leaves), as well as caused by microorganisms. However, in our case we are considering exclusively microbial fermentation (or microbial fermentation).

This oldest of all biotechnology techniques uses living cells or the molecular components of their “production equipment” to produce desired products. Living cells are usually single-celled microorganisms such as yeast or bacteria; Of the molecular components, various enzymes are most often used - proteins that catalyze biochemical reactions.

Fermentation- a process in which the transformation of raw materials into a product occurs using the biochemical activity of microorganisms or isolated cells.

Almost synonymous the words "fermentation" can be considered terms such as cultivation, growing of microorganisms, biosynthesis h (see)

Microbial fermentation must be distinguished from biocatalysis(in which a previously obtained enzyme or biomass of microorganisms is used as catalysts for the biochemical process of synthesis of a product from raw materials and reagents) and from biotransformation(in this process a biocatalyst is also used in the form of an enzyme or biomass of microorganisms, but the starting substance differs little in chemical structure from the biotransformation product).

So, a type of fermentation - microbial fermentation - has been unknowingly used by humans for thousands of years to produce beer, wine, yeast bread and canned foods - pickled vegetables, salted (actually fermented) fish, etc. When the role of microorganisms in fermentation was discovered in the mid-18th century and people realized that it is to the biochemical processes of their vital activity that we owe the existence of all these products, the use of fermentation methods expanded significantly. Currently, we use a fairly wide range of capabilities of natural microorganisms, which ensure the production of the products we need, such as antibiotics, contraceptives, amino acids, vitamins, industrial solvents, dyes, pesticides and additives needed for cooking.

Microbial fermentation, in combination with the recombinant DNA method, is used to produce a large number of products of biological origin: human insulin; hepatitis B vaccines; an enzyme used to make cheese; biodegradable plastic; enzymes included in washing powders and much more. In addition, fermenters are used to grow cultures of a wide variety of animal and plant cells.

Fermentation is a set of processes that result in a culture liquid.

Culture fluid(culture broth) [lat. cultus - cultivation, processing] is a complex multicomponent system, the aqueous phase of which contains producer cells, their metabolic products, unconsumed components of the nutrient medium, etc. At the stage of isolating the target product, the location of its localization should be taken into account: extracellular or intracellular. In other words, a culture liquid is a liquid medium obtained by cultivating various pro- and eukaryotic cells in vitro and containing residual nutrients and metabolic products of these cells.

GROWTH AND REPRODUCTION OF BACTERIA ON LIQUID NUTRIENT MEDIUM

When describing fermentation processes, we often mention the “growth” and “reproduction” of microorganisms. But many people often confuse the meanings of these words or mistakenly consider them to be different names for the same process. This is wrong. The growth of a prokaryotic cell is understood as a coordinated increase in the amount of all the chemical components from which it is built.

Bacterial growth is the result of many coordinated biosynthetic processes under strict regulatory control, and leads to an increase in the mass (and, consequently, size) of the cell. But cell growth is not unlimited. After reaching a certain (critical) size, the cell undergoes division, i.e. reproduces.

Bacteria reproduction determined by the generation time. This is the period during which cell division occurs. The duration of generation depends on the type of bacteria, age, composition of the nutrient medium, temperature, etc.

Microorganism cultivation process- fermentation - begins from the moment when pre-prepared seed material is introduced into the reactor. Reproduction of a microorganism culture is characterized by four time phases: lag phase; exponential; stationary; extinction.

Fig.1. Phases of bacterial cell reproduction on a liquid nutrient medium

1)- Lag phase(resting phase); duration - 3-4 hours, bacteria adapt to the nutrient medium, active cell growth begins, but there is no active reproduction yet; at this time the amount of protein and RNA increases. During the lag phase, cell metabolism is aimed at synthesizing enzymes for reproduction in a specific environment. The duration of the lag phase can be different for the same culture and environment, since it is influenced by many factors. For example, how many non-growing cells were in the seed.

2)- Exponential phase- this is a period of logarithmic reproduction, when cell division occurs with an exponential increase in population size; reproduction prevails over death. This period is limited in time by the amount of nutrient medium. Nutrients run out or cell growth slows due to the release of a toxic metabolite.

Rice. 2. The process of bacterial cell division

3)- Stationary phase. Growth stops and the so-called stationary phase begins. The bacteria reach their maximum concentration, i.e. the maximum number of viable individuals in the population; the number of dead bacteria is equal to the number of bacteria formed; there is no further increase in the number of individuals; Metabolism continues and the release of secondary metabolites may begin. In many cases, the goal is not to obtain biomass, but rather secondary metabolites, since they can be used to obtain valuable products and drugs. In these cases, the fermentation is deliberately kept in the stationary phase.

4)- Dying phase. If you continue fermentation further, the cells will gradually lose activity, i.e. die out. This is the phase of accelerated destruction; the processes of death prevail over the process of reproduction, since the nutrient substrates in the environment are depleted. Toxic products and metabolic products accumulate. This phase can be avoided if you use the flow cultivation method: metabolic products are constantly removed from the nutrient medium and nutrients are replenished.

ABOUT THE FERMENTATION STAGE

Fermentation stage is the main stage in the biotechnological process, since during it the interaction of the producer with the substrate and the formation of target products (biomass, endo- and exo-products) occur. This stage is carried out in a biochemical reactor (fermenter) and can be organized in various ways depending on the characteristics of the producer used and the requirements for the type and quality of the final product. Fermentation can take place under strictly aseptic conditions and without observing sterility rules (so-called “unprotected” fermentation).

Fermentation in liquid and solid phase media

Cultivation in liquid media can be divided into surface and deep fermentation. The surface flows in cuvettes with the medium. The cuvettes are placed in air-ventilated chambers. As a result of the process, biomass is formed on the surface of the medium in the form of a film or solid layer.

Deep fermentation occurs throughout the entire volume of the liquid medium. This type of fermentation is carried out in both batch and continuous ways.

Solid state fermentation, in a solid, granular or pasty medium with a humidity of 30 to 80%, is carried out in three ways (Fig. 3):

• During surface processes, the substrate is placed on trays in a thin layer (3...7 mm);
• deep solid-phase fermentation is carried out in deep open vessels, the substrate is not stirred;
• solid-state fermentation is carried out by stirring the substrate in an aerated mass.

Fermentation (cultivation) can occur under both aerobic and anaerobic conditions:

Aerobic cultivation used in cases where aerobic producing microorganisms are involved in the process. Aeration of the mixture is carried out by supplying air or other gases through gas supply tubes, nozzles, etc.

Anaerobic processes occur in sealed containers or by purging the cultured medium with inert gases. The design of the fermenter for anaerobic fermentation is simpler than for aerobic fermentation.

Different fermenter designs have been developed for each type of fermentation process (Fig. 2).

CLASSIFICATION OF FERMENTATION PROCESSES

Rice. 3. Classification of fermentation processes

Based on the target product The fermentation process can be of the following types:

1. Fermentation, in which the target product is the biomass of microorganisms itself; it is precisely such processes that are often denoted by the words “cultivation”, “growing”;
2. The target product is not the biomass itself, but metabolic products - extracellular or intracellular; such processes are often called biosynthetic processes;
3. The task of fermentation is to utilize certain components of the original medium; These processes include bio-oxidation, methane fermentation, biocomposting and biodegradation.

The starting medium in fermentation processes or its main component is often referred to as substrate .

According to the mainphase, in which the fermentation process takes place, differ:

1. Superficial (advantage solid phase) fermentation (cultivation on agar media, on grain, production of cheese and sausages, biocomposting, etc.);
2. Deep (advantage liquid phase) fermentation, where the biomass of microorganisms is suspended in a liquid nutrient medium through which air or other gases are blown if necessary;

In relation to oxygen - They distinguish between aerobic, anaerobic and facultative anaerobic fermentation by analogy with the classification of microorganisms themselves.

In relation to the light- light (phototrophic) and dark (chemotrophic) fermentation.

By degree of security from foreign microflora - aseptic, conditionally aseptic and non-aseptic fermentation. Sometimes aseptic fermentation is called sterile, which is incorrect: there are target microorganisms in the medium, but no foreign ones.

By convention, aseptic fermentation allows for a certain level of ingress of foreign microflora, which is able to coexist with the main one or whose content does not exceed a certain limit.

According to the number of types of microorganisms - A distinction is made between fermentations based on monoculture (or pure culture) and mixed cultivation, in which the joint development of an association of two or more cultures takes place.

FERMENTATION PROCESSES BY METHOD OF ORGANIZATION:

• periodic;
• continuous;
• volumetric-topping;
• periodic with substrate replenishment;

All these types of fermentation (by the method of their organization) are easily identified by the method of loading raw materials and unloading the product.

In batch processes Loading of raw materials and seed into the apparatus is carried out at the same time, then the process takes place in the apparatus for a certain time, and after its completion, the resulting fermentation liquid is unloaded from the apparatus.

In continuous processes Loading and unloading of the medium occurs continuously and simultaneously, and the rate of supply of fresh nutrient medium into the apparatus is equal to the rate of withdrawal of the fermentation liquid from the apparatus. As a result, the volume of the medium in the apparatus remains constant for a long time (Fig. 4.2), theoretically - indefinitely, and practically - until some kind of malfunction.

In volume-filling processes Fermentation in the intervals between loading and unloading the apparatus proceeds as a periodic process, but after some time, determined by the state of the process, part of the fermentation medium is unloaded and replaced with fresh medium.

In a batch process with substrate feeding part of the medium is loaded at the beginning of fermentation, and the other part is added continuously as the process progresses (Fig. 4.5). The natural end of the process is the overflow of the apparatus, so it is necessary to switch to a strictly periodic process with the maximum volume of medium and quickly complete it.

BIOREACTORS (FERMENTERS)

Rice. 4. Classification of fermenters

For deep cultivation of bacteria In industrial and laboratory conditions, bioreactors or fermenters are used. A fermenter (bioreactor) is a device that mixes the culture medium during the process of microbiological synthesis; it is a hermetic boiler into which a liquid nutrient medium is poured. Fermenters are equipped with automatic devices that allow maintaining a constant temperature, optimal pH and redox potential, and a dosed supply of necessary nutrients.

It is used in the biotechnological industry in the production of medicinal and veterinary drugs, vaccines, food industry products (enzymes, food additives, glucose syrups), as well as in the bioconversion of starch and the production of polysaccharides and oil destructors.

There are mechanical, airlift and gas-vortex bioreactors, as well as aerobic (with the supply of air or gas mixtures with oxygen), anaerobic (without oxygen supply) and combined - aerobic-anaerobic.

GENERAL SCHEME OF MICROBIOLOGICAL PRODUCTION

Rice. 5. Diagram of a conventional fermenter

A conventional fermenter is a closed cylinder in which the medium and microorganisms are mechanically mixed. Air, sometimes saturated with oxygen, is pumped through it. The temperature is controlled using water or steam passed through the heat exchanger tubes. The design of the fermenter should allow you to regulate the growth conditions: constant temperature, pH (acidity or alkalinity) and the concentration of oxygen dissolved in the medium.

1. Preparation of the nutrient medium

The nutrient medium serves as a source of organic carbon - the main building block of life. Microorganisms absorb a wide range of organic compounds - from methane (CH 4), methanol (CH 3 OH) and carbon dioxide (CO 2) to natural biopolymers. In addition to carbon, cells need nitrogen, phosphorus and other elements (K, Mg, Zn, Fe, Cu, Mo, Mn, etc.) An important element in the preparation of nutrient media is sterilization in order to destroy all foreign microorganisms. It is carried out using thermal, radiation, filtration or chemical methods.

2. Obtaining pure strains for introduction into the fermenter.

Before starting the fermentation process, it is necessary to obtain a pure, highly productive culture. A pure culture of microorganisms is stored in very small volumes and under conditions that ensure its viability and productivity (usually this is achieved by storage at low temperatures). It is necessary to maintain the purity of the culture at all times, preventing its contamination by foreign microorganisms.

3. Fermentation is the main stage of the biotechnological process.

Fermentation is the entire set of operations from the introduction of microbes into a prepared and heated to the required temperature environment to completion biosynthesis of the target product or cell growth. The whole process takes place in a special installation - a fermenter.

At the end of fermentation, a mixture of working microorganisms, a solution of unconsumed nutritional components and biosynthesis products is formed. They call her culture fluid or broth.

4. Isolation and purification of the final product.

Upon completion of fermentation, the desired product is purified from other components of the broth. For this purpose, various technological methods are used: filtration, separation (sedimentation of suspended particles under the influence of centrifugal force), chemical precipitation, etc.

5. Obtaining commercial forms of the product.

The last stage of the biotechnological cycle is obtaining commercial forms of the product. They are either a mixture or a purified product (especially if it is intended for medical use).

On a note:

FACTS ABOUT BACTERIAL REPRODUCTION

Under favorable conditions, microorganisms multiply very quickly. It is believed that the bacterium divides in half every 20-30 minutes. According to the calculations of the botanist Cohn, with unhindered reproduction for 5 days, the offspring of one medium-sized bacterium (2 microns in length and 1 microns in width) would occupy a volume equal to the volume of all seas and oceans. But the proliferation of bacteria is limited by a number of factors and does not reach such fantastic proportions.

The extremely small size of bacteria and the speed of their reproduction are of great importance for understanding the conditions of interaction between microbes and the environment. A volume of water of 0.001 ml can accommodate up to 10 9 bacteria. When adding such a number of bacteria to 1 ml of water, if they are evenly distributed throughout the entire volume, there will be 10 6 bacteria per 1 liter of water or 1000 bacteria per 1 ml of water. That is why, for example, an insignificant (!) amount of a substance contaminated with pathogenic bacteria is sufficient for the spread of infectious diseases transmitted through water.