Editor's by S. M. Gun’ko, G. I. Podpriatov Technology of grain storage Handbook Kyiv 2009




Yüklə 80.75 Kb.
tarix28.04.2016
ölçüsü80.75 Kb.
Editor's by S.M. Gun’ko, G.I. Podpriatov

Technology

of grain storage
Handbook

Kyiv 2009


УДК 631.56(073)

ББК 41


C 42


Reviewers: V.V. Khareba, Ph.D. of agricultural sciences, correspondent member

of UAAN;



L.M. Khomichak, Ph.D. of agricultural sciences, professor
Translator: S.M. Gun’ko, N.A. Hlukhovs’ka


C 42 S.M. Gunko, G.I. Podpriatov

Technology of grain storage. Handbook. – K.: «Centre of information technologies», 2009. – 230 p.

Recommended by the Learned Council of faculty Agrarian management of the National university of life science and environmental resources of Ukraine

protocol №__from “ __ ___________ 2009.







ББК 41

© S.M. Gun’ko, G.I. Podpriatov, 2009


Introduction.


Cereals are monocotyledonous plants dial belong to die grass family. Based on botanists approximation, there are about 350,000 plant species, of which about 195,000 species are economically important flowering plants. Nearly 50 species are cultivated worldwide and as few as 17 species provide 90 % of human food supply and occupy about 75 % of the total tilled land on earth. They consist of wheat, rice, com. potato, barley, sweet potato, cassava, soybean, oat, sorghum, millet, rye, field bean, pea and coconut. The cereal grains such as wheat, rice, com, barley, oat, rye, sorghum, and millet provide 50 % of the food energy and 50 % of die protein consumed on earth. Wheat, rice, and com together make up three-fourths of the world's grain production. In general, cereal grains have been considered as the source of carbohydrates to supply food energy to die diet. Cereal grains, especially rice and wheat, provide the bulk of energy consumed on earth.

The cereal crops that are grown for their edible fruit are generally called grain, but botanically referred to as caryopsis. The cereal seed consists of two major components, the endosperm and embryo or germ. The endosperm encompass the bulk of the seed and is the energy source of stored food. An outer wall called the pericarp that develops from the ovary wall encases the endosperm. A semipermcable layer under the pericarp, which is called testa, surrounds die embryo and is derived from the inner ovary wall. The testa is permeable to water, but not to dissolved salts, and is important for germination. The third layer, which is called aleurone, contains thick-walled cells that are free of starch. The pericarp, testa, and aleurone layer are collectively called die bran.

The legumes such as chickpea, black gram, mung bean, and pigeon pea. have an estimated 16,000-19.000 species in 750 genera. The term legume originated from the Latin le-gumen, which means seed harvested in pods. The expression food legumes usually means the immature pods and seeds as well as mature dry seeds used as food by humans. Based on Food and Agricultural Organization (FAO) practice, the term legume is used for all leguminous plants. Legumes are important sources of food in developing countries. In some countries, depending on the climatic condition and food habits, other legumes are grown. Legumes are next to cereals in terms of their economic and nutritional importance as human food sources. They arc cultivated not onlv for their protein and carbohydrate content, but also because of the oil content of oilseed legumes such as soybeans and peanuts.

Once a cereal crop is harvested, it may have to be stored for a period of time before it can be marketed or used as feed or seed. The length of time, cereal can be safely stored, will depend on the condition, it was harvested and the type of storage facility being utilized. Grain binned at lower temperatures and moisture contents can be kept in storage for longer periods of time before its quality will deteriorate. The presence and build up of insects, mites, molds and fungi, which are all affected by grain temperature and grain moisture content, will affect the grain quality and duration of grain storage.



Chapter 1 – Introduction into course. Scientific and methodical bases of course
1.1 The role of storage in the economy. In most countries grains are among the most important staple foods. However they are produced on a seasonal basis, and in many places there is only one harvest a year, which itself may be subject to failure. This means that in order to feed the world's population, most of the global production of maize, wheat, rice, sorghum and millet must be held in storage for periods varying from one month up to more than a year. Grain storage therefore occupies a vital place in the economies of developed and developing countries alike.

The market for food grains is characterized by fairly stable demand throughout the year, and widely fluctuating supply. Generally speaking people's consumption of basic foods such as grains does not vary greatly from one season to another or from year to year. The demand for grain is inelastic, which means that large changes in the market price lead to relatively small changes in the amount of grains which people purchase.

Market supply, on the other hand, depends on the harvest of grains which is concentrated within a few months of the year in any one area, and can fluctuate widely from one year to the next depending on climatic conditions. New varieties that have shorter growing periods, and variation in climatic conditions and farming systems in different regions of a country, can help to even out the fluctuations in market supply. But even in a country such as Indonesia, which has diverse climatic and farming conditions and where 90 per cent of rice land is under short duration high yielding varieties, about 60 per cent of production is harvested within a three month period (Ellis et al. 1992).

The main function of storage in the economy is - to even out fluctuations in market supply, both from one season to the next and from one year to the next, by taking produce off the market in surplus seasons, and releasing it back onto the market in lean seasons. This, in turn, smoothes out fluctuations in market prices. The desire to stabilize prices of basic foods is one of the major reasons why governments try to influence the amount of storage occurring, and often undertake storage themselves.

1.2 History of branch and science development. For the last dozen years industry of storage and processing of plant-grower products had passed difficult way of development and perfection. The capacity of granaries on beginning of the XX century in Ukraine was about 4 million ton, including elevator — under 0.5 million ton. Beginning from 1924 started building of elevators, granaries the capacity of which in 1932 to was increased fourfold, and in 1941 else to three times more. During war about half of granaries were destroyed, which in 1955 were rebuilt in Ukraine. Many granaries were built during 1971 – 1975. In this period began to use a new equipment for scales grain, stationary mechanized installation of load and unloading of grain, high-productive movable technique, grain cleaners, laboratory equipment. Part of elevators in the general amount of granaries grew up to the third. For the last decades it is built many metallic elevators.

Till recent time the purveyance of grain took place after the difficult system of administrative dependences: Cabinet of Ministers of Ukraine > Ministry of agrarian policy of Ukraine > State joint-stock company «Bread of Ukraine» > regional production associations of elevator and grain processing industry > district grain collection and purveying enterprises > mills, bakeries and etc. Therefore this chart will be optimized.

Presently DAK «Bread of Ukraine» has powers for storage of 30 million ton of grain, that sufficiently for maintenance of harvest up to 50 million ton grain for a year. 305 elevators are included, 173 of them for acceptance of grain and 132 — industrial. Among 24 elevators have power over 100 thousands of tons, 54 — over 50 thousand of ton, other — from 45 thousand of ton and less. In elevators over 35 % grains are located, other keeps in granaries, 93 % of which are mechanized.

In DAK «Bread of Ukraine» functions 1247 stationary dryers with power of 48 637 t/hour and 387 mobile power of 2904 t/hour, 2647 machines for cleaning of grain, 731 — for treatment of corn. Granaries with equipment for active ventilation 1673 with general power 5364 thousands of tons, 2844 are installation of active ventilation, much equipment for weighing and unloading of grain.

Except for the granaries of DAK «Bread of Ukraine», there are granaries and equipments of firms and farmers.

In post-revolution Ukraine, among food industry, a leading place was occupied by flour-miller industry. For the last decades many large commodity mills and bread plants are built. At the same time cheap handicraft industry of flour and bread is lost. Presently, practice of small bakeries is restored that promote better providing of population with fresh bread, and also to the considerable transport cost cutting on supply grains and deliveries of flour and bread.

In the beginning of the XXI century average annual productivity of all grain-processing enterprises made 7.2 million tons of flour and 800 thousands of crops. In Ukraine 195 mill enterprises, 30 of them are fully reconstructed in the last years. A lot of mini-plants are functioning by general power about 2 million tons per year.

History of processing of grain counts a millennium, what archeological excavations testify to. Thus, 6 — 8 thousands years ago original granaries for grain existed. Wine and oil was kept the protracted period in special amphorae. Nomads used dugouts. Researchers find graters for grain since olden times. With transition to the settled way of life people built granaries in the special places, barriering them ditches and paling. Grain was kept also in barrels and in the rocks hole.

At a feudal period peasants built special barns for storage of grain. For its grind began to use millstones. On territory of churches and monasteries grain was kept in buildings under church. First attempts to save large stocks of grain in Ukraine were made in the end of the XV century, when a necessity to provide it for army was. In this period in cities began to create corn courts, bread shops. Grain in granaries was annually renewed no less as on the third, thus not fresh-cut, after it protracted storage.

Organization of storage of bread supplies considerably became better at the beginning of the XVIII century. Central state justice was established — Proviant order for providing of army food. Development of agrarian science is begun. A. T. Bolotov established edition of the first agricultural magazines. In 1765 Independent economic society was founded. Its members proposed project of the first elevator, gave recommendation in relation to allocation granaries for grain, prolonged its storage without access of moist air and use for this purpose of pits, densely closed the thick layer of quicklime.

Proviantmaster of army B. E. Engelmann developed the original construction of brick granary of silo-type with 24 silos (height – six sagene and width – two sagene). In XVIII century became known principle of blowing out of corn masses by air bellows. In 1816 ratified by general Barclay de Tolly “Rules for proviant armies” began to act, which set the norms of humidity, cleanness and smell of grain. Severe determination of quality of grain in the conflict cases of the predicted bread baking and preparation of porridges for fitness determination of flour and groats for a consumption. The method of stacking of grain and flour on storage and control their quality after storage was developed. The norms of natural losses were set at storage of grain. Recommendations were based on the results of researches, which was intensively conducted already at the end of XVIII and beginning of the XIX centuries. In the handbook «Agriculture chemistry» published in 1825 author V. A. Pavlov described the value of gluten of wheat for the qualitative indexes of bread. In the handbook of M. Scheglova «Economy botany» (1928) technological description of grain of cereal cultures is given.

Independent economic society repeatedly declared all comers for development of the most comfortable and cheapest methods of drying and storage of grain and other agricultural raw material. From 1867 the member of society I. Chernopyatov published «Guidance on drying and storage of bread», where expounded a theory and practice of drying and storage of grain, flour, groats, described the constructions of granaries, showed estimates on their building.

The scientists of many countries were studied of properties of cereal masses, methods of defense of grain from spoilage. Among domestic scientists, needs separate, is work of P. Alexandrov “The experience of agricultural technology». Great research in field of quality, storage, processing of grain, technology of processing of industrial crops, was conducted by D. Mendeleyev.

For his assistance Russian translation of nine publications «Technology» by Wagner (1862 - 1879) was carried out, devoted the question of processing of agricultural raw material. In Petrovsky agricultural academy and the agricultural faculty of the Kiev polytechnic institute among the first 15 disciplines «Agricultural and forest technology» was studied, special departments were organized. Part of questions of technology, in particular drying of grain, was studied in the course «Doctrine about agricultural machines and tools» by V. P.Goryachkina.

Realization of many valuable inventions of domestic scientists were prevented backward of empire. On bread market dominate chaos, elevators often were empty.

In development of course «Technology of agricultural products» large deposit did Y.Nikitinskiy. Based on information of such sciences, as physics, chemistry, biology, he deepened bases of scientific knowledge of discipline, organized numerous scientific researches, pay large attention to the questions of utilization of ways of processing of agricultural produce. In the days of Mendeleyev domestic scientists put a question about the necessity of creation economically advantageous processing industry.

Technology of storage and processing of agricultural products as science was developing by efforts of research institutes of technological type. Thus, in 1888 — 1889 two-volume edition of M. Tavildarova «Chemical technology of agricultural products», this contained the detailed description of starched, sugar-beet, brewing and vine making production. P. O. Afanasyev published «Course of milling grinder».

At the beginning of the XX century many books about technology of agricultural products were published, in particular P. O. Kozmina «Milling production». At this time the first specialized laboratories began to act from the technological evaluation of raw material. In 30 years of ours the question of upgrading, storage and processing of agricultural products, lighted up in works written by K.Timiryazev, M. Vavilov, K. Debu, and P. Lukyanenko. A considerable effort in determination of reasons of grain losses during storage was done O. Oparin, O. Bang, V. Kretovich and L.Trisvyatskiy. A large merit in development of merchandizing, biochemistry and industry of storage of fruit and vegetable products is belongs F. Cerevitinovu, I. Kolesniku, E. Shirokovu, P. Sokol, G. Dzhaneevu and etc.

On the modern stage of development of industry leading role act scientific-research institutes of Ukrainian Academy Agrarian Sciences, in which the effective methods of storage and processing of agricultural produce are developed.

For the last decades a large value for development of science has works of M. Khelemskogo, B. Lesika, S. Polischuka, development of departments of storage and processing of products of Institute of gardening, Institute of vegetable-growing and water-melon, Institute of potato growing, other experimental and educational establishments of Ukraine.

1.3. The short characteristic of branch storage and processing of plant products. In nowadays in Ukraine there are 796 bread making, 126 brewing, 510 mixed fodder, 17 oily, 57 alcohol, 29 macaroni factories and 175 confectionaries. As the result, question has appeared to store up agricultural products not in full volume of commodity production, but measured by necessities of national trade, branches of national economy, health protective system, army etc. At the same time, questions are discussing: we need to establish such purchase prices which allow the appropriate storage of agricultural products.

Grain collection enterprises carry out grain procurement, location and purification, form commodity consignment of grain for flour-grinding, grits and mixed fodder enterprises. In Ukraine acting 204 grain purchase enterprises, which store up, keep and ship grain to processing enterprises; 76 bread base to keep state reserves and strategically grain reserves; 91 grain elevator; 151 processing and packing factories, which produce meal, grits, and mixed fodder. All these organizations supply products to 27 realization bases. Except that, we have developed system of private companies in our country, including UGA- Ukrainian Grain Association. Increase in using practice of processing and keeping grain of agricultural producers, who using material-technical base of bread-receiving enterprises, provide to save the quality of grain and possibility to use it in necessary measures.

Bread-receiving enterprises have productive department for treatment of hybrid seed of corn, cereal and other crops, provide hay and herbal flour.

There are a lot of enterprises which procurement, storage and processing of plant products in Ukraine. There are enterprises of grain-collection, fruit-and-vegetable bases and the enterprises of processing of technical crops.

Among bread-receiving enterprises distinguish grain purchase (procurement and storage of bread-grain and seed grain), selling (procurement, storage, processing and selling final products of grain processing (flour, groats, mixed fodders and etc.), reserve fund (for prolonged storage of grain and products of grain processing). The most developed is the net of store bread-receiving enterprises, which are related to grain and oil plants producers (every region has it). Flour-miller enterprises are located in large industrial centers and cities, crop- in places of storage (in the central and south regions), mixed fodder - near the poultry factories and stock-raising complexes.

Grain and seeds of oil plants farmers supply by the agreements contracting. In contract marked the name, assortment, quantity, quality, price, terms of product sales and product receiving.

Purveying, storage and processing provided by fruit and vegetable bases, which supply it in order to satisfy needs of population of cities, processing factories of state submission and also private and collective form of ownership. It is popular in many regions to organize association of producers and remakers, where all produced commodities store till the moment of realization in fresh condition or before the delivery to processing. They are produced on the base of existing agricultural collective enterprises and farms. Efforts of all processing and purveying organizations are directed to decrease losses during transportation, storage and processing agricultural products. Its material-technical base is permanently improving. In particular, many lines of processing plant products were created, which supply its high quality and competitiveness.

Raw material of industrial crops is provided by processing plants of state submission and cooperatives, which were created on the base producers of technical raw. Today their relations are improving, discussing questions about renewing of processing equipment, building of new depositories for raw and final products.

It is difficult to overestimate the value of plant purveyor and processing brunches. Storage of seminal funds, food and technical raw material provided continuity of processes of agricultural and industrial production. Trouble-free providing of population of Ukraine by the products of daily necessity — bread, meat, milk, eggs, green-stuffs, fruit at the seasonal production of plant-grower goods would be impossible without the properly developed industries of storage and processing. An actual task is not only providing of industrial base of country but also expansion of its possibilities, as an exporter of many types of plant-grower products.

1.4. Main tasks of the course. The first task is studying questions of quality of plant products in a complex.

The second task is studying of bases theories and practice of storage of plant products.

The third is training of specialists and managers of agriculture in the area of technology of storage and processing of plant products.

1.5. Main tasks of the branch. To storage of plant products and seeds with the minimal losses of weight and without decrease in quality.

To raise quality of plant products during storage, applying corresponding technological regimes and modes.

It is most profitable to organize storage of plant products.

1.6. Fighting with looses in quality and weight of plant products. There are two types of losses of plant products during the storing:

- losses of weight;

- losses of quality.

They are interdependent in most cases that are losses of weight are escorted by losses of quality and vice versa. By nature losses can be physical and biological.

The interconnection between losses of weight and losses of quality presented for example storage of grain (tabl. 1.1)


Table 1.1 – losses of weight and quality at storage of grain


Losses of weight

Biological

Losses of quality

breathing of grain

germination of grain

evolution of microorganisms

evolution of insects and ticks

self-heating

extermination by rodents

extermination by birds

Physical (mechanical)

injuries

pulverize

spilling

1.7. Scientific and methodical bases of course. Effective storage of plant products is based on the perfect knowledge of three equally important components:



  1. the object of storage (chemical structure, physiology), its physical properties, physical and physiological of its aggregate (seeds or potatoes amount and etc.), special features of interaction with environment;

  2. factors that influence on processes which take place in the plant products during storage or processing;

  3. scientific principals that the foundation of storage of the certain type of plant products.

Principals of storage of plant products are established on the base of studying physiological, biochemical and microbiological processes which take place in certain conditions and regimes. These principles are classified by Nikitinskyy (tabl. 1.2). He has put in their basis four conditions which there can be a biological object (bioz, anabioz, tsenoanabioz and abioz). It is main component, which influence on the partial or complete braking of biological processes in object of storage. It is known that the level of vital functions of living organism is predetermined the certain parameters of environment: by a temperature, relative humidity, gas composition of air and etc. If these parameters satisfy the physiology necessities of organism provide peculiar for its level of vital functions — bioz. For example, fruits and vegetables intended for canning, potatoes before entering to processing on the starch are kept in the state of eubioz (variety of bioz).

If products set to protracted storage without physiology disorders, provide the expressly certain conditions of storage for every object. Thus, the tubers of potato, root crops, onions, corn the masses with height humidity and most garden-stuffs, are kept in the state of gemybioz with a decline to the certain limits of temperature and content of oxygen in the atmosphere of environment. Duration of storage in such state depends on content of spare nutritive and also of the inherited properties of kind, cultivar of object storage. If chemical composition of products changes in the process of the protracted storage but before the use of it enter in the mode of complete bioz (eubioz) for restored in characteristic for it properties (warming tubers of potato).



If plant products can not be storage without losses in the condition of bioz, come running to stopping or sharp braking of biological processes in it (basic component – microflora and etc.), that arrive at the state of its anabioz. It should be noted that in this favorable condition may be restore activity of microflora and insects in the products of storage. Depending on the method of carry out plant product to the condition of anabioz (by the change of temperature, humidity, osmosis pressure and etc.) distinguish thermoanabioz, xeroanabioz osmoanabioz acidoanabioz, narcoanabioz.

The condition of thermoanabioz arrive at the decline of temperature and products freezing using properties of separate constituents of organism (albumens, enzymes) to react on decreasing temperatures. The types of thermoanabioz are



psychroanabioz and cryoanabioz. To the state of thermoanabioz carry out plant products the declines of temperature to 0°C, at which cellular juice with dissolved in it matters does not freeze. Cryoanabioz is foreseen by freezing of objects of storage.

In the condition of psychroanabioz products (berries of currant, grapes, plums, peaches, apricots, cherry-plum and etc.) are kept in refrigerators at temperature -1… - 3 °C. At these conditions vital functions of objects of storage and activity of microflora are sharply breaking. At increasing temperatures microflora (particularly of mould fungi) begins quickly to propagate oneself at first on weakened (withering, injured, overripe) objects, gradually spreading on other products. Therefore to realize products after such method of storage need as quick as possible.

The certain types of products (ground up green-stuffs, small fruits and berries) keep in the state of cryoanabioz, that frozen at minus 3 °C and below. The living structures of storage object and basic groups of microflora are destroyed. At maintenance of temperature after freezing at level –15… – 16 °C such products can be kept during great time. This method in combination with the correctly conducted


Table 1.2 – Principals of storage of plant products according to Nikitinskyy


State

Substate

Definition

Products which storage

І. Bioz


А. Еubioz

Storage and transportation whole, alive organisms to time of its processing.

Temporary storage of fruits and vegetables, potatoes before its processing.


B. Gemybioz

Principal of partial bioz. Storage in the fresh of fruits and vegetables.

Temporary storage of fruits and vegetables with reduced of temperature and concentra-tion of oxygen in an atmosphere. Storage of grain mass with reduced humidity.

ІІ. Anabioz

А. Тhermoanabioz

Storage in cooling or freezing conditions.

Psychroanabioz – reduction temperature to 0 °С.



Cryoanabioz - storage lower temperature 0 °С.



Storage of fresh fruits of vege-tables.

Storage of the frozen fruits and vegetables.

B. Xeroanabioz

Storage as a result of full or partial dehydration

Raisin, dried apricots, dried fruit and vegetables.

C. Osmoanabioz

Change osmosis pressure in a product under action of salt or sugar.

Concentration of salt is 12-13 % - osmosis pressure 7 MPa, concentration of sugar is 65 % - 35 MPa.

D. Acidoanabioz

Changing of the acidity of product's environment as a result of insertion of acid

Artificial ensilage fodder. Manufacturing of vegetable and fruit marinades.

E. Narcoanabioz

Using the anesthetization agent

Adding of chloroform, salts propionic, ant and acetic acids, carbon dioxide.

ІІІ. Tsenoanabioz


A. Acidotsenoanabioz

Conservation by using acids which was produced by microorganisms (lactobacillus).


Pickle of tomatoes, cucumber and cabbage.

B. Alcoholetsenoanabioz

Conservation by using alco-hol which was produced by microorganisms (yeast).

Wines

ІV. Abioz

А. Thermosterilization

Heating to the high temperature (85-120 oC)


Vegetables of marinades, juices, jams, compotes of fruit and etс.

Б. Chemical ste-rilization

Insertion of antiseptics

Used sulfur anhydride

В. Mechanical steri-lization

Filtration on sterilization filters (ultrafiltration, micro-ltration)

Wines, juices.

Г. Photosterelisation

Using different rays (ultra-violet rays, heat rays and etс.)



deforestation provides the saved of not only food but also biological value of products.

Considerable quantity of storage objects (dry grain, green-stuffs, fruit, hay, straw and other dried products of plant-grower) is carry out to not viable state by intensive release from free moisture (xeroanabioz). Only at presence of free moisture, which chemically unconnected with matters storage object, possible active breathing of living organisms (grain, grass, juicy garden-stuffs). The amount of connected water depends on content in the products of colloid matters (albumens, starch and etc.), which connect water. Optimum humidity of the dried products is %: fruit — 15, green-stuffs — 12, seed of oil-bearing cultures — 6-7. Such humidity is unfavorable environment for development of microflora and most insects. Therefore in a state of xeroanabioz products can be kept long time, not losing the technological and sowing qualities. This principle is underlain all methods of drying — air-sun, thermal, vacuum, by an infra-red irradiation and etc. It should be noted that at moistening possible activation of microorganisms and spoilage of the dried products.



The methods of storage of plant products, which increase osmosis pressure of environment is name osmoanabioz. Under the action of certain matters (salt, sugar) cells of microflora and object of storages carry out to the state of osmoanabioz. The concentration of solution of salt here must be 12 — 13 %, that is appropriately under osmosis pressure about 7 MPa, and sugar solutions for achievement of the state of plazmolisis of all cells — not less then 65 % and accordingly up to 35 MPa.

The state of anabioz can be attained also by creations of certain concentration of ion hydrogens that means by creation of certain acidity of environment. The last one influences on dispersion of protoplasm of living cell. At the certain concentration of ion hydrogens the vital functions of cells are stoped.

In particular, putrid bacteria (proteus, fluorescence, subtilis and etc.) actively develop in a neutral environment at pH 7 and higher. At pH 6 their action is oppress, at pH 5 they are not propagate oneself and collibacillus is perish, at pH 4,5 the putrid and lactic bacterium are perish, there are pH 3-4 – lactobacillus, at pH 2,5 - 3 – yeasts, at pH 1,2 - 3 – fungus. Creating pH 1 - 1,5 by a 3 – 5 % solution of acetic acid, products are carry out to the state of acidoanabioz, in which it can be kept long time. In practice this principle is used at the artificial ensilage of forage. Production of food vegetable and fruit marinades of related with canning of green-stuffs with the low concentration of acid (up to 1 % acetic acid). Such products carry out to the state of anabioz by sterilization.

There is also a method of carry out of living organisms to the state of anabioz by pumping out of oxygen from the environment of storage and satiations of environment by inert or anesthetic matters. This principle of storage — narcoanabioz – apply for protracted storage of corn mass. A microflora is perishes and intensity of grain breathing is broken at the certain concentration of chloroform or salts of propionic acid. Analogical principle operates also in introduction to corn mass of carbon dioxide of height concentration and the storage of fruit and vegetable products in the conditions of the managed gas environment (MGE). Thus depositories for storage of products must be hermetically closed.

Fermentative garden-stuffs can be produced by principle of tsenoanabioz. Creating conditions which are appropriate for development of one type of microorganisms and are destructive for others, reach at a certain concentration of preservative which provides stable storage of basic product. Such microorganisms are mainly lactobacillus (salting, pickling) and yeast (in the winemaking). These types of cenoanabiosis have the name accordingly acidotsenoanabioz and alcoholetsenoanabioz. By creation of optimum conditions for development of lactobacillus (increasing of temperature, addition of sugars) and using of their properties to propagate oneself in environment without oxygen limit development of other microorganisms and activation of lactic fermentation. At content of lactic acid 1 – 1.2 % products (green-stuffs, garden-stuffs, mushrooms and etc.) are preserved and continuously nonspoiled on condition of storage of them in a cool apartment and non-penetrating oxygen. For development of yeast an environment must be sourer, than for lactobacillus. For alcoholic fermentation is needed pH 2,5 - 3, enhanceable concentration of sugar and presence of the proper races of yeasts. Only at certain conditions it is possible to provide piling up of 9–12 volume percents of alcohol, sufficient for the protracted storage of wine.

To the state of abioz objects of storages lead to absents in it living organisms and vegetative forms of microflora, such methods are used here: thermosterilization, pasterization, chemical preservation, sterilizations (mechanical, aseptic, ray).

Thermosterilization carry out at temperature above 100 °C. Products are kept in hermetically bottled to glass or to the tin container. Duration of sterilization depends on consistency and acidity of product, capacity of container and etc.

For achievement of the state of abioz products apply the current of high-frequency (CHF) or ultrafrequency. After 30 — 120 sec of action ultrafrequency current on a product hermetically bottled in a container is sterilized and can be kept long time without the change of commodity and gustatory qualities.

Separate types of products, at canning, of which the combined action of a few preservative modes are used pasterization at a temperature 80 – 85 °C. It enables to save the best commodity type of products due to diminishing of biochemical changes for them by comparison to thermosterilization. The spore forms of bacterias here are not destroyed and the stored of product is provided the increase of concentration of hydrogen ions (by high acidity of product or addition 0.6 – 0.7 % acetic acid). Such treatment is named pasterization. It is widespread enough in production of juices, drinks and canned green-stuffs and fruit products. The pasterization products must be hermetically bottled.



Chemical sterilization used for the milling products which before the use will be treatment. Before the use of products chemical matters, applied for sterilization are decompose or escape (from grain, fruit products). Such chemical matter is sulphuric acid (sulphuric anhydride), the sterilizing action of which appears during the concentration of it in a product is 0.2 – 0.3 %. Treatment of products by sulphuric anhydride or acid sulfatation is named a sulphitation. It can be used at other types of canning, for example, when is a threat of moistening of the dried products (green-stuffs, fruit and etc.). A temporal sterilization effect can be attained treatment of corn the masses by salts of propionic acid.

Salt of sorbic acid have a partial sterilizing action. Salt of sorbic acid brake development of funguses only — mould and yeast do not influencing on development of bacteria. The selective action of salt of sorbic acid is used for salting or pickling of products, limiting development of fungus in its superficial layers. It enables considerably to decrease wastes at the use of such products.



Chemical sterilization is widespread enough at disinfection of granaries for destroying insects and rodents (poisonous decoy) and also for destroying (chloropicrin, dichloroethane and other) insects at storage of corn and its products, fight against illnesses of plants.

Last period for carry out of products to the state of abios apply ray sterilization. Thus conduct ultraviolet, infrared, X-rays and γ-radiation. In particular, action of infra-red irradiation is similar to termosterilization. Before treatment the preliminary prepared products are placed in the hermetically bottled container.

Products are treated by ultraviolet ray keep can some time without the use of cold.



Sterilization effect of α- and ß-radiation at storage of corn of short duration. This method of abioz is presently perfected.

Milling products and juices sterilize by mechanically passed them through filters which detain the cells of separate types of microorganisms. Permanent abioz arrives at the additional heating of products.






Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©azrefs.org 2016
rəhbərliyinə müraciət

    Ana səhifə