Storage and preservation technology and progress o

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Vegetable storage and preservation technology and progress (I)

Abstract: vegetable preservation is a hot topic in recent years. This paper introduces the basic principle and general methods of vegetable preservation in detail. At the same time, it also introduces the latest progress in vegetable preservation. Through these introductions, we can infer the general trend of vegetable preservation in the future

vegetables are one of the main sources of various nutrients for people. Vegetables are rich in amino acids, protein and carbon. Experimental speed: 6 mm/min water compounds, vitamins and a variety of trace elements. These nutrients are indispensable for people to carry out normal physiological activities and maintain such activities. However, only in fresh vegetables, the content of these nutrients is very high, and it is easier for the human body to absorb them. If vegetables go bad or rot, these nutrients that are useful to human body may be transformed and decomposed, resulting in loss, and some may even be transformed into toxic and harmful substances to human body, making the output report content more standardized. Therefore, vegetable preservation is very important for maintaining the nutritional value of vegetables

in addition, China is a large agricultural country, and agricultural economy plays a very important role. China is also a country with a large population, and there is a great demand for agricultural and sideline products every day. Therefore, vegetable preservation technology plays a very important role in improving the level of agricultural economy, improving people's living standards, increasing farmers' economic income and reducing the loss of the national economy. So we should understand the methods and progress of vegetable preservation technology

now, let's talk about some basic principles of preservation technology. Technology and the latest progress are introduced to you:

first, the general principle of vegetable preservation ⑴

we know that fresh vegetables are still a living organism after harvest, which is the difference between them and other foods. Therefore, vegetables have certain storage resistance and disease resistance. It can keep fresh for a certain period of time. However, when life activities disappear, these properties of life will no longer exist. Harvesting is an important change for vegetables. It is separated from the plant and becomes an independent individual. At this time, the metabolic function within the vegetable tissue must undergo a series of changes to adapt to this changed situation and external environmental conditions. So as to maintain life. So for the storage and preservation of vegetables, the first thing is to maintain the life of vegetables. Only when the life is maintained, can we talk about storage resistance and disease resistance. Then it is to maintain this kind of life activity. Only when the life activity is maintained normally can it play the role of storage resistance and disease resistance. The last is to further maintain slow life activities on this basis, so as to delay the storage and preservation period. People have found through research that the life activities of post harvest vegetables are still the continuation of pre harvest. It is also regular. Therefore, only mastering the basic content of postharvest physiology of vegetables is the key to the development of vegetable storage and preservation. These basic contents are:

(I) the role of respiration and storage and preservation

under normal circumstances, plants mainly carry out aerobic respiration: 1. Plants use carbohydrates through respiration to obtain energy needed for life activities. At the same time, starch is also decomposed into glucose, three carbon sugar, two carbon sugar and some organic acids. These substances are the raw materials for the formation of amino acids and proteins. Therefore, respiration is the leading process of life activities. If the respiration is out of order, it will affect the unity, balance and coordination of metabolism, and make metabolism disordered, which will weaken the storage resistance and disease resistance of vegetables and produce physiological diseases. To keep vegetables fresh for a long time, we should not interfere with their normal respiratory activities. At the same time, we should artificially change the storage environment to weaken and slow down the intensity of respiration under normal conditions, so as to delay the duration of vegetable life activities and prevent the transformation and loss of useful ingredients

(II) transpiration and wilting

fresh vegetables have high water content, up to 65%~96%. Plant cells must be full of water and inflated to make the tissue appear firm, crisp, shiny and elastic. Only in this way can the vegetables be considered fresh. If the water content decreases and the cell swelling pressure decreases, the tissue will wither, shrink and the luster will fade. At the same time, it will also lead to the increase of the concentration in the cell fluid, the intensification of the hydrolysis process, and the destruction of the normal metabolic process. And the resulting changes in cell structural characteristics and other adverse effects, thereby weakening the storage resistance and disease resistance of vegetables. And the more serious dehydration, the more severe the decline of storage resistance and disease resistance. In addition, transpiration can also cause dewing on the bag wall. These condensed water is very conducive to bacterial reproduction and aggravate vegetable decay. Research shows that the transpiration of plants is related to the relative humidity of the air in the environment. Therefore, the relative humidity of the air in the storage environment can be controlled to restrict the activities of microorganisms and delay the later life activities of vegetables

(III) the consequences of ripening and aging will be more troublesome process

after the vegetables after harvest reach a certain degree of maturity, they begin to enter the aging process. At this time, the storage resistance and disease resistance of vegetables will also decline. Besides environmental factors, the ripening and senescence of vegetables are also affected by plant hormones and intracellular calcium content. These plant hormones are: 1. Auxin (can promote growth and prevent aging) 2. Gibberellin, cytokinin (promote aging and dormancy) 3. Ethylene, abscisic acid. When vegetables reach maturity, the contents of auxin, gibberellin and cytokinin will decrease, while the contents of ethylene and abscisic acid will increase. Therefore, reducing the ethylene content in the storage environment or treating vegetables with auxin and cytokinin can prevent vegetables from aging and prolong the fresh-keeping period. In addition, we can reduce the respiratory intensity of vegetables and delay aging by increasing the content of calcium in cells

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