MySheen

Fresh-keeping principle of Edible Fungi

Published: 2024-11-22 Author: mysheen
Last Updated: 2024/11/22, The mushroom body of edible mushroom fresh-keeping (theprincipleoffresh-keepingforediblefungi) without culture medium still has vitality, and the living organism is resistant to adverse external environment and microbial infection. However, the stronger the life activity is, the faster the freshness decreases. Therefore, under the premise of not destroying the normal physiological function of the body, by controlling the various factors that affect the physiological and biochemical changes of fresh mushroom products, make the life activity of mushroom body under as much as possible.

The mushroom body of edible mushroom fresh-keeping (theprincipleoffresh-keepingforediblefungi) without culture medium still has vitality, and the living organism is resistant to adverse external environment and microbial infection. However, the stronger the life activity is, the faster the freshness decreases. Therefore, under the premise of not destroying the normal physiological function of the body, by controlling various factors affecting the physiological and biochemical changes of fresh mushroom products, the life activity of mushroom body can be kept in the lower limit state as far as possible, and its shelf life can be extended. The physiological basis of the decline of freshness of edible fungi:

1. Growth and development: young mushrooms with normal growth will continue to complete their development process regardless of whether they are harvested or not. for example, Agaricus bisporus can continue to grow from the second development stage to the third to the seventh development stage. Button mushroom becomes an old flat mushroom. The law of development is determined by species genes, but the speed of process progress is restricted by environmental conditions.

2. Respiration: the physiological and biochemical changes of fresh mushrooms after harvest are directly or indirectly related to respiration. Respiration is a biological redox reaction chain catalyzed by enzymes, including aerobic respiration and anaerobic respiration. Respiratory products are carbon dioxide, water, ethanol or formaldehyde, etc., and release respiratory heat. Respiratory substrates are sugars, organic acids, fats and so on, in which mannitol is an important substrate for respiratory response of edible fungi. Respiratory intensity is expressed by the amount of carbon dioxide released or oxygen inhaled per unit weight of the product, which is usually 200,500mg carbon dioxide per kilogram of fresh mushrooms per hour at 20 ℃. In addition to environmental factors, respiratory intensity is related to variety and fruiting body maturity. Respiratory quotient (RQ) refers to the volume ratio of oxygen inhaled to carbon dioxide released VCO2/VO2, which can be estimated from the ratio of aerobic or anaerobic respiration.

3. Browning: mainly enzymatic browning, active phenoloxidase, free ion oxygen molecules and substrates with hydroxyl groups exist and contact with each other at the same time, which is a necessary condition for enzymatic browning. After harvest, the colorless phenols in the mushroom were oxidized to reddish brown quinones and water, which were then oxidized and polymerized to form dark brown substances. Maillard reaction of carbohydrates and lipids without enzyme self-oxidation also causes discoloration and odor.

4. Microbial infection: causing deterioration and decay of physiological diseases of mushroom body. The main factors affecting the physiological and biochemical changes of harvesting plants are temperature, relative humidity, gas environment and pH. Various factors comprehensively affect the process of change, and proper control will help to curb the process of deterioration.

 
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