Color Protection And Quality Preservation Research On Agaricus Bisporus

Agaricus bisporus is rich in nutritional value,a functional food for both medicine and food,and is one of the largest edible mushrooms grown in China,However,the delicate and soft tissues of the Agaricus bisporus mushroom,with its high respiratory and metabolic activity,are prone to dehydration,browning and decay after harvesting,which affects the value of the product.Bisporus mushroom crisps are crispy,tasty,low in fat,low in calories and high in fibre,making them a popular and promising product for young and old alike.This paper focuses on the optimisation of colour protection and sugar dipping processes in the preparation of Agaricus bisporus crisps.The colour protection process of Agaricus bisporus crisps was optimised through single-factor and response surface experiments;the effect of colour protection on the quality of Agaricus bisporus crisps was investigated;the decolourisation process of sugar dipping solution was optimised through single-factor and response surface experiments.1.The effect of citric acid,calcium chloride,chitosan,L(+)-ascorbic acid,sodium chloride and L-cysteine on the inhibition of browning of Agaricus bisporus slices was studied,using the inhibition rate of browning of Agaricus bisporus as an index.The single-factor experiment found that calcium chloride and chitosan are generally effective in inhibiting browning,and the best formulation is determined using the response surface method for the remaining four color-preserving reagents.The optimum formulation was 1.04‰ citric acid,1.21‰ L(+)-ascorbic acid,2.00‰ Na Cl and 0.45‰ L-cysteine,which resulted in 75.36% browning inhibition.2.The effect of color-preserving reagents on the changes of polyphenol oxidase(PPO)and peroxidase(POD)activities,on malondialdehyde(MDA),total phenols,ascorbic acid,total soluble sugars and total soluble protein content and on the scavenging rate of the DPPH radical was investigated.The results showed that PPO and POD activity decreased significantly after color-preserving reagents,reducing the rate of increase in PPO and POD activity over time;color-preserving reagents reduced the MDA content and significantly inhibited the rate of increase in MDA.Also,compared with the control group,color-preserving reagents promoted the accumulation of total phenols,ascorbic acid,total soluble sugars and total soluble protein,and curbed the loss of nutrients from Agaricus bisporus;color-preserving reagents helped safeguard the scavenging rate of the DPPH radicals by Agaricus bisporus.3.The effects of solid-liquid ratio(weight of activated carbon: volume of sugarimpregnated liquid),decolourisation time,decolourisation temperature and activated carbon particle size on the decolourisation rate of sugar-impregnated liquid were investigated.The results showed that the highest decolourisation rate of sugar dipping solution was achieved at a solid-liquid ratio of 2.5:1(g/100 m L),decolourisation time of 20 min,decolourisation temperature of 40 °C and small particles,respectively.The optimum parameters were determined using the three-factor,three-level response surface method for solid-liquid ratio,decolourisation time and decolourisation temperature.The optimum parameters were: solid-liquid ratio of 2.40,decolourisation time of 21.5 min and decolourisation temperature of 42 °C.The decolourisation rate of the sugar leach solution was 93.73%.