Effect Of Different Pretreatment On The Quality Of Hypsizygus Marmoreus

[Objective]In order to develop the deep processing of Hypsizygus marmoreus,we want to study the changes of its quality in the processing.So this study is mainly to study the effect of pretreatment on the quality of Hypsizygus marmoreus.[Methods]The Hypsizygus marmoreus was heated at 60 ℃ 75 ℃,85 ℃and 100 ℃ for 15 s,30 s,2 min,5 min,10 min,15 min,20 min respectively.Then we determined the color with chromatic meter and the hardness elasticity,cohesiveness and chewiness by texture analyzer.We observed the changes of organizational structure by scanning electron microscope.The activity of PPO and POD was determined by chemical analysis.Through the comprehensive evaluation of selected quality,the best heat treatment temperature and time was selected.After the color protecting and hardening treatment,heat treatment was carried out at the optimum temperature and time.The color and texture quality,the changes of organizational structure,enzymatic browning index and the non enzymatic browning index including total sugar,reducing sugar,protein,soluble protein and total phenol was determined.The volatile components were determined by GC-MS.[Results](1)The color difference value increased at 60 ℃ 100 ℃ with the increase of treatment temperature and time;the hardness、elastic、cohesion、chewiness reached its maximum at 60 ℃ 15 s.;PPO and POD activities decreased gradually,which PPO and POD can be passivated after heat treatment,The optimum conditions for inactivation of PPO enzyme activity were 85 ℃ ISmin,100 ℃ 5min and 100 ℃ 0.5min,respectively.The optimum conditions for inactivation of POD enzyme activity were 85℃ 5min and 100℃ 0.5min,respectively.Combination of enzymatic browning related enzymes PPO and POD passivation treatment required temperature and time,so that the processing of Hypsizygus marmoreus should adopt appropriate color protecting and hardening treatment in order to maintain the texture quality.Enzymes can be passivated at higher temperature treatment.(2)Compared with the control group,the mushroom color value increased significantly after the heat treatment and color hardening heat treatment;compared with the heat treatment group,color protecting and hardening heat treatment group decreased significantly.The browning can be reduced to some extent,but could not improve.(3)Compared with the control group,the hardness,elasticity,mushroom cohesiveness and chewiness decreased significantly after heat treatment,the fiber structure became loose;compared with groups of heat treatment,hardness,springiness,cohesiveness and chewiness of the group of color hardening heat treatment increased,the hardness and chewiness of the difference reached a significant level.The fiber structure is tight.The results showed that the hardening treatment can maintain the hardness,chewiness and ordered arrangement of microstructure to a certain extent,but it can’t be improved completely.(4)Compared with the control group,the heat treatment group of PPO,POD,SOD,CAT activity and MDA content decreased and the differences were extremely significant;compared with the heat treatment group,the activity of PPO,POD,SOD of the color hardening heat treatment group reduced,PPO and SOD significantly reduced.However,the activity of CAT increased significantly,MDA content change was not significant.The activity of PPO and SOD can be inhibited to a certain extent after color hardening treatment;the activity of CAT which prevented browning was protected.Therefore,it is necessary to combine the relative changes of each enzyme to determine whether to carry out color hardening and heat treatment.(5)Compared with the control group,after heat treatment and color hardening heat treatment,the total sugar content,reducing sugar content,mushroom crude protein content,total phenol content and soluble protein content increased significantly;compared with the heat treatment group,color protecting and hardening heat treatment group of that did not change significantly.It indicated the color protection had no significant effect on the mushroom composition.(6)Compared with the control group,after heat treatment and color hardening heat treatment,the mushroom volatile substances both changed;compared with the heat treatment group,the changes of volatile substances was larger in color protecting and hardening heat treatment group,it showed that color protecting had a great influence on the mushroom volatile substances.[Conclusions]Heat treatment has certain effects on the quality characteristics,microstructure,browning,enzymes,components and volatile flavor compounds of the mushroom.Color protecting and hardening heat treatment can improve the quality of the seafood mushroom characteristics,microstructure,can also inhibit enzymatic browning enzyme activity in a certain extent,has no significant effect on its composition,its specific mechanism needs further study.