| Agaricus Blazei Murrill(ABM)belongs to Basidiomycotina,Hymenomycetes, Agaricales,Agaricaceae,and Agariceae,is a kind of precious fungus used for food and medicine.Different drying technologies were applied to ABM drying in this paper. Effects on drying characteristics of different drying technologies in ABM were studied and optimal drying technology was determined.Meanwhile,optimization process of optimal drying technology was studied.And then,effects on quality characteristics of different drying technologies in ABM were studies.HACCP system was established based on grasping the key points of quality changes.Therefore an recommendation for high quality process was offered.1.Effects of different drying technologies,such as natural drying,hot air drying, vacuum drying,microwave drying,freeze drying,on ABM drying characteristics which included drying rate and dehydrating rate were studied.The result showed that it was hard to get the safety moisture stage by natural drying,and natural drying was a relatively time needed and inefficient method on ABM drying.With the temperature increasing,drying rate increased and the drying-end time were shortened by the methods of hot air drying,vacuum drying and freeze drying.And by microwave drying,with the microwave power increasing,dehydrating rate increased in the stage of constant rate of drying and the drying-end time was shortened too.2.The optimum organoleptic evaluation and rehydrating rate value which was about the drying product of ABM by different drying technologies was compared.The order of organoleptic evaluation value was that freeze drying(freeze temperature 50℃)＞60~℃hot air drying＞60℃vacuum drying＞385W microwave drying and the order of rehydrating rate value was that freeze drying(freeze temperature 50℃)＞60℃hot air drying＞60℃hot air drying＞385W microwave drying. Comparatively speaking,at the freeze temperature of 50℃,the quality of drying product was the best,the value of organoleptic evaluation was 77.5,and the value of rehydrating rate was 5.02.3.The optimization process of freeze drying was studied.It was defined that the eutectic and co-melting point of ABM were -16℃and -4℃respectively.By comparison,the optimal pre-freezing method of ABM was medium speed freezing. The optimal parameters of ABM vacuum freeze drying process was that medium speed freezing to -21℃,freeze-trap temperature -40℃,working pressure 50Pa, sublimation temperature 30℃,releasing temperature 55℃,when the temperature of drying product closed to heating temperature,the freezing was ended.4.Effects of different drying technologies on quality characteristics which was about shrinkage,rehydration ratio and organization structure of ABM were studied. The four drying technologies were hot air drying,vacuum drying,microwave drying and freeze drying.It was indicated that the different drying technologies had different effects on the shrinkage,and the order of shrinking degree was that freezing drying＜microwave drying＜hot-air drying＜vacuum drying.The rehydrating rate of product was decided by the damage conditions of cells structure in different drying technologies.Among the different drying technologies,the product of freeze drying had best rehydrating rate,and then the order of the rehydrating rate were the product of hot-air drying,microwave drying and vacuum drying.Obvious distortion,shrinkage and collapse were happened to ABM's organization structure which was the product of hot-air drying and vacuum drying,and the products of microwave drying and freezing drying had better original organization structure,especially,the best space structure was kept by freezing drying,it could kept ABM's original appearance furthest.5.The application of the HACCP system in the processing of freeze-dried ABM was studied.After identifying the critical control points,setting up supervise procedures and correct measures to monitor the critical control points and to verify that the system was working properly,the sanitary quality safety of the products was improved.
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