Effects Of Drying Characteristics And Quality Of Shiitake Mushrooms Using Mird Combined Had Drying Processes

Shiitake is one of the most important edible fungus in the world,accounting for about 25% of global mushroom production.Yield growth of mushrooms is faster than any other species,but the moisture content of fresh mushrooms can reach 80%~95%.Perishable and spoiled when stored at normal temperature,which affects its commercial value.It is usually dried to extend the shelf life and increase its flavor.However,there are few reports on the comprehensive research to improve the quality of shiitake mushrooms and the unit energy consumption of the drying system.Therefore,this article takes shiitake mushrooms as the research object,and studies the effects of different combined drying methods on the drying characteristics,unit energy consumption,nutrients and volatile components of shiitake mushrooms.Changes in drying time,energy consumption,hardness,volume shrinkage,water rehydration ratio,protein,total sugar,volatile compounds of shiitake mushrooms by HAD,MIRD,HAD—MIRD,MIRD—HAD.The main research results are as follows: 1.Studies on the drying characteristics and quality of shiitake mushrooms by different single drying processes show that:The comprehensive quality evaluation of MIRD of shiitake mushrooms at 70°C is relatively good,and the drying rate is fast,but the unit energy consumption is relatively high.Compared with MIRD and HAD of shiitake mushrooms,the drying time of MIRD is relatively short,and the hardness,volume shrinkage,rehydration ratio,microstructure and nutritional indicators of MIRD are better than HAD.The relative contents of volatile compounds such as isoamyl alcohol,n-hexanol,1-octene-3-ol,methylsulfonylmethane,4-hydroxybutyric acid acetate,acetic acid,and isobutyric acid are compared in MIRD dried shiitake mushrooms.Too high drying temperature and long drying time increase the hardness of dried shiitake mushrooms,increase the volume shrinkage,reduce the rehydration ratio,increase tissue collapse and cell damage,reduce nutrient content and lose some volatility ingredient.2.Studies on the drying characteristics and quality of shiitake mushrooms by different combined drying processes show that:When the combined drying process of shiitake mushrooms is MIRD70?—HAD50?(moisture conversion point 70%),the comprehensive evaluation is relatively good,t he drying rate is fast,the quality is good,and the unit energy consumption is low.W hen the drying process is MIRD70?—HAD70?(moisture conversion point 25%),thedrying time of shiitake mushrooms is the shortest,which is 440 min.The moisture rati o and the moisture content decrease with the increase of the drying time.When the d rying process is MIRD70?—HAD50?(moisture conversion point 70%),the total uni t energy consumption is the lowest,which is 23.39 k J/g.When the drying process is MIRD70?—HAD50?(moisture conversion point 40%,55% and 70%),HAD50?—MIRD70?(moisture conversion point 25% and 40%),the hardness of shiitake mushro oms is relatively low,which are 16092 g,15541 g,15523 g,15439 g and 16132 g.Whe n the drying process is MIRD70?—HAD50 ?(moisture conversion point 70%)and HAD50—MIRD70?(moisture conversion point 25%),the volume shrinkage is relative ly low,which are 73.77% and 74.28%,respectively.When the drying process is MIR D70?—HAD50?(moisture conversion point 70%),the rehydration ratio is relativelylar ge,which is 342.61%.The drying process is MIRD70?—HAD60?(moisture conversi on point 25%,40% and 70%),HAD50?—MIRD70?(moisture conversion point 40%),the total sugar content is relatively large,which are 37.91%,37.74%,37.98% an d 38.12%;the total sugar content is relatively inferior when the drying process is MI RD70?—HAD60?(moisture conversion point 70%),which is 37.00%.The drying pr ocess is HAD50?—MIRD70?(moisture conversion point 25%),the crude protein co ntent is relatively large,which is 29.81 g /100 g.A total of 83 volatile components wer e identified in the dried shiitake mushrooms by different drying processes.MIRD70?—HAD70?(moisture conversion point is 40%)has the most kinds of volatile compo nents,with 46 types,and the main volatile component is 1-octene-3-alcohol,isoamyl a lcohol,benzyl alcohol,phenethyl alcohol,dimethyl trisulfide,methylsulfonylmethane,aceti c acid,4-hydroxybutyric acid acetyl ester,and valprolactone.This experiment provides a theoretical basis for further optimizing the production process of energy-saving and quality-enhancing drying of shiitake mushrooms,and has important application value and guiding significance for the commercial production of shiitake mushrooms.