Effects of different drying methods on the quality and volatile flavor components of Stropharia rugosoannulata
Objective:This study aims to investigate the effect of different drying methods on the drying characteristics and volatile flavor of Stropharia rugosoannulata as raw material.Methods:The fresh S.rugosoannulata was dried by freeze-drying,heat pump drying,hot air drying,and microwave drying,and then the physical and chemical indexes were investigated.Results:The contents of crude protein,crude fat,ash,potassium,calcium,total flavonoids,essential amino acids,flavor amino acids and total amino acids are the highest in freeze drying.The six teenamino acids achieved 16.88 g/100 g in the freeze-drying.The rehydration rate and color all play the best performance in freeze drying.The scavenging rate of DPPH radical of S.rugosoannulata polysaccharide reached 61.14%in hot air drying;The rate was hot air drying>heat pump drying>microwave drying>freeze drying.Similarly,the scavenging rate of ABTS radical reached 67.97%in heat pump drying;The rates were heat pump drying>hot air drying>microwave drying>freeze drying.The monosaccharide of S.rugosoannulata is mainly composed of glucose Glc and Galactose gal,among which the content of freeze-dried glucose Glc is the most,accounting for 36.79%of the total sugar;The maximum molecular weight of S.rugosoannulata was freeze-drying;The volatile flavor of S.rugosoannulata different under different drying methods,and the volatile flavor of S.rugosoannulata after drying is quite different from that of fresh S.rugosoannulata.The volatile components in freeze-dried S.rugosoannulata are the most abundant,and some components are high.Conclusion:Freeze-drying has advantages over other drying methods in terms of nutritional composition,rehydration rate,color,and flavor.It has the least impact on the quality of S.rugosoannulata and is the most suitable drying method.