Assessment of the Quality Characteristics of Stropharia rugosoannulata Subjected to Five Different Drying Methods

Abstract

The effect of solar drying (SD), room-temperature shaded drying (RSD), hot-air drying (HD), vacuum freeze drying (VFD), and microwave drying (MD) was compared on the sensory quality, nutrient substances, bioactive constituents, and antioxidant activities of dried Stropharia rugosoannulata. The results revealed that, in comparison with SD, RSD, HD, and MD, VFD mushrooms exhibited a better appearance with less shrinkage and an ideal colour with lower a colour difference. Meanwhile, a significantly higher content ( $p<0.05$ ) of protein, carbohydrate, total sugar, and vitamin C was retained in VFD samples. The HD and VFD samples both had abundant total free amino acids and best met the ideal protein standard. Furthermore, VFD had advantages in terms of better preserving bioactive constituents and stronger antioxidant activities compared to other treatments. Therefore, the VFD-dried S. rugosoannulata obtained a better overall quality compared to the other four drying methods.