Preservability of residual β-glucosidase in dried mushrooms

Abstract

To utilize residual enzymes in dried mushrooms as enzyme preparations, we determined the β-glucosidase activity in 5 species of dried edible mushrooms that were purchased fresh. The enzyme activity in dried shiitake (Lentinus edodes) was higher at 37℃ than at 60℃, but the activity in dried maitake (Grifola frondosa) and bunashimeji (Hypsizygus marmoreus) was higher at 60℃ than at 37℃. After storage for 1 year, enzyme activity was detected in all dried mushrooms tested, and was best preserved in dried eringi (Pleurotus eryngii) and bunashimeji. To examine the effect of heat during drying on the enzyme activity, we checked two methods of drying; oven drying, used for preparation of dried shiitake, and vacuum drying. Just after preparation of dried mushrooms, the activity in the vacuum-dried mushrooms was higher than in oven-dried mushrooms. But one year after preparation, the activity was almost the same for both types of dried preparations. The residual enzymes in the oven-dried mushrooms were stable, suggesting that the same drying method and oven used for dried shiitake preparation will be applicable for production of dried mushrooms as enzyme preparations.