Abstract:

Edible mushroom Lentinula edodes (shiitake mushroom) was treated with hot-air drying, vacuum drying and vacuum freeze drying respectively, and their effects on formaldehyde content and quality of the edible fungus were studied. Results showed that the formaldehyde content in shiitake mushroom subjected to enzyme inactivation followed by each of these drying treatments was reduced to below 35 mg/kg, and vacuum freeze dried shiitake mushroom exhibited the best sensory quality and the highest rehydration rate. The optimum production process of dried shiitake mushroom was based on vacuum drying for 5 h after 2 min microwave treatment for enzyme inactivation followed by freeze treatment at － 30 ℃ for 10 h. The product obtained using the optimal process exhibited a mushroom formaldehyde content reduced to 20.18 mg/kg and a rehydration rate up to 8.29 g/g dry basis, and was good in sensory quality.

Key words: mushroom, formaldehyde, drying