Studies on drying characteristics and effect of pretreatments on the quality of sun-dried oyster mushroom Pleurotus florida

Sun-drying, a low-cost method of drying the agricultural commodities in the tropical and subtropical regions, was attempted to dehydrate the oyster mushroom (Pteuroms florida) in the temperate region like Himachal Pradesh, and to study the effect of various washing pretreatments on the quality ofthe sun-dried oyster mushreom. Samples of oyster mushroom were sun dried after giving various washing pretreatments viz; 0.05% Potassium meta bisulphite (KMS), 0.1 % citric acid, 0.05% KMS + 0,1% citric acid, 125 ppm EDTA, 125 ppm EDTA + 0.1% citric acid, 100 ppm ascorbic acid, 100 ppm ascorbic acid + 125 ppm EDTA, 100 ppm ascorbic acid + 0.10/0 citric acid, 0.05% KMS + 125 ppm EDTA, 2 % , 4 % and 6 % hydrogen peroxide. It took 15 hours to get a desired final dried product with 9% moisture content, The quality of the dehydrated oyster mushroom was significantly influenced by the pretreatments; mushrooms washed with 0.05 0/0 KMS +0.1% citric acid gave the good quality dried product with maximum reflectance value both before drying (71) and after drying (70) compared to other treatments, The drying characteristics of the product involving drying rate, drying time with moisture content were also studied.