STUDY ON THE DEHYDRATION PROPERTIES OF OYSTER MUSHROOM (Pleurotous sajor caju) UNDER DIFFERENT PRE-TREATMENT CONDITIONS

Abstract

The aim of present work was to study the effect of pretreatments on dehydration characteristics of mushroom. Raw materials (Pleurotous sajor caju) were purchased from Simadia VDC of Sunsari district. Mushroom was dried in a hot air oven at 60ºC with different pre-treatments. After dehydration product was analyzed for vitamin C, rehydration ratio, non-enzymatic browning, sensory quality and drying rate. The mushroom pre-treatments were blanching, sulfiting, blanching and sulfiting and untreated. Blanching was done in water of 85ºC for 3 min while sulfitation was done in 0.3% KMS for 10 minutes. ANOVA was carried out to study the effect of pretreatments on product characteristics. The effects of pretreatments on rehydration ratio, vitamin-C content and Yield of final product were significant at 5% level of significance. The rehydration ratio varied from 2.65 to 3.12 while vitamin-C content varied from 13.55 to 24.54mg/100g dry matter. Effect of pretreatments varied the yield from 82.55 to 84.02g/kg while color and overall acceptability score varied from 5 to 7.4 and 5.12 to 6.8 respectively. Effects of pretreatments on analyzed parameters were compared by LSD method. Optimization of dehydration process was done on the basis of rehydration ration, color and overall acceptability. The product which was blanched and sulfited was found to be superior. The product had rehydration ration of 3.12 and got score 7.4 and 6.8 for color and overall acceptability