EFFECT OF PRETREATMENTS AND DRYING TEMPERATURE ON QUALITY CHARACTERISTICS OF DEHYDRATED AMLA (Phyllanthus emblica)

Abstract

Amla, a richest source of vitamin C were subjected to different pretreatments and drying temperature to investigate the effect of pretreatments and drying temperature on quality characteristics of dehydrated amla. Amla were subjected to following pretreatments viz. cut blanching, cut sulphiting, cut (blanching + sulphiting), whole blanching, whole sulphiting, whole (blanching + sulphiting) and dried at 60±2ºC at cabinet drier to a final moisture content 6±1%. Further, the best pretreatment was then subjected to 3 different drying temperature range viz, 55±2ºC, 60±2ºC and 65±2ºC to a final moisture content 6±1%. Among the different pretreatments, samples pretreated by pretreatment whole (blanching + sulphiting) showed higher retention of vitamin C (411.3 mg/100 g, db) (71.18%) along with improved rehydration ratio (2.227:1), coefficient of rehydration (0.422) and best organoleptic properties. Amla pretreated by pretreatment whole (blanching + sulphiting) and dried at 55±2ºC showed maximum retention of Vitamin C, best rehydration characteristics and better organoleptic property compared to other temperature range. Vitamin C retention was maximum at temperature 55±2ºC (429.67 mg/100 g, db) (74.36%) which was significantly different (p≤0.05) with the samples dried at other temperature range. Temperature showed significant effect on rehydration ratio. Amla dried at 55±2ºC showed maximum rehydration ratio (2.507:1) and coefficient of rehydration (0.4747). Sensory quality of the product dried at 55±2ºC was found superior to that obtained from 60±2ºC and 65±2ºC. The sensory attributes of all three products; dried at 55±2ºC, 60±2ºC and 65±2ºC were found significantly different (p≤0.05) to each other. The final optimized dried amla composition was found 6%, 3.3, 5.2%, 4.6%, 2.4% and 429.67 mg/100 g in terms of moisture content, pH, total sugar, reducing sugar, acidity and vitamin C respectively.