Vol. 11, Issue 10 (2022)

Author(s):
Srujana Eda, V Sudhavani, DR Salomi Suneetha and RV Sujatha

Abstract:
The present investigation was carried out in Department of Post-Harvest Technology at College of Horticulture, Dr. Y.S.R. Horticultural University, Venkataramannagudem, West Godavari District of Andhra Pradesh during 2017 and 2018 to study the effect of different pretreatments on physical characteristics of onion slices. In preparation of dehydrated onion slices, four pre-treatments viz., 0.5% potassium metabisulfite (KMS), 2% calcium chloride (CaCl₂), 2% Sodium chloride (NaCl) and control. The experiment was conducted in completely randomized factorial design with the above two factors at unequal levels and replicated thrice. Among the pretreatments and varieties, powder prepared from Agrifound Dark Red variety pretreated with 0.5% KMS (13.15%) recorded maximum recovery percentage. Regarding moisture content, powder prepared from the slices pretreated with 2% CaCl₂ recorded lowest (4.12%) among pretreatments. Among the varieties, lowest was observed in Agrifound Dark Red (4.76%). Concerning Dehydration ratio was noticed minimum in powder prepared from Agrifound Dark Red variety pretreated with 0.5% KMS (7.60). Among the pretreatments, maximum rehydration ratio recorded in powder prepared from the slices pretreated with 0.5% KMS (5.06). Among the varieties, Phule Safed recorded minimum rehydration ratio (4.94). Among the pretreatments, lowest water activity was recorded in powder prepared from the slices pretreated with 0.5% KMS (0.53). Among the varieties, Agrifound Dark Red recorded lowest water activity (0.56). Onion powder could be stored up to 60 days of storage at ambient conditions with less loss in quality. Microbial spoilage (bacteria and fungi) was observed in eight treatments but was under permissible limit until 30^th day of storage. It was found that onion powder prepared from Agrifound Dark Red variety pretreated with 0.5% KMS was found with better retention of physical attributes.