Shelf-life and microbiological safety studies of refrigerated petha sweet

Abstract

This study was conducted at Indian Institute of Vegetable Research, Varanasi (I.I.V.R.), Uttar Pradesh from 2006 to 2009 for evaluating comparative physico-chemical, microbiological and sensory attributes of crystallized and Kashi petha at refrigerated storage (4 ± 1 °C) condition up to 90 days. The petha were manufactured using 2 varieties of ash gourd developed at I.I.V.R. i.e.; Kashi Dhawal and Kashi Ujwal, selected based on different parameters suitable for petha sweet preparation. The used packaging materials for storage studies were laminated pouch, low density polyethylene, high density polyethylene. The physiochemical analysis and sensory evaluation were performed at 15 days interval upto 90 days for storage study in both Kashi Petha and crystallized petha, while microbial observation was recorded up to 90 days in crystallized petha and up to 50 days Kashi Petha. Physico-chemical analysis exhibited the continuous increase in moisture (25.79-26.80 % and 31.68-32.63 %) and titratable acidity (0.022-0.029 %) and (0.022-0.030 %) and reduction in ascorbic acid content (5.50-5.00 mg/100 g and 5.12-4.84 mg/100 g), respectively in crystallized and Kashi petha. The increasing trend in microbial population was more pronounced in Kashi petha in comparison to crystallized petha. The spoilage bacteria included Bacillus spp., Staphylococcus spp. and lactic acid bacteria while Aspergillus, Penicillium and Saccharomyces were observed among fungal contaminants. The bacteria, yeast and mold were identified on the basis of cultural, morphological and biochemical characterization with respect to storage period. On the basis of the overall findings of comparative physico-chemical, microbiological and sensory evaluation, 30 and 50 days of storage was considered as safe for the consumption of Kashi and crystallized petha, respectively under refrigerated environment (4 ± 1 °C).