Rajendra SinghRajni Singh2016-11-232016-11-232007http://krishikosh.egranth.ac.in/handle/1/87176The study was conducted on aonla juice to standardize a time-temperature combination for thermal processing of aonla juice with minimum losses in ascorbic acid content. The various physico-chemical characteristics of fresh aonla juice, heat treated aonla juice and stored juices were studied. The aonla fruit yielded about 32% pulp and 52% clarified juice with 9.9% TSS, 2.9% acidity, 3.2% tannins, 426 mg/100g ascorbic acid and a pH of 2.45. This aonla juice was heat treated at different temperatures viz. 600C, 700C, 800C and 900C for different time periods viz. 5, 10, 15 and 20 min. for 600C & 700C and 1, 3, 5 and 10 min. for 800C and 900C. These heat treated juices were analyzed for various physico chemical characteristics and yeast and mold count. On the basis of this study two best combinations were selected viz. 800C/3 min. and 700C/15 min. which had minimum losses in ascorbic acid content upon thermal processing and negligible yeast and mold growth. These combinations were used for storage study of 2 months at room temperature. During storage, ascorbic acid and acidity decreased whereas browning increased. There was no significant growth of yeast and mold even after two months of storage of heat treated juices. Thus the study indicated that considering the destruction of yeasts and molds and retention of vitamin C content of the juice, processing of aonla juice at 800C/3 min. and 700C/15 min. were found suitable.enAonla juice, Thermal processing, Time-temperature combinations, Heat treatmentThesis