Aparnathi, K. D.Sharma, Pragati2018-06-292018-06-291999http://krishikosh.egranth.ac.in/handle/1/5810055927A study for enhancement of shelf life of khoa was undertaken in four phases. In phase one, suitable packaging materials were selected; in phase two, the effect of vacuum packaging was studied and phase three comprised evaluation of the effect of different physical and chemical treatments and storage studies were conducted at 32±1°C. The most effective treatments from the three phases were selected and in the final phase khoa was given the best treatment, packed in the best packaging material under vacuum and shelf life was studied at 32±1°C as well as 4±2°C. Packaging materials studied in the phase I include (A) LDPE; (B) LD:LLD; (C) HD:LD:HD;" (D) HMHD; (E)PET:Aluminium foil:LDPE; and (F) PET:Aluminium foil:(LD:LLD). Three packaging materials A, D and E were selected and then in the phase II, influence of vacuum packaging on the shelf life of khoa was observed. In phase III, the effect of thermization (Tn); microwave exposure (TMW); incorporation of potassium sorbate (TKS) and addition of sugar (Ts) for improvement in the shelf life of khoa was assessed. Finally, in phase IV, the effects of the best packaging material, vacuum packaging and TKS were combined and their performance was compared with the samples packed under atmospheric pressure without any treatment. The samples were stored at room temperature (32+1 °C) as well as at refrigerated temperature (4+2°C). The fresh khoa samples were analysed for their chemical composition and microbiological quality. Deterioration during storage was monitored by measuring changes in chemical parameters viz. titratable acidity, free fatty acids content and tyrosine value. Microbiological changes were estimated as total viable count, yeast and mold count and coliform count. Fresh as well as stored samples of khoa were evaluated for their sensory attributes by a panel of 10 judges. During storage the samples were analysed daily for 3 days in Phase I and II and 4 days in Phase III. In the fourth phase the samples stored at 32+1 °C were analysed on 1, 3, 5 and 7 day and samples stored at 4±2°C on 1, 3, 5, 7, 14 and 21 day. One of the samples (with added potassium sorbate and packed under vacuum) kept at 4+2°C was analysed upto day 45. Four replications were carried out in each phase and the data were analysed statistically. Statistical analysis using Randomized Block Design indicated that the packaging materials included in the study had no significant effect on the shelf life of khoa. Regression analysis of the data, however, showed that rate of spoilage was better controlled by aluminium foil laminates closely followed by HMHD. Vacuum packaging significantly (P<0.05) reduced the rate of lipolysis and microbial growth (total viable count and yeast and mold count). Similarly, sensory (flavour and overall acceptability) scores were also found to be significantly (P<0.05) higher during storage under vacuum. However, vacuum packaging hadV no significant effect on rate of proteolysis, titratable acidity and coliform count. Various treatments (TH, TMW, TKS and Ts) significantly (P<0.05) increased the shelf life of khoa. However, Ts and TKS were found to be better than TMW and TH. Simple refrigerated (4±2°C) storage increased the shelf life of khoa to about 14 days, whereas, a combination of vacuum packaging, incorporation of potassium sorbate and low temperature storage increased the shelf life to about 45 days.enDAIRY CHEMISTRYA STUDYThesis