Prema, LSheeja, NKAU2020-11-232020-11-231994170534https://krishikosh.egranth.ac.in/handle/1/5810155593MScThe present investigation was undertaken to study the influence of pretreatments and processing on the shelf-life quality of papaya products. The papaya squash, jam and candy developed were found to satisfy the FPO recommendations. The pretreatments administered were blanching, sulphiting, exposure to sulphur fumes and immersion in citric acid solution. An analysis of the proximate composition of the three products revealed that moisture and sugars were high in squash and jam pretreated with sulphur fumes while candy pretreated with citric acid solution was high in acidity, sugars and carbohydrates. The organoleptic evaluation of the fresh products indicated that squash was most acceptable. The pretreatement with sulphur fumes was affective in improving the appearance and colour of all the three products. The shelf-life qualities of the three products were assessed periodically for one year. Periodical testing of stored papaya squash showed little variation in acid soluble ash, specific gravity and pulp content. Negative results were obtained for fermentation test and mold content. The periodical testing for acidity, reducing sugar, total sugar and TSS in squash showed an increase during storage, while pH and overall acceptability decreased with storage. The monthly evaluation of papaya jam revealed that storage at low temperature was effective in retaining the quality. Among the pretreatments, products prepared with fruits exposed to sulphur fumes showed the maximum shelf –life period (84 percent) compared to control (43 percent) which showed the least shelf – life. The periodical evaluation of papaya jam indicated negligible changes in bulk density. Acidity and reducing sugar showed an increase while pH and overall acceptability decreased with storage. The microbial evaluation of jam revealed that the main causative organism were bacteria, yeast and mold. The pretreatment with sulphur fumes was effective in preventing the microbial attack. At the same time the refrigerated samples were found fresh even after one year. The analysis of the shelf – life period of papaya candy revealed that pretreated refrigerated samples had a longer shelf-life of more than one year than control. At ambient conditions. Samples processed fruits from exposed to sulphur fumes had the highest shelf – life period (75 percent) compared to the control (34 percent) which was the least. The periodical evaluation of candy showed only negligible variation in bulk density. Acidity and reducing sugar was found to increase while pH and overall acceptability showed a decrease with storage. The microbial evaluation of the damaged product revealed that the major causative organism were yeast and mold. The shelf-life evaluation of the products indicated that the refrigerated samples gave quality products compared to that at ambient condition. All the refrigerated samples showed a slower rate of change in the chemical constituents. The evaluation of the three products revealed that pretreatment with chemical compounds, especially with sulphur compounds produced a better effect both qualitatively and orgnoleptically. Pretreatments attempted in the study indicates the advantages of there procedures with respect to the shelf – life qualities of the products. Among there pretreatments, exposure to sulphur fumes process to be the most ideal one, is a very simple technology which can easily be adopted moderately educated farm women.EnglishThesis