Sharon, C LRemya, P RKAU2020-12-162020-12-162020174752https://krishikosh.egranth.ac.in/handle/1/5810156768PhDThe concept of food has changed from its basic definition of satisfying hunger and nourishing the body, to health maintenance and prevention of diseases. Probiotics are one among such foods. The incorporation of probiotics to locally available foods may help to develop its nutritional profile and therapeutic value. Hence, the study entitled “Process optimisation and quality evaluation of jackfruit based probiotic food products” was undertaken with the objective of standardising probiotic food mixtures with raw jackfruit flour, instant shake mixes with the probiotic food mixture, probiotic yoghurt with ripe jackfruit and also to evaluate the nutritional, organoleptic and shelf life qualities of these developed food products. Probiotic food mixtures were developed with the incorporation of raw jackfruit flour, defatted soya flour, jackfruit seed flour, tomato and papaya in various proportions. The proportion of ingredients were standardised with four sets of treatments and from each set, one food mixture with maximum organoleptic scores were selected. The experiment was repeated for both koozha and varikka varieties. The food mixture containing 60 per cent raw jackfruit flour was selected from set 1 and 2 whereas food mixture containing 50 per cent raw jackfruit flour and 20 per cent jackfruit seed flour was selected from set 3 and 4. For all the selected food mixtures, the conditions were optimised for attaining the maximum viable count of L. acidophilus. Fifty grams of the food mixture at pH 4.5 fermented with 300 μl of inoculum for 24 hours at 370C gave the maximum viable count of L. acidophilus ranging from 10.90 to 10.94 log cfu/g. The selected food mixtures from each set along with their respective unfermented samples were freeze dried and packed in laminated polyethylene pouches and kept for storage studies under ambient conditions for a period of six months. Titratable acidity (2.32 to 2.96 %), protein (22.84 to 25.16 g/100g), thiamine (0.064 to 0.090 μg/100g), riboflavin (0.048 to 0.088 μg/100g), in vitro starch digestibility (79.89 to 81.94 %) and in vitro protein digestibility (77.49 to 83.83 %) were significantly higher in the fermented food mixtures when compared with the unfermented samples. The probiotic count of the food mixtures ranged from 10.85 to 10.90 log cfu/g. Based on the nutritive, sensory and probiotic viability, the food mixtures with 50 per cent raw jackfruit flour, 20 per cent defatted soya flour, 20 per cent jackfruit seed flour and 10 per cent tomato pulp were selected from both koozha and varikka varieties for further analysis. Glycemic index of the food mixtures were assessed and a low glycemic index of 45.35 for koozha and 47.99 for varikka was obtained. Using the best probiotic food mixture one each from koozha and varikka varieties, two instant shake mixes were prepared. The developed shake mixes contain 50 per cent fermented food mixtures along with other ingredients. The shake mixes were packed in laminated polyethylene pouches for a period of two months and the quality (nutritional, organoleptic and shelf life) aspects were analysed at 15 days interval. Both the shake mixes were nutritionally and organoleptically acceptable without the presence of fungi, yeast and insect infestation throughout the storage period. The probiotic count of the developed instant shake mixes varied from 10.14 to 10.19 log cfu/g. Jackfruit incorporated probiotic yoghurts were standardized and the yoghurt with 30 per cent jackfruit pulp was found to be the most acceptable. Yoghurts were prepared using homogenized milk (HM), skimmed milk (SM) and a combination of both. The conditions for the growth of L.acidophilus were optimised for all the selected yoghurts. Twenty five grams of the yoghurt, fermented with 100 μl of inoculum at 38 0C gave the maximum total viable count of L.acidophilus ranging from 10.84 to 10.92 log cfu/g. The prepared yoghurts were kept under refrigeration for a period of 15 days for quality evaluation. The probiotic yoghurts were found to be acceptable with a mean score of more than seven even at the 15th day of storage and the probiotic viability ranged from 10.62 to 10.79 log cfu/g. The cost of probiotic fermented food mixture was Rs. 260.31 /100g, instant shake mix was Rs. 138.54 /100g and that of probiotic yoghurt was Rs. 18.56-19.56 /100 ml. The study revealed that jackfruit can be a suitable substrate for probiotic fermentation and the probiotic food mixtures, instant shake mixes and probiotic yoghurt can be successfully developed. Further research can be done for the development of innovative probiotic products from jackfruit.EnglishThesis