Sahota, Param PalManmeet Kaur2017-04-282017-04-282016http://krishikosh.egranth.ac.in/handle/1/5810010265The enzyme β-glucosidase hydrolyzes cellobiose and short chain cello-oligosaccharides to glucose. The study was conducted to evaluate the production of enzyme β-glucosidase using economically viable substrate citrus fruit waste with optimized batch scale fermentation using Clavispora lusitaniae strains KF633446 and KP131848.1 as yeast inoculum. The process parameters optimized during study are: substrate concentration (117.9g/L lemon peel powder or 46.875 g/L lime) or 16.8 g/L banana peel powder, temperature (35°C) and pH (5) , inoculum concentration of 0.75% v/v, time period of 36 h and 30h using yeast strains KP131848.1 and KF633446 respectively. Use of citrus fruit waste as substrate for enzyme production has proved to be economical; the maximum enzyme activity 0.49 IU/ml with lemon peel, followed by lime (0.28 IU/ml) and banana peel (0.337 IU/ml). The enzyme activity (IU) of β-glucosidase after partial purification was found to be 18.52 IU. The partially purified β-glucosidase was highly stable at temperature 45°C and pH 5. The value of Km and Vmax was 1.25mM and 17.98 IU/ml respectively using pNPG (para-nitrophenyl-β-Dglucopyranoside) as substrate. The addition of enzyme @ 0.4 ml per 100 ml of juice resulted in increased reducing sugar content in sweet lime juice (58.42%), grapefruit juice (57.36%), lemon juice (55.26%) and kinnow juice (53.19%), with storage time period of 15 days. Sensory analysis on 9 point hedonic scale revealed maximum score of 8.4±0.2 for aroma and 7.85±0.25 for flavour of lemon juice. This study revealed the commercial utilization of peel as substrate for β-glucosidase production and wide applicability of β-glucosidase enzyme in aroma and flavor enhancement along with debittering properties of enzyme Naringinase and Limonin dehydrogenase.ennullThesis