Biotechnological Production of Xylitol from Banana Peel and Its Impact on Physicochemical Properties of Rusks

Abstract

Xylitol is the first rare sugar that has global market due to having beneficial health properties and being an alternative to current conventional sweeteners. Biotechnological production of xylitol by Candida tropicalis DSM 7524 as an alternative to chemical method for the fermentation of xylose to xylitol was studied. Banana peel was used as a substrate for xylitol production. Hydrolysate was detoxified by neutralization, activated charcoal treatment and vacuum evaporation. Effect of pH was tested for C. tropicalis at three different levels and pH value of 2.5 was found to be the best; producing 24.7 g L-1 xylitol. Rusks were prepared by replacing sucrose with xylitol at different levels. Physicochemical analysis of rusks at different intervals of storage i.e. 0, 10, 20 and 30 days was carried out. Hardness decreased significantly (P< 0.05) from the treatment having 100% sucrose (4,950.6 g) to 100% xylitol (3,090.3 g) upon replacing sucrose with xylitol, while fracturability value increased from 71.90 to 74.26 mm for the treatment containing 100% xylitol. Color value and water activity of rusks increased significantly with the replacement of sucrose with xylitol. The increase in moisture content and decreasing trend in other parameters with storage were observed in rusks. Xylitol has low calorific value as compared to sucrose so it can be incorporated into dietetic foods which may help in controlling sugar level in diabetic patients. Keywords: Banana peel, Biotechnology, Rusk, Texture, Xylitol.