Preparation of Sweet Potato Flour and its Fermentation to Ethanol

A sweet potato variety Red') contained 14-15% starch, 3.0 to 3.5% free sugars and 1.0 to 1.2% pectin on wd
weight basis. Hand peeling of steamed sweet potato gave on processing better yield of dry flour (5.1 kg) per 20 kg
of fresh sweet potato than lye peeling (4.1 kg) and abrasive peeling (4.8 kg) methods. Addition of pectinase (60 U/
mil followed by gelatinisatlon before mashing of Sweeet potato or Its flour facilitated belter conversion of starch to
fermentable sugars by amylases. Fermentatlon of the mash with Saccharomyces cerevisae CFTRI 10 I by modified
Toyama's method yielded more ethanol (83.0 g/kg. 0.49g/g of sugar, % theoretical yield 95.3) than that of CFTRI
method and Toyama's method. The use of Endomycopsis fibulgera IFO 0104 culture filtrate as source of amylases,
yielded almost same amount of ethanol (8l.0g/kg, 0.49g/g, % theoretical yield 95.6) as that of modified Toyama's
method. A wine-like product with ethanol upto 8.6% (w/v). desirable aroma and colour was also prepared.