Bioconversion of solid food wastes to ethanol

Abstract

Solid food processing wastes and by-products are cofermented with cheese whey to produce ethanol. The experimental procedure involves the use of an enzymatic process to convert starch and lactose into fermentable sugars. These reducing sugars are then fermented to alcohol by distiller’s dried yeast and a high-ethanol tolerant yeast, Saccharomyces cerevisiae. Cheese whey is used as a wetting agent and provides macro- and micronutrients for the microorganisms. Cofermenting food processing wastes with cheese whey, in the presence of high- and low-temperature enzymes, induces a 33-36% increase in alcohol yield. This procedure also significantly reduces the fermentation time from 60 to 12 h.