Ethanol fermentation of chemically gelatinized starch and uncooked raw starch was nested with various starchy materials.
Starches were gelatinized by 5.4% NaOH and neutralized by sulfuric acid. The patterns of CO₂ evolving and the ethanol yield for the chemically gelatinized starch resemble those obtained with thermally gelatinized starch.
The alcoholic fermentation of raw starch was carried out by the simultanous saccharification-fermentation using a commercial glucoamylase and yeast. Ethanol yield from uncooked rice starch fermentation was highly comparable to that from cooked one. CO₂ evolving rates of the uncooked starches of corn, barley, tapioca and sweet potato were lower than those of the cooked starches. However, the final ethanol yields were similar or slightly lower, depending on the types of starch.