Enrichment of Protein Content in Rice-Based Dried Distillers’ Grain from Food-Ethanol Factory by Chemical Method ☆

Dried distillers’ grain (DDG) from rice-based alcohol factories contains relatively high protein (ca. 79% of dry matter). However, this vegetative protein source has only been used for animal feeding. To enhance the value of this by-product, i.e. toward application for the food industry, this study has applied different approaches for the enrichment of protein content in this by-products. These approaches were either using solvents to directly extract and precipitate protein or removing non-protein components in rice-based DDG. The results showed that the direct extraction and precipitation of protein was not effective as the removal of non-protein components. The use of NaOH 10 mM has increased protein content up to 87% of dry matter by washing out the non-protein components such as starch from DDG. Preliminary, the protein-enriched DDG was used up to 15% as an ingredient for cookies without negative effect on the taste or color of this product.