Protein enrichment of spent sorghum residue using <i>Candida</i> species and <i>Saccharomyces cerevisiae</i>

Abstract

Three different yeast isolates were used to improve the nutritional value of spent sorghum, a byproduct obtained during the production of a local drink ''Akamo" in Nigeria. The yeast isolat~s used were  Saccharomyces cerevisiae (dry yeast), Candido AI isolated from locally processed milk "nono" and Candida A2 isolated from a local beverage "burukutu" Using S cerevisiae and treated spent sorghum at 4.0g/ I 00 ml, the optimum period of fermentation, 11^th day of fermentation was, determined. The optimum concentration of spent sorghum for protein enrichment with S. cerevisiae was 7.Sg/100 ml. The protein content  ofunfermented sorghum (4. 1-4.5% of dry matter) increased significantly on It'" day of fermentation for all the isolates (I 0.0 -12.5% of dry marter). The ether extract content of the unfermented spent sorghum also  increased from  2.0% to 6.0% during fermentation by S. cerevisiae, Candida A I and Candida A2 respectively. The crude  protein and the ether extract contents of fermented spent sorghum are comparable to the levels found in most animal feeds available in the market. So  inclusion of this nutritionally enriched byproduct in animal diet may be recommended preceded by animal trials.

Key words: S.cerevisiae, Candida sp., sorghum, protein enrichment, animal feed.