Changes in Amino Acid Composition of African Yam Beans (Sphenostylis stenocarpas) and African Locust Beans (Parkia filicoida) on Cooking

Abstract

Amino acid composition of raw and cooked African yam beans and African locust beans have been determined. The results showed that cooked or raw beans contained all the amino acid commonly found in protein food materials. Cooking has significant effect on some essential amino acid contents of the two seeds (P>0.05). When the samples were cooked, the essential amino acid content of African yam beans and African locust beans were observed to change from 1.12 to 0.97g per 16g N and from 1.69 to 1.79g/16g N respectively. African locust beans showed isoleucine and threonine to be its limiting amino acids. Their values increased slightly on cooking from 2.27 to 2.31(African yam beans) and from 2.91 to 3.33g per 16g N(African locust beans). The advanced amino acid profile of the two cooked seed samples compares favourably with whole hen`s egg and most of them meet the daily requirement of FAO and WHO. The amounts of lysine, proline and glutamic acids amounts reduces cooking any of the two studied beans, while the remaining amino acids showed slight but varied percentage changes on cooking. Results are also compared with literature values for other contemporary plant seeds and legumes. The two seeds are projected as alternative sources of cheap food protein.