NUTRIFICATION OF DRY BEAN (Phaseolus vulgaris, L.) BY METHIONINE INFUSION

Abstract

ABSTRACTThe technological conditions for the nutrification of beans by methionine infusion are described. The best conditions seem to be infusion for 1 hr with a 5% methionine solution at 50°C. By this procedure the methionine was raised from 1.2 to 24 g/100g of bean protein and the absorbed water was only 40% of the beans weight. The beans infused under these conditions, after drying, could be mixed 1:7 (w/w) with original beans and the mixture after cooking in the presence of the soaking water still contained 3% methionine on the protein basis. During soaking (prior to cooking) about one‐third of the infused methionine was diffused out in the remaining water. Therefore, elimination of the soaking water before cooking should be discouraged. Infusion with methionine raised the bean PER from 0.9 to 2.6 and the efficiency of a 10% bean protein diet from 9.4 to 26.6%. There was no difference in preference between the original and infused beans when the Directional Paired Comparison test was applied. However, when the Non Structured Scale test was used for the odor and taste of cooked beans there was no preference for the original beans when seasoning was used, whereas there was a significant difference at 5% probability level in favor of the original beans when the samples were cooked and tasted without seasoning.