Soybeans as an extender of common beans

Soybeans were used as extenders of common beans in the form of whole beans and precooked, powdered form. Mixtures containing 20, 25, 30, 35, 40, 45 and 50% soybeans were studied. Sensory evaluations (preference tests) showed no preference for mixtures containing up to 50% soybeans over 100% common beans. On the other hand, nutritional differences were detected between common beans and mixtures with more than 20% soybean. The mixture with 50% common beans and 50% soybeans contained 27.9% crude protein, 13.2% lipids and 47.2% carbohydrate. The amino acid composition was improved particularly by increasing cystine from 0.6 to 1.2% of the protein and methionine from 0.7 to 1.2%. The protein efficiency ration (PER) values fo the 50:50 mixture for rats was 1.6 compared to 1.0 for the common bean. Acceptability of the 50:50 mixture in different institutional trials did not differ in consumption from that of common beans and no sign of physiological disturbance was observed. When the mixture was precooked, dried and ground to a powder, it served as an excellent base for an instant soup. The formulation containing 80% of the 50:50 mixture, 10% corn starch and seasonings had (%) 21.3 protein, 10.8 lipid, 5.3 crude fiber and 51.9 carbohydrate with total metabolizable energy of 390 Kcal/100 g and an NDP Cal%=12. The hydration capacity of the 50:50 mixture was 162 g water/100 g mixture whereas that of the soup with all ingredients added was 205 g water/100 g soup. The acceptability as well as the storage stability of the soup was good.