Bean seeds (Phaseolus vulgaris, L.) are cultivated and consumed all over the world and are a staple food in most countries of South America. The low biological value of bean proteins may be due to, among others, the effect of antinutritional factors on the tegument. The objective of this work was to evaluate, through biological assays, the effect of removal of black bean tegument, anthocyanins and other polyphenols on protein quality. The protein efficiency ratio, the protein liquid efficiency ratio, the protein liquid utilization and the digestibility were analyzed. The results indicated that removal of the tegument of cooked beans reduced their protein value (PER) when compared to whole cooked beans. The ethanolic extraction of 27.5% of polyphenols did not increase the protein quality of beans. It was concluded that removal of the tegument and polyphenols of beans did not improve their protein quality.
pigments; anthocyanins; beans
