NUTRITIVE COMPOSITION OF BROTH FROM SELECTED BEAN VARIETIES COOKED FOR VARIOUS PERIODS

Ten bean varieties with white, yellow, red and black seed coats were subjected to cooking regimes of 60, 90 and 120 min on a hot plate. The cooking broth was analysed for total soluble solids, dry matter, protein, tannin, calcium, magnesium, iron and available L-tyrosine during in-vitro protein digestion. The results indicated that tannin levels were high in cooking broth from bean varieties with red seed coats compared with broth from those with white and yellow seed coats. Digestibility was higher in white and yellow varieties than in red seed coat bean varieties, suggesting that tannins have a negative effect on bean protein digestibility. All parameters evaluated showed a significant increase with cooking time. Iron occurred in trace amounts and its concentration was not affected by cooking time.