Oligosaccharides, Antinutritional Factors, and Protein Digestibility of Dry Beans as Affected by Processing

ABSTRACT Dry beans ( Phaseolus vulgaris ) were subjected to soaking, cooking or a combination of both prior to fermentation, and then assessed for oligosaccharides, antinutritional factors and in‐vitro protein digestibility. Results showed an important decrease in raffinose oligosaccharides and antinutritional factors. However, an increase of trypsin inhibitor and tannin contents occurred respectively in cooked or soaked‐cooked fermented beans and in raw or soaked fermented beans. Appreciable improvement in in‐vitro protein digestibility was only observed in cooked or soaked‐cooked beans. After fermentation, the largest decreases were observed in soaked‐cooked beans (92.75%) for raffinose, in cooked beans (31.57%) for phytic acid, in soaked beans (90.86%) for stachyose, and in raw beans for trypsin inhibitor (38.77%). The highest increase due to fermentation was observed in raw beans for in‐vitro protein digestibility (1.73%).