Effects of processing methods on antinutrient composition of seeds from a wild legume bauhinia Petersiana

The effects of processing on the levels of antinutrients in Bauhinia petersiana seeds were investigated. On dry weight basis, raw seeds had the highest levels of tannins (0.6 + 0.1 g catechin equivalents (CE)/100 g), alkaloids (7.1 + 0.1 g/100 g), saponins (9.8 + 0.5 g diosgenin equivalents (DE)/100 g), cyanogen glycosides (6.3 + 0.3 g /100 g), phytates (73 + 8 mg/100 g), oxalates (216 + 21 mg/100 g), and trypsin inhibitors (174 + 60 trypsin inhibitor units (TIU) /100 g). Upon cooking, levels of most of the antinutrients decreased. The difference in phytic acid content of boiled (57 + 9 mg/100 g) and roasted seeds (55 + 2 mg/100 g) was not significant (P> 0.05). There was no significant difference (P> 0.05) in the levels of oxalate in the raw and roasted samples. No hemagglutination activity was observed in the raw and cooked seeds. Malonaldehyde was detected only in the cooked seeds ranging from 24 + 4 mg/100 g in the boiled seeds to 29 + 5 mg/100 g in roasted seeds. The oligosaccharides raffinose, starchyose and verbascose were present at low concentrations in both the raw and cooked seeds. The information obtained could be of essence in promoting consumption of this wild legume for the benefit of rural communities.