Anti-nutrient reduction and nutrient retention capacity of fermentation, germination and combined germination-fermentation in legume processing

Research has proven that the processing of legumes improves nutritional value. However, the extent of anti-nutrient reduction and nutrient retention of combined processing methods compared to single processing methods has not been extensively studied. Therefore, this study investigated the anti-nutrient reduction and nutrient retention potentials of fermentation, germination and combined germination/fermentation in pigeon pea flour. Pigeon pea seeds were naturally fermented, germinated, and further fermented for 24 and 48 h separately. The processed flour was analyzed for nutrients and anti-nutrients composition. Ranges of phytate, tannin and hemagglutinin contents of raw and processed pigeon pea flour were 97-1235 mg/100 g, 49-304 mg/100 g and 18.69-59.29 mu g/mg, respectively. Fermentation (96%) and germination (67%) reduced significantly more anti-nutrients compared to the combined processes (42%). Calcium content of raw pigeon pea sample (22.93 mg/100 g) increased significantly with fermentation (56%), germination-48 h fermentation (16%) and germination (11%). Iron content (18.88 mg/100g) decreased significantly in germinated (7%) and germinated-48 h fermented (5%) samples. The treatments had significant (p < 0.05) negative effects on zinc and Vitamin A levels by 9-23% and 5-17%, respectively. Fermentation was effective in the processing of pigeon pea. However, enrichment of fermented pigeon pea flour with zinc and Vitamin A is recommended.