Influence of Traditional Processing Methods on the Nutritional Composition and Antinutritional Factors of Red Peanuts (Arachis hypogea) and Small Red Kidney Beans (Phaseolus vulgaris)

Abstract

Comparative effects of traditional processing methods such as germination, roasting and germination followed by roasting on nutritional composition and reduction of antinutritional factors in red peanuts (Arachis hypogea) and small red kidney beans (Phaseolus vulgaris) were studied. The seeds were germinated at 28-30°C in the dark for 96 h for peanuts, 72 h for beans and roasted at 140°C for 20 min. Raw and processed peanuts showed the highest levels of energy, fat and proteins, while beans showed the highest levels of antinutritional factors such as phytates, condensed tannins, trypsin and -amylase inhibitors. Dehulling caused a significant increase (p<0.05) in energy and protein and totally eliminated condensed tannins in both legumes. The combination of germination and roasting was the best method in reducing antinutritional factors in both legumes when compared to germination and roasting.