Nutritional and anti-nutritional composition, and in vitro protein digestibility of Kabuli chickpea (Cicer arietinum L.) as affected by differential processing methods

Abstract

Chickpea is an important food legume and is a major source of nutrient in many diets. We investigated the effects of different processing methods, soaking and non-soaking followed by moist heating (pressure cooking and microwave cooking) and dry heating (roasting), on chemical composition, amino acid profile, mineral concentration, anti-nutritional factors, protein solubility and in vitro digestibility of chickpeas. Oil content significantly (P < 0.05) increased in all processed samples, except soaked/microwave cooked sample. All processing methods improved amino acid profile, with the greatest increase caused by soaking/microwave cooking. There was a significant reduction in mineral content after processing except in soaked sample that showed the highest level of mineral retention. All processes significantly reduced tannin and phytate concentrations. The soaked/microwave cooked sample had the largest reduction of tannins, while soaking/pressure cooking caused the highest reduction in phytate. Compared to raw counterpart, protein solubility in all processed samples significantly decreased, while in vitro protein digestibility significantly improved, with the highest values for soaked/pressure cooked and soaked/microwave cooked samples. In-vitro protein digestibility showed a positive correlation with both total amino acids (r = 0.774) and total essential amino acids (r = 0.838), but a negative correlation with total macroelements (r = −0.925), tannins (r = −0.847) and phytate (r = −0.818). Soaking/microwave cooking seems to the best method for improving the nutritional quality of chickpea samples analyzed in the present study.