Effect of Home Processing on the Protein Quality of Selected Legumes

Redgram ( Cajanus cajun ) Var. Hyderabad 3A, Blackgram ( P. mungo ) Var. T9, Greengram ( P. aureus ) Var. Ps 16 and Bengalgram ( Cicev arietinum ) Var. BEG 482 were processed in the usual home processing methods. The protein quality of the processed legumes was assessed on the basis of PER, nitrogen absorption, retention, and utilization percent. FDNB available lysine of the samples was determined by chemical method. By deducting the fecal excretion of methionine and cystine from intake, availability of these amino acids was determined. Processing improved the protein quality of the legumes significantly (P < 0.05). Moist heat methods of processing improved the protein quality to a greater extent than dry heat methods. Fermentation and germination had no advantage over moist heat methods in improving the biological quality of protein. The available lysine of roasted legumes was less than boiled and pressure cooked legumes. However the available methionine and cystine of roasted legumes was not lower than the boiled and pressure cooked legumes. No correlation was observed between PER and percent of nitrogen absorbed and retained, but the correlation between PER and total nitrogen retained was highly significant (P < 0.05).