Biological and chemical evaluation of chick pea seed proteins as affected by germination, extraction and alpha-amylase treatment.

摘要

The effects of germination, extraction (double extraction with 70% ethanol and water at isoelectric point) and alpha-amylase treatments of chickpea (Cicer arietinum) seed flours on crude protein, total carbohydrate, protein efficiency ratio (PER), biological value (BV), true digestibility (TD), net protein utilization (NPU), essential amino acid composition, in vitro protein digestibility (IVPD) and actual amino acid indices (essential amino acid index or amino acid score) were estimated. Crude protein content was increased (8-149%), while total carbohydrate was decreased (11-62%) by germination, extraction and alpha-amylase treatments. alpha-Amylase treatment was more efficient at decreasing total carbohydrate and increasing the protein content than extraction treatment. Protein quality of chickpea flours, estimated by PER, BV, TD, NPU, IVPD and corrected amino acid indices (actual amino acid indices X IVPD), was significantly improved by these treatments. Protein quality of germinated-alpha-amylase treatment was comparable with casein, while germinated-alpha-amylase extruded seeds seemed to be nutritionally superior to casein. The corrected amino acid indices gave better prediction of PER, BV, TD and NPU than actual amino acid indices. PER washighly correlated with corrected amino acid score (r = 0.93). PER could be predicted from the following simple regression equation: PER = -1.827 + 0.0561 X corrected amino acid score. It was suggested that germinated-alpha-amylase and germinated-alpha-amylase-extracted treatments could be used successfully as a source of concentrated high quality protein for infant food production.