Physicochemical, functional, thermal and structural properties of isolated Kabuli chickpea proteins as affected by processing approaches

Kabuli chickpea seeds were processed by soaking only and soaking followed either by pressure cooking or roasting. Proteins were isolated from both raw and processed seeds, and the effects of these processing approaches on the physicochemical, functional, thermal and structural properties as well as SDS-PAGE profiles of the protein isolates were investigated. Thermal processes significantly (P<0.05) decreased protein yield, content, colour difference, emulsifying properties and protein solubility of the protein isolates, but increased lightness and water and oil absorption capacities. Protein thermal properties, secondary structure and SDS-PAGE banding patterns were significantly changed in thermal-processed samples, especially those that were pressure cooked. No endothermic peak was detected in differential scanning calorimetry thermograms, and peak intensity of amide I absorption band at 1600-1700cm(-1) in Fourier transform infrared spectra reduced. The results reveal that pressure cooking had more pronounced effects on the properties of the protein isolates than other processing approaches.