Enhancing the functionalities of chickpea protein isolate through a combined strategy with pH-shifting and cold plasma treatment

Abstract

This study investigated the impact of combining pH-shifting and cold plasma (CP) treatment on chickpea protein isolate (CPI) functionality. Compared with pH-shifting treatment alone, the functional properties of CPI were significantly improved when the pH was shifted under acidic (pH = 2) or alkaline (pH = 12) conditions, followed by a 30 s CP treatment before neutralization at pH 7. Particularly, the method conducted at pH 12 followed by 30 s CP treatment proved most efficient, significantly improving solubility (from 65.51 ± 1.07% to 73.01 ± 0.65%), gel strength (from 27.19 ± 1.51 g to 66.57 ± 1.69 g), fat absorption capacity (from 2.39 ± 0.02 g/g to 4.22 ± 0.05 g/g), emulsifying activity (from 57.47 ± 0.06 m2/g to 71.95 ± 0.19 m2/g), foaming capacity (from 58.33 ± 2.36% to 123 ± 5.1%), and in vitro protein digestibility (from 47.49 ± 0.44% to 55.78 ± 0.8%). These improvements were attributed to reduced protein aggregates, increased solubility, and enhanced surface hydrophobicity. Furthermore, alterations in the secondary and tertiary protein structure following these treatments positively impacted CPI's functional properties, offering important implications for protein modification with improved functional profiles.