Gaseous ozone assisted Maillard reaction of chickpea protein isolate- arabinose: Improving structural and functional properties and enhancing emulsion stability

To break through the limitation of technological functionalities of chickpea protein isolate (CPI) in food processing conditions (e. g. high temperature and pH variations) and broaden CPI application, glycosylation modification was used to improve the structural and functional properties of CPI. Herein, ozone treatment was utilized to unfold CPI structure for promoting the Maillard reaction between CPI and arabinose (Ara). Then the influence of glycosylation modification on the structural and functional properties of CPI was investigated, and the stability of oil-in-water (O/W) emulsions loaded with β-carotene prepared with glycosylated products was evaluated. Compared to CPI, CPI pretreatment with ozone (CPI/O3) conjugated with Ara efficiently, with a (CPI/O3)/Ara mass ratio of 1:2, the degree of graft reached 25.3 %, suggesting the successful covalent binding of Ara to the protein. Fourier transform infrared spectroscopy (FTIR), intrinsic fluorescence spectroscopy and surface hydrophobicity analyses demonstrated that glycosylation could alter secondary and tertiary structure of CPI. Notably, the glycosylation significantly improved solubility, oil holding capacity, emulsifying properties and interfacial characteristics. Moreover, emulsions prepared with CPI/O3-Ara conjugates, especially CPI/O3-Ara 1:2 conjugate, showed a higher encapsulation efficiency for β-carotene, smaller droplet size, stronger ζ-potential and lower turbiscan stability index compared to emulsions made with CPI, displaying excellent stability under heating treatment and pH variation. Collectively, the results revealed that the ozone-assisted glycosylation is an efficient approach for the improvement of the functional and interfacial properties of CPI.