等离子体对鹰嘴豆分离蛋白溶解性和乳化特性的影响.

Chickpea protein isolates (CPI) with high nutritional value have promise as a potential source of novel food ingredients, but the functional properties cannot meet the needs of the modern food industry. It is of great interest to know how dielectric barrier discharge (DBD) plasma treatments affect the properties of CPI. This work aimed to clarify the impact of DBD plasma treatments as a function of treatment times (0, 1, 2, 3, and 4 min) on the conformation, physicochemical, solubility, and emulsifying properties of CPI. Moreover, an evaluation was made on the relation of structural properties of DBD-treated CPI to functional properties. The parameters of CPI were measured, including the pH value, conductivity, particle size, the content of free sulfhydryl, surface hydrophobicity, secondary structures, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), solubility, emulsification activity, and stability. A scanning electron microscopy (SEM) was used to characterize the surface micromorphology of CPI treated by DBD plasma. The results showed that the pH decreased from 6.98 to 6.58, while the conductivity increased, with the increase of the treatment time from 0 to 4 min. The best solubility and emulsifying properties were achieved in the DBD plasma for 4 min, indicating DBD plasma was suitable for the increase in the solubility, emulsifying activity, and emulsion stability of CPI. Dynamic light scattering indicated a decrease in the mean particle diameter of CPI from 477 to 418 nm. The SDS-PAGE showed that the plasma treatment cannot change the composition and types of CPI, but the band intensity of 7S and 11S increased. The content of α-helix increased significantly (P < 0.05), while the content of the random coil decreased (P < 0.05), indicating that the higher structure of the protein changed after plasma treatment. In addition, a combined analysis of reactive sulfhydryl content and surface hydrophobicity indicated that the CPI may undergo a conformation unfolding, thereby becoming looser and more flexible, and finally promoting the interactions of protein-water and protein-oil. SEM images showed that the sample size was reduced, while the surface structure became looser with the extension of treatment time. Pearson's correlation and principal component analysis showed that a strong correlation between the change of protein structure and the improvement of functional properties was obtained after DBD plasma treatments. It infers that the DBD plasma changed the conformational characteristics of CPI, enhancing solubility and emulsifying properties. The better solubility and emulsification properties of CPI can be achieved after plasma treatment for 4 min. The finding can provide technical support for the utilization of new chickpea protein products in the actual production. [ABSTRACT FROM AUTHOR]