Design and fabrication of pea protein isolate nanoparticles and evaluation of its structural and functional properties.

Abstract

Introduction: The need to use natural systems such as emulsions for beneficial food formulations, both from the perspective of greater protection of sensitive and bioactive compounds and not using artificial emulsifiers such as surfactants, is more important than in the past. Also, nowadays, the food industry is looking for plant substitutes with the same functionality as animal proteins. After soy, pea is a widely used vegetable protein in foods. Objective: The main objective of this study is to investigate the effects of different heating treatments, ultrasound, pH adjustment, and interaction with ascorbic acid on the physicochemical characteristics of the colloidal suspension of pea protein particles in order to improve or exploit the potential properties of pea vegetable protein for use in food industry purposes and in The result is replacing it with synthetic compounds such as various surfactants, hydrogenated fats, etc., which have harmful effects on health. Materials and methods: After preparing pea protein nanoparticles in optimal concentration (1% v/w) and under different heating treatments, ultrasound, pH adjustment, and interaction with ascorbic acid, to understand the effects of each treatment on the structure and performance of pea protein nanoparticles, solubility, FTIR, DSC, SDS-PAGE, particle size, zeta potential, contact angle, surface tension, and intrinsic viscosity were investigated. In the following, the effect of these factors on the formation and physical and oxidative stability of Pickering emulsion with a volume ratio of 50% corn oil was discussed and investigated. Results: The solubility of pea protein after different treatments was from 31 (for PP sample) to 58% (for SPP.AA.pH sample), which shows that the solubility of protein in all treatments was higher than that of pure pea protein. The results of FTIR and SDS-PAGE confirmed the formation of a covalent bond between pea protein and ascorbic acid, which occurred in the heating treatment more strongly than in other treatments. Samples containing pea protein and ascorbic acid showed significantly smaller particle sizes with higher contact angles. Also, samples containing ascorbic acid had a higher denaturation temperature than samples without ascorbic acid at constant pH. It was observed that pure pea protein cannot stabilize the water and oil phases in a 50:50 mixing ratio, but under ultrasound treatments and interaction with ascorbic acid, Pickering emulsion with high physical and oxidative stability was obtained. Confocal laser scanning microscope images of the emulsions confirmed that the prepared emulsion is a Pickering type of oil-in-water emulsion, and the pea particles surround the oil droplets. Conclusion: The results of this research show that pea protein can be used in the development of low-fat formulations with improved oxidative stability, and for this purpose, various treatments can be used to improve protein performance, including ultrasonication treatment and the formation of a complex between pea protein and ascorbic acid. Keywords: Pea Protein, Ascorbic