Ultrasonic treatment improves physical and oxidative stabilities of walnut protein isolate-based emulsion by changing protein structure
Lin Shi, Xue Yang, Tian Gong, Ching Yuan Hu, Ye Hua Shen, Yong Hong Meng
LWT
Abstract
In this study, the effect of ultrasonic, heating, and enzymatic treatments on the structural and emulsifying attributes of walnut protein isolate (WNPI) was assessed and compared. Ultrasonic, heating, and enzymatic treatments all effectively improved WNPI's emulsifying capacity and stability, especially ultrasonication. Ultrasonication (400 W, 30 min) obviously made WNPI's structure looser and more unfolded, in turn led to 1.57-fold and 2.67-fold increase in EAI and ESI of WNPI, respectively. Besides, the exposure of WNPI′ hydrophobic groups induced by sonication, reflected in a 3.64-fold increase in WNPI's surface hydrophobicity, may also contributes to the increase of WNPI's emulsifying properties. Furthermore, the emulsion stabilized by UT-WNPI exhibited the best lipid and protein oxidative stabilities during storage at 55 °C for 7 days. Compared to emulsion stabilized by the untreated WNPI, hydroperoxide, TBARS, and protein carbonyl contents in the emulsion stabilized by UT-WNPI decreased by 46.92%, 40.74%, and 33.89%, respectively. Our results clarify ultrasonication is the best for improving the emulsifying properties of walnut protein, thereby broadening walnut protein's application in the emulsified food.
Extracted Claims
4 claims extracted from this paper into the knowledge graph
ultrasonic treatment improves lipid and protein oxidative stabilities
“Furthermore, the emulsion stabilized by UT-WNPI exhibited the best lipid and protein oxidative stabilities during storage at 55 °C for 7 days.”
ultrasonic treatment increases surface hydrophobicity
“Besides, the exposure of WNPI′ hydrophobic groups induced by sonication, reflected in a 3.64-fold increase in WNPI's surface hydrophobicity, may also contributes to the increase of WNPI's emulsifying ...”
ultrasonic treatment decreases hydroperoxide, TBARS, and protein carbonyl contents
“Compared to emulsion stabilized by the untreated WNPI, hydroperoxide, TBARS, and protein carbonyl contents in the emulsion stabilized by UT-WNPI decreased by 46.92%, 40.74%, and 33.89%, respectively.”