Ultrasonic modification of whey protein isolate: Implications for the structural and functional properties

• Published in: Food science & technology 2021-12, Vol.152, p.112272, Article 112272
• Main Authors: Meng, Yueyue, Liang, Zhiqiang, Zhang, Chenyi, Hao, Siqi, Han, Hongyang, Du, Peng, Li, Aili, Shao, Hong, Li, Chun, Liu, Libo
• Format: Article
• Language: English
• Subjects: Antioxidant activity; Emulsifying property; Foaming property; Ultrasound; Whey protein isolate
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2021.112272

The present study aimed to investigate the implications of ultrasonic treatment on the conformational and functional properties of whey protein isolate (WPI). SDS-PAGE showed that ultrasonication did not change the molecular weight of WPI. FTIR spectroscopy demonstrated that sonication caused secondary structure alterations in WPI, with a reduction in α-helix and β-sheet, and an enhancement in β-turn, and random coil content. An increase in surface hydrophobicity was observed after ultrasound treatment, suggesting that modification in tertiary structure of WPI were induced by sonication. The sizes of aggregates in WPI were found reduced after sonication by the analysis of particle size distribution and scanning electron microscopy (SEM). Additionally, the foaming, emulsifying and antioxidant attributes of WPI were enhanced after treated with ultrasonication. These results suggest that ultrasonication can be used as a useful technology to modify the functional characteristics of whey proteins. •Effects of sonication on properties of WPI was assessed.•Sonication did not change the molar masses of WPI.•Sonication caused conformational changes in WPI at secondary and tertiary structure.•Sonication reduced sizes of aggregates in WPI.•Sonication improved the foaming, emulsifying and antioxidant properties of WPI.