Influence of high-intensity ultrasound application on the physicochemical properties, isoflavone composition, and antioxidant activity of tofu whey

• Published in: Food science & technology 2020-01, Vol.117, p.108618, Article 108618
• Main Authors: Zhao, Chang-Cheng, Kim, Pyo-Hyeon, Eun, Jong-Bang
• Format: Article
• Language: English
• Subjects: Antioxidant activity; High-intensity ultrasound; Isoflavone composition; Microstructure; Tofu whey
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2019.108618

The aim of this study was to evaluate the influences of ultrasound treatment on the color attributes, total protein, total phenol and flavonoid content, isoflavone composition (genistin, daidzin, glycitin, genistein, daidzein, and glycitein), and antioxidant activity of tofu whey. Fourier transform infrared assay was performed and the microstructure of treated tofu whey was evaluated. The results showed ultrasound application significantly increased the total phenolic and flavonoid content, isoflavone glucoside (genistin, daidzin, and glycitin), aglucones (genistein, daidzein, and glycitein) content, and antioxidant activity, especially at 40 min. In contrast, a negligible effect on color attributes, pH, total soluble solids, and total protein content was observed after ultrasound treatment. Microstructure analysis showed the formation of irregular shapes, tearing, and loss of tissue when high-intensity ultrasound was applied. Consequently, ultrasound treatment has the potential to enhance the bioactive compound content and antioxidant activity of tofu whey to improve health functionality. •Ultrasound was applied to improve the functional properties of tofu whey sample.•Isoflavone glucoside and aglucones content were significantly increased.•Total phenolic and flavonoid content and antioxidant activity were increased.•No significant effects on physicochemical properties of tofu whey was observed.