Physicochemical Properties and Antioxidant Activities of Yanggaeng Added with Different Grape Varieties

In this study, we evaluated the antioxidant activity, physicochemical properties, and sensory characteristics of Yanggaeng made with grapes. Freeze-dried powders and juices were prepared from three grape varieties (Campbell Early, Kyoho, and Shine Muscat). Yanggaeng was then prepared at concentrations of 2, 4, and 8%. Antioxidant activity was evaluated by measuring total polyphenols and DPPH and ABTS radical-scavenging activities. The physicochemical properties measured included solid content, Brix, pH, total acidity, moisture content, color, and texture profile analysis (TPA). The results showed that the total polyphenol content increased as the number of grapes increased, with the 8% Shine Muscat juice (JS 8%) sample having the highest polyphenol content and ABTS radical-scavenging activity. The highest moisture content was observed in the control treatment. The L* value decreased, whereas the a* and b* values increased as the grape concentration increased. The 8% Campbell Early (JG 8%) sample exhibited extremely high a* and b* values. When freeze-dried powder was used, the pH decreased and the total acidity increased compared to that using the juice samples.