Comparative Analysis of Physicochemical Characteristics, Antioxidant Compound Contents, and Antioxidant Activities of Five Guava (Psidium guajava L.) Cultivars Harvested in Korea

Guava (<i>Psidium guajava</i> L.) is considered a rich source of bioactive compounds with high antioxidant activity; however, information on cultivars grown in Korea remains limited. This study aimed to compare the physicochemical characteristics, antioxidant compound contents, including lycopene content, and radical scavenging activities of five guava cultivars ('Gihyun gold no. 2', 'Gihyun gold no. 3', 'Gihyun green', 'Gihyun red', and 'Redlee') cultivated in Eumseong, Korea, during the 2022 season. Significant differences were observed among cultivars in soluble solids, acidity, firmness, and color, as well as in their organic acid, sugar, and polyphenol profiles. Lycopene was detected only in red-fleshed cultivars, with 'Gihyun gold no. 2' showing the highest content (5.21 ± 0.20 mg/100 g FW), while 'Redlee' exhibited the highest levels of total phenolics (474.92 ± 9.37 mg GAE/100 g FW), ascorbic acid (292.38 ± 4.40 mg/100 g FW), and radical scavenging activities in both assays (432.16 ± 13.37 mg VCE/100 g FW for DPPH and 640.59 ± 50.44 mg VCE/100 g FW for ABTS). In contrast, 'Gihyun gold no. 2' consistently showed the lowest antioxidant values. Correlation analysis revealed that total phenolics and ascorbic acid were strongly associated with both DPPH and ABTS radical scavenging activities. These findings indicate that guava cultivars grown in Korea possess high nutritional and functional value, and highlight 'Redlee' as a promising source of vitamin C, polyphenols, and lycopene with potential applications in health-promoting foods, nutraceuticals, and value-added product development.