Genotypic variation in carotenoid, ascorbic acid, total phenolic, and flavonoid contents, and antioxidant activity in selected tomato breeding lines

Genotypic diversity of antioxidants is important for the development of tomato cultivars with high antioxidant contents. The contents and antioxidant activities of major antioxidant phytochemicals (carotenoids, ascorbic acid, total phenolics, and flavonoids) of 119 cherry and non-cherry tomato genotypes (16 commercial cultivars and 103 germplasm lines) were analyzed. Antioxidant activity was evaluated using FRAP, ABTS, and DPPH aßsays. Significant genotypic differences were observed in the content and antioxidant activity of all of the studied antioxidant phytochemicals. Relatively higher genotypic variation was found in carotenoid, ascorbic acid, and flavonoid content than in total phenolic content and antioxidant activities. Most variation in total carotenoid content of tomato fruits was caused by lycopene, followed by ß-carotene and lutein. One cherry tomato line, TG-110, and 3 non-cherry tomato germplasm lines, IT237605, IT237703, and IT237706, had much higher lycopene contents (> 1930 mg·kg ^-1), and thus higher total carotenoid contents, than did the other lines. The highest ascorbic acid and total flavonoid contents were found in TG-106 (388 mg·kg ^-1) and TC-053 (2353.0 mg·kg ^-1), respectively. Two cherry tomato lines, TC-019 and TC-053, and 3 non-cherry tomato lines, TG-107, TG-112, and TG-113, had significantly higher total phenolic contents and antioxidant activities than did the commercial cultivars. The genotypes selected on the basis of their phytochemical content could be used to develop new tomato cultivars with high antioxidant contents and activities.