Antioxidants in tomato (Lycopersium esculentum) as a function of genotype

Abstract

Consumption of tomato products has been associated with decreased risk of some cancer types. Epidemiological findings confirm the observed health effects due to the presence of varied antioxidants in tomato. The bio-antioxidant content and antioxidant activity of 12 tomato genotypes was therefore studied. Significant differences were found between lycopene, ascorbic acid and phenolic contents among various genotypes. Lycopene and ascorbic acid contents showed 1–4 fold and 1–2 fold variation on both fresh and dry weight basis, respectively. Antioxidant activity was found to vary significantly among genotypes. In both free radical quenching assay and FRAP assay, significant activity was found. Activity was higher in the hexane fraction containing lycopene than the methanol fraction containing phenolics. Tomato peels, in addition to lycopene, contain significantly high amounts of ascorbic acid and phenols. Cherry tomatoes, particularly variety 818 cherry, with the highest contents of antioxidants (lycopene, ascorbic acid and phenols) and highest antioxidant activity represents a valuable genotype not only for improving the status of dietary antioxidants in our diet but also for increasing nutritional value through germplasm enhancement programmes. The cherry varieties also merit considerable attention for processing because of their high total soluble solids and titrable acidity.