Enhancing Health Benefits of Tomato by Increasing its Antioxidant Contents through Different Techniques: A Review

Tomato is known to be a great dietary source of antioxidant lycopene which is found to be linked with reduced risk of life-threatening diseases like heart attack and cancers. Antioxidants delay the aging process by mopping up reactive free radicals from cells, those if present may damage our DNA and other vital cellular organelles. Antioxidant metabolites are a group of vitamins, carotenoids, phenolic compounds, and phenolic acids that can provide effective protection against Reactive Oxygen Species (ROS) by neutralizing free radicals, which are unstable molecules linked to the development of many degenerative diseases and medical conditions. There are pre and postharvest techniques available in the literature and these when adopted by the researchers showed significant progress in enhancing antioxidant contents of tomato fruit. In addition, there are various biochemical and genetic modification approaches to improve the expression of several antioxidant enhancing phytonutrients, enzymes and genes in tomato fruit. Trichoderma enriched bio-fertilizer application in tomato enhanced ascorbic acid under the treatment of 100% bio-fertilizer and betacarotene was increased under 75% Bio-Fertilizer+25% N whereas elevated lycopene contents were observed in case of recommended dose of NPK. Various omics approaches like genomics, transcriptomics, miRNAomics, proteomics, and metabolomics have emerged as extremely helpful tools for the plant scientists in improving the beta-carotene, lycopene and antioxidant levels resulting in highly desirable new tomato cultivars. Thus, in light of immense advantages of these techniques, the present study was undertaken to collect all the necessary information about different techniques employed by numerous researchers to increase the antioxidant contents in tomato and to document here the optimized experimental conditions that can be beneficial for future studies in this field. However, still in-depth genome wide studies are needed for better understanding and further enhancement of traits like flavor, quality and antioxidant contents in context to rapidly changing and uncertain climate.