Abstract:
Organic farming is rapidly growing due to its perceived potential for producing higher
nutritional quality. However, studies of organically- and conventionally-grown crops have not
always shown differences between the systems. The objective of this research was to compare
the antioxidant activities of organically-grown tomato to those from a conventional production
system during postharvest cold storage. “Tub Tim Dang” tomato (Solanum lycopersicum L.) fruit were
harvested at the breaker stage of maturity from both organic and conventional farms. Fruit were
cold-stored at 10 ◦C for 20 days, and samples were collected at intervals to measure the activities of
superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities, and total
antioxidant activity by the 2,20
-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant
power (FRAP) assays. The activities of SOD, CAT and APX of organic tomato fruit did not differ from
those of conventional fruit during cold storage. In addition, there was no effect of production system
on FRAP activity. In contrast, DPPH activity of organic tomato fruit was lower than conventional
fruit through 10 days of cold storage, but it was higher at 15 and 20 days. These results indicated that
organic production did not have a significant effects on these antioxidant traits of tomato.
