The tomato debate: Postharvest-ripened or vine ripe has more antioxidant?

Abstract

The vast majority of the tomato crop is harvested at mature green stage and ripened off of the plant for fresh market consumption. The other large amount of crop is harvested when the fruit has reached to fully mature red stage which is called “vine-ripened”. Here we attempt to answer and clarify if there is any difference between the antioxidant capacity of postharvest ripened and vine ripe tomatoes. Greenhouse grown tomatoes (cv. Newton) were harvested at four different ripening stages of unripe and vine ripe. Total phenolic (TP) contents and antioxidant capacity by the FRAP (ferric reducing antioxidant power) and TEAC (trolox equivalent antioxidant capacity) assays were performed on all ripening stages. Results of the present study demonstrated that tomato peel has significantly higher TP content and antioxidant capacity than the pulp tissues in all maturity stages tested. TP and antioxidant capacity of tomato fruits were affected during postharvest ripening process. If only pulp tissue considered, TAC of vine-ripened and postharvest ripened pink tomatoes has similar amount, but significantly higher content than mature green, breaker and turning maturity stages. If peel tissue measured, the mean separations identified three groups. Postharvest ripened mature green stage has the most TAC, followed by vine-ripened and pink stage. Postharvest breaker and turning stages have the least amount of TAC.