Ilić, Z., Faculty of Agriculture, 38228 Zubin Potok, Serbia
Aharon, Z., ARO-Volcani Center, Department of Postharvest Science of Fresh Produce, P.O. Box 6, Bet Dagan 50250, Israel
Perzelan, Y., ARO-Volcani Center, Department of Postharvest Science of Fresh Produce, P.O. Box 6, Bet Dagan 50250, Israel
Alkalai-Tuvia, S., ARO-Volcani Center, Department of Postharvest Science of Fresh Produce, P.O. Box 6, Bet Dagan 50250, Israel
Fallik, E., ARO-Volcani Center, Department of Postharvest Science of Fresh Produce, P.O. Box 6, Bet Dagan 50250, Israel

Changes in total antioxidant activity-TAA (Lipophylic-LAA and Hydrophilic- HAA) during ripening of tomatoes (Lycopersicon esculentum Mill.) were studied at three different ripening stages (mature green-MG, light pink-LP and light red-LR). The TAA of tomato fruits measured by TEAC (Trolox equivalent antioxidant capacity). This assay measures both the HAA-hydrophilic (vitamin C) and LAA-lipophilic (carotenoids and vitamin E) contents based on the total radical scaveng+ing capacity, and the ability of a scaverenge the stable ABTS radical (ABTS+) described by Vinocur and Rodov (2006). Fruit were stored at 5°C or 12°C during 2 weeks plus 4 days at 20°C (shelf life simulation). TAA in MG fruit immediately after harvest was 2.05 (0.31 LAA and 1.74 HAA) jimol TE/g fr.wt, in LP ripening stage was 2.25 (0.48 LAA and 1.77 HAA) and in LR stage TAA was 2.52 (0.72 LAA and 1.80 HAA). In tomatoes this ratio (lipophilic and hidrophilic) changed from approximately 1:5 in mature green fruit to 1:3 in light pink one and 1:2,5 in light red one. After 2weeks storage at 5°C + 4days shelf life on 20°C total TAA slowly growing up and obtained content of 2.48 in MG fruit, 2.50 in LP fruit and 2,62 μmol TE/g fr.wt. in LR fruit. This is mainly due to changes in the lipophilic antioxidant activity-LAA, depending on stage of maturity (MG 0.94, LP-0.96 and LR-1.31 μmol TE/g fr.wt). Hydrophilic antioxidant activity-HAA remains practically unchanged, comparing with activity on beginning of storage. In tomato fruit stored at 12°C the total activity, increased most probably due to the accumulation of carotenoids, especially after shelf life (4 days on 20°C). Those, LAA was 1.14 in MG-fruit, 1.52 in LP-fruit and 1.68 μmol TE/g fr.wt in LR-fruit. In parallel, the total activity, increased from 2.63 in MG-fruit, 3,24 in LP and 3.42 jmol TE/g fr.wt in LR fruit. After storage ratio between lipophilic and hidrophilic activity changed from 1:1,5 in MG fruit to 1:1 in light red fruit.