Total antioxidant activity (TAA) of bell pepper during prolonged storage on low temperature

Faculty of Agriculture, Zubin Potok, Kosovska Mitrovica (1)
ARO- he Volcani Center, Postharvest Science of Fresh Produce, Israel (2,3,4,5)

Abstract:

Bell pepper (Capsicum annum L.) is a vegetable known for its antioxidant content, highly important for its nutritional values. The total antioxidant activity (TAA) of pepper fruits is measured by TEAC (Trolox equivalent antioxidant capacity). This assay measures both the hydrophilic (HAA) (vitamin C) and lipophilic (LAA)(carotenoids and vitamin E) contents based on the total radical scavenging capacity and the ability of a scaverenge the stable ABTS radical (ABTS + ) described by Vinocur and Rodov (2006). Fruit were cleaned and disinfected with hot water by rinsing and brushing (HWRB) at 55°C as it is described by Fallik et all ., (1999). Tap water wash was served as control. Fruit were stored at 2°C or 7°C during 3 weeks plus 3 days at 20°C (shelf life simulation). TAA in red bell pepper, immediately after harvest, was 4.29 (0.74 lipophilic and 3,55 hydrophilic) mol TE/g fr.wt. After 3 weeks storage at 2°C, TAA in pepper with cold wash treatment was 4.14 and 3.97 TEAC mol TE/g fr.wt. in HWRB treatment. After 3weeks +3days shelf life on 20°C TAA slowly growing up and obtained content of 5.24 in cold wash and 5.16 TEAC mol TE/g fr.wt. in HWRB. This is mainly due to changes in the lipophilic activity-LAA (treatment with cold water-1.79 and 1.81 mol TE/g fr.wt. in HWRB, comparing with 0.74 mol TE/g fr.wt. on beginning of storage). Hydrophilic antioxidant activity-HAA remains practically unchanged. In fruit, stored at 7°C, pepper ripeness has been associated with carotenoids accumulation especially after shelf life, TAA was 5.33 TEAC ( LAA 2.03) mol TE/g fr.wt.

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