Apple peel antioxidant status in relation to genotype, storage type and time

It is expected that crop cultivars with a higher antioxidant ability have better stress resistance, nutritional quality and storage characteristics. In this study the antioxidant metabolism in apple peel, as a primary target of unfavorable environmental factors during common cold (CCS) or controlled atmosphere (CA) storage in cultivars varying in their storage potential was monitored over two seasons. In general, the examined cultivars kept their antioxidant status, but it was difficult to definitively link its value with the extent of apple storage length ability. 'Jonagold', which expressed the highest storability, had the poorest antioxidant characteristics, but with a quite good stability level specified, especially in relation to enzyme activity. Since storage characteristics might be probably more attached to antioxidant status after harvest, followed by supporting high redox state enzymes and antioxidant precursors finally keeping relative stability of bioactives through storage, than by their global pool. Differences between storage types in preserving antioxidant status were more distinct after longer time of storage. The first storage period (45 days) resulted in an increase of the antioxidant pool. The increase of ascorbate, thiols and phenolic compounds was more pronounced in the CA conditions. After the second storage period (90 days) the antioxidant status was kept more efficiently in CA as compared to CCS. Glutathione maintained its reduced form and redox state at a higher level than ascorbate. (c) 2008 Elsevier B.V. All rights reserved.