Polyphenol content and antioxidant capacity of apple fruit: effect of cultivar and storage conditions

Abstract

The benefits of fruits and vegetables are often attributed to their high antioxidant content. Research supports a role of secondary plant metabolites particulary polyphenols in the prevention of degenerative diseases e.g. cardiovascular diseases and cancer. Apple fruit are an important source of secondary plant metabolites and one of the major phenol sources being consumed during the whole year. The present investigation was undertaken to determine antioxidant capacity in selected apple cultivars depending on cultivar and different modes of postharvest storage. Additional storage at 20 °C was tested to simulate the conditions at the consumers’ home (shelf life). Antioxidant capacity differed between the cultivars. Cold storage (1 °C) for 4.5 months increased the antioxidative capacity and polyphenol content in most of the cultivars. Shelf life led to a decrease in polyphenol content and in antioxidant capacity. Storage under controlled atmosphere led to low increases of both antioxidant capacity and polyphenol content. In some cultivars polyphenol content remained stable. After the shelf life period lower values for antioxidant capacity were determined, in combination with no changes in phenol content. Correlation analysis showed a positive correlation between total phenols and antioxidant capacity (TEACValue). Lipophilic antioxidants decreased during storage.
Storage experiments indicated that a high content of polyphenols and antioxidants can be sustained by optimal storage conditions, these fruit may contribute to an antioxidant rich diet and may impart health benefits.