Phenolics, ascorbate and the antioxidant potential of kiwiberry vs. common kiwifruit: The effect of cultivar and tissue type

• Kiwiberry peel was up to 12.6 × richer in phenolics than its flesh.
• Kiwiberry peel was up to 3.0 × richer in ascorbate than its flesh.
• Kiwifruit peel was 4.7 × richer in phenolics and lower in ascorbate than its flesh.
• The similar serving of kiwiberry was up to 1.8 × richer in phenolics than kiwifruit.
• The similar serving of kiwiberry was about 1.2 × richer in ascorbate than kiwifruit.

The kiwiberry (Actinidia arguta) has become increasingly popular not only due to its taste, but also due to its benefits for health. The kiwiberry contains a range of bioactive compounds, with antioxidant activity predominantly associated with phenolic compounds and ascorbate. The aim of this study was to determine the phenolic compounds and the total ascorbate concentration of the peel and flesh, as well as the total antioxidant ability in six kiwiberry cultivars relative to the commercially cultivated kiwifruit ‘Hayward’ (Actinidia deliciosa). Kiwiberry peel was up to 12.6 and 3.0 times richer in phenolics and ascorbate respectively than its flesh. Kiwifruit peel was only 4.7 times richer in phenolics and contained less ascorbate than its flesh. In contrast to kiwifruit, kiwiberry peel can be considered a meaningful source of potentially healthy bioactive compounds, with its contribution to the health benefits offered by the whole fruit depending on its flesh-to-peel ratio.