Evaluation of biochemical components and antioxidant capacity of different kiwifruit (Actinidia spp.) genotypes grown in China

Abstract

Kiwifruit from eight Actinidia genotypes were evaluated for soluble sugar content (SSC), titratable acidity content (TAC), sugar–acid ratio (SAR), vitamin C (Vc) content, superoxide dismutase (SOD) activity, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity using four assays: 2,2ʹ-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging assay; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay; oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assay. These analyses demonstrated that ‘AnminR1’ and ‘AnminR2’ of Actinidia arguta have significantly higher SSC, TAC and SAR than other Actinidia genotypes, indicating better flavour. The analyses also demonstrated that the antioxidant capacity of Actinidia kolomikta and A. arguta fruits was significantly higher than that of other genotypes (Actinidia chinenesis and Actinidia deliciosa), which was approximately 2.37–5.51 fold higher than A. deliciosa cv. There was extensive variety in the Vc content, SOD activity, TPC and TFC amongst Actinidia genotypes, which significantly correlated with TAC. We determined that significant genotypic differences exist in the biochemical components and TAC of Actinidia fruits. The hardy A. kolomikta and A. arguta genotypes have significantly higher antioxidant capacity than the commercial cultivars of A. chinenesis and A. deliciosa indicating that the hardy Actinida genotypes have more health benefits than the commercial cultivars of Actinidia.

Keywords

• Actinidia
• biochemical components
• antioxidant capacity