Analysis of fruit quality and sensory evaluation of 36 kiwifruit (Actinidia) germplasm accessions

Thirty-six different accessions of kiwifruit (Actinidia), including seven Actinidia chinensis var. deliciosa (A. Chev.) A. Chev., 16 A. chinensis var chinensis Planch., nine A. rufa (Sieb. & Zucc.) Planch. ex Mi. × A. chinensis var. chinensis Planch., and four A. chinensis var. chinensis × ‘Chaohong’ (A. eriantha Benth. × A. chinensis var. chinensis Planch.) grown in a same kiwifruit germplasm garden in Danjiangkou City, Hubei Province, were used as study materials. The fruits were harvested once soluble solids content (SSC) reached 7.0%. Fruit maturity at harvest and internal quality of ripe fruit were measured, and sensory evaluation and correlation with internal qualities were also analyzed. Results indicated significant differences in fruit quality traits among the 36 accessions, particularly fruit fresh weight and vitamin C (Vc) content, which had the highest coefficients of variation (43.61% and 103.16%, respectively). The significant variations were associated with samples from the A. rufa × A. chinensis and A. chinensis × ‘Chaohong’ groups. These two groups had small fruit size (< 45 g of average fresh weight), with the former having the lowest level of Vc (39.89 mg/100 g) and the latter having the highest (466.27 mg/100 g). Average SSC, soluble sugar, and total acidity of the 36 kiwifruit accessions were 14.70%, 8.96%, and 1.24%, respectively, and average SSC was highest in the A. chinensis var. deliciosa group and lowest in the A. chinensis × ‘Chaohong’ group. The sensory evaluation scores also revealed significant differences among samples, with the A. rufa × A. chinensis group showing the best sensory qualities. Overall liking was highly positively correlated with flavor liking and sweetness (Pearson r ≥ 0.94), but negatively correlated with acidity (r = −0.53). Overall liking revealed a higher correlation with sweetness indices (SSC and soluble sugar) than the acidity index (total acidity), but no clear correlation with Vc.