Abstract:
To explore quality differences among main cultivated table grape cultivars in Guanzhong Area of Shaanxi Province, and quality differences among same cultivar grapes but from different growing areas, four cultivars, namely Hutai No.8, Shine Muscat, Red Globe and Crimson Seedless were collected from six different growing areas.Ten quality indicators including moisture content, soluble solids content, total sugar content, titratable acid, solid-acid ratio, sugar-acid ratio, vitamin C content, total phenols content, total flavonoids content and proanthocyanidins content in grapes were measured and analyzed.Principal component analysis(PCA)was then used to establish a quality evaluation system for table grapes.Results have shown that there were no significant differences among four cultivars in content of moisture, soluble solids, total sugar, total phenols and total flavonoids, However, significant differences were found in titratable acid content, solid-acid ratio, sugar-acid ratio, vitamin C content, and proanthocyanidins content.PCA results have indicated that sugar-acid ratio, solid-acid ratio, vitamin C content, proanthocyanidins content, total phenols content, and total flavonoids content could serve as reference indicators for evaluating table grape quality.In PCA evaluation system, comprehensive scores for four cultivars were ordered as follows: Crimson Seedless > Shine Muscat > Red Globe > Hutai No.8.Ranking dispersion degree has revealed that Crimson Seedless, Shine Muscat and Hutai No.8 exhibited relatively consistent comprehensive performance across different growing areas in Guanzhong Area of Shaanxi Province, whereas Red Globe showed greater variations in comprehensive performance among different growing areas.