Physicochemical Attributes and Bioactive Compounds of Grape Cultivars Grown Under Warm Climate

Fruit characteristics and composition vary among the cultivars and the environmental conditions. The current experiment was planned to observe fruit morphological and biochemical properties of various table grape cultivars grown under the hot climate of south Punjab, Pakistan. Fruit of nine different cultivars were harvested including ‘Sultanina-C’, ‘Early Gold’, ‘Perlette’, ‘Sugraone’, ‘Red Globe’, ‘NARC Black’, ‘Vitro Black’, ‘Flame Seedless’ and ‘Kings Ruby’. Significant differences were observed among berry and bunch characters. ‘Sultanina-C’ cultivar had the highest berry length and bunch compactness, whereas ‘Red Globe’ exhibited the highest berry weight and berry width. The highest number of berries per cluster and maximum bunch length was recorded in ‘Flame Seedless’, while the highest bunch weight was recorded in ‘Kings Ruby’ followed by ‘Sultanina-C’ and ‘Flame Seedless’. Maximum total soluble solids was observed in ‘Kings Ruby’ (19.6 °Brix) followed by ‘Sultanina-C’ and ‘Early Gold’, respectively. Less titratable acidity was recorded in ‘Early Gold’ (0.49%) as compared to ‘Perlette’. Vitamin C contents ranged from 17.4 to 58.7 mg 100 ml⁻¹ among cultivars, and the highest amount was found in ‘Sultanina-C’. Total phenolic content was maximum in ‘Sugraone’ grapes (548.59 µg ml FW⁻¹). ‘Vitro Black’ grapes showed the highest antioxidant activity (87.79% inhibition), while the minimum was recorded in ‘Perlette’ (68.38% inhibition). Antioxidant activity was positively correlated with vitamin C contents. The biplot analysis of the first two principal components showed that ‘Sultanina-C’, ‘Flame Seedless’, ‘Kings Ruby’ and ‘Sugraone’ are more responsive with superior fruit quality traits for table grapes than other cultivars grown under the warm climate.