Analysis on Fruit Ripening Process and Quality Difference of Cabernet Sauvignon at the Eastern Foot of Helan Mountain

Based on the monitoring of fruit quality changes from the veraison period to harvest in eight Cabernet Sauvignon vineyards at the eastern foot of Helan Mountain, the fruit development process and quality differences at harvest time of Cabernet Sauvignon in different regions were analyzed and compared. The results showed that the reducing sugar content increased from 49.66 g/L to 231.85 g/L, and the titratable acid content decreased from 33.51 g/L to 7.44 g/L during the ripening process of Cabernet Sauvignon. The total phenolics and tannins in the pericarp increased from 28.78 mg/g to 37.79 mg/g and 5.83 mg/g to 8.63 mg/g, respectively, and they showed an upward trend in general, but decreased to a certain extent in the later stage, and the change trend was consistent. The anthocyanins content increased from 0.098 mg/g to 1.40 mg/g, showing an upward trend, and the flavanol content decreased from 1.92 mg/g to 1.32 mg/g, showing a downward trend generally. Both of them rose or fell rapidly in the early stage and fluctuated in the later stage. The reducing sugar content of fruit in Meiyu was the highest (257.42 g/L), and the sugar content of fruit in Yuquanying and Huangyangtan (less than 210 g/L) was significantly lower than that in other areas (P<0.05); the titratable acid content of fruit in Huangyangtan was high, up to 10.08 g/L, and the acid content of fruit in Meiyu and the Erjidi was lower than 6 g/L; the total phenol content of pericarp in Yuma was the highest (43.76 mg/g), and that in Yuanlinchang was the lowest (32.15 mg/g); the tannin content of pericarp in Yuma was the highest, close to 10 mg/g, the anthocyanin content of pericarp in Yuma and Jinsha was significantly higher than that in other areas (P<0.05). In the process of fruit ripening, the flavanol content of peel in Yuma and Erjidi was higher, and that in Yuquanying and Yuanlinchang farm was lower.The maturation sequence was as follows: Guanlan-Meiyu-Yuma-Jinsha and Erjidi-Yuquanying and Yuanlinchang-Huangyangtan. The grape quality of Cabernet Sauvignon from different regions was analyzed by principal component analysis, the fruit quality of Cabernet Sauvignon in Yuma plant base was the best, with rich phenolic substances and suitable sugar and acid, followed by Jinsha plant base. The results of this study provide data support for selecting the best planting area of Cabernet Sauvignon grape and judging the harvest time in each region at the eastern foot of Helan Mountain, Ningxia.