Quality analysis of sweet cherry fruits in different ecological areas in

Abstract: 【Objective】This study analyzed the fruit quality of 5 sweet cherry varieties in 3 ecological regions including Tongchuan, Tianshui and Ledu.【Methods】Quality parameters measured included single fruit weight, hardness, fruit shape index, total sugar, titratable acid, ratio of sugar to acid, vitamin C, total phenols, total flavonoids and proanthocyanidins. Sweet cherry fruits were analyzed with principal component analysis and cluster analysis for comprehensive evaluation of quality.【Results】Except for Rainier, the other varieties had the high total sugar content in all the three ecological regions. There were differences in total sugar content between different varieties and in titratable acid content among different ecological regions and different varieties. Except for Brooks, the other varieties had the highest contents in Ledu. The ratio of sugar to acid differed among different varieties. Except for Tieton,there was no significant difference among the three different ecological zones. Except for Brooks, there was basically no significant difference among the other varieties. The total phenol content was the highest in Tianshui except for Summit and Tieton. There were differences between different varieties in Tianshui and Tongchuan. The total flavonoid content was different in different ecological areas as well as among varieties. Except for Hongdeng, the proanthocyanidin content was the lowest in the Tianshui. There were differences between different varieties in Tongchuan and Ledu. Using principal component analysis to comprehensively evaluate sweet cherry fruits, multiple fruit quality indicators can be grouped into four main components. The eigen value of the first principal component was 3.335, with a variance contribution rate of 33.348%. The eigen value of the second principal component was 1.930 with a variance contribution rate of 19.300% . The eigen value of the third principal component was 1.689 with a variance contribution rate of 16.890%. The eigen value of the fourth principal component was 1.298 with a variance contribution rate of 12.298. The eigen values of the four principal components were all greater than 1, and the accumulative variance contribution rate reached 82.136% . The comprehensive evaluation result could be reflected by the scoring model of the 4 principal components. In the case of Brooks, the score was in the order of Ledu>Tianshui>Tongchuan. For Tieton, the score was Ledu>Tongchuan>Tianshui. For Summit the score was Ledu>Tongchuan>Tianshui. For Hongdeng the score was Ledu>Tianshui>Tongchuan. For Rainier the score was Ledu>Tianshui>Tongchuan. The 15 varietie and region combination could be clustered into 3 categories. The first category included Tieton, Hongdeng and Rainier in Tianshui, Summit in Ledu, and Tieton in Tongchuan; the second included Summit, Hongdeng and Rainier in Tongchuan, and Summit in Tianshui. The third included Brooks in Tianshui, Brooks, Hongdeng, Rainier and Tieton in Ledu’s, and Brooks in Tianshui.【Conclusion】The main characteristics of Summit, Hongdeng and Rainier grown in Tongchuan and Summit in Tianshui included small fruit size, low contents of total sugars, proanthocyanidins and total flavonoids,and high contents of Vc and total phenols. The main characteristics of Tieton, Hongdeng and Rainier from Tianshui, Summit from Ledu, and Tieton from Tongchuan were of low fruit quality, high fruit hardness, low titratable acid content, and low sugar- acid ratio. The main characteristics of Brooks from Tongchuan, Brooks from Ledu, Hongdeng, Rainier, Tieton, and Brooks from Tianshui included large fruit size, high fruit quality, high sugar-acid ratio, and high contents of total sugar, total flavonoids and proanthocyanidins. Titration acid and total phenol content are low