Analysis of fruit quality of Wonhwang pear from different regions

Abstract:【Objective】Wonhwang pear has good fruit quality and high economic value, and has a large planting area in China. However, there has been limited investigation of fruit quality in different regions in China. There are great differences in climate and ecological environment among different regions, which may have impact on fruit quality. To find out the fruit quality of Xianyuan pear from different re- gions in China, and to explore the fruit quality differences of Wonhwang pear in different regions, we carried out this study.【Methods】The fruits of Wonhwang pears from 19 different areas were used as the experimental materials. Eleven fruit quality indexes including as single fruit weight, shape index, soluble solid content, titratable acid content, soluble sugar content, sugar to acid ratio, soluble solid to acid ratio, peel hardness, pulp hardness, vitamin C content and stone cell content were determined. SPSS was used for fruit quality data analysis. At the same time, the extremum normalization method was applied to transform the fruit quality data, and principal component analysis and cluster analysis were conducted. Comprehensive score ranking was made according to the principal component results combined with the corresponding weights.【Results】Fruit shape index ranged from 0.809 to 1.067 and fruit weight from 208.67 to 457.00 g. The highest fruit weight was obtained in Ningling of Henan Prov- ince. The soluble solid content ranged from 11.70% to 15.93%, and the highest soluble solid content was obtained in Funan of Anhui Province. Titratable acid content ranged from 0.18% to 0.42%, and the highest titratable acid content was found in Zhijiang of Hubei Province. Total soluble sugar content was in the range from 5.01% to 12.90%, and the highest was obtained in Jinan of Shandong Province. The ratio of sugar to acid ranged from 14.44 to 70.36, and the highest was found in samples from Jinan of Shandong Province. The ratio of soluble solid to acid varied from 29.92 to 80.18, and the highest was obtained in samples from Jinan of Shandong Province. The rind hardness was between 604.67 and 1 055.67 g · mm- 2; the peeling hardness varied between 228.67 and 368.67 g · mm- 2. Vitamin C ranged from 2.04 to 7.22 mg · 100 g- 1, and the region with highest vitamin C was Bijie of Guizhou Province. Stone cell content varied from 0.012 0% to 0.096 7%, and the lowest stone cell content was found in samples from Jinan of Shandong Province. The variation coefficients of stone cell content and sugar to acid ratio in fruit from different regions were the highest. After principal component analysis of the nor- malized data, four principal components were obtained, with a cumulative contribution rate of 83.490%. The contribution rate of the first principal component, which included titratable acid content, sugar to acid ratio and solid to acid ratio, was 38.844%. The contribution rate of the second principal component including peel hardness and pulp hardness, was 18.168%. The contribution rate of the third principal component composed of the content of stone cells and the weight of single fruit was 17.346%. The fourth principal component consisting of vitamin C was 9.132%. Jinan and Feixian of Shandong Province were dominant in the first principal component; Gaoan of Jiangxi Province and Weihai of Shandong Province were dominant in the second principal component; Ningling of Henan Province was dominant in the third principal component;Bijie of Guizhou Province, Chongqing and Zhongxiang of Hubei Province were dominant in the fourth principal component. Ningling of Henan Province, Feixian of Shandong Province were at the top rank based on comprehensive scores. Systematic cluster analysis showed that the 19 producing areas could be divided into 5 groups at euclidean distance of 16. Zhongx- iang, Zhijiang and Gongan of Hubei Province, Chongqing and Gaoan of Jiangxi Province and Taijiang of Guizhou Province were the high acid areas. Shenzhou of Hebei Province, Laohekou of Hubei Prov- ince, Fangcheng of Henan Province and Bijie of Guizhou Province were the regions with high soluble solid content. Xiantao of Hubei Province was a high nutrition area of small fruit. Xuzhou of Jiangsu Province and Weihai of Shandong Province were high in sugar-acid ratio regions. Beijing, Ningling of Henan Province, Funan of Anhui Province, Jinan and Feixian of Shandong Province, Jinxi of Jiangxi Province were with large fruit and high sugar.【Conclusion】Through principal component analysis and cluster analysis of fruit quality data of Wonhwang pear from different regions, this study showed the quality performance of the introduced Wonhwang pear in different regions of China and the fruit quality differences between different regions. According to the fruit quality data, the main producing areas of Wonhwang pear could be divided into five types. The results provide reference for determining the opti- mal ecological area for production of pear in China.