A quantitative model for the comprehensive evaluation of the fruit quality of the Bingtang sweet orange

Abstract: 【Objective】In order to ensure that the results of citrus fruit quality analysis can be compared directly and accurately, we selected the Bingtang sweet orange for this study. The standardized value weighting method for a comprehensive evaluation of citrus quality, which is a standardized value weighting method, is implemented for 3 consecutive years by tracking the quality of the Bingtang sweet orange and its fine series product from the major producing areas in Hunan province. The primary intent of this research is to transform the indicators of different units into standardized values, which feature retaining the order of the original observed values and erasing the indicator units and turning them into pure numeric values.【Methods】This research collects 30 samples of Bingtang sweet oranges and their fine series products from different producing areas in Hunan province for 3 consecutive years with each sample containing 30 fruits. 5 fruits are selected randomly in each test to be measured and the process is repeated 3 times. The indicators of the fruits being measured include soluble solid content, titrable acid content, ratio of soluble solid content to titrable acid content, vitamin C content, single fruit mass, length of the fruit, thickness of the pericarp, edible rate and juice yield and the average of these indicators is also determined. The quantitative model utilized in this research includes 4 steps. The first step is the trend adjustment of the quality indicator. There are three types of trend indicators, which are the trend indicator for higher value, medium value and lower value respectively while the latter twoneed to be adjusted according to their relevant formulas. The second step is to standardize the adjusted indicators, which will transform the observed value of the indicator into a pure numeric value. The third step is to give weight to all the indicators based on their professional importance and the distribution of weight is calculated through an expert's assessment. The quality indicator for the fruits of the Bingtang sweet orange totals 100 points, while the appearance indicator accounts for 30 points, among which the weight of a single fruit is 10 points, the fruit shape indicator is 10 points and the thickness of the fruit is10 points. The quality indicator accounts for 70 points, among which the soluble solids are 15 points, the titrable acid is 10 points, the soluble solids to acidity ratio is 15 points, the vitamin c is 10 points, the edible rate is 10 points and the juice yield is 10 points. The fourth step is to add the points in an accumulative way after multiplying the standardized values of all indicators and weights for determining the total points of the fruit quality and then ranking the grades.【Results】The following results are achieved by establishing the quantitative model of the standardized value weighting. First, this model is able to conduct comprehensive ranking for the quality of 30 Bingtang sweet oranges from different origins in an accurate way, which also matches the reality and can fully compare the fruit quality in a visualized way instead of offering a blurry judgment. Second, in terms of origins, 2 of the top 3 selected samples are from Yongxing while 7 of the top 15 are also from Yongxing. This shows that the quality of the Bingtang sweet orange from the Yongxing district of Hunan province is better than those from other areas. Third, in terms of the regional experience of‘Nongda 1'and‘Nongda 2'of the fine series of Bingtang sweet oranges, the comprehensive grades of‘Nongda 2'are better than those of‘Nongda 1'whether in Hongjiang, Mayan or Jishou. So this demonstrates that the fruit quality of‘Nongda 2'is better than‘Nongda 1.'Fourth, the‘Chuntian Bingtang sweet orange'found in Mayang is in stable condition and the comprehensive grades of three consecutive generations from the maternal line to the subsystems all rank at the top. So this establishes the fact that Mayang's Chuntian Bingtang sweet orange and its offsprings are a fine breed.【Conclusion】This research processes the data from analyzing fruit quality through standardized value weighting and transforms the indicators of different units into pure numeric values so as to directly add the evaluated values of the same breed but with different indicators. Therefore, a comprehensive evaluated grade is determined, which can reflect fruit quality in a visualized way.The standardized value weighting established in this research is able to offer a comprehensive evaluation of the fruit quality in a scientific and objective way, which also offers a reliable new method for the comprehensive evaluation of fruit quality in the future.