Development and application of comprehensive evaluation system for blood orange fruit quality

Abstract: 【Objective】By tracking the fruit quality data of blood orange varieties in Wanzhou district of Chongqing, we analyzed the relevant data using the standardized value weighting method, established a quantitative formula for comprehensive evaluation on blood orange fruit quality, and developed a analy-sis system software. This analysis system is closely integrated with the variety characteristics of blood orange fruits, which can accurately process and analyze the fruit quality data, objectively and scientifi-cally evaluate the merits and demerits of blood orange fruit quality and improve the efficiency of blood orange seed selection and breeding.【Methods】Citrus fruit quality is a fundamental factor to determine its market competitiveness, and quality evaluation is an important part in good seed and fruit selection.Firstly, the fruit quality data of 12 blood orange varieties arranged by the Changsha Branch of the Na-tional Citrus Improvement Center of Hunan Agricultural University for regional trials in Wanzhou dis-trict of Chongqing were followed for 7 a (years), and the fruit quality of 12 blood orange varieties (T.Meli, T. Messina rotondo, T. Tapi nuc., T. Gallo, T. Nucellare, T. Gabella, T. del Muso, T. Scire, T. Ip-polito, T. S. Alfio, T.Rosso and Moro) was randomly sampled. Thirty fruits of each variety were collect-ed, boxed and shipped back to the laboratory by courier. Five fruits were randomly selected for measure-ment in each trial andreplicated three times. Secondly, the standardized value weighting method was ap-plied to analyze the averages of fruit quality and to establish a quantitative formula for the comprehen-sive evaluation on blood orange fruit quality. The principle of this method is to convert indicators of dif-ferent units into standardized values, which is characterized by retaining the order of the original mean value, erasing the indicator units and converting them into pure values to facilitate ranking. The specific calculation steps are as follows: the first step is the measurement of fruit quality indicators and the cal-culation of the average of the indicators. The measured indexes include 11 quality indexes of single fruit mass, fruit shape index, pericarp thickness, edible rate, juice yield, titratable acid content, soluble solid content, ratio of soluble solid content to titratable acid content, vitamin C content, anthocyanin content in fruit juice and peel color. The second step is the determination and adjustment of fruit quality indicators convergence. The number of fruit evaluation indicators is large, but each indicator is essen-tial, so it is necessary to adjust the indicators to three tendencies, which are large, medium and small in-dicators. Among them, the convergence indicators include soluble solids content, ratio of soluble solid content to titratable acid content, edible rate, juice yield, vitamin C content, peel color and anthocyanin content; the convergence indicators include single fruit quality, fruit shape index and skin thickness; the convergence indicators include titratable acid content. The optimal value of the tendency index was de-termined by the average value of each batch of samples. The third step is the standardization of index observations. In the determination of quality indicators, different indicators exist in different scales and orders of magnitude, so the indicators need to be standardized to make them in the same order of magni-tude to facilitate subsequent sorting, and the meaning of standardized value is to convert the indicators of different units into pure values centered on 0 to facilitate subsequent processing. The fourth step is the fruit quality index weighting distribution. Using the expert evaluation method to assign weights to each index, the fruit quality index of blood orange had 100 points. Appearance indexes accounted for 30 points, including 10 points for individual fruit, 10 points for fruit skin color, 5 points for fruit shape in-dex, and 5 points for fruit skin thickness; internal quality indexes accounted for 70 points, including 10 points for titratable acid content, 15 points for soluble solids content, 10 points for solid/acid ratio, 10 points for vitamin C content, 5 points for edibility, 5 points for juice yield, and 15 points for anthocyan-in content of fruit juice. The fifth step is to multiply the standardized values of each index with the weights and then add up the points to obtain the total points of fruit quality, and then rank the grades. Fi-nally, the established quantitative formula was used to develop a comprehensive evaluation and analysis system software for bleeding orange fruit quality. Then, expert tasting sessions were organized to vali-date the analysis system software.【Results】The three varieties popular in the market, T.Tapi nuc., T. Ip-polito and T. Nucellare, were ranked in the top 3 in the analysis system, which was consistent with the results of the expert tasting session evaluation. The analysis showed a highly significant and positive correlation between the system ranking and the expert ranking (r=0.909, p ＜ 0.01), which indicates that the evaluation system is reasonable and feasible to be applied in practice.【Conclusion】The analy-sis system software can reduce the workload of fruit quality data analysis, improve the efficiency of the selection and breeding of new blood orange varieties, and make the results more accurate and reliable. Moreover, it can make accurate and scientific analysis and evaluation on blood orange fruit quality, and provide scientific basis for quality evaluation, the selection and breeding, improvement and planting scheme of new blood orange varieties.