Evaluation And Non Destructive Classification Of 'Bingtang' Sweet Orange Fruit Quality

In order to evaluate 'Bingtang' sweet orange fruit quality in different regions in Hunan province, fruit external and internal quality of 30 'Bingtang' sweet orange fruit samples were analyzed for two years in some 'Bingtang' sweet orange orchards at the counties of Mayang, Yongxing, Hongjiang, Jishou, Shimen in Hunan province. Meanwhile, non-destructive analysis system for fruit quality and grading of 'Bingtang' sweet orange fruit was developed and pilot demonstration of fruit quality grading was performed on a packing line. By comprehensive evaluation using principal components analysis, orange juice was evaluated for potential processing. The results were follows.1. The highest comprehensive value of fruit quality was No.18, small fruit of "Bingtang" sweet orange in Yong Xing, which was flavorous, low-acid and round in fruit shape. The comprehensive quality of No.6, No.7, No.8, No.9 resulted in good level. Nongda No.2 had better quality than that of Nongda No.1. Nongda No.2 produced in Hongjiang showed better quality than it was produced in Jishou and Mayang. Among the No.1-No.4 of big fruit clones of Yongxing, No.4 big fruiy Yongxing Bingtang sweet orange was of the best quality. The common Bingtang sweet orange had inferior quality compared to other selected clones. According to the comprehensive evaluation, the following Bingtang sweet orange clones were suggested for widely cultivated in Hunan area:Yongxing small Bingtang, Mayang acidless Bingtang, Nongda No.2, Yongxing big fruit Bingtang, Qianyang Bingtang sweet orange clones. Bingtang sweet orange fruit quality in Yongxing was graded as the best, followed by that in Hongjiang, and then Those in Mayang and other places.2. Fruit TSS and acid content were analyzed by sampling from the main production areas with the conventional destructive methods for a long period. Based on the standard, the NIR transmission spectrum at 710-960 nm was utilized for fruit quality analysis, and repeated correction and verification were performed in comparison with the conventional quality analysis data to evaluate the accuracy in non-destructive fruit quality analysis and sorting. Classification standard of 'Bingtang' sweet orange was established. Fruit size classification was set up based on fruit diameters:large 68-74 mm, medium 62-67 mm, and small 56-61 mm. And fruits were further classified into 4 classes based on the TSS and acid content, i.e. Super class:Birx=14 and acidity=0.4%, Class ?:12=Birx<14 and acidity= 0.4%, Class ?:Birx=14 and 0.6%= acidity >0.4%, and Marketable class:Birx<12 and acidity=0.4%.3. Using comprehensive score method of sensory index (color, flavor, appearance, etc.) and the physical and chemical indicators (soluble solids, titratable acid, juice yield, volatile oil, solid acid ratio, vitamin C, etc.), the juicing adaptability and fruit orange juice quality of big fruit'Bingtang' sweet orange at Hongjiang, Mayang and Yongxing were investigateded, in comparison with that of Hongjiang common Bingtanch sweet orang. When the fruits were processed immediately after being harvested, the juice processing was good for all the fruit samples with high juice quality, which was able to mix with different acidity of orange juice. Only Ma Yang big fruit sweet orange fruit could be still suitable for orange juice processing with very good quality after 4 months of storage at room temperature.