Juice Processing Characteristics of Local Sweet Orange Cultivars in Hunan Province

摘要

The development of orange juice processing has increased during the recent years, and selection of suitable cultivars for juicing becomes more and more important for the Chinese citrus industry. Sweet orange cultivar improvement has been carried out for over 40 years in Hunan province and many cultivars have been released. In the past, great attention was paid only to the fresh fruit cultivars, while some with the juicing potential were never evaluated for their processing characteristics. From 2006 - 2008, 7 local sweet orange cultivars including ' Dahong ' , ' Dahong seedless ' , ' Xupu ' , ' Xupu seedless ' , ' Bingtangcheng' , Large fruit ' Bingtangcheng' and ' Succari' were evaluated for juicing suitability. Juice content, total soluble solid (TSS) , ratio of TSS to acid, vitamin C were determined, and juice color, appearance, flavor and possible defect were evaluated. 'Xupu seedless' and 'Xupu' had the highest colligation scores (90 and 85.9) with the juice rate 59.5% and 50.9% , followed by ' Dahong' and ' Dahong seedless' (82.0 and 79.9) with the juice content of 48. 9% and 50. 8%. Both ' Large Fruit Bingtangcheng' and ' Bingtangcheng' had the colligation scores of 85. 4 and 79. 5 with the juice rate 47. 6% and 41. 5%, respectively, but the juice of the two cultivars became bitter after being heated. ' Succari' had the lowest score (63.3)with heavy bitter flavour. The former 6 juicing cultivars were stored for 4 months (from January to April) under room temperature to get a better understanding their possible processing period. It was found that ' Xupu' , ' Dahong' and Dahong ' seedless' had higher colligation scores (89. 1, 83. 8 and 83. 7, respectively) with increased juice content 53. 3% , 54.5% and 52.3%. In conclusion, ' Xupu seedless' , ' Xupu' , ' Dahong' and ' Dahong seedless' showed excellent juice processing characteristics, the later 3 could even have their processing period prolonged to 3 months more. ' Large fruit Bingtangcheng' and ' Bingtangcheng' were of the basic requirements for processing, and their juice could be used for making blended juice drinks. ' Succari' was not suitable for juicing.