Juice Processing Characteristics Of Local Sweet Orange And Looseskinned Oranges Cultivars In Hunan Province

Oranges is a dominate industry for fruit trees planted in Hunan province, which occupies an important position of agriculture. However, the study of oranges juice processing characteristics was relatively less, because of backward in technique of further processing. In addition, mass research were concentrated in seed breeding and its production recently years. In order to strengthen improved cultivar process and utilization in Hunan province and the selection of processing cultivar, which was more suitable for orange juice processing, the paper evaluate orange juice processing characteristics and analyses the indices for evaluation of fruti juice and the main factors for vairation of the content of bitter substance via a comparison of local sweet orange cultivar in Hunan province and rutaceae citrus reticulata. The results showed as follows:There was significant difference of juice processing characteristics among sweet orange varieties. The best of sweet orange cultivar for juice processing characteristics in Hunan province was long sweet seedless orange in xupu, whose evaluation scores was 91.48 and the juice ratio was 55.86. Evaluation scores of the Xupu sweet orange of xupu town was 87.28, which was improved cultivar of sweet orange cultivar. It was suitable for juice processing characteristics of Dahong sweet orange and seedless Dahong sweet orange, whose evaluation scores of fruit juice processing were 83.75 and 83.68, respectively, but acdity was relatively high and the ratio of pomace and acdity was relatively low. It could be processed into juice of Bingtang sweet orange, which disadvantage was a quantitive degree of bitter. However, Bingtang sweet orange juice was a good flavoring additive that consider be add to other sweet orange of high acdity because of high sugar degree and low acdity.There was significant change of juice processing characteristics among different harvest period and storage period, and was upward of juice processing characteristics basically with the delay of harvest stage. Furthermore, there was different response of juice processing characteristics with 4 different harvest period in different sweet orange cultivar. The overall Xupu Changxing seedless orange processing adaptation of universal after storage, and ordinary sweet orange storage after processing, storing up for flexibility has to be a large sweet juicy; Dahong sweet orange and Dahong sweet orange seedless are suitable stored, juice and sour are increase and therefore, appropriate storage:orange juice and a candy store four months later, juice rate and TA decrease,there is no juice.There was difference of juice processing characteristics among different harvest poried of ponkan in xiangxi autonomous oblast. The juice processing characteristics increase when the harvest was postponed. The evaluation scorse of fruit harvest at November 10 was only 62.21, which was not suitable for juice processing because of high acidity and low ratio of juice Citrus Ponkan Fruitshave varied marks at four period, as the latency, the juice processing characteristics strengthen, the orange juice, and flexibility to November 10 and November 20 fruits of the header values only 60, is not suitable for juicing, the TA of orange juice high, In November 30 and December 10th of the fruits of the evaluation up gradually increased to 70 or more thing, it resolved by TA, can be used for juicing, and for December 10 of the orange juice from fruit juicing have their best to 76.69.There was significant difference of bitter substance content in citrus different parts, the order:seeds>peel>capsule flap>juice. there was satistically significant difference of the content of bitter substance variation with different heating temperature at the same heating time. The maximun content of bitter substance was 0.103μg/g when heating temperature was 60℃and heating time was 20 min among different temperature on the heating time. The maximun content of limonine and nomilin were 0.42μg/g,0.03μg/g, respectively, when the heating time were 15 min and 20 min among different heating time at the same heating temperature.