The Impact Of Essential Oil Content On Citrus Juice Quality

Aroma has long been known to be one of the most important quality attributes of citrus juice.A part of the citrus essential oils are unstable.which will degrade and affect the flavor of citrus juice and reduce the quality of citrus juice. Encompassing the central task of the effect of essential oil content on citrus juice quality, comparing three extraction methods of essential oils and taking the citrus juice from Jinchen cultivars planted in Song zi of Hubei Province in China as an example.By adding essential oils back to the Jinchen jucie, the volatile compounds and aroma active components of Jinchen jucie were identified by SPME-GC-MS under different treatment conditions.With a systematic study, conclusions were made as follows:l.The essential oils of Jinchen jucie were extracted by steam distillation, simultaneous distillation extraction and distillation titration. Optimized the conditon of steam distillation and simultaneous distillation extraction.The content of essential oils extracted by simultaneous distillation extraction was highest, steam distillation and distillation titration were in the next place. The same kind of citrus juice,the order of the essential oils content of four types citrus is as follow:Xuegan>Jinchen>Hamulin>Beibei4472. On the whole, when the additive amount of essential oils is the same, the kinds of volatile compounds and aroma active components of Jinchen jucie which are maximum in 60℃and 70℃heating temperature,which are declined in 80℃and 90℃heating temperature detected by GC-MS. When the additive amount of essential oils is 0.035ml/100g NFC (Not From Concentrate), there is little or no volatile compounds and aroma active components of Jinchen jucie in 90℃heating temperature detected by GC-MS and discoverd the 2-n-propylpyridine which seriously affect the flavor of citrus juice in 80℃heating temperature.When the additive amount of essential oils is 0.040ml/100g NFC, there is little or no volatile compounds and aroma active components of Jinchen jucie in 80℃heating temperature detected by GC-MS,the esters and the ketones can not be detected.3. On the whole, when the heating temperature is same and the additive amount of essential oils is different, the kinds of volatile compounds and aroma active components of Jinchen jucie are increases first and begin decrease when the additive amount of essential oils is 0.035ml/100g NFC.4. When the additive amount of essential oils is the same,on the whole,the variation in the kinds of volatile compounds and aroma active components of Jinchen jucie are much smaller along with the increase of heating time.But the kinds of volatile compounds and aroma active components of Jinchen jucie are maximum in 20min heating time and that other matters are detected along with the increase of heating time by GC-MS.5. On the whole, when the heating time is same and the additive amount of essential oils is different, the variation in the kinds of volatile compounds and aroma active components of Jinchen jucie are much smaller.But other matters are detected in 10min heating time 0.035ml/100g NFC and 20min,30min,40min,50min heating time 0.030ml/100g NFC by GC-MS.6. When the additive amount of essential oils is the same,on the whole,the variation in the kinds of volatile compounds and aroma active components of Jinchen jucie increase along with the increase of illumination time. On the whole, when the illumination time is same and the additive amount of essential oils is different, the variation in the kinds of volatile compounds and aroma active components of Jinchen jucie are much smaller.But the kinds of volatile compounds and aroma active components of Jinchen jucie begin decrease when the additive amount of essential oils is 0.035ml/100g NFC.7. Total acidity,soluble solid and heating temperature have positive correlation.the content of VC decrease along with the increase of heating temperature. Citrus juice may increase browning when the additive amount of essential oils is 0.035ml/100g NFC and heating temperature is 80℃or more.