Study On Aroma Active Compounds And Adulteration Detection Of Orange Juice

Aroma is one of the most important attribute to orange products quality. It is significant to keep the characteristic aroma of the orange products in order to enhance the sensory quality of the orange products and competitiveness of the orange processing enterprises. The present study focused on the aroma active compounds of Jincheng, lime, blood and Hamlin oranges. Simultaneous distillation-extraction, head-space technique, solvent extraction and solid phase microextraction were used for the extraction of volatile compounds. The aroma active compounds in Jincheng oranges were determined by SPME-GC-MS and GC-Olfactometry. Preliminary research on the identification of orange juice types by the use of aroma compositions was also studied. The main research subjects and results are listed as follows:1. Isolation the volatile compounds from Jincheng oranges.The volatile compounds of Jinchen orange juice were extracted by simultaneous distillation-extraction, head-space technique, solvent extraction and solid phase microextraction. The solid phase microextraction was the valid method to isolate volatile compounds.2. Analysis of the aroma active compounds in Jincheng oranges.Totally 30 aroma active compounds were identified in Jincheng oranges, including 8 hydrocarbons, 5 alcohols, 4 esters, 4 aldehydes, 1 ketone and 8 unknown compounds. Linalool and Limenone had the strongest aroma factors.3. Preliminary research on the identification of orange juice types by the use of aroma compositions.The quantitative results showed that there were 127 aroma components in the 10 juice samples, and hydrocarbons, esters, alcohols, ketones, and aldehydes were the major constituents. With Chinese and foreign literature, 18 of which mainly contributed to orange juice aroma were analyzed by LDA, and established two Fisher linear discriminant function according to aroma compounds which quantified relatively. The gained discriminant functions can not only determine the unknown samples, but also can be determined from the known samples. The discriminant functions with 100% accuracy were constructed. Therefore, it was practical to make use of aroma compounds to identify the type of orange juice.