Study On The Form, Variation And Aroma Regulation Of Typical Aroma In Apple Juice Processing

Focusing on aroma-enhancing regulation of apple juice, the following research works have been conducted: (l)separate the free and bound volatile by Amberlite XAD-2 resin, and survey the form and mechanism of apple aroma ;(2)enzyme hydrolysis the glycosidic bound by P-glucosidase from almond and Aspergillus Niger, releasing the aroma materials;(3)analysis the variation of aroma in juice processing and storage; (4)extract the apple oil by SFE , and analysis the effect of extraction pressure, temperature ,time ,CO2 flow rate, grind degree on extraction rate.The following conclusions have been drawn:1. Both bound and free forms of aromatic components exist in either apple juice or the peel. The bounded aromatic components are connected with glycone by glycosidic bound. Enzyme hydrolysis can break out the glycosidic bound effectively, and release the potential aromatic components to enhance aroma naturally .2. Absorbed by Amberlite XAD-2 resin. Elute with ether and pentane mixture (1:1) and methanol, the bound and free aroma can isolated efficiently.3. The optimum enzymatic parameters of enhancing enzyme come from microorganisms are that temperature is 40癈, time is 90 min, and the usage of enzyme is 4g/100L.4. Extraction pressure, temperature and grind degree are three major factors on extraction rate, the optimum extraction parameter are: pressure 1750PSI, temperature 30℃,CO2 flow rate 4mL/min,moisture content 5%,grind degree 0.21mm,the ratio of static and dynamic extraction time 3:3.