超临界CO2 萃取氧化羊脂中的挥发性香味成分

以萃取物的状态、气味特征及萃取率为指标，考察萃取温度、萃取压力、萃取时间的影响，确定超临界CO2 萃取氧化羊脂(过氧化值=197mmol 氧/kg 脂肪、酸值=3.90mg KOH/kg 脂肪)中挥发性香成分的较佳条件：萃取压力20MPa、温度45℃，分离釜Ⅰ压力4.8MPa、温度20℃，分离釜Ⅱ压力4.8MPa、温度20℃，CO2 流速45L/h，萃取时间1h。用GC-MS 和GC-O 分析萃取物，通过保留指数将二者的分析结果关联，得出对氧化羊脂香味起重要作用的是醛类和羧酸类，其中(E)-2- 己烯醛、(Z)-2- 庚烯醛、(E)-2- 辛烯醛、癸醛、(E)-2- 癸烯醛、(E,E)-2,4- 癸二烯醛等六种短链脂肪醛，及庚酸、壬酸、癸酸等三种短链脂肪羧酸认为是构成氧化羊脂香味的主要成分。

Supercritical CO2 Fluid Extraction of Volatile Flavor Compounds from Oxidized Mutton Fat

Supercritical CO2 fluid was used to extract volatile flavor compounds from an artificially oxidized mutton fat (peroxide value, 197 mmol oxygen/ kg fat; and acid value, 3.90 mg KOH/kg fat). The influences of extraction temperature, pressure and time on appearance and odor characteristics and yield of extract were evaluated. The optimal technological parameters were determined as follows: extraction vessel at 20 MPa and 45 ℃, separation vessel I at 4.8 MPa and 20 ℃, separation vessel II at 4.8 MPa and 20 ℃, CO2 flow rate 45 L/h, and extraction duration 1 h. Correlation analysis between GC-MS and GC-O analytical results with retention time revealed that the characteristic odor of oxidized mutton fat was due to aldehydes and carboxylic acids, of which 6 short-chain fatty aldehydes including (E)-2-hexenal, (Z)-2-heptenal, (E)-2-octenal, decanal, (E)-2-decenal and (E, E)- 2, 4-decadienal, and three short-chain fatty acids including heptanoic acid, nonanoic acid and decanoic acid, were considered as key odorants contributing to odor of oxidized mutton fat.