食品加工条件对于产品反式脂肪酸含量的影响

选取食用油-橄榄油、大豆油和棕榈油,模拟日常烹饪体系,采用气相色谱法分析加热和煎炸情况下食用油中反式脂肪酸的种类和含量。试验结果表明,食用油单独加热情况下,加热温度、时间和循环加热次数影响食用油中反式脂肪酸的种类和含量,高温、长时间加热、反复加热均会使反式脂肪酸的含量有所增加。煎炸情况下,在一定温度范围和加热时间内,食用油的反式脂肪酸的含量增加并不明显。因此,普通的烹饪过程中,应注意减少高温加热时间、避免食用油的反复使用。

The Influence of Food Processing Conditions on the Amounts of Trans Fatty Acids

To assess the impact of food processing conditions on the content of trans fatty acids(TFAs),3 kinds of edible oils were selected,namely olive oil,soybean oil and palm oil.The type and content of TFAs in cooking conditions was estimated by a heating and frying model system,measured by gas chromatography(GC).For the heating model,results suggested that heating temperature,heating time and heating cycles had an impact on the type and content of TFAs.High temperature,long time and repeated heating increased the content of TFAs in edible oils.For the frying model,the content of TFAs was a little bit higher than the heating model.Time rather than types of food materials had an impact on the content of TFAs.These results suggested that high temperature,long time and repeated heating should be avoided in an ordinary cooking process.