FT-IR法测定温度对牛奶脂肪酸结构的影响

Effect of Temperature on Structure of Fatty Acids in Milk by FT-IR

利用傅里叶变换红外光谱法研究不同温度下牛奶中脂肪酸结构的变化。IR谱图表明45℃时牛奶中脂肪酸在974 cm-1处出现吸收峰,说明牛奶中的不饱和脂肪酸结构开始由顺式变为反式结构。在65℃时该吸收峰强度增大,表明大部分的不饱和脂肪酸结构由顺式变为反式结构。在105℃时974 cm-1处的吸收峰仍然存在,牛奶中的不饱和脂肪酸结构以反式结构存在更加稳定。实验结果表明,温度对牛奶中的不饱和脂肪酸结构有一定的影响。

The infrared spectrum was used to discuss structure change of the fatty acids in milk.At 45 ℃,an absorption peak appeared in the wavenumber of 974 cm-1 and conclude that the configuration of unsaturated fatty acid in milk changed from the cis-form to trans-from.At 65 ℃ the absorption peak was enhanced,it indicate that more unsaturated fatty acid in milk changed from cis-form to trans-from.The absorption peak in the wavenumber of 974 cm-1 didn＇t change when the milk at 105 ℃,it indicated that the trans-unsaturated fatty acid was more stable in milk.The results indicated that temperature can influence the structure of fatty acids in milk.