石油醚与乙醚测定含糖类样品中脂肪含量的准确率比较

目的为了提高脂肪提取的准确度,采用石油醚及乙醚对含糖类样品进行提取并比对。方法采用GB/T 5009.6-2003《食品中脂肪测定》第二法对其进行提取。结果结果显示,含糖类样品中脂肪测定时,用乙醚提取后测定的结果比用石油醚提取后测定的结果高。由于水解后的物质,更易溶解在极性相对较高的乙醚中,却不会较好地溶解在石油醚中,因而,乙醚提取脂肪含量偏高,准确度下降。结论实验表明,含糖类样品脂肪测定时,用石油醚测定脂肪的准确度高。

Comparison of accuracy between petroleum ether and diethyl ether to determine the fat content in sugary samples

Objective To improve the accuracy of fat extraction, petroleum ether and diethyl ether were used as extracts to compare the results. Methods The second method of GB/T 5009.6-2003 "Determination of fat in food" was applied to determine the content of fat. Results It showed that when the fat content in the sugary samples was measured, the results by using diethyl ether as extracts were higher than those of using petroleum ether as extracts, which was due to the materials be hydrolyzed in the samples was better dissolved in the relatively high polarity ether, not in the oil ether. So, the fat content by using diethyl ether as extracts was higher, with lower accuracy. Conclusion It showed that when the fat content in sugary samples was measured, the accuracy with petroleum ether as extracts was higher than that of diethyl ether.