低场核磁技术检测芝麻油掺假.pdf

1102014,Wb.35.No.20
品学
※分析检
低场核磁技术檢测芝麻油掺假
邵小龙2,张蓝月',冯所兰
(1.南京财经大学食品科学与工程学院,江苏南京210023:2.粮食储运国家工程实验室,江苏南京210023)
摘要:为评价低场核磁检测油脂掺假的能力,先用低场核磁结合主成分分方法区分大豆油和3种芝麻油(分别为
精炼、冷榨和热榨工艺)样品,然后用偏最小二乘法分析不同掺兑比例的模拟掺假样品数据。结果表明,大豆油和
芝麻油样品的特征信号区域在0~900ms弛豫时间段,低场核磁能够较好地区分芝麻油和大豆油样品;低场芝麻油
中掺入大豆油的最低检测比例为体积分数5%~10%,精炼芝麻油中掺入冷榨或热榨芝麻油的最低检测比例为体积
分数10%~20%。因此低场核磁技术可以作为油脂掺假的快速初筛检测方法之一。
关键词:低场核磁共振;油脂掺假;快速检测;偏最小二乘法:检出限
Application of LF-NMR for Detection of Sesame Oil Adulteration
SHAO Xiao-long ", ZHANG Lan-yue', FENG Suo-lan
(1. College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China;
2. National Engineering Laboratory of Grain Storage and Transportation, Nanjing 210023, China
Abstract: To evaluate the ability of low field nuclear magnetic resonance(lf-nmr)in detecting oil adulteration, LF-NMR
and principal component analysis(PCA) were applied jointly to discriminate pure soybean oil from pure sesame oils(refined,
cold pressed and hot pressed), and partial least squares(PLS)regression was applied to analyze three sesame oils adulterated
with soybean oil and mixtures of two different sesame oils. The results showed that transverse relaxation time(0 to 00 ms)
was an important signal region for discrimination of oil samples. LF-NMR could completely distinguish four different pure
oil samples. The limit of detection(LOD)for sesame oil adulteration with soybean oil was 5%o to 10, and the OD for
refined sesame oil adulteration with cold or hot pressed sesame oil was 10% to 20%o. Therefore, LF-NMR can be used as a
rapid screening method to detect adulteration of oil
Key words: low field nuclear magnetic resonance; oil adulteration; rapid detection; partial least squares; detection limit
中图分类号:TS207.3
文献标志码:A
文章编号:1002-6630(2014)20-0110-04
doi:10.750/5pkx1002-6630-201420022
芝麻油选用芝麻种子焙炒后水代或机榨工艺制成,营中红外、拉曼光谱"の、低场核磁技术”1、电子鼻
养价值高、气味香醇,是一种高档调味油脂?。由于芝麻和电子舌?等检测油脂掺假。其中低场核磁能同时检
油市售价远高于常见油脂品种,部分厂商掺入如大豆油
测样品的物理和化学信息,取得样品质子/核子的唯
棉籽油和棕榈油等低价植物油,或者桐油和矿物油等非食
指纹”信息71,在油脂掺假检测上有一定的检测
用油,甚至勾兑芝麻油香精冒充芝麻油出售凹。油脂掺假效果1。然而,低场核磁对掺假油脂的检测能力暂
不仅损害消费者健康,也损害行业利益。油脂掺假检测方无详细报道,能检测的油脂最低掺假比例问题等尚不
法主要有感官评定法、显色法、分光光度法和色谱法。清楚。另外因芝麻油生产工艺不同而产品类型较多,
感官评定需要经验丰富的从业人员,而显色法、分光光掺假问题比较复杂。因此为解决此类问题,本研究将
度法和色谱等检测方法操作复杂、耗时长,并且需要消大豆油和3种典型工艺的芝麻油(包括精炼、冷榨和热
耗大量化学品,难以实现快速检测,因此需要开发一种榨)进行互掺实验,结合低场核磁技术和多元统计方
快速准确的芝麻油掺假检测方法。
法进行快速检测研究,以期为芝麻油掺假的快速检
目前研究报道了相关快速检测技术,如近红外?、与鉴定提供参考
收稿日期:2014-04-18
基金项目:国家自然科学基金青年科学基金项目(31201443);公益性行业(粮食)科研专项(201313002-02);
江苏省属高校自然科学面上项目(12KJB550004)
作者简介:邵小龙(1981-),男,讲师,博士,研究方向为粮油储运、快速无损检测。E-mail:silion2@gmail.com
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