Chapagain Bishnu P, Wiesman Zeev
The Phyto-Lipid Biotechnology Laboratory, Department of Biotechnology Engineering, The Institutes for Applied Research, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
J Agric Food Chem. 2009 Feb 25;57(4):1135-42. doi: 10.1021/jf8025277.
Triacylglycerols (TAGs), composed of three esterified fatty acids with an attached glycerol backbone, are the main component of vegetable oil (approximately 95%) and an important source of energy and nutrition for humans, so their compositional analysis merits extensive interest. Intact TAG composition of oil in native form is highly important, rather than the fatty acid profile itself. This paper reports the analysis of the TAG profile of olive oils produced from the six common olive cultivars grown in the Negev desert of Israel (Barnea, Souri, Arbequina, Picual, Leccino, and Koroneiki) together with the content of some additional common oil quality parameters closely associated with TAG composition and integrity. Matrix-assisted laser ionization-desorption time-of-flight/mass spectrometry (MALDI-TOF/MS) fingerprintings were employed for TAG profiling. With 2,5-dihydroxybenzoic acid (DHB), MALDI-TOF/MS was able to fingerprint the intact TAG profiles in olive oils in a fast and easy manner without any derivatization. Triolein (31.53%) was found to be the main intact TAG followed by dioleoyl-palmitoyl (23.06%) and dioleoyl-linoleoyl (14.31%). MALDI-TOF/MS also enabled calculation of the main fatty acids and their compositions in a simple manner from the TAG profiles; the results are found to be very similar to conventional methods determined by GC and HPLC. Average free fatty acids and peroxide value were found to be less than 0.8% and 10 mequiv of O(2)/kg of oil, respectively, in all of the tested oils. Relatively high levels of tocopherols (av = 325 microg/kg) and phytosterols (av = 2375 mg/kg) were found. This study demonstrates MALDI-TOF/MS technology as an easy and fast methodology for TAG and fatty acid profile analysis in olive oils. Additionally, this study also shows the high levels of tocopherols and phytosterols in the olive oils produced from the common cultivars grown in the Israeli Negev desert.
三酰甘油（TAGs）由三个酯化脂肪酸与一个连接的甘油主链组成，是植物油的主要成分（约95%），也是人类重要的能量和营养来源，因此其成分分析备受关注。原生形式的油中完整TAG组成非常重要，而非脂肪酸谱本身。本文报道了对以色列内盖夫沙漠种植的六个常见橄榄品种（巴尼亚、苏里、阿贝基纳、皮夸尔、莱基诺和科罗内基）生产的橄榄油的TAG谱分析，以及一些与TAG组成和完整性密切相关的其他常见油质参数的含量。采用基质辅助激光电离-解吸飞行时间/质谱（MALDI-TOF/MS）指纹图谱法进行TAG分析。使用2,5-二羟基苯甲酸（DHB），MALDI-TOF/MS能够快速简便地对橄榄油中的完整TAG谱进行指纹图谱分析，无需任何衍生化。发现三油精（31.53%）是主要的完整TAG，其次是二油酰-棕榈酰（23.06%）和二油酰-亚油酰（14.31%）。MALDI-TOF/MS还能够从TAG谱中以简单的方式计算主要脂肪酸及其组成；结果发现与通过气相色谱（GC）和高效液相色谱（HPLC）测定的传统方法非常相似。在所有测试的油中，平均游离脂肪酸和过氧化值分别低于0.8%和10 mequiv O₂/kg油。发现生育酚（平均 = 325 μg/kg）和植物甾醇（平均 = 2375 mg/kg）含量相对较高。本研究证明MALDI-TOF/MS技术是一种用于橄榄油中TAG和脂肪酸谱分析的简便快速方法。此外，本研究还表明，在以色列内盖夫沙漠种植的常见品种生产的橄榄油中生育酚和植物甾醇含量较高。
