Picariello Gianluca, Paduano Antonello, Sacchi Raffaele, Addeo Francesco
Istituto di Scienze dell'Alimentazione, Consiglio Nazionale delle Ricerche, Avellino, Italy.
J Agric Food Chem. 2009 Jun 24;57(12):5391-400. doi: 10.1021/jf9008795.
Triacylglycerol oxidation of thermally stressed (6 h at 180 degrees C, simulating deep-frying conditions) edible vegetable oil (sunflower and olive) was studied using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Chromatographic separation of the nonpolar and polar components from the heated oil performed on silica gel prior to MS analysis significantly enhanced the detection of oxidized components. The spectra contained signals that were assigned to triacylglycerols (TAG), diacylglycerols (DAG), triacylglycerol oxidative dimers, oxidized TAG, and TAG fragments arising from the homolytic beta-scission of linoleyl, peroxy, and alkoxy radicals. Enrichment of the polar compounds prevented mass spectrometric ion suppression, thus allowing the detection of minor species originating from thermal oxidation. In addition, this allowed the monitoring of polar compounds in vegetable oils undergoing mild thermal treatment. As such, chromatographic separation coupled with MALDI-TOF MS analysis provided a rapid, sensitive, and specific tool to assess the thermal oxidation of vegetable oils.
采用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）研究了热应激（180℃下6小时，模拟油炸条件）的食用植物油（向日葵油和橄榄油）的三酰甘油氧化。在质谱分析之前，对加热油中的非极性和极性成分在硅胶上进行色谱分离，显著提高了氧化成分的检测率。光谱中包含的信号被归属于三酰甘油（TAG）、二酰甘油（DAG）、三酰甘油氧化二聚体、氧化TAG以及由亚油酰基、过氧自由基和烷氧基自由基均裂β-断裂产生的TAG片段。极性化合物的富集可防止质谱离子抑制，从而能够检测到热氧化产生的微量物质。此外，这还能监测经过温和热处理的植物油中的极性化合物。因此，色谱分离与MALDI-TOF MS分析相结合，为评估植物油的热氧化提供了一种快速、灵敏且特异的工具。
