Lerma-García María J, Ramis-Ramos Guillermo, Herrero-Martínez José M, Simó-Alfonso Ernesto F
Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia, 46100 Burjassot, Valencia, Spain.
Rapid Commun Mass Spectrom. 2007;21(22):3751-5. doi: 10.1002/rcm.3272.
Amino acid profiles, established by direct infusion mass spectrometry, have been used to classify vegetable oils according to their botanical origin. The proteins present in hazelnut, sunflower, corn, soybean, olive, avocado, peanut and grapeseed oils were precipitated with acetone, and the residue was hydrolyzed in acid medium, diluted in a hydrochloric acid/ethanol mixture, and infused into the mass spectrometer. The spectra of the hydrolyzed protein extracts showed [M+H]+ ions of the following amino acids: glycine, alanine, serine, proline, valine, threonine, cysteine, isoleucine + leucine, aspartic acid, lysine, glutamic acid, methionine, histidine, phenylalanine, arginine and tyrosine. These ions were used to construct linear discriminant analysis (LDA) models. The ratios of the ion signal intensities selected by pairs were used as predictors. With the sequential application of three LDA models, the eight botanical origin categories of the samples were well resolved.
通过直接进样质谱法建立的氨基酸谱已被用于根据植物油的植物来源对其进行分类。榛子油、向日葵油、玉米油、大豆油、橄榄油、鳄梨油、花生油和葡萄籽油中的蛋白质用丙酮沉淀，残渣在酸性介质中水解，在盐酸/乙醇混合物中稀释，然后注入质谱仪。水解蛋白提取物的光谱显示了以下氨基酸的[M+H]+离子：甘氨酸、丙氨酸、丝氨酸、脯氨酸、缬氨酸、苏氨酸、半胱氨酸、异亮氨酸+亮氨酸、天冬氨酸、赖氨酸、谷氨酸、蛋氨酸、组氨酸、苯丙氨酸、精氨酸和酪氨酸。这些离子被用于构建线性判别分析（LDA）模型。成对选择的离子信号强度之比用作预测因子。通过依次应用三个LDA模型，样品的八个植物来源类别得到了很好的区分。
