Rotondo Archimede, La Torre Giovanna Loredana, Dugo Giacomo, Cicero Nicola, Santini Antonello, Salvo Andrea
Department of Biomedical and Dental Sciences and Morpho-functional Imaging, University of Messina, Polo Universitario Annunziata, Viale Annunziata, 98168 Messina, Italy.
Department of Pharmacy, University of Napoli Federico II, via D. Montesano 49, 80131 Napoli, Italy.
Foods. 2020 Mar 26;9(4):384. doi: 10.3390/foods9040384.
(1) Background: Extra-virgin olive oil (EVOO) is a precious and universally studied food matrix. Recently, the quantitative chemical composition was investigated by an innovative processing method for the nuclear magnetic resonance (NMR) experiments called Multi-Assignment Recovered Analysis (MARA)-NMR. (2) Methods: Any EVOO 13-carbon NMR (C-NMR) profile displayed inconsistent signals. This mismatch was resolved by comparing NMR data to the official gas-chromatographic flame ionization detection (GC-FID) experiments: the analyses concerned many EVOOs but also the "exotic" oil (CSO). (3) Results: NMR and GC-FID evidenced the overwhelming presence of -vaccenic esters in the CSO and, more importantly, -vaccenic C-NMR resonances unequivocally matched the misunderstood C-NMR signals of EVOOs. The updated assignment revealed the unexpected relevant presence of -vaccenic ester (around 3%) in EVOOs; it was neglected, so far, because routine and official GC-FID profiles did not resolve oleic and -vaccenic signals leading to the total quantification of both monounsaturated fatty esters. (4) Conclusions: The rebuilt MARA-NMR and GC-FID interpretations consistently show a meaningful presence of -vaccenic esters in EVOOs, whose content could be a discrimination factor featuring specific cultivar or geographical origin. The study paves the way toward new quantification panels and scientific research concerning vegetable oils.
(1) 背景：特级初榨橄榄油（EVOO）是一种珍贵且被广泛研究的食品基质。最近，通过一种名为多赋值恢复分析（MARA）-核磁共振（NMR）的创新处理方法对其定量化学成分进行了研究。(2) 方法：任何EVOO的13-碳核磁共振（C-NMR）图谱都显示出不一致的信号。通过将核磁共振数据与官方气相色谱火焰离子化检测（GC-FID）实验进行比较，解决了这种不匹配问题：分析涉及许多EVOO，也包括“外来”油（CSO）。(3) 结果：核磁共振和GC-FID证明CSO中大量存在反式-11-十八碳烯酸酯，更重要的是，反式-11-十八碳烯酸的C-NMR共振明确匹配了EVOO中被误解的C-NMR信号。更新后的赋值揭示了EVOO中意外存在的相关反式-11-十八碳烯酸酯（约3%）；到目前为止，它一直被忽视，因为常规和官方的GC-FID图谱无法分辨油酸和反式-11-十八碳烯酸信号，导致两种单不饱和脂肪酸酯的总量化。(4) 结论：重建的MARA-NMR和GC-FID解释一致表明EVOO中存在有意义的反式-11-十八碳烯酸酯，其含量可能是区分特定品种或地理来源的一个因素。该研究为植物油的新定量方法和科学研究铺平了道路。
