Fondazione Edmund Mach, Research and Innovation Centre, Via E. Mach, 1 38010 San Michele all'Adige, Trento, Italy.
Institute of Agriculture and Tourism, Karla Huguesa 8, 52440 Poreč, Croatia.
Molecules. 2019 Aug 9;24(16):2896. doi: 10.3390/molecules24162896.
In order to differentiate the extra virgin olive oils (EVOO) of different origin of purchase, such as monovarietal Italian EVOO with protected denomination of origin (PDO) and commercial-blended EVOO purchased in supermarkets, a number of samples was subjected to the analysis of volatile aroma compounds by both targeted gas chromatography/mass spectrometry (GC-MS) and untargeted profiling by comprehensive two-dimensional gas chromatography/mass spectrometry (GC×GC-TOF-MS), analysis of phenols by targeted high-performance liquid chromatography/mass spectrometry (HPLC-DAD-ESI/MS), and quantitative descriptive sensory analysis. Monovarietal PDO EVOOs were characterized by notably higher amounts of positive LOX-derived C6 and C5 volatile compounds, which corresponded to the higher intensities of all the assessed positive fruity and green odor sensory attributes. Commercial-blended EVOOs had larger quantities of generally undesirable esters, alcohols, acids, and aldehydes, which coincided with the occurrence of sensory defects in many samples. Many minor volatile compounds that were identified by GC×GC-TOF-MS were found to differentiate each of the two investigated groups. The differences between the groups with respect to phenols and taste characteristics were evident, but less pronounced. The results that were obtained in this study have undoubtedly confirmed the existence of the large heterogeneity of oils that are sold declared as EVOO. It was shown that GC-MS, GC×GC-TOF-MS, and HPLC-DAD-ESI/MS analyses have complementary outputs, and that their use in combination has advantages in supporting the results of sensory analysis and objectively differentiating these groups of EVOO.
为了区分不同来源的特级初榨橄榄油（EVOO），如具有原产地保护名称（PDO）的单一意大利品种 EVOO 和超市购买的商业混合 EVOO，对一些样品进行了挥发性香气化合物的分析，采用靶向气相色谱/质谱（GC-MS）和非靶向全二维气相色谱/质谱（GC×GC-TOF-MS）进行轮廓分析，采用靶向高效液相色谱/质谱（HPLC-DAD-ESI/MS）分析酚类化合物，并进行定量描述性感官分析。单一品种 PDO EVOO 的特点是 LOX 衍生的 C6 和 C5 挥发性化合物含量显著更高，这与所有评估的阳性水果和绿色气味感官属性的强度相对应。商业混合 EVOO 具有更大数量的一般不想要的酯、醇、酸和醛，这与许多样品中出现感官缺陷相对应。通过 GC×GC-TOF-MS 鉴定的许多次要挥发性化合物被发现可以区分这两个研究组。两组在酚类化合物和口感特征方面的差异明显，但不那么明显。本研究的结果无疑证实了所售 EVOO 油存在巨大的异质性。结果表明，GC-MS、GC×GC-TOF-MS 和 HPLC-DAD-ESI/MS 分析具有互补的输出，并且它们的联合使用在支持感官分析结果和客观地区分这些 EVOO 组方面具有优势。
