McReynolds Naomi, Auñón Garcia Juan M, Guengerich Zoe, Smith Terry K, Dholakia Kishan
School of Physics and Astronomy, University of St Andrews, UK.
Biomedical Science Research complex, University of St Andrews, UK.
Appl Spectrosc. 2016 Nov;70(11):1872-1882. doi: 10.1177/0003702816645931.
We demonstrate the ability to discriminate between five brands of commercially available extra-virgin olive oil (EVOO) using Raman spectroscopy or fluorescence spectroscopy. Data was taken on both a 'bulk optics' free space system and on a compact handheld device, each capable of taking both Raman and fluorescence data. With the compact Raman device we achieved an average sensitivity and specificity of 98.4% and 99.6% for discrimination, respectively. Our approach illustrates that both Raman and fluorescence spectroscopy can be used for portable discrimination of EVOOs. This technique may enable detection of EVOO that has undergone counterfeiting or adulteration. The main challenge with this technique is that oxidation of EVOO causes a shift in the Raman signal over time. It would therefore be necessary to retrain the database regularly. We demonstrate preliminary data to address this issue, which may enable successful discrimination over time. We show that by discarding the first principal component, which contains information on the variations due to oxidation, we can improve discrimination efficiency.
我们展示了使用拉曼光谱或荧光光谱区分五种市售特级初榨橄榄油（EVOO）品牌的能力。数据是在“体光学”自由空间系统和紧凑型手持设备上采集的，这两种设备都能够采集拉曼和荧光数据。使用紧凑型拉曼设备，我们在区分方面分别实现了98.4%和99.6%的平均灵敏度和特异性。我们的方法表明，拉曼光谱和荧光光谱均可用于EVOO的便携式鉴别。该技术可能有助于检测经过假冒或掺假的EVOO。这项技术的主要挑战在于，EVOO的氧化会导致拉曼信号随时间发生偏移。因此，有必要定期重新训练数据库。我们展示了用于解决该问题的初步数据，这可能使我们能够长期成功地进行鉴别。我们表明，通过舍弃包含氧化引起的变化信息的第一主成分，可以提高鉴别效率。
