Spatari Claudia, Ioele Giuseppina, Ragno Gaetano, Grande Fedora, De Luca Michele
Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy.
J Food Sci Technol. 2019 Feb;56(2):614-623. doi: 10.1007/s13197-018-3516-0. Epub 2018 Dec 4.
The thermal and light stability of linseed oil has been studied by monitoring the concentrations of fatty acids and lignans, as main nutraceutical components. Linseed oil was subjected to stressing light and temperature conditions, in accordance with the ICH international rules, and monitored by UV-vis spectroscopy and HPLC-DAD. The change of UV spectra along the photodegradation tests, setting the irradiation power at 350 W/m, confirmed a significant overall sensitivity of linseed oil to light. At the same time, the HPLC determination of the major fatty acids showed a marked variation in their concentration up to a residual concentration of 62.3 and 67.2% for α-linolenic and linoleic acid, respectively, after 18 h. In contrast, thermal tests at 60 °C showed some stability, with a concentration of residual fatty acids in the range 82-95% after 48 h. The examined lignans showed significant stability when exposed to both light and heat. Several photoprotection approaches have been also studied to increase the photostability of linseed oil. A significant increase in the stability of fatty acids has been observed using amber glass containers or ascorbic acid or by combining the two protection factors.
通过监测作为主要营养成分的脂肪酸和木脂素的浓度，对亚麻籽油的热稳定性和光稳定性进行了研究。按照国际人用药品注册技术协调会（ICH）的国际规则，使亚麻籽油经受光照和温度胁迫条件，并通过紫外可见光谱法和高效液相色谱 - 二极管阵列检测法（HPLC - DAD）进行监测。在光降解试验中，将辐照功率设定为350 W/m，紫外光谱的变化证实了亚麻籽油对光具有显著的整体敏感性。同时，主要脂肪酸的高效液相色谱测定结果表明，18小时后，α-亚麻酸和亚油酸的浓度分别显著变化至残留浓度62.3%和67.2%。相比之下，60℃的热试验显示出一定的稳定性，48小时后残留脂肪酸浓度在82 - 95%范围内。所检测的木脂素在光照和加热条件下均表现出显著的稳定性。还研究了几种光保护方法以提高亚麻籽油的光稳定性。使用琥珀色玻璃容器或抗坏血酸，或结合这两种保护因素，已观察到脂肪酸稳定性显著提高。
