Dueik V, Bouchon P
Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, PO Box 306, 6904411, Chile.
Department of Chemical and Bioprocess Engineering, Pontificia Universidad Católica de Chile, PO Box 306, 6904411, Chile.
Food Res Int. 2016 Oct;88(Pt A):166-172. doi: 10.1016/j.foodres.2016.03.032. Epub 2016 Apr 6.
Polyphenols are very unstable and may be degraded when exposed to harsh conditions, such as those found in frying. The inclusion of vacuum seems to be a reasonable solution to avoid these adverse effects. Accordingly, the purpose of this study was to analyze the effect of olive-leaf polyphenol extract on quality parameters of vacuum and atmospheric fried gluten-starch matrices. Matrices were prepared using 12% (d.b.) gluten and 88% (d.b.) starch, using either native or a mixture of native (90%) and pre-gelatinized starch (10%). Polyphenols were added as a freeze-dried powder. Atmospheric and vacuum (91.4kPa, T=46°C) frying were compared using an equivalent thermal driving force, which is defined as the difference between oil temperature and water boiling point at the working pressure. Bioavailability of polyphenols was evaluated using simulated digestion and caco-2 cells absorption. The addition of pre-gelatinized starch significantly decreased oil absorption in vacuum fried matrices, however, no significant differences were noted when added into atmospheric fried ones. Polyphenols retention was higher than 70% in vacuum fried matrices. Their bioavailability was 15%, much higher than in atmospheric fried ones (8%), and that the one reported in other studies. Interestingly, polyphenol addition reduced the oil content of vacuum fried snacks by 20%. This could be attributed to the hydrating effect of polyphenols, which may facilitate starch gelatinization, improving structure formation during vacuum frying, which will be the focus of future research.
多酚非常不稳定，暴露于恶劣条件下（如油炸时的条件）可能会降解。采用真空处理似乎是避免这些不利影响的合理解决方案。因此，本研究的目的是分析橄榄叶多酚提取物对真空油炸和常压油炸面筋-淀粉基质品质参数的影响。基质采用12%（干基）面筋和88%（干基）淀粉制备，使用天然淀粉或天然淀粉（90%）与预糊化淀粉（10%）的混合物。多酚以冻干粉末形式添加。使用等效热驱动力比较常压油炸和真空（91.4kPa，T = 46°C）油炸，等效热驱动力定义为工作压力下油温与水沸点之差。使用模拟消化和caco-2细胞吸收评估多酚的生物利用度。添加预糊化淀粉显著降低了真空油炸基质中的吸油量，然而，添加到常压油炸基质中时未观察到显著差异。真空油炸基质中多酚保留率高于70%。它们的生物利用度约为15%，远高于常压油炸基质中的生物利用度（约8%）以及其他研究报道的生物利用度。有趣的是，添加多酚使真空油炸零食的油含量降低了20%。这可能归因于多酚的水合作用，其可能促进淀粉糊化，改善真空油炸过程中的结构形成，这将是未来研究的重点。
