College of Life Science and Engineering, Shaanxi University of Science and Technology , Xi'an 710021, China.
J Agric Food Chem. 2014 Mar 5;62(9):2104-11. doi: 10.1021/jf404593f. Epub 2014 Feb 20.
Effects of selected aqueous phase emulsifiers on lipid oxidative stability of water-in-walnut oil (W/O) emulsions stabilized by polyglycerol polyricinoleate (PGPR) were evaluated. The formation of primary oxidation products (lipid hydroperoxides) and secondary oxidation products (headspace hexanal) increased with increasing dodecyltrimethylammonium bromide (DTAB) concentration (0.1-0.2 wt % of emulsions). In contrast, the addition of sodium dodecyl sulfate (SDS) in the aqueous phase reduced lipid hydroperoxide and hexanal formation. In addition, the presence of Tween 20 in the aqueous phase did not significantly influence lipid oxidation rates in W/O emulsions compared to the control (without Tween 20). Whey protein isolate (WPI) was observed to inhibit lipid oxidation in the W/O emulsions (0.05-0.2 wt % of emulsions). Aqueous phase pH had an important impact on the antioxidant capability of WPI, with higher pH improving its ability to inhibit lipid oxidation. The combination of WPI and DTAB in the aqueous phase suppressed the prooxidant effect of DTAB. The combination of WPI and SDS resulted in improved antioxidant activity, with inhibition being greater at pH 7.0 than at pH 3.0. These results suggest that the oxidative stability of W/O emulsions could be improved by the use of suitable emulsifiers in the aqueous phase.
研究了不同水相乳化剂对聚甘油蓖麻醇酯（PGPR）稳定的核桃油/水（W/O）乳液的脂质氧化稳定性的影响。随着十二烷基三甲基溴化铵（DTAB）浓度（乳液的 0.1-0.2wt%）的增加，主要氧化产物（脂质氢过氧化物）和次要氧化产物（顶空己醛）的形成增加。相比之下，水相中添加十二烷基硫酸钠（SDS）会减少脂质氢过氧化物和己醛的形成。此外，与对照（不含 Tween 20）相比，水相中添加吐温 20 对 W/O 乳液的脂质氧化速率没有显著影响。乳清蛋白分离物（WPI）被观察到抑制 W/O 乳液中的脂质氧化（乳液的 0.05-0.2wt%）。水相 pH 值对 WPI 的抗氧化能力有重要影响，较高的 pH 值提高了其抑制脂质氧化的能力。水相中 WPI 和 DTAB 的组合抑制了 DTAB 的助氧化作用。WPI 和 SDS 的组合导致抗氧化活性提高，在 pH 7.0 时的抑制作用大于在 pH 3.0 时。这些结果表明，通过在水相中使用合适的乳化剂，可以提高 W/O 乳液的氧化稳定性。
