Ghnimi Sami, Budilarto Elisabeth, Kamal-Eldin Afaf
Dept. of Food Science, College of Food and Agriculture, United Arab Emirates Univ., P. O. Box 15551, Al-Ain, UAE.
Compr Rev Food Sci Food Saf. 2017 Nov;16(6):1206-1218. doi: 10.1111/1541-4337.12300. Epub 2017 Oct 14.
The consumption of omega-3 fatty acids provides a wide range of health benefits. However, the incorporation of these fatty acids in foods is limited because of their high oxidative instability. A new paradigm has emerged to better explain the oxidation mechanism of polyunsaturated fatty acids, which will be discussed here with reference to bulk lipids considered a special case of water in oil microemulsion. This paradigm suggests that lipid oxidation reactions are initiated by heterogeneous catalysis by metal oxides followed by the formation of micelles containing initial hydroperoxides, water, and other amphiphilic compounds. The induction period comes to the end when the formed micelles reach a critical micelle concentration and start to decompose opening the way to intense free radical reactions. Antioxidants and synergists extend the induction period not only by scavenging free radicals but also by stabilizing the micelles. With better understanding of the lipid oxidation mechanism, a tailored choice of antioxidants and synergistic combinations, and efficient encapsulation methods may be optimized to provide stable encapsulates containing highly n-3 polyunsaturated fatty acids. Smart processing and encapsulation technologies utilizing properly stabilized oils as well as optimized packaging parameters aiming to enhance n-3 fatty acid stability by smart selection/design of antioxidants, control of the interfacial physics and chemistry, and elimination of surface oil are needed for this purpose.
摄入ω-3脂肪酸对健康有诸多益处。然而，由于这些脂肪酸的氧化稳定性较差，它们在食品中的添加量受到限制。一种新的范例已出现，能更好地解释多不饱和脂肪酸的氧化机制，在此将结合被视为油包水微乳液特殊情况的大量脂质进行讨论。该范例表明，脂质氧化反应由金属氧化物的非均相催化引发，随后形成含有初始氢过氧化物、水和其他两亲性化合物的胶束。当形成的胶束达到临界胶束浓度并开始分解，引发剧烈的自由基反应时，诱导期结束。抗氧化剂和增效剂不仅通过清除自由基，还通过稳定胶束来延长诱导期。随着对脂质氧化机制的深入理解，可以优化抗氧化剂和增效组合的定制选择以及有效的包封方法，以提供含有高含量n-3多不饱和脂肪酸的稳定包封物。为此，需要利用适当稳定化的油以及优化的包装参数的智能加工和包封技术，通过智能选择/设计抗氧化剂、控制界面物理化学以及去除表面油来提高n-3脂肪酸的稳定性。
