Falkeborg Mia, Cheong Ling-Zhi, Gianfico Carlo, Sztukiel Katarzyna Magdalena, Kristensen Kasper, Glasius Marianne, Xu Xuebing, Guo Zheng
Department of Engineering, Aarhus University, Gustav Wiedsvej 10C, DK-8000 Aarhus C, Denmark.
Department of Engineering, Aarhus University, Gustav Wiedsvej 10C, DK-8000 Aarhus C, Denmark; Department of Biology, Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
Food Chem. 2014 Dec 1;164:185-94. doi: 10.1016/j.foodchem.2014.05.053. Epub 2014 May 17.
Alginate oligosaccharides (AOs) prepared from alginate, by alginate lyase-mediated depolymerization, were structurally characterized by mass spectrometry, infrared spectrometry and thin layer chromatography. Studies of their antioxidant activities revealed that AOs were able to completely (100%) inhibit lipid oxidation in emulsions, superiorly to ascorbic acid (89% inhibition). AOs showed radical scavenging activity towards ABTṠ, hydroxyl, and superoxide radicals, which might explain their excellent antioxidant activity. The radical scavenging activity is suggested to originate mainly from the presence of the conjugated alkene acid structure formed during enzymatic depolymerization. According to the resonance hybrid theory, the parent radicals of AOs are delocalized through allylic rearrangement, and as a consequence, the reactive intermediates are stabilized. AOs were weak ferrous ion chelators. This work demonstrated that AOs obtained from a facile enzymatic treatment of abundant alginate is an excellent natural antioxidant, which may find applications in the food industry.
通过海藻酸裂解酶介导的解聚作用从海藻酸盐制备的海藻酸寡糖（AOs），采用质谱、红外光谱和薄层色谱对其结构进行了表征。对其抗氧化活性的研究表明，AOs能够完全（100%）抑制乳液中的脂质氧化，优于抗坏血酸（89%抑制率）。AOs对ABTS˙、羟基和超氧阴离子自由基具有清除活性，这可能解释了它们优异的抗氧化活性。自由基清除活性主要源于酶解聚过程中形成的共轭烯酸结构的存在。根据共振杂化理论，AOs的母体自由基通过烯丙基重排而离域，因此，反应中间体得以稳定。AOs是弱亚铁离子螯合剂。这项工作表明，通过对丰富的海藻酸盐进行简便的酶处理获得的AOs是一种优异的天然抗氧化剂，可在食品工业中找到应用。
