Instituto de Investigaciones Marinas (CSIC), Eduardo Cabello 6, Vigo, Spain.
J Agric Food Chem. 2010 Jun 23;58(12):7423-31. doi: 10.1021/jf100832z.
Polyphenolic fractions extracted from pine (Pinus pinaster) bark, grape (Vitis vinifera) pomace, and witch hazel (Hamamelis virginiana) bark were selected for investigating the influence of the number of phenolic units, polymerization, and the content of esterified galloyl residues (galloylation) on their efficacy for inhibiting lipid oxidation in fish lipid enriched foodstuffs. Experiments carried out with nongalloylated pine bark fractions with different polymerization degrees demonstrated that the number of catechin residues per molecule modulates their reducing and chelating properties in solution. In real food systems such as bulk fish oil and fish oil-in-water emulsions, the efficacy against lipid oxidation was highly dependent on the physical location of the antioxidant at the oxidative sensitive sites. The lowest polymerized fractions were the most efficient in bulk fish oil samples, whereas proanthocyanidins with an intermediate polymerization degree showed the highest activity in fish oil-in-water emulsions. Galloylation did not influence the antioxidant effectiveness of proanthocyanidins in bulk fish oils. The presence of galloyl groups favored the antioxidant activity of the polyphenols in emulsions, although results indicated that a high degree of galloylation did not improve significantly the activity found with medium galloylated proanthocyanidins. The results obtained in this research provide useful information about the relationship between structure and antioxidant activity in order to design antioxidant additives with application in fish oil-enriched functional foods.
从松树（Pinus pinaster）树皮、葡萄（Vitis vinifera）果渣和金缕梅（Hamamelis virginiana）树皮中提取的多酚类化合物被选来研究酚类单元数量、聚合度和酯化没食子酰基残基（没食子酰化）含量对其抑制富含鱼类脂质食品中脂质氧化的效果的影响。用不同聚合度的非没食子酰化松树皮部分进行的实验表明，每个分子中的儿茶素残基数量调节其在溶液中的还原和螯合特性。在真实的食品体系中，如大量鱼油和水包油乳液中，抗氧化剂对脂质氧化的抑制效果高度依赖于抗氧化剂在氧化敏感部位的物理位置。在大量鱼油样品中，聚合度最低的部分最有效，而具有中等聚合度的原花青素在水包油乳液中表现出最高的活性。没食子酰化对大量鱼油中原花青素的抗氧化效果没有影响。没食子酰基的存在有利于多酚类化合物在乳液中的抗氧化活性，尽管结果表明，高度没食子酰化并不能显著提高具有中等没食子酰化原花青素的活性。本研究结果为了解结构与抗氧化活性之间的关系提供了有用的信息，以便为富含鱼油的功能性食品设计具有应用前景的抗氧化添加剂。
