Mediterranean diet vegetable foods protect meat lipids from oxidation during <i>in vitro</i> gastro-intestinal digestion

Meat lipids oxidation during digestion gives rise to a post-prandial oxidative stress condition, which negatively affects human health. Mediterranean Diet vegetables contain high amount of phenolic compounds, which potentially may reduce the oxidative phenomena during digestion. <i>In vitro</i> co-digestion of turkey meat with a typical Mediterranean Diet salad containing tomato, onion, black olives, extra-virgin olive oil (EVOO) and basil, dose-dependently reduced lipid peroxidation. Onion and EVOO were more effective in limiting oxidation than the other foods, resulting in negligible concentrations of lipid hydroperoxides after digestion. Specific phenolic classes dominated the phenolic profile of the different foods, such as flavonols and anthocyanins in onion, phenolic acids in tomato and basil, and tyrosol-derivatives in black olives and EVOO. The correlation between lipid peroxidation inhibition, phenolic constituents and antioxidant properties was evaluated by principal component analysis (PCA). Flavonols and anthocyanin were the major contributors to the bioactive response of vegetable foods.消化过程中肉类脂质氧化会引发餐后氧化应激状态，该状态会对人体健康产生负面影响。地中海饮食（Mediterranean Diet）所用蔬菜富含酚类化合物（phenolic compounds），这类物质有望抑制消化过程中的氧化反应。以火鸡肉与包含番茄、洋葱、黑橄榄、特级初榨橄榄油（extra-virgin olive oil, EVOO）及罗勒的经典地中海饮食沙拉进行体外（in vitro）共消化实验，结果显示脂质过氧化（lipid peroxidation）反应呈剂量依赖性降低。相较于其他食材，洋葱与特级初榨橄榄油的抗氧化效果更为显著，消化后脂质过氧化物（lipid hydroperoxides）浓度可降至可忽略水平。不同食材的酚类组成谱以特定酚类亚型为主：洋葱中以黄酮醇（flavonols）与花青素（anthocyanins）为主，番茄及罗勒中以酚酸（phenolic acids）为主，黑橄榄与特级初榨橄榄油中则以酪醇衍生物（tyrosol-derivatives）为主。本研究通过主成分分析（principal component analysis, PCA）评估了脂质过氧化抑制效果、酚类成分与抗氧化活性三者间的相关性。黄酮醇与花青素是蔬菜食材产生生物活性响应的主要贡献因子。