College of Food Science, Southwest University, Chongqing, China.
Chongqing Key Laboratory of Special Food Co-Built by Sichuan and Chongqing, Southwest University, Chongqing, China.
J Food Sci. 2023 May;88(5):1924-1938. doi: 10.1111/1750-3841.16510. Epub 2023 Mar 22.
The present research aimed to assess the protective effects of purslane polyphenols on rabbit meat myofibrillar protein (MP) under malondialdehyde (MDA)-induced oxidation. The major polyphenols in purslane extract were analyzed by ultrahigh performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). To analyze the protective mechanism of purslane polyphenol monomers on MP in the oxidation system, we determined the retained MDA content in the suspension and analyzed the structure and nuclear magnetic resonance (NMR) of MP. The UPLC-QTOF-MS identification analysis indicated that purslane polyphenols mainly contained chlorogenic acid, caffeic acid, ferulic acid, rutin, kaempferol, and quercetin. Polyphenols in purslane can prevent MDA from binding to MP effectively. Chlorogenic acid showed the best inhibitory effect, and the retention content of MDA decreased to 54.79%, which was significantly lower than those of other groups. Purslane polyphenols had protective effects on sulfhydryl groups, free amino groups, intrinsic tryptophan fluorescence, α-helix structure, and morphology of MP. Moreover, the carbonyl contents, increase in surface hydrophobicity, and random coil contents of MP were reduced. In addition, the NMR results indicated that polyphenols inhibited the oxidation of protein induced by MDA through competitive inhibition. PRACTICAL APPLICATION: This study showed the efficiency of purslane polyphenol monomers in protecting the structure and function of myofibrillar protein under malondialdehyde-induced oxidative stress and their potential to preserve the nutritional value of foods rich in proteins and lipids.
本研究旨在评估马齿苋多酚对丙二醛（MDA）诱导氧化兔肌肉肌原纤维蛋白（MP）的保护作用。采用超高效液相色谱-四极杆飞行时间质谱联用仪（UPLC-QTOF-MS）分析马齿苋提取物中的主要多酚类物质。为分析马齿苋多酚单体在氧化体系中对 MP 的保护机制，我们测定了悬浮液中 MDA 的残留含量，并对 MP 的结构和核磁共振（NMR）进行了分析。UPLC-QTOF-MS 鉴定分析表明，马齿苋多酚主要含有绿原酸、咖啡酸、阿魏酸、芦丁、山奈酚和槲皮素。马齿苋中的多酚可以有效阻止 MDA 与 MP 结合。绿原酸的抑制效果最好，MDA 的保留含量降低至 54.79%，明显低于其他组。马齿苋多酚对 MP 的巯基、游离氨基、内源色氨酸荧光、α-螺旋结构和形态具有保护作用。此外，MP 的羰基含量、表面疏水性增加和无规卷曲含量降低。此外，NMR 结果表明，多酚通过竞争性抑制抑制 MDA 诱导的蛋白质氧化。实际应用：本研究表明，马齿苋多酚单体在保护 MDA 诱导氧化应激下肌原纤维蛋白的结构和功能方面具有效率，并且可能有助于保持富含蛋白质和脂肪的食物的营养价值。
