Márquez-Lázaro Johana, Méndez-Cuadro Darío, Rodríguez-Cavallo Erika
Analytical Chemistry and Biomedicine Group, University of Cartagena, Cartagena de Indias 130001, Colombia.
Foods. 2020 Feb 11;9(2):170. doi: 10.3390/foods9020170.
Although the impact of oxidation on human health has been of growing interest, the oxidation of proteins, major component of meat, has received little attention. This paper describes the effect of five fluoroquinolones (FQs) on carbonylation of sarcoplasmic and myofibrillar proteins of beef when found at concentrations close to the maximum residue limit (MRL). Samples were treated individually with the FQs, determining in each protein fraction the carbonyl index, protein content and oxidized proteins identification, using 2,4-dinitrophenyhydrazine (DNPH) alkaline assay, Western blot and Bradford methods, and mass spectrometry, respectively. Besides, the effect of these residues on gastric and duodenal digestion of proteins was evaluated. The carbonylation induced by FQs affected both protein fractions being significant with respect to the blank in 73.3% of cases. This damage was correlated with loss of solubility and digestibility, with sarcoplasmic proteins the most affected. Danofloxacin and enrofloxacin were the FQs with greatest oxidant effects, especially affecting glycolysis and glycogen proteins. Our results suggest that these residues induce irreversible oxidative damage on the main beef proteins and could affect their nutritional value.
尽管氧化对人类健康的影响越来越受到关注，但肉类的主要成分蛋白质的氧化却很少受到关注。本文描述了五种氟喹诺酮类药物（FQs）在浓度接近最大残留限量（MRL）时对牛肉肌浆蛋白和肌原纤维蛋白羰基化的影响。样品分别用FQs处理，分别使用2,4-二硝基苯肼（DNPH）碱性测定法、蛋白质印迹法和 Bradford 法以及质谱法测定每个蛋白质组分中的羰基指数、蛋白质含量并鉴定氧化蛋白。此外，还评估了这些残留物对蛋白质胃消化和十二指肠消化的影响。FQs诱导的羰基化影响了两种蛋白质组分，在73.3%的情况下相对于空白具有显著性。这种损伤与溶解度和消化率的损失相关，肌浆蛋白受影响最大。达氟沙星和恩诺沙星是具有最大氧化作用的FQs，尤其影响糖酵解和糖原蛋白。我们的结果表明，这些残留物会对牛肉中的主要蛋白质造成不可逆的氧化损伤，并可能影响其营养价值。
