传统腌腊鱼中RCS生成及其对嗜盐菌的胁迫作用与机制

Lipid oxidation and microbial contamination are two key factors in the process of spoilage of the storage of dried aquatic products. Although there are a lot of studies on the mechanism and control of food deterioration by each of them, the interactions between the two factors have not been reported. The preliminary study on the traditional cured fish showed that the lipid oxidation products showed a certain stress on the halophilic bacteria, the dominant contaminating bacteria of the cured fish, but the specific mechanism has not been studied. In this study, reactive carbonyl species (RCS), an important process product of automatic oxidation of lipid, will be used as the representative lipid oxidative reactive substance; and halophilic bacteria with different RCS sensitivities will be used as the research object. Based on the analysis of RCS production pathways in traditional preserved cured fish products, typical RCS will be determined and their effects on the biofilm structure, ion channels and surface potential of halophilic bacteria will be studied. The effects of RCS on cell membrane lipoprotein and intracellular protein and nucleic acid structures will be analyzed by Raman spectroscopy and FT-IR technique, and the key reaction protein components will be analyzed by proteomics technique. Moreover, the effect of the introduction of free radical quenching agents on RCS production and the effect of RCS stress on halophilic bacteria will be studied. Through comprehensive analysis of the above resutls, the effects of RCS on halophilic bacteria and its mechanism will be elucidated. The results of the present study will provide scientific basis for enriching the theory of lipid oxidation and microbial control and coordination of fence factors in aquatic product processing and shelf stability.

脂肪氧化和微生物污染是引起干制水产食品加工贮藏过程变质的二个主要因素。目前对其单一致食品变质的机理已有大量研究，但对二者共同致食品变质及其相关性未曾报道。前期对腌腊鱼的研究中发现，脂类氧化产物对共存的优势嗜盐菌具有胁迫作用，但其具体作用及其机制仍有待进一步研究。鉴于此，本项目以油脂自动氧化的典型过程产物——羰基化合物（RCS）为代表性脂肪氧化活性物质，以不同RCS敏感性的嗜盐菌为研究对象，在解析腌腊鱼中RCS生成途径基础上，研究典型RCS对嗜盐菌生物膜结构、离子通道及表面电位等的影响，利用拉曼光谱和FT-IR技术分析其对细胞膜脂蛋白及胞内蛋白质和核酸等生物大分子结构的影响，并通过蛋白质组学技术进一步揭示其关键响应蛋白，同时比对分析自由基淬灭基引入对RCS胁迫嗜盐菌作用的影响，综合阐明RCS对嗜盐菌的胁迫作用及其机制。研究结果可丰富加工水产品贮藏与保鲜过程中脂质氧化和微生物控制理论基础。

脂肪氧化和微生物污染是引起干制水产食品加工贮藏过程变质的两个主要因素，但目前对其共同致食品变质及其相关性未见报道。针对此。本研究重点阐明了RCS对腌腊鱼中优势耐盐菌的胁迫作用及其机制，主要取得以下四个方面的研究成果：（1）通过分析腌腊鱼贮藏过程中RCS生成及其变化规律，揭示了HNE、MDA和HHE等典型RCS的生成途径及其与脂质氧化和产品品质指标的相关性；（2）通过分析贮藏期间菌群结构的变化与RCS的相关性，揭示了MDA和HHE是影响菌相变化的主要因素；（3）分析了RCS对耐盐菌形貌、胞内物质以及生物大分子结构的影响，并进一步通过代谢组学技术解析了RCS对微生物的胁迫机制；（4）通过将槲皮素应用于腌腊鱼的腌制过程中，探讨了槲皮素对自由基的清除能力以及对脂质氧化和微生物的作用效果。结果显示，RCS与腌腊鱼的品质变化密切相关，而且对腌腊鱼中的优势微生物具有抑制作用。此外，槲皮素对ABTS自由基的清除率均比相同浓度的抗坏血酸。研究结果丰富了加工水产品贮藏与保鲜过程中脂质氧化和微生物控制理论基础，对干腌水产品的脂质氧化控制提供了技术支撑。