Bigeye tuna (Thunnus obesus) is an important fish species worldwide due to its desirable flavour and rich nutrition. Cold chain logistics is one of the most common methods to store and sell bigeye tuna (Thunnus obesus). The purpose of this study was to investigate how bigeye tuna (T. obesus) deteriorate during simulated cold chain logistics with fluctuating temperatures by monitoring the quality changes and water distribution. The physical and chemical results showed that the sensory score, texture profile analysis (TPA), and water holding capacity (WHC) decreased, while total volatile basic nitrogen (TVB-N), K value, aerobic plate counts (APC), and psychrotrophic bacterial counts increased with fluctuating temperatures during 132 h. Low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) detection showed that the T21 (trapped water) and proton density decreased, while T22 (free water) decreased initially and then increased, indicating continuous water loss and water migration during storage. Principal component analysis (PCA) revealed that springiness, hardness, chewiness, T21, and sensory score were correlated with each other (p < 0.05) and the linear combination of quality indicators and T2 transverse relaxation time was established. Besides, temperature fluctuation (batch 3) accelerated the deterioration of bigeye tuna according to the comprehensive score of PCA. Results were based on LF-NMR which can be used to monitor quality changes in a fast non-invasive manner.

中文翻译：

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一种利用低场核磁共振结合PCA在模拟冷链物流过程中定量监测大眼金枪鱼（Thunnus obesus）质量变化和水分迁移的无创方法

大眼金枪鱼（Thunnus obesus）因其美味的味道和丰富的营养而成为世界范围内的重要鱼类。冷链物流是储存和销售大眼金枪鱼（Thunnus obesus）最常见的方法之一。本研究的目的是通过监测质量变化和水分布，研究大眼金枪鱼 (T. obesus) 在温度波动的模拟冷链物流过程中如何变质。理化结果显示，感官评分、质地剖面分析（TPA）和持水能力（WHC）下降，而总挥发性碱性氮（TVB-N）、K值、需氧菌落数（APC）和嗜冷菌细菌数量在 132 小时内随着温度的波动而增加。低场核磁共振（LF-NMR）和磁共振成像（MRI）检测显示T21（俘获水）和质子密度降低，而T22（游离水）先降低后升高，表明持续失水和水存储期间迁移。主成分分析 (PCA) 显示弹性、硬度、咀嚼性、T21 和感官评分相互关联 (p < 0.05)，并建立了质量指标和 T2 横向松弛时间的线性组合。此外，根据PCA的综合评分，温度波动（第3批）加速了大眼金枪鱼的变质。结果基于 LF-NMR，可用于以快速非侵入性方式监测质量变化。而T22（游离水）先下降后上升，表明贮藏过程中水分不断流失和水分迁移。主成分分析 (PCA) 显示弹性、硬度、咀嚼性、T21 和感官评分相互关联 (p < 0.05)，并建立了质量指标和 T2 横向松弛时间的线性组合。此外，根据PCA的综合评分，温度波动（第3批）加速了大眼金枪鱼的变质。结果基于 LF-NMR，可用于以快速非侵入性方式监测质量变化。而T22（游离水）先下降后上升，表明贮藏过程中水分不断流失和水分迁移。主成分分析 (PCA) 显示弹性、硬度、咀嚼性、T21 和感官评分相互关联 (p < 0.05)，并建立了质量指标和 T2 横向松弛时间的线性组合。此外，根据PCA的综合评分，温度波动（第3批）加速了大眼金枪鱼的变质。结果基于 LF-NMR，可用于以快速非侵入性方式监测质量变化。和感官评分相互关联（p < 0.05），并建立质量指标与 T2 横向弛豫时间的线性组合。此外，根据PCA的综合评分，温度波动（第3批）加速了大眼金枪鱼的变质。结果基于 LF-NMR，可用于以快速非侵入性方式监测质量变化。和感官评分相互关联（p < 0.05），并建立质量指标与 T2 横向弛豫时间的线性组合。此外，根据PCA的综合评分，温度波动（第3批）加速了大眼金枪鱼的变质。结果基于 LF-NMR，可用于以快速非侵入性方式监测质量变化。