School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China.
National Engineering Research Center of Seafood, Dalian, People's Republic of China.
J Sci Food Agric. 2020 Mar 30;100(5):1940-1948. doi: 10.1002/jsfa.10206. Epub 2020 Jan 21.
In this study, low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) were used to investigated the moisture migration of beef during refrigeration storage, and its relationships to some physicochemical quality indicators were analyzed using partial least squares regression.
Three water components ascribed to bound water, immobilized water and free water in beef matrix were revealed by LF-NMR relaxation results. The transverse relaxation time and peak area of immobilized water declined as storage proceeded, as a result of disruption to the microstructure revealed by scanning electron microscope images. MRI images found obvious water migration of beef during refrigeration storage, and scanning electron microscopy images revealed that the integrity of the muscle fiber bundle was destroyed. In addition, increased storage time also led to increases in pH, total volatile basic nitrogen, TBARS (thiobarbituric acid reactive substances) value, weight loss, cooking loss and b* value, and to decreases in water holding capacity (WHC), L* and a* values, and textural properties.
The strong correlations between water migration and the physicochemical quality changes suggested the possibility of LF-NMR as a rapid and non-invasive method to evaluate beef quality. © 2019 Society of Chemical Industry.
本研究采用低场核磁共振(LF-NMR)和磁共振成像(MRI)技术研究牛肉在冷藏过程中的水分迁移规律,并采用偏最小二乘回归分析水分迁移与部分理化质量指标的关系。
LF-NMR 弛豫结果表明,牛肉基质中存在结合水、束缚水和自由水三种水相。随着贮藏时间的延长,由于扫描电镜图像显示的微观结构受到破坏,束缚水的横向弛豫时间和峰面积减小。MRI 图像发现牛肉在冷藏过程中有明显的水分迁移,扫描电镜图像显示肌肉纤维束的完整性被破坏。此外,随着贮藏时间的延长,pH 值、总挥发性碱性氮、TBARS(硫代巴比妥酸反应物)值、失重率、蒸煮损失和 b值增加,而水分保持能力(WHC)、L和 a*值以及质构特性降低。
水分迁移与理化质量变化之间存在很强的相关性,这表明 LF-NMR 作为一种快速、非侵入性的牛肉质量评价方法具有一定的可行性。 © 2019 英国化学学会。