A nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) system with a 45 mm variable temperature (VT) sample probe (VT-NMR-MRI) was developed as an innovative technique for in situ monitoring of food phase transition. The system was designed to allow for dual deployment in either a freezing (−37 °C) or high temperature (150 °C) environment. The major breakthrough of the developed VT-NMR-MRI system is that it is able to measure the water states simultaneously in situ during food processing. The performance of the VT-NMR-MRI system was evaluated by measuring the phase transition for salmon flesh and hen egg samples. The NMR relaxometry results demonstrated that the freezing point of salmon flesh was −8.08 °C, and the salmon flesh denaturation temperature was 42.16 °C. The protein denaturation of egg was 70.61 °C, and the protein denaturation occurred at 24.12 min. Meanwhile, the use of MRI in phase transition of food was also investigated to gain internal structural information. All these results showed that the VT-NMR-MRI system provided an effective means for in situ monitoring of phase transition in food processing.

中文翻译：

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可变温度核磁共振和磁共振成像系统作为食品相变原位监测的新技术

开发了具有45毫米可变温度（VT）样品探针（VT-NMR-MRI）的核磁共振（NMR）和磁共振成像（MRI）系统，这是一种用于食品相变原位监测的创新技术。该系统的设计允许在冰冻（-37°C）或高温（150°C）的环境中双重部署。所开发的VT-NMR-MRI系统的主要突破在于它能够在食品加工过程中同时现场测量水的状态。通过测量鲑鱼肉和鸡蛋样品的相变来评估VT-NMR-MRI系统的性能。NMR弛豫测定结果表明，鲑鱼肉的凝固点为-8.08℃，鲑鱼肉的变性温度为42.16℃。鸡蛋的蛋白质变性为70.61°C，蛋白质变性发生在24.12分钟。同时，还研究了在食物的相变中使用MRI的方法，以获取内部结构信息。所有这些结果表明，VT-NMR-MRI系统为现场监控食品加工中的相变提供了有效的手段。