Texture changes in frozen cod mince measured by low-field nuclear magnetic resonance spectroscopy

Studies were carried out on changes in water proton relaxation, Instron parameters, dimethylamine (DMA) content and sensory texture scores during storage of cod mince at -10°C, -20°C and -70°C. The longest transverse proton relaxation time measured by pulsed low-resolution nuclear magnetic resonance (NMR) spectroscopy increased with temperature and duration of frozen storage. These variations in the NMR parameter paralleled changes observed with analytical methods commonly used for evaluating fish texture, ie Instron measurements, as well as dimethylamine and sensory analyses. It is concluded that the NMR method can be an alternative tool to study textural modifications of cod during frozen storage.