Low-field NMR study of heat-induced gelation of pork myofibrillar proteins and its relationship with microstructural characteristics
Publication date: Available online 9 June 2014
Source:Food Research International
Author(s): Minyi Han , Peng Wang , Xinglian Xu , Guanghong Zhou
The changes of water mobility and fractal dimension (Df) during pork myofibrillar proteins (PMP) heat-induced gelation were investigated using low-field nuclear magnetic resonance (NMR) and image analysis, respectively. The NMR data were related to the gel microstructure which was explained as fractal dimension and pore size using principal component analysis (PCA). Distributed exponential analysis of the T2 relaxation revealed that three water components corresponding to the three water molecule states exist during the heat-induced gelation. A significant change of T2 was occurred when the temperature increased, T21 relaxation times decreased significantly from 403.70ms to 231.01ms with the temperature increasing from 50 to 70°C. The fraction of T21 distributions declined from 99.27% to 77.01% as the temperature increased from 40 to 60°C. Pronounced different gel network structure was observed during the myofibrillar proteins heat-induced gelation and different Df which was determined by box count method was found between all treatments although evidencing a narrow scale range (from 2.835 to 2.860). Good correlations were detected between the NMR T2 parameters and microstructural data. Overall, combined low-field NMR, image analysis and PCA provide powerful tools for elucidating the pork myofibrillar protein heat-induced gelation.
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