Insight into the mechanisms of combining direct current magnetic field with phosphate in promoting emulsifying properties of myofibrillar protein.

This study investigated the combined effects of direct-current magnetic field (DC-MF, 9.5 mT) and tetrasodium-pyrophosphate (TSPP, 1-5 g/L) on emulsified gel properties of porcine myofibrillar protein (MP). Results showed that MP at DC-MF and 3 g/L TSPP had decreased spectrum intensity of UV and fluorescence compared to that without DC-MF, owing to the changes of MP tertiary structure caused by DC-MF, especially tryptophan and tyrosine. The emulsion treated with DC-MF behaved better emulsifying activity and stability than that without DC-MF under such condition. And emulsion had lower creaming index and better storage stability. Gels prepared by this MP emulsion had low porosity and stable structure, accompanying with smaller size and more uniform distribution of oil droplets. Microstructure images showed that gels were covered with microporous structure, which was conducive to the good WHC of the emulsified gels (97.12%). These results showed the feasibility of DC-MF and TSPP in improving MP emulsion/emulsified gel.

Effect of magnetic field mediated CaCl2 on the edible quality of low-sodium minced pork gels.

Magnetic field combined with calcium chloride (CaCl2,) treatment is a highly promising technique for reducing sodium chloride (NaCl) in meat. Therefore, this paper investigated the effect of reducing NaCl addition (0-10%) by CaCl2 in combination with a magnetic field (3.8 mT) on the edible quality of low-salt pork mince. It is desired to drive the application of magnetic field and CaCl2 in low-sodium meat processing in this way. Results showed that the cooking yield, color, hardness, elasticity, mouthfeel, apparent texture, and orderliness of protein conformation of all minced pork were improved as compared to the control group, while the electron nose response values of their volatile sulfides and nitrogen oxides were decreased. In particular, the best edible quality and perceived salty intensity of minced pork gel was obtained by using CaCl2 in place of 5% NaCl under magnetic field mediation. In addition, energy dispersive X-ray spectroscopy scans showed that the reduced NaCl treatment by magnetic field combined with CaCl2 could increase the signal intensity of sodium in minced pork matrices to some extent. Magnetic field-mediated substitution of NaCl for CaCl2 treatment was also found to be favorable for inducing the transition of the protein secondary structure from an irregularly coiled to a ß-folded structure (demonstrated by infrared spectroscopy). In short, magnetic fields combined with CaCl2 instead of NaCl was a highly promising method of producing low-NaCl meats.