Abstract
The effect of seven different thawing methods (atmospheric temperature thawing (AT), microwave thawing (MT), microwave magnetic nanoparticles thawing (MMT), microwave vacuum thawing (MVT), far-infrared thawing (FT), far-infrared magnetic nanoparticles thawing (FMT) and far-infrared ultrasonic thawing (FUT)) on water holding capacity, water mobility and microstructure of frozen pork was examined. The results showed that the thawing loss (1.5 %), cooking loss (22.5 %), and centrifugal loss (20.8 %) of MVT treatment were lower than those of other methods. Low field nuclear magnetism (LF-NMR) and magnetic resonance imaging (MRI) results showed that in MVT and FUT treatment, the proportion of bound and immobilized water increased, while free water decreased. The microstructure of frozen pork was significantly improved by microwave or far-infrared thawing assisted by magnetic nanoparticles, having a more compact and granular microstructure. In summary, MVT might be a favorable method to improve thawing meat quality and had broad potential applications in thawing meat processing.