Physico-chemical properties changes during the frozen storage of farmed Pseudosciaena crocea muscle after freezing by different methods

Farmed Pseudosciaena croceas were frozen either by pressure shift freezing (PSF) or by conventional air freezing (CAF) , and then stored at-20℃for 3 months.Results showed that:firstly, large and little ice crystals were formed during the CAF process and then irreversiable damage to muscle fibres were formed.On the other hand, smaller and more regular intracellular ice crystals were observed in samples frozen by PSF, especially during the PSF (205MPa) process.Secondly, these frozen by PSF didn't experience significant changes during the frozen storage, such as microstructure and the salt extractable protein.In the case of CAF muscle, content of salt extractable protein decreased significantly (p<0.05) during the frozen storage.Thirdly, springiness and chewiness of the muscle were improved significantly after freezing by PSF (p<0.05) .Therefore, PSF could serve as a promising technique for commercial quality enhancement of Pseudosciaena croceas.