Abstract:Porcine longissimus muscle was processed by air-blast cooling and immersion-frozen to make its center temperature decreased from 10 ℃ to 0 - 4 ℃ (air-blast cooling), -5 ℃ and -18 ℃ (immersion-frozen) after 12 h. Then 0 ~ 4 ℃ and -18 ℃ chilling meats were preserved in the refrigerator with 0 ~ 4 ℃ and -18 ℃, while -5 ℃ processed meat was preserved in the -5 ℃ (one-stage frozen) and -18 ℃ (two-stage frozen) refrigerator respectively. Besides, a comparative study between these four preserved meats was carried out in terms of conductivity, water retention, drip loss, cooking loss, textural characteristics, TVB-N, the total number of colonies, pH and color (L*, a*, b*). The experimental result showed that: one-stage frozen meat had better quality than two-stage frozen one among immersion-frozen process. Immersion-frozen meat (-18 ℃) that stored for 4 weeks or less had the same quality with cooling meat which stored for 4 days or less. However, the water retention, texture features and color of cooling meat were superior to the immersion-frozen groups, but in aspects of TVB-N and the total number of colonies, it showed a reverse result.
