本文运用风冷冷却与浸渍式冷冻两种方式对猪背长肌进行处理，使预冷12 h后，温度约为10 ℃的猪背长肌中心温度降为0~4 ℃（风冷冷却），-5 ℃与-18 ℃（浸渍式冷冻）。然后把0~4 ℃与-18 ℃的肉块放入相应温度的冰箱保藏，-5 ℃的肉块则分别放入-5 ℃（一段式）与-18 ℃（二段式）的冰箱保藏。并对四种保藏处理下的猪肉在一定贮藏期内（冷却肉7 d，浸渍冷冻肉7周）的导电率、保水性、滴水损失、蒸煮损失、质构特性、TVB-N、菌落总数、pH、色泽（L*、a*、b*）进行了对比研究。研究表明：浸渍式冷冻工艺中，二段式冷冻没有一段式冷冻品质好。浸渍式冷冻肉-18 ℃贮藏4周内的品质与冷却肉贮藏4 d内的品质相当。冷却肉在保水性、质构特性、色泽方面要优于浸渍式冷冻组，但在TVB-N、菌落总数方面则不如浸渍式冷冻肉。

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.

2011年国家自然科学基金资助项目(31171710)