软冷冻和臭氧处理对猪肉的保鲜效果比较

Comparative Effects of Soft Freezing and Ozone in Preserving the Freshness of Fresh Pork

为了提高肉类等食品在冰箱软冷冻条件下的贮藏效果,研究以新鲜猪肉为原料,设定软冷冻(-7℃)+臭氧组(Ⅰ)、软冷冻(-7℃)组(Ⅱ)、-18℃冷冻组(Ⅲ)3个低温保藏环境,通过测定pH值、菌落总数、挥发性盐基氮含量、新鲜度K值及感官评价比较分析猪肉新鲜度及品质变化。结果表明:-7℃软冷冻在21 d内可以保持肉的品质在一级鲜度,35 d保持在二级鲜度,有利于家庭应用;软冷冻结合臭氧可以将一级鲜度延长至45 d,降低pH值和菌落总数,且与-18℃冻藏相比能有效保持猪肉色泽,可以用于商品化生产。

As a new technology, soft freezing is a new concept proposed in the refrigeration industry in recent years. It can freeze food at -7℃, and the frozen food is easy to cut off in a short time for processing. In order to provide evidence for improving the quality of food stored in a refrigerator under soft freezing conditions, a comparative analysis of the changes in pH, total bacterial count, total volatile base nitrogen （TVB-N）, the freshness indicator K-value and sensory evaluation was carded out on fresh pork stored in three low-temperature environments, soft freezing at -7 ℃ plus ozone （ Ⅰ ）, soft freezing at -7 ℃ （ Ⅱ ） and -18℃ freezing （Ⅲ）. The results showed that pork freshness was maintained at the first level over the storage period of 21 d under soft freezing conditions, and at the second level up to 35 d, supporting the use of soft freezing in households. The first grade of freshness was prolonged to 45 d by combined use of soft freezing and ozone treatment through reducing the pH and total bacterial count, and the color was preserved better than under -18℃ freezing condition. Thus the combination of soft freezing and ozone has potential for commercial application.