中文摘要：

采用浸渍冷冻（-35℃）与风冷冷冻（-35℃）两种方法,将猪背长肌中心温度从10℃分别降到-5℃与-18℃,再置于相应温度的冰箱里保藏。在1个月贮藏期间,测定解冻汁液流失率、蒸煮损失率与加压失水率,同时利用低场核磁共振技术（LF-NMR）测定弛豫性质变化（T2）,来反映贮藏期间猪肉持水力的变化,并探讨T2值与解冻汁液流失率、蒸煮损失率与加压失水率之间的相关性。结果表明：浸渍式冷冻肉块的各项指标均优于风冷式冷冻,在贮藏14 d之前,浸渍-5℃肉块的T21值（30～60 ms）、T22值（100～400 ms或200～500 ms）、解冻汁液流失率、蒸煮损失率与加压失水率都显著低于浸渍-18℃组,但贮藏14 d后反之。通过核磁共振技术测定出的T21值、T22值与蒸煮损失率、解冻汁液流失、加压失水率具有相同的变化趋势。

英文摘要：

With pig back long muscle as raw material, used impregnat- ed frozen（-35℃ ）and air-cooled refrigeration（-35℃ ）two methods to deal with pork back longus and make their center temperature from 10℃ to -5℃ and -18℃ respectively.then put into the corresponding temperature refrigerator for preservation. In order to discuss the changes of different freezing methods to pork water holding capacity and the re- lationship between T2 with the rate of thaw drip loss, cooking loss and pressing loss during storage time ,this study uses the rate of thaw drip loss, cooking loss and pressing loss these indicators to reflect the changes of water holding capacity of pork meat processed by different freezing methods,while adopts low-field NMR technology （LF-NMR） to determine T2 changes during storage.The results show that： all indicators of impregnated freezing method are better than air-cooled chiller＇s, the Tn values, T22 values, thaw drip loss, cooking loss rate and pressing loss of impregnated -5℃ meat were significantly lower than dipping -18℃ group before storing 14 days, but it shows a opposite result after storing 14days. T21 values and T22 values determined by nuclear magnetic reso- nance technology has the same trend with cooking loss rate, thaw drip loss and pressing loss.