低场核磁共振技术研究超高压处理对乳化肠质构和水分分布的影响

Texture properties and water distribution analysis in emulsion type sausages by different high pressure processing supported by low-field NMR technology

目的:通过对高压结合热处理的乳化肠质构及其复合热凝胶体系中水分子状态分布的相关性研究,从水分子弛豫特性变化的角度揭示高压处理改善乳化肠质构特性的原因。方法:以低温乳化香肠为实验材料,研究不同压力处理组乳化肠的硬度和剪切功、水分子T2弛豫特性以及各指标之间的相关性。结果:与未高压组相比,随着压力增大,高压乳化肠硬度先增加后减小,而剪切功持续减小;低场核磁工作(NMR)T2弛豫测定结果表明高压处理对凝胶体系中不易流动水(T23)的影响最大,随着作用压力增大该状态水分子不仅含量增加,而且与肌原纤维蛋白的结合程度增强(p<0.05);相关性分析显示,香肠硬度与T22和T23的峰面积百分数显著相关,而剪切功与T21、T22和T23的弛豫时间显著相关。结论:超高压处理可以显著影响乳化肠硬度,降低剪切功,且硬度与弛豫峰面积百分数显著相关,剪切功与弛豫时间显著相关。

Objective： To study the texture properties of combined processes of high pressure treated sausages and discuss its relevance to the water distribution. Methods： Samples were sausages in low - temperature treated by high pressure processing. Firmness, work of shear, water distribution data and their relationship were analysised. Results： Firstly, compared with the control group, with the increasing of high pressure processing, firmness significantly increased and then decreased （p 〈0.05） ,while shear of work significantly decreased （p〈0.05）. Secondly.the results of the NMR T2 relaxation data showed that high pressure processing had a significant effect on immobilized water（T 23） of gels. With the increasing of high pressure processing, the content of immobilized water increased and its levels of combined with myofibrillar were increasing as well. Thirdly ,a significant correlation was found between the firmness and the peak area fraction of T 22 and T 23 respectively. Besides, the relationship between shear of work and T2 relaxation time of T21, T 22 and T 23 respectively was observed as we. Conclusions： It showed that high pressure processing could make contribution to the firmness and decrease the work of shear of the sausages. In addition, there was a significant correlation between the firmness and the peak area fraction, the work of shear and T2 relaxation data, respectively.