加热温度对热诱导乳化凝胶形成过程中~1H分布状态及迁移规律的影响

The Effect of Heating Temperature on ~1H Distribution and Migration of Meat Batters during the Formation of Heat-induced Gelation

应用低场核磁共振技术(Low-Field NMR)研究肉糜体系中1H分布状态及迁移规律,并结合肉糜水分含量、离心失水率、颜色、p H变化分析加热温度对肉糜体系保水性及乳化凝胶品质的影响。结果表明,随着加热温度的上升,肉糜的水分含量逐渐降低,离心损失增加。同时,不易流动水的弛豫时间T22缩短,其所占的峰面积比也降低,而自由水的弛豫时间T23所占的峰面积比逐渐增加。相关性分析结果显示,弛豫时间T22的峰面积比与水分含量(r=0.755)呈极显著正相关(P<0.01),与弛豫时间T23的峰面积比(r=-0.990)、离心损失率(r=-0.798)、肉糜的亮度(L*)值(r=-0.597)和p H(r=-0.573)均呈极显著负相关(P<0.01)。这说明热诱导乳化凝胶形成过程中,蛋白质对结合水的束缚逐渐增强,部分结合水转化成自由水,乳化凝胶的保水性降低,同时伴有肉糜亮度和p H值升高。

Low-field nuclear magnetic resonance（LF-NMR） was applied to investigate the1 H distribution and migration in meat batters and the influence of heating temperature on the meat batter water holding capacity（WHC） and qualities of heat-induced emulsion gel was evaluated by the determination of the moisture content, centrifugal loss, color and p H change. The results showed that the moisture content was gradually decreased and the centrifugal loss was gradually increased with rising temperature. Simultaneously, the T22 relaxation time and its peak area fraction, which attribute to immobilised water decreased with increasing temperature, but the T23 water fraction which attribute to the amount of free water gradually increased. The result of correlation analysis indicated that there was a very positive significant（P〈0.01）correlation between the moisture content（r = 0.755） and the peak area fraction of T22, and a very negative significant（P〈0.01） correlation was found between the peak area fraction of T23（r =-0.990）, the centrifugal loss（r =-0.798）, the L＊value（r =-0.597）, p H（r =-0.573） and the peak area fraction of T22 respectively. With the formation of heat-induced emulsion gel, the water molecules combined with protein more tightly and parts of immobilized water turn into free water.Simultaneously, the water holding capacity of meat batters was decreased and the L＊value and p H was increased.