The basic Research and Application of Gelation Mechanism of Food Macromolecules under High Pressure

1.明胶：明胶凝胶的熔化温度（Tm）的压力依赖性进行了研究，在压力区域高达3000大气压。(dTm/dO）为（3-4）× 10^<-3>K cm ^2/kg，与明胶浓度无关。凝胶化的体积变化是负的，尽管由于聚合物链的脱水，通常伴随着卷曲-螺旋转变的体积增加。这一结果表明，在凝胶的浮渣连接处存在聚合物-水-聚合物氢键.琼脂糖：（dTm/dP）为2.3 x 10^<-3>K cm ^2/gk。凝胶体积变化仍为负值，但与明胶相比，其值很小。负体积变化也不能用简单的高分子-高分子氢键机理来解释，与卡拉胶凝胶不同.牛奶酪蛋白：在P &lt; 1500 atm时，酶处理的酪蛋白胶束发生解离，但压力升高反而促进胶束的缔合。这一结果与P &lt;1500时压力对凝乳的抑制作用相一致。这一结果为进一步了解凝胶化机理提供了有用的信息，也可用于食品工业中食品大分子凝胶形成能力的调控。

1. GELATIN: The pressure dependence of melting temperature (Tm) of gelatin gel was studied under pressure region up to 3000 atm. (dTm/dO) was (3-4) x 10^<-3> K cm^2/kg independent of gelatin concentration. The volume change on gelation was negative although a coil-helix transition generally accompanies the volume increase due to dehydration of polymer chains. This result suggests that there are some polymer-water-polymer hydrogen briges in the dross-link junctions of gel.2. AGAROSE: (dTm/dP) was 2.3 x 10^<-3> K cm^2/gk. The volume change on gelation was still negative but its value was very small as compared with that of gelatin. The negative volume change also can not explained by a simple polymer-polymer hydrogen bond mechanism, different from carrageenan gels.3. MILK CASEIN: Micelle of enzyme-treated caseins was dissociated with under P < 1500 atm, but higher pressure oppositely enhanced the association of micelle. This result consists with the observation that the milk curdlink is depressed by pressure under P < 1500.These results indicate that high pressure would pressent useful informations for understanding the gelation mechanism and also be applicable for regulation of gel-forming ability of food macromolecules in the food industry.