柠檬酸钙和大豆分离蛋白对大米淀粉质构分级的影响

目的 探究了柠檬酸钙和大豆分离蛋白对大米淀粉液体食品质构分级的影响机制。方法 本研究通过国际吞咽障碍饮食标准(International Dysphagia Diet StandardisationInitiative, IDDSI)质构测试、物性分析、快速黏度分析及扫描电镜等技术方法分析柠檬酸钙(0.1%、0.2%和0.3%)和大豆分离蛋白(5%、10%和15%)对大米淀粉质构分级的影响。结果 IDDSI质构测试结果表明，柠檬酸钙使大米淀粉质构等级呈上升趋势(0.3%时，由2级变为3级)，而大豆分离蛋白使大米淀粉质构等级呈下降趋势。物性分析(A/BE模式)结果表明，添加比例为0.3%的柠檬酸钙的淀粉样品黏度升高55.1%，添加比例为15%的大豆分离蛋白的淀粉样品黏度下降19.4%。快速黏度分析淀粉样品的终值黏度结果与物性分析的黏度结果趋势一致。粒径分析结果表明，柠檬酸钙提高了淀粉颗粒的尺寸，促进了淀粉颗粒的膨胀。大豆分离蛋白减小了淀粉颗粒的尺寸，抑制了淀粉颗粒的膨胀。红外光谱分析表明，钙盐和蛋白的添加量越大，淀粉分子之间的氢键数量减少的越明显。此外，通过扫描电镜观察到柠檬酸钙使淀粉的层状结构变得更紧密，而大豆分离蛋白破坏了淀粉的层状结构，使其出现明显的空腔结构。结论 两者对大米淀粉质构分级的影响机制不同，柠檬酸钙通过离子键增强了淀粉之间的相互作用，大豆分离蛋白通过空间位阻减弱了淀粉之间的相互作用。研究结果为大米淀粉液体食品的质构设计提供了理论依据。

Effects of calcium citrate and soy protein isolate on texture classification of rice starch

:Objective To explore the effects of calcium citrate and soy protein isolate on the texture classification of rice starch liquid food. Methods In this study, the effects of calcium citrate (0.1%, 0.2% and 0.3%) and soy protein isolate (5%, 10% and 15%) on the texture classification of rice starch were analyzed by means of IDDSI (International Dysphagia Diet StandardisationInitiative, IDDSI) texture test, texture profile analysis, rapid viscos analyzer and scanning electron microscope.Results The results of IDDSI texture test showed that calcium citrate increased the texture grade of rice starch (from grade 2 to grade 3 at 0.3%), but soy protein isolate decreased the texture grade. The results of texture profile analysis (A/BE mode) showed that the viscosity of starch samples with 0.3% calcium citrate increased by 55.1%, and that with 15% soy protein isolate decreased by 19.4%.The final viscosity results of the rapid viscos analyzer were consistent with those of the texture profile analysis.The results of particle size analysis showed that calcium citrate increased the size of starch particles and promoted the expansion of starch particles.Soybean protein isolate reduced the size of starch particles and inhibited the expansion of starch particles.The infrared spectrum analysis showed that the more calcium salt and protein were added, the more the number of hydrogen bonds between starch molecules decreased.In addition, it was observed by scanning electron microscope that calcium citrate made the starch layer structure tighter, but soy protein isolate destroyed the starch layer structure and made it appear obvious cavity structure.Conclusion The influence mechanism of the two on the texture grading of rice starch is different. Calcium citrate enhances the starch interaction through ionic bonding.Soy protein isolate weakened the starch interaction through steric hindrance. The results provided a theoretical basis for the texture design of rice starch liquid food.