【作者】 于淼；

【导师】 邬应龙；

【作者基本信息】 四川农业大学 ， 食品科学， 2011， 硕士

【摘要】 本文以甘薯淀粉为研究原料,分别以三偏磷酸钠(STMP)及辛烯基琥珀酸酐(OSA)作为交联剂和酯化剂,对甘薯原淀粉进行双重复合改性,制备交联辛烯基琥珀酸甘薯淀粉酯(CLOSA-SPS),对CLOSA-SPS的制备工艺、物理化学性质进行研究,并对CLOSA-SPS的毒理学及对高脂血症大鼠血脂的调节功能进行研究,旨在得到兼具优良的性质及功能性强的甘薯改性淀粉,拓宽其在食品领域的应用范围,为甘薯改性淀粉的生产提供充分的理论依据。1.以结合磷的含量为指标,通过正交试验得到制备交联甘薯淀粉的最佳工艺条件为STMP的添加量为10%,交联反应pH值为11.5,交联反应时间为2.5h,交联反应温度为50℃,各因素的影响顺序为：交联反应STMP的添加量>交联反应时间>pH值>交联反应温度,最终结合磷含量能达到0.2%；然后以酯化取代度(DS)为指标,运用Design-expert7.0软件进行响应面设计及分析淀粉乳浓度、酯化反应pH值、酯化反应温度对CLOSA-SPS的DS的影响。DS的回归方程为：DS=0.014+(1.875E-004)×X1+(9.375E-004)×X2+(3.750E-004)×X3-(6.000E-004)×X1X2 +(7.750E-004)×X1X3+(6.750E-004)×X2X3-(6.500E-004)×X12-(1.800E-003)×X22-(3.750 E-004)xX32。各因素的影响顺序为：酯化剂pH值>酯化温度>淀粉乳浓度。通过响应面分析得到制备CLOSA-SPS的最佳条件为：酯化pH值为8.28,酯化温度40℃,淀粉乳浓度为40%,最终得到的DS为0.015。2.对制得的CLOSA-SPS的物理化学性质进行了进一步的研究,结果表明：①通过红外光谱图可看出,甘薯淀粉经过交联及OSA酯化复合改性后淀粉分子结构上引入了新的官能团,在1723.97,1599.01cm-1处出现了新的特征峰,其中1723.97cm-1处的特征峰表明酯羰基的存在,此外OSA酯化反应是在微碱性的条件下进行的,因此1599.01cm-1处出现的特征是缘于RCOO的不对称伸缩振动；②经过交联及OSA酯化双重复合改性后的甘薯淀粉较原淀粉及单一交联淀粉的峰值黏度、热糊及冷湖黏度都升高,起糊温度降低,具备更好的糊液稳定性；③LOSA-SPS的透明度、凝沉性、乳化性及冻融稳定性较原淀粉及交联淀粉都有明显的改善；④经过交联及OSA酯化后,甘薯改性淀粉的消化性能降低,SDS及RS的含量明显增加,淀粉糊化后经体外消化试验测定甘薯原淀粉RDS约为94%、SDS及RS约为2%、4%；一定条件下的CLOSA-SPS RDS约为76%、SDS及RS约为4%、20%。3.对CLOSA-SPS的毒理学研究及调节血脂功能进行了研究,结果表明CLOSA-SPS是安全无毒的,且对高脂血症大鼠具有降低胆固醇(TC)、甘油三脂(TG)及低密度脂蛋白胆固醇(LDL-C),增加高密度脂蛋白胆固醇(HDL-C)并改善肝脏脂肪变性的功能。更多还原

【Abstract】 Preparing cross-linked octenyl succinic anhydride sweet-potato modified starch(CLOSA-SPS) were used sweet-potato starch as material, sodium trimetaphosphate(STMP) as cross-linking agent, octenyl succinic anhydride(OSA) as esterifying agent in this paper. First of all, preparation technology, physical-chemical properties were investigated. Then the toxicological safety assessment and regulatory effect on blood lipid level of CLOSA-SPS in hyperlipidemia rats were studied. It was in order to get having the good properties and functionality of the sweet-potato modified starch, widen the application of CLOSA-SPS in the food field and provide abundant theory for the sweet-potato modified starch of practice.1.The bound phosphours were concerned, the optimum conditions of preparing the cross-linked sweet potato starch by orthogonal experiment optimization were:the mount of STMP 10%, cross-linking reaction pH 11.5, cross-linking reaction time 2.5h,cross-linking reaction temperature 50℃. The order of factors which influenced on the bound phosphours was:the mount of STMP> time>cross-linking reaction pH> temperature. Finally, the content of STMP was 0.2%.Then degree of substitution (DS) as indexes, Use Design-expert7.0 response surface design and analysis method to study the influence on DS of starch slurry mass fraction, esterifying reaction pH, esterifying reaction temperature. The regression equation of DS is: DS=0.014+(1.875E-004)*Xi+(9.375E-004)*X2+(3.750E-004)*X3-(6.000E-004)*X1X2+ (7.750E-004)*X1X3+(6.750E-004)*X2X3-(6.500E-004)*X12-(1.800E-003)*X22-(3.750E-004)*X32. The order of each factors which influenced on DS is:esterifying reaction pH> esterifying reaction temperature> starch slurry mass fraction. The optimum conditions of preparing the CLOSA-SPS by response surface analysis method:starch slurry mass fraction 40%,esterifying reaction pH 8.28, esterifying reaction temperature40℃.At last, degree of substitution was 0.015.2.The physical-chemical properties of CLOSA-SPS were investigated. The results showed that:①FTIR spectra showed that cross-linking and OSA esterification dual modified sweet-potato starch obtained new chemical group, which appeared new characteristic peaks at 1723.97cm-1 and 1599.01cm-1. This peak of at 1723.97cm-1 corresponded to the characteristic IR stretching vibration of C= O, which suggested the formation of ester carbonyl groups. Another new peak appeared at 1599.01cm,which was ascribed to the asymmetric stretching vibration of carboxylate (RCOO-);②Compared with the unmodified sweet-potato starch and cross-linking sweet-potato starch, the peak viscocity, thermal paste viscosity and final viscosity of CLOSA-SPS were increased, gelatinization temperature were advanced, paste properties has a better solution stability;③Compared with the unmodified sweet-potato starch and cross-linking sweet-potato starch,dual modified sweet-potato starch improved transmittancy, retrogradation stability, emulsifying stability, freeze-thaw stability;④ross-linking and esterification dual modification can decrease the digestibility of sweet-potato starch and increase the content of SDS and RS. Gelatinized starch measured in vitro digestibility of raw potato starch, RDS was 94%, SDS was 2%, RS was 4%, The certain conditions of CLOSA-SPS, RDS was 76%, SDS was 4%, RS was20%.3.The the toxicological safety assessment and regulation of blood lipids function of CLOSA-SPS were studied, the results showed that the CLOSA-SPS was safe and nontoxic, and it had lower cholesterol (TC), triglyceride (TG) and low Density lipoprotein cholesterol (LDL-C), increase high-density lipoprotein cholesterol (HDL-C) in hyperlipidemia rats and improve the function of liver steatosis.更多还原