【作者】 李莹；

【导师】 马莺；

【作者基本信息】 哈尔滨工业大学 ， 生物化工， 2007， 硕士

【摘要】 多孔淀粉是一种新型变性淀粉,作为吸附剂,具有高效、无毒、安全、可生物降解等优点,可广泛应用于食品、药品、日用化工、农业等行业,正逐渐成为一个研究热点。本论文以玉米淀粉为原料,主要研究了玉米多孔淀粉的制备、交联改性、形成过程中各种性质变化及其应用。以玉米多孔淀粉的吸油率和玉米原淀粉的水解率为指标,研究了各工艺条件对玉米多孔淀粉性能的影响,在单因素试验的基础上进行正交实验,得到最佳工艺参数为:酶配比α-淀粉酶:葡萄糖淀粉酶为2:1(w:w),复合酶用量为2.4%,反应温度50℃,体系pH值为6.0,反应时间为24h。该条件下制得的玉米多孔淀粉水解率为50.32%,吸油率为59.61%,吸附性能优越。为了提高玉米多孔淀粉的稳定性,扩大其应用范围,选用POCl3(三氯氧磷)为交联剂,以沉降体积为评价指标,考察交联过程各工艺条件对交联效果的影响,得到交联多孔淀粉最佳工艺参数为:体系pH值为11,反应底物浓度为70%,交联剂用量为1%(占淀粉干基),温度40℃,反应时间120min ,该条件下制得的交联玉米多孔淀粉的沉降体积为1.15ml。研究了玉米多孔淀粉、交联玉米多孔淀粉的物理性质参数,结果表明:淀粉开孔后,比容积、透光率、溶解度增加;吸油率和吸水率约为玉米原淀粉的2.4倍,比表面积是原淀粉的2.5倍左右,孔容约为5.5×10-3cc/g。Brabender粘度分析表明,玉米多孔淀粉的糊化温度和糊粘度稳定性比原淀粉低,交联改性后结构增强,糊化温度升高,淀粉糊稳定性增强。电镜观察玉米多孔淀粉的微观结构表明开孔后淀粉颗粒上形成从表面至中心的直径在0.75μm~1.5μm的孔洞。针对多交联多孔淀粉优良的吸附缓释性能,实验以亚甲基兰为模型药物进行交联玉米多孔淀粉包载小分子药物的研究,以紫外分光光度法为检测手段,结果表明交联玉米多孔淀粉的载药量达到29.5mg/g,包封率达到68%,具有良好的载药性能。将冻干的包载有亚甲基兰的玉米多孔淀粉置于人工胃液、人工肠液环境中考察其体外释放性能,结果表明,交联玉米多孔淀粉相对于原淀粉缓释和控释效果明显提高。更多还原

【Abstract】 Porous starch, a new type of modified starch, has various advantages as a kind of absorbent with high efficiency, innocuity, safety and biodegradability. It can be widely used in many industries, including food, medicine, commodity and agriculture, and is becoming a study hotpot. This paper mainly focused on the production process, characteristics and applications of porous starch and cross-linked porous starch which was made from corn starch.During the production process of porous starch, oil absorption ratio of porous starch and degree of the corn starch hydrolysised were use as the index to evaluate the porous starch. Based on single factors and orthogonal experiment designed, optional conditions of porous starch production were obtained: the ratio of alpha-amylase: glucoamylase is 2:1(w:w), the content of enzymes added is 2.4%, reaction temperature is 50℃, pH is 6.0 and the reaction time is 24h. The oil absorption of porous corn starch is 50.23% and the hydrolysis degree of corn starch is 50.23% under this condition. In order to enhance the porous stach’s stability, the porous starch was further modified by being cross-linked with POCl3. Settling volume was used as the index to evaluate the cross-linking degree. Finally, we obtained the best reaction conditions: pH is 11, the starch concentration is 70%, 1% (starch weight) POCl3, reaction temperature is 40℃, and the reaction time is 120 min. The settling volume of the cross-linked porous corn starch obtained under this condition is 1.15ml. The physicial properties of porous corn starch and cross-linked porous corn starch were determined. Compared with the native starch, the penetration and solubility increased, the oil absorption and water absorption ratio were 2.4 times of the native corn starch, the surface area were about 2.5 times of the native corn starch and the pore volume is about 5.5×10-3cc/g. The Brabender viscosimeter analysis indicated that: the gelatinization temperature and the stability were lower after enzyme hydrolysis, but after cross-linking these values of porous starch were heightened. The SEM photographes showed that there were many pores on the surface of the starch granule and the diameters were 0.75μm ~1.5μm. For cross-linked porous corn starch was always used as the adsorption and protection medium. The drug loading properties were studied by use methylene blue as the model drug and the quantity of loaring drug, encapsulate efficiency used as the evaluate index. The quantity of loaring drug can reach 29.5mg/g and the encapsulate efficiency reach 68% after. Putting the dry drug loaded cross-linked porous corn strach in artificial gastric fluid and artificial intestinal fluid, the cross-linked porous corn strach show the markedable sustained release properities compared to the native corn starch.更多还原