交联酯化机械活化玉米复合变性淀粉的制备及其性能研究

以机械活化玉米淀粉为原料,三偏磷酸钠为交联剂,醋酸酐为醋化剂进行复合变性,制备机械活化玉米交联酯化复合变性淀粉,考察反应温度、交联剂用量、交联pH值、交联时间、酯化剂用量、酯化pH值、酯化时间等因素对交联酯化淀粉糊冷黏度的影响,与原玉米淀粉合成的交联酯化淀粉进行比较,研究了产物的理化特性,并利用红外光谱、X射线衍射对产物的结构进行表征分析。结果表明:各因素对机械活化玉米淀粉的交联酯化反应均有影响。对于机械活化1.0 h的玉米淀粉,在反应温度40℃、三偏磷酸钠1.0%、交联pH值10.0、交联时间2.0 h、醋酸酐用量0.5 mL、酯化pH值9.0、酯化时间60 min的条件下,所制备的机械活化玉米交联酯化淀粉糊的冷黏度由活化淀粉的466 mPa.s提高到1 629 mPa.s,淀粉糊液黏度的稳定性、抗酸性、抗老化性明显提高。红外光谱和X射线衍射图谱显示,淀粉经过交联酯化复合变性处理后,分子结构上引入新的化学基团,交联酯化淀粉属于V型结晶。

Preparation and Properties of Cross-linking and Esterifying Pregelatinization Starch of Mechanical Activated Maize Starch

Cross-linking and esterifying starch of mechanical activated maize starch was prepared by mechanical activated maize starch as raw material,and sodium trimetaphosophate as cross-linking agent and acetic anhydride in acetification.The effects of reaction temperature,cross-linking agent and esterifying agent dosage,pH value and cross-linking time on the cold viscosity of cross-linking and esterifying starch paste were investigated.The physical and chemical parameters of the cross-linking and esterifying starch of mechanical activated maize starch and cross-linking and esterifying starch of raw maize starch were studied.The structure of cross-linking and esterifying of mechanical activated maize starch were characterized by using Fourier transform infrared spectrogram(FTIR) and X-ray diffraction(XRD).The results indicated that the reaction conditions affected the preparation of cross-linking and esterifying mechanical activated maize starch.Under reaction temperature 40℃,1.0% amounts of natrium trimetpahophate,crosslinking pH at 10.0,crosslinking time 2.0 h,0.5 mL acetic anhydride amount,esterifying pH value 9.0,esterifying time 60 min,the cold viscosity of cross-linking and esterifying starch paste was enhanced from 446 mpa.s to 1 629 mPa·s.The stability,acidity-resistance,staling resistance of the viscosity of cross-linking and esterifying starch paste were significantly improved.FTIR and XRD spectra indicated that after dual-modification treatment,new chemical group was introduced,and type crystal starch was formed.