海藻酸钠结合超低温冷冻处理对甘薯淀粉颗粒结构和性质的影响

为改善甘薯淀粉耐低温、耐热和抗剪切稳定性,通过测定甘薯淀粉颗粒的粒度分布、观察微观结构并测定结晶特性、热力学特性以及糊化特性,研究不同冷冻温度和添加海藻酸钠处理对甘薯淀粉颗粒尺寸、结晶结构、表面结构、糊化性质和热性质的影响.结果表明,冷冻温度由-20℃降至-80℃时,甘薯淀粉颗粒粒径减小,淀粉颗粒表面由数量少的大孔洞转...     

超声波辅助韧化改性甘薯淀粉的结构及理化特性

为研究超声波辅助韧化对甘薯淀粉特性的影响，在其韧化处理不同阶段施加超声波，并对其表观直链淀粉含量、相对分子质量、支链淀粉链长分布、淀粉颗粒形态、结晶结构、糊化、流变、凝胶性质等理化特性进行表征。结果表明，在韧化处理中施加超声波对支链淀粉侧链分布和淀粉颗粒形态特征无显著影响；超声波辅助韧化在一定程度上改变了甘薯淀粉的结晶结构，韧化中间阶段施加超声波使其相对结晶度从31.98%减少至25.71%；与单独韧化相比，超声波辅助韧化使甘薯淀粉具有更高的回升值（1220 cp）和更低的崩解值（1594 cp），同时使甘薯淀粉凝胶的G″与G′值升高，大幅提高了甘薯淀粉凝胶的弹性和黏性；超声波辅助韧化使甘薯淀粉的凝胶硬度、胶黏性和咀嚼性增加。     

压热法制备黑青稞抗性淀粉工艺及性质研究

为探讨黑青稞淀粉在压热改性为抗性淀粉过程中淀粉乳浓度、压热温度、压热时间、冷藏时间等因素对抗性淀粉得率、结构及性质的影响,开发黑青稞抗性淀粉在食品加工中的应用价值。该试验以黑青稞为材料,采用压热法制备抗性淀粉,考察淀粉乳浓度、压热温度、压热时间、冷藏时间对抗性淀粉得率的影响。通过红外光谱分析、扫描电子显微镜及X-射线衍射对抗性淀粉的结构表征,并对部分理化性质进行测定。结果表明,当淀粉乳浓度30%,压热温度125℃,压热时间50 min,冷藏时间24 h时,抗性淀粉的得率为黑青稞抗性淀粉的得率为10.596%。扫描电镜分析表明,与原淀粉相比,黑青稞抗性淀粉的形貌及结晶结构都发生了显著变化,黑青稞原淀粉颗粒呈圆球形,而抗性淀粉呈层片形。X-射线衍射分析表明,淀粉的晶体结构由此前的A型晶体结构转变为抗性淀粉的C型晶体结构。理化性质测试表明,经过压热法制得的黑青稞抗性淀粉溶解度、膨胀度、透光率均降低,持水率升高,且抗性淀粉颗粒粒径变大,结构更加紧密,但化学结构未发生改变。     

不同热处理下橡子淀粉理化性质和体外消化性分析

该研究系统比较了干热、预糊化、湿热处理后橡子淀粉理化性质和体外消化特性,结果表明：橡子淀粉表面光滑,主要为椭圆形、球形和不规则形状,粒径分布范围为0.42~26.30 μm,糊化温度为76.75 ℃,干热处理使水分子迁移和脱除,未涉及明确的淀粉糊化与回生,对橡子淀粉的颗粒形状、粒径大小、糊化温度和A型晶体结构等理化指标亦无显著影响;预糊化处理、湿热处理改变了原淀粉的颗粒结构和结晶类型,增大了淀粉颗粒尺寸,粒径分布范围为1.26~416.87 μm,淀粉颗粒变为不规则形状,表面粗糙,糊化温度降为50.17 ℃,ΔH、To、Tp、Tc、冻融稳定性显著降低（P<0.05）;橡子淀粉体外消化速率大小顺序为：干热处理>对照组>湿热处理>预糊化处理,抗性淀粉（RS）含量与之相反,预糊化处理RS含量最高,为38.21%,干热处理RS含量最低,为16.15%。本研究为橡子淀粉的深加工提供一定参考依据,有利于高品质橡子淀粉制品的开发。     

甘薯淀粉性质的研究

研究了甘薯淀粉的理化性质,结果表明:其颗粒粒径的平均值为5~31mm,结晶结构属C型,直链淀粉含量18.5%,糊化温度为60.8~78.5℃。甘薯淀粉的透明度为42%,凝胶强度为98g。     

淀粉型甘薯RS3制备工艺及体外抗消化特性

以淀粉型甘薯为原料,利用单因素试验研究不同淀粉乳质量浓度、pH值、压热温度、压热时间及冷却回生时间对甘薯三型抗性淀粉（resistant starch type 3,RS3）得率的影响,并通过响应面设计优化制备工艺。结果显示,响应面试验得出的最优制备条件为淀粉乳浓度13%、pH5.5、压热温度110℃、压热时间35 min,此时RS3得率为37.94%,与预测值仅相差0.92%,响应面模型与实际情况拟合良好。甘薯抗性淀粉RS3的体外抗消化特性研究表明,RS3的酶解率和模拟消化道的消化率低,展示很强的抗酶解、抗消化特性。电镜结果显示,RS3颗粒呈不规则块状,表面凹凸不平;结晶型以B型为主,颗粒有序度降低,双螺旋程度和结晶度提高,与原淀粉相比结构更加紧密,这些结构特性可以解释甘薯RS3的抗消化特性。     

甘薯抗性淀粉理化特性研究

选择3个不同类型甘薯品种,以提取获得的抗性淀粉为研究对象,通过X-射线衍射分析仪、差示扫描量热分析仪(DSC)、快速黏度测定仪(RVA)、紫外-可见吸收光谱仪、近红外光谱分析仪(NIRS)和扫描电镜等仪器分别对甘薯原淀粉和其对应抗性淀粉晶体结构类型、熔融温度、淀粉糊化特性、平均聚合度和淀粉分子结构等理化特性深入研究与分析。结果表明,不同甘薯品种间抗性淀粉熔融温度具一定差异,抗性淀粉与其原淀粉间糊化特性、晶体结构等特性呈明显差异。     

韧化处理对甘薯淀粉分子结构的影响

采用颗粒形貌观察、红外光谱扫描、淀粉粒度分析等方法研究了不同韧化时间、韧化温度和含水量等韧化作用条件对甘薯淀粉分子结构的影响。结果表明,韧化处理后的甘薯淀粉颗粒边缘有明显破损现象,颗粒表面结构发生了改变。不同韧化温度处理后,甘薯淀粉颗粒中位径、小颗粒淀粉体积分数和红外结晶指数随着韧化处理温度的升高而显著增加,处理温度50℃时,中位径增加了0.1μm,红外结晶指数由1.44增加到了1.75。不同韧化时间处理后,淀粉颗粒中位径随着韧化时间的延长而略有增加,红外结晶指数相比原淀粉增加了26.39%。不同水分含量韧化处理后,淀粉颗粒中位径没有显著变化,水分含量在85%时红外结晶指数由原来的1.44升高为1.79。韧化处理导致甘薯淀粉颗粒平均粒径、结晶度增加,这对增加食品中慢消化淀粉比例,提高食品营养品质具有重要的意义。     

紫薯淀粉理化性质的研究

以制得的紫薯淀粉为原料,研究了紫薯淀粉的化学组分、颗粒表面结构、结晶结构、凝胶质构、热力学性质和流变学特性,并与马铃薯淀粉、玉米淀粉和甘薯淀粉进行比较.结果显示:干基紫薯淀粉含量为98.78％,直链淀粉含量为19.74％;其淀粉颗粒平均粒径为17μm,属中粒淀粉,晶型为C型;淀粉凝胶弹性和咀嚼性高,硬度适中,为3.095×102 g,黏着性适中,为24.72 g·s;糊化温度范围为61.5℃到78.0℃,峰值温度为72.6℃;紫薯淀粉糊为有屈服应力的非牛顿型流体.     

物理协同酶法处理对青稞淀粉结构的影响

为研究物理协同酶法处理对青稞淀粉结构特性的影响,采用超声、压热协同普鲁兰酶对青稞淀粉进行处理,测定了处理后样品的颗粒形貌、晶体结构、官能团结构、粒径大小。试验结果表明,处理可以提高抗性淀粉和直链淀粉含量,降低支链淀粉的含量。改性处理使青稞淀粉颗粒的原始结构遭到了严重破坏,呈现出团状结构,表面粗糙,布满褶皱、裂纹和孔洞;淀粉的偏光十字消失。改性后的青稞淀粉表面积平均粒径增大,大颗粒数目增加。物理协同酶法处理增加了青稞淀粉的结晶度,晶型由A型晶体向B型转变。改性处理没有产生新的化学基团和化学键,只是改变了青稞淀粉内部结构的重新排列。此外与青稞原淀粉相比,改性青稞淀粉的有序度（DO）值增大,其中普鲁兰酶处理后的青稞淀粉的DO比值最大。改性处理使青稞原淀粉颗粒中的淀粉分子分解成小分子又重新结晶,形成的改性青稞淀粉含有更加致密的大淀粉晶体。     

淀粉预处理方法对多孔淀粉的影响

多孔淀粉的制备原料有玉米淀粉、木薯淀粉、马铃薯淀粉等。在制备过程中,淀粉原料某些性质的变化对多孔淀粉性质有一定影响,不同原料、或同一原料的不同处理方式都会影响多孔淀粉的形成。有效的预处理方法对改变淀粉原料的性质,提高多孔淀粉的生产效率,降低生产成本,改善多孔淀粉的性质十分重要。     

当前淀粉及淀粉深加工的宏观形势

1美国近5年发展情况 美国是淀粉及淀粉深加工世界产量第一的国家，2003年玉米产量2．56亿t，占世界产量的42％，淀粉产量2490万吨占世界产量的50％。因此了解一下美国情况具有代表性。1999-2003年美国的发展形势是：     

淀粉类吸附剂--多孔淀粉与环糊精的比较

从制备方法、成孔机理、吸附作用和吸附机理等方面对多孔淀粉与环糊精之间的差异进行了比较,并论述了两者在实际运用中的异同,显示出多孔淀粉良好的应用前景。     

Effect of damaged starch on wheat starch thermal behavior

The influence of damaged starch (DS) on gelatinization and retrogradation wheat starch properties was investigated. Samples with different content of DS were obtained and evaluated. DSC was used for monitoring the changes in thermal behavior of the starch samples at different water amounts. Starch thermal transitions were affected simultaneously by DS content and water content. The Flory–Huggins parameters were modified by DS. A significant raise in the T°_m, and x_1–2, and a decrease in ΔH_u was recorded. The AP retrogradation kinetics was evaluated by Avrami model. A significant increase of the AP crystallization rate was observed when DS increased. The results demonstrated the importance of the presence of physically damaged granules on wheat starch properties.     

Biosynthesis of starch; identification of potato starch enzymes

Two important starch enzymes, granule-bound starch synthase and branching enzyme, were purified from potato tubers and characterized by immunological comparison with the corresponding enzymes of other plants. Granule-bound starch synthase was identified as a 60-kd protein homologous to the corresponding enzymes of maize and amaranth; the enzyme was missing in amylose-free potato starch granules. Branching enzyme of potato tubers was purified as a single protein species of 79 kd which appeared to be homologous to maize branching enzyme I, but much less to branching enzymes IIa and IIb.     

芋头淀粉提取工艺优化及淀粉特性研究

以NaOH为浸泡剂,探讨了料液比、pH、浸泡时间、浸泡温度对芋头淀粉提取率及色泽的影响,并对芋头淀粉特性进行了初步研究。结果显示芋头淀粉提取最佳工艺条件为：pH10.0、浸泡温度25℃、料液比1：3、浸泡时间80min。提取率可达84.82%,淀粉白度高达94.11,优于现有文献报道及市售其它常用淀粉;淀粉特性研究显示,芋头淀粉的体积平均粒度在10μm以下,d（0.5）为14.6μm,稍大于10μm;芋头淀粉具有优良的热稳定性、冷稳定性,凝胶强度和凝成特性等特性。     

直链淀粉含量对抗性淀粉形成的影响

考察不同直链淀粉含量的高直链玉米淀粉形成抗性淀粉的能力。结果表明:随着直链淀粉含量的增加抗性淀粉含量增大,最高可达20.74%,普通玉米淀粉的抗性淀粉得率仅为9.09%。     

Utilization of rice starch with gums in Asian starch noodle preparation as substitute for sweet potato starch

Starch noodles were produced using a medium grain rice starch in the presence of various gums, and physical properties of the noodles were compared with sweet potato starch noodle. Pasting viscosity of the rice starch was lower than that of sweet potato starch (830 vs. 1,618 cp as peak viscosity). The peak viscosity, however, was increased by the addition of gums (0.1% based on dispersion), and especially xanthan was the most effective in increasing the peak viscosity (1,478 cp). The cooking loss for the rice starch noodles (1.5 mg/mL), greater than that for the sweet potato starch noodle (0.2 mg/mL), was effectively reduced to 0.8 and 0.9 mg/mL, respectively, by the addition of locust bean gum (LBG) and curdlan. The addition of LBG or gellen gum also increased the hardness of the rice noodles. Aging (extended retrogradation) the noodles was effective in reducing the cooking loss and improving the textural properties of the rice starch noodles. The combination of the gum addition (like LBG) and aging of the rice starch noodle might be useful for utilizing rice starch as a substitute for sweet potato starch in Asian noodle preparation.     

Gelatinisation of starch and wheat flour starch—A review

Gelatinisation of wheat starch is reviewed, making comparisons with other starches.Starch in wheat kernel endosperm is briefly described. Various aspects of gelatinisation of starch in water are considered, including swelling and interaction with water before the onset of gelatinisation, increase in consistency during gelatinisation, gelatinisation temperature, types of gelatinised system and gel and paste formation upon cooling. In addition, the traditional rationale of gelatinisation and gelatinisation from the viewpoint of water mobility are discussed.Experimental methods used to study gelatinisation are also reviewed, as are the effects of starch concentration, protein, pentosans, surface active agents, fats, salt and sugars on gelatinisation and shear rate on consistency.