酸法优化木薯微孔淀粉的工艺及性能研究

利用盐酸对木薯淀粉进行处理,通过L9（3^4）正交实验,研究盐酸质量分数、反应时间、反应温度和搅拌速度对微孔淀粉吸附性能的影响,并通过差示扫描量热分析（DSC）、X射线衍射分析（XRD）研究微孔淀粉的结构。结果表明：盐酸制备木薯微孔淀粉的最佳工艺条件是：盐酸质量分数2．0％,反应时间8h,反应温度40℃,搅拌速度为1500r／min。通过XRD、DSC分析发现：木薯微孔淀粉的结晶部分比例增加。     

木薯微孔淀粉的成孔机理研究

为微孔淀粉的工业化生产提供理论依据,利用盐酸对木薯淀粉处理制备微孔淀粉。通过SEM、DSC、XRD分析微孔淀粉的成孔机理。研究表明,酸首先作用在原淀粉颗粒表面的不规则部分以及较容易水解的无定型区,在颗粒的表面形成了浅浅的沟壑状,接着往颗粒内部进行水解,开始形成针孔状的小孔。盐酸继续纵向深入颗粒内部水解的同时,也横向的水解颗粒内部,使得颗粒内部形成中空的结构。     

木薯微孔淀粉的制备及性质研究

以木薯淀粉为原料,探讨α-淀粉酶用量、反应温度、反应pH值和反应时间等因素对其微孔化反应的影响,并对微孔淀粉的吸水率、吸油率和X射线衍射以及扫描电子显微镜结构表征进行了研究。     

酸法制备木薯微孔淀粉的工艺及吸附性研究

利用盐酸对木薯淀粉进行处理,可以得到一种具有吸附功能的微孔淀粉载体。实验证明:木薯微孔淀粉对柠檬黄色素、油脂的吸附性能高于原淀粉对柠檬黄色素、油脂的吸附性能;盐酸制备木薯微孔淀粉的最佳工艺条件是:盐酸用量1.5%,温度35℃,反应时间10h。     

酸酶两步法制备玉米微孔淀粉及其差示扫描量热分析

以玉米淀粉乳为原料,先后经过盐酸处理、含有α-淀粉酶和葡萄糖苷酶的pH值缓冲液处理,制成微孔淀粉。最佳工艺条件为：先使用8%HCl,在50℃处理4h,再使用1.5%α-淀粉酶,0.5%葡萄糖苷酶,于50℃、pH值5.0的磷酸氢二钠-柠檬酸缓冲液中处理12h。差示扫描量热分析（DSC）分析发现,前期的酸解处理主要起到降低淀粉颗粒结晶化程度作用,后期的酶解过程实际起到了增加微孔的作用。     

酸法制备小麦微孔淀粉的结构研究

利用酸法制备小麦微孔淀粉,通过SEM(扫描电镜)、IR(红外光谱法)、DSC(差示扫描量热法)、XRD(X射线衍射)研究微孔淀粉的结构.结果表明:与原淀粉相比,微孔淀粉表面形成微型孔洞,孔径沿径向增大,且微孔淀粉分子结构未见变化.微孔淀粉DSC吸热峰的峰值温度减小,峰面积增大,结晶度增加.微孔淀粉XRD图的峰强减弱,结晶区部分水解.     

高吸油性木薯微孔淀粉复合酶法的制备工艺

研究木薯微孔淀粉复合酶法的制备工艺,以吸油性能为指标,通过单因素和正交正交试验,研究淀粉乳浓度、复合酶用量、复合酶的配比、反应体系pH值、反应温度和反应时间等因素对木薯微孔淀粉吸油性能的影响.复合酶法生产木薯微孔淀粉的最佳工艺条件:底物浓度60%,酶用量2.5%,α-淀粉酶和糖化酶酶活力配比为1:5,pH为6.0,反应温度60℃,反应时间7 h,所得木薯微孔淀粉的吸油率和比表面积比原淀粉分别提高了53%和54%.     

羟丙基木薯淀粉对冷冻鱼丸水分特性的影响

在鱼丸中添加羟丙基木薯淀粉,以不添加淀粉和添加木薯原淀粉为对照和对比,用真空烘干法、核磁共振和差示扫描量热为研究方法,研究羟丙基木薯淀粉对冷冻鱼丸中水分特性的影响。结果表明,淀粉糊化膨胀后填充到鱼丸肌原纤维蛋白网格中,有利于束缚鱼丸中的结合水和束缚水,降低水分的移动性,同时提高了鱼丸的总水分含量,而减少了冻融过程的水分损失。羟丙基淀粉分子中羟丙基基团的引入会阻止其本身的联接,同时增强淀粉分子无定型区的吸水能力,进而增强淀粉颗粒的水合作用和膨胀度,因此相对于添加原淀粉,添加羟丙基木薯淀粉的鱼丸有更好的保水性和束缚性。此外,差示扫描量热表明,鱼丸中添加羟丙基木薯淀粉有利于冷冻时冰晶的分布均匀和细小,减少低温给鱼丸带来的破坏作用和鱼丸解冻后汁液的流失。     

酸法制备微孔淀粉的技术研究

用盐酸对玉米淀粉进行处理，可以得到一种具有吸附功能的微孔淀粉载体。研究表明，微孔淀粉对色素和水溶性维生素的吸附能力远远高于原淀粉。通过交联反应能加强这种淀粉载体的结构性能和吸附性能。     

双酶协同水解制备木薯微孔淀粉的结构研究

为木薯微孔淀粉的工业化生产提供依据,用双酶协同水解制备木薯微孔淀粉。通过扫描电镜(SEM)、比表面积(BET)、X射线衍射分析(XRD)、热重分析(TGA)等手段研究微孔淀粉的结构。研究表明,双酶协同水解处理木薯淀粉后形成微孔,且木薯微孔淀粉的比表面积远远大于木薯淀粉的比表面积。与原淀粉相比,木薯微孔淀粉的热稳定性降低,结晶部分所占的比例增加。     

Morphology of modified starches prepared by different methods

Morphologies of modified starches prepared using different methods were examined by scanning electron microscopy (SEM). These SEM micrographs provide the following results. To begin with, starch granules underwent a series of changes which resulted in the morphology of modified starch quite different from the native starch with different the methods during the process of modification. For example, hollows emerge on the granules of maltodextrin with low value of dextrose equivalent (DE) prepared by means of spray-drying, but they fell to pieces with the increasing value of DE. The granules of pregelatinized starches manufactured with extrusion technology also showed irregular stone shapes and holes within them while those produced by means of drum-drying presented irregular laminar structure. Furthermore, the granules of granulated cold water soluble (GCWS) starch obtained from alcoholic-alkaline treatment had indented appearance and larger volume than those of the original native granules. The conclusion can be safely drawn that the granule structure of slight modified starches did not change but the surface of the granule was porous.     

Characterization of nanoparticles prepared by acid hydrolysis of various starches

Various starches of different AM contents and origins such as wx maize, normal maize, high AM maize, potato, and mungbean starches were hydrolyzed using a H₂SO₄ solution (3.16 M) at 40°C for 7 days, and the starch particles were isolated from the hydrolysates by centrifugation. The hydrolysis rates varied from 61.4 to 90.9% depending on the starch type. Unexpectedly, A‐type starches were more resistant to the acid hydrolysis than B‐type starches. XRD results revealed that the starch particles with B‐crystalline type exhibited a decrease in peak intensity. In addition, in a DSC analysis, the crystals remaining in the B‐type starch particles were readily disrupted in the water dispersion so that no melting endotherm appeared. Electron microscopy confirmed that the starch particles had round or oval shapes with diameters ranging from 40 to 70 nm, which possibly represented the starch blocklets in granules. The acid degraded mainly AM and long AP chains, resulting in increasing the proportion of short chains.     

盐酸制备小麦微孔淀粉的性能及结构研究

利用盐酸制备小麦微孔淀粉,研究盐酸浓度、反应时间、反应温度和搅拌速度对微孔淀粉吸附性能的影响,并通过红外光谱(IR)、差示扫描量热分析(DSC)、X射线衍射分析(XRD)研究微孔淀粉的结构.结果表明:盐酸制备小麦微孔淀粉的最佳工艺条件是:盐酸浓度4.0%,反应时间16h,反应温度45℃,搅拌速度为1500r/min.通过XRD、DSC分析发现:小麦微孔淀粉的结晶部分比例增加.     

以木薯淀粉为原料制备B型淀粉球晶

以木薯淀粉为原料,采用快速冷冻结晶法制备B型淀粉球晶.采用X射线衍射、电子扫描电镜对制得的淀粉球晶进行了表征.结果表明:对酸解悬浮液采用Na2CO3饱和溶液洗涤效果最好,可以大大地缩短洗涤时间.X射线衍射分析表明,制备得到的淀粉球晶具有典型的B型晶体结构,并且球晶粒度均匀,球形度好,大小在1～ 2μm之间.     

微波辐射对木薯淀粉性质影响

研究微波辐射前后木薯淀粉物化性质变化,采用微波对30%水分含量木薯淀粉进行处理,结果表明,微波处理增强对应X–射线衍射峰强度,降低膨胀度、溶解度和冻融稳定性;木薯淀粉经处理后糊化起始温度升高、粘度降低,但其粘度曲线不改变。以上数据表明,在淀粉颗粒内无定形区和结晶区直链淀粉与直链淀粉、直链淀粉与支链淀粉发生交互作用,微波处理使淀粉分子发生一定程度降解。     

Glycerol-enhancing heat-moisture treatment of A-type rice and cassava starches and B-type potato and canna starches

Effects of glycerol on the heat-moisture treatment (HMT) of A-type rice and cassava starches and B-type potato and canna starches were investigated. Starch samples were soaked in water or glycerol solution, adjusted to 25% moisture, and then subjected to HMT at 100 °C for 1, 6, and 16 h. Pasting profiles of all four starches plasticised with water clearly showed the B-type potato and canna starches were more susceptible to HMT than the A-type rice and cassava starches. The effect of HMT on the pasting properties of glycerol-plasticised samples was inconclusive; the B-type canna and A-type cassava starches were altered, but not the B-type potato and A-type rice starches, which remained comparable to the water-plasticised samples. Thus, the type of plasticiser as well as the environment surrounding the crystalline region, which is specific to each starch type, also affect the alteration of starch during HMT.     

Physicochemical properties of cassava,potato and jicama starches oxidised with organic acids

The oxidising effects of organic (acetic, citric and lactic) acids on the physicochemical properties of starches from cassava, potato and jicama were investigated. Cassava starch oxidised with lactic and citric acids had the highest carbonyl contents (5.43 and 5.84 g kg^?1 respectively), while oxidised potato starch had the highest carboxyl contents. Oxidised jicama starch showed the lowest carbonyl and carboxyl contents. Oxidation increased the maximum viscosity of cassava starch (from 426.61 to 670.11 relative viscosity units (RVU)) and jicama starch (from 160.17 to 561.50 RVU) but decreased that of potato starch (from 669.44 to 206.92 RVU). When carbonyl and carboxyl groups were incorporated into jicama starch granules, the resistance of these granules to stirring at constant temperature (holding) increased, as did their final and retrogradation viscosities. However, the behaviour of oxidised cassava and potato starches, as indicated by a Rapid Visco Analyser, was different. The highest values of endotherm enlargement were found for native and oxidised jicama starch, while the lowest values were found for native and oxidised cassava starch. Native and oxidised potato starch had the highest enthalpy values (14.30–18.30 J g^?1), while jicama starch had the lowest (9.50–11.9 J g^?1). The high intrinsic viscosity of native potato starch was attributed to B‐type starch with a longer‐than‐average amylopectin chain length and a lower degree of crystallinity. Oxidised granules showed little erosion in the form of grooves; on the contrary, oxidation left the grains with a very smooth surface. Copyright © 2007 Society of Chemical Industry