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Tang Hongbo Lin Haibo Li Yanping Dong Siqing 《International Journal of Food Science & Technology》2015,50(4):1009-1018
Pea starch (PS) appears to be very attractive for the peculiar physicochemical characteristics, which is used for the vermicelli, film‐forming material due to the high amylose content. The aim of this study was to optimise the hydroxypropylation technology parameters of the microcrystalline pea starch based on pea starch as a raw material, hydrochloric acid as an hydrolysis reagent, epoxy propane as an etherisation reagent by the Box–Behnken method. The thermal properties of hydroxypropylated microcrystalline pea starch were characterised by the thermogravimetric analyser and differential scanning calorimeter, respectively. Through the analysis of Design‐Expert software, the regression model and corresponding variances were obtained. In this case, the determination coefficient (R2) was 0.9631. This implied that 96.31% of the variation could be explained by the regression model. The best reaction conditions for preparing the hydroxypropylated microcrystalline pea starch were as follows: reaction temperature 40 °C, reaction time 16 h, amount of epoxy propane 14%, amount of sodium hydroxide 1.2% and amount of anhydrous sodium sulphate 12%. After the microcrystalline pea starch was hydroxypropylated, its peak temperature, melting enthalpy, temperature range of the endothermic peak increased, but its the thermal stability, onset temperature decreased. 相似文献
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糯米粉经羟丙基化变性后,颗粒形貌和X-光衍射图样发生变化,结晶区被削弱。羟丙基糯米粉受热易成糊和分散,粘度提高,粘度曲线形状类似于鲜木薯淀粉,糊冻融稳定性极佳,糊透明度、抗剪切性变化与羟丙基淀粉一样。 相似文献
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羟丙基和磷酸酯化对不同玉米杂交种淀粉糊化特性的影响 总被引:1,自引:0,他引:1
采用了实验室方法提取了高直链、糯性和普通玉米杂交种的淀粉,并分别进行了羟丙基化和磷酸酯化反应。采用快速粘度分析仪(RVA)和差示扫描量热仪(DSC)分别分析了淀粉的糊化和热力学性质。结果表明:羟丙基化和磷酸酯化反应都不同程度地降低了所有淀粉的热焓值和糊化温度,缩短了出峰时间,增加了峰值粘度。二者相比,羟丙基化更显著地降低了原淀粉的糊化温度和热焓值,缩短了出峰时间;而磷酸酯化则更明显地提高了原淀粉的峰值粘度和终粘度. 相似文献
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Alummoottil N Jyothi Subramoney N Moorthy Kallikat N Rajasekharan 《Journal of the science of food and agriculture》2007,87(10):1964-1972
Cassava starch was subjected to hydroxypropylation in three different media, which included water, water in the presence of a phase transfer catalyst, and 2‐propanol, all at 30 ± 2 °C for 24 h. Propylene oxide was used in four different concentrations (50, 100, 150 and 200 g kg?1 of starch dry weight). The products were characterized by determining their molar substitution (MS), structural and functional properties. The analyses were done in triplicate and the data were analyzed using the statistical package 8.01. The MS of the products ranged from 0.26 to 1.41. The MS of the hydroxypropyl derivatives were found to be higher when the reaction was carried out in the aqueous medium in the presence of tetrabutylammonium bromide, a phase transfer catalyst, when compared to the reaction in 2‐propanol, which was found to be not very effective at 30 ± 2 °C. The etherification altered the granular properties of starch, as could be seen from scanning electron micrographs. Hydroxypropylation resulted in starch pastes which were stable and with higher swelling volume, solubility, light transmittance and water binding capacity as compared to native starch. The hydroxypropyl starches showed significantly lower pasting temperatures and setback viscosities. The enzyme digestibility of the derivatives was seen to decrease with increase in MS and there was a significant reduction in the syneresis of the starch pastes of hydroxypropyl derivatives. Texture profile analysis showed that hydroxypropylated starch gels exhibited higher hardness, springiness (elasticity) and gumminess and lower cohesiveness than the native starch. Copyright © 2007 Society of Chemical Industry 相似文献
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研究了高取代度羟丙基木薯淀粉溶液(分子取代度MS=1.6~4.5)的流变特性及羟丙基取代度对流变特性的影响规律。结果表明,高取代度羟丙基木薯淀粉呈现假塑性流体特征,符合幂定律τ=Kγm。m值在0.7~0.8范围,表明羟丙基化使木薯淀粉偏近牛顿流体。高取代度羟丙基木薯淀粉具有触变性和剪切稀化性质,并随溶液浓度升高而增大。羟丙基取代度对木薯淀粉流变特性有很大影响,当MS≤3.5时,溶液的表观粘度和剪切稀化现象随MS的增高而减小,当MS>3.5时,溶液的表观粘度和剪切稀化现象随MS的增高而增大。这种变化规律符合羟丙基化反应机理。 相似文献
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Mohammad Nurul Islam B M Noor Mohd Azemi 《Journal of the science of food and agriculture》1998,76(2):161-167
The digestibility of native and hydroxypropyl rice starches in the presence of calcium was investigated. Calcium interacted with native and hydroxypropyl rice starches and altered their relative crystallinity. Hydroxypropylation was measured in terms of molar substitution (MS) which in turn enhanced calcium binding. Depending upon the amount of calcium added (50–250 μg calcium per g dry starch) and levels of MS (ranging from 0·02 to 0·12), 25·4– 34·1 μg calcium was bound per g of hydroxypropyl starch. Native starch bound 25·4 μg calcium per g dry starch, which was much less than the hydroxy-propylated starches. Crystallinity decreased with the increase of MS and calcium concentration. Digestibility of ungelatinised hydroxypropyl starches increased with MS (2·5–4·1 mg reducing sugar released per g dry starch) and the trend is reversed in the gelatinised form. Calcium-induced amylolysis of the starches by porcine pancreatic α-amylase but somehow inhibited amyloglucosidase attack. © 1998 SCI. 相似文献
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研究了糯米粉和羟丙基糯米粉糊的流变特性,以及温度影响流变特性的规律。实验表明在实验的测定温度下,糯米粉糊呈现假塑性流体的特征,符合幂定律τ= Kγm ,m 处于050 ~080 间。随制品醚化程度的提高,糊的假塑性增强。温度对糊粘度影响较大,它们之间的关系可用η= A·TB 表示 相似文献
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Etherification optimization for preparing partially hydrolized hydroxypropylated guar gum and its properties
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The partially hydrolized hydroxypropylated guar gum (PHHGG) was prepared using GG as the raw material, hydrochloric acid as the hydrolysis agent, epoxy propane as the etherifying agent, ethanol as the solvent to obtain better property combination. The effect of the reaction temperature, reaction time, and amounts of sodium hydroxide, ethanol, and epoxy propane on the substitution degree of the partially hydrolized hydroxypropylated GG was investigated. These process parameters were optimized by the orthogonal test. Using polarized light microscopy, infrared spectrometer, differential scanning calorimetry, and thermogravimetric analyzer, the appearance, structure, and thermal property of the partially hydrolized hydroxypropylated GG (PHHGG) were observed and measured. The results indicated that the best process conditions for preparing the PHHGG were: reaction temperature = 60°C, reaction time = 12 h, amount of sodium hydroxide = 1.2%, amount of ethanol = 60%. The acid resistance and alkali resistance of GG were obviously improved by the acidolysis and hydroxypropylation. The particle appearance of GG was a thin strip after it was hydrolized by acid and hydroxypropylated by epoxy propane. The acidolysis increased the melting onset temperature, peak temperature, and end temperature of GG but the hydroxypropylation decreased them. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40489. 相似文献