共查询到19条相似文献,搜索用时 93 毫秒
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高交联马铃薯淀粉非晶化特性研究 总被引:25,自引:3,他引:22
研究了以三氯氧磷为交联剂的高交联马铃薯淀粉的制备方法,报道了高交联马铃闰随反应承代度增加而逐渐非晶化的现象,同时,采用偏光显生镜和广角X-射线衍射对其由多晶态向非晶态的渐变过程进行了研究,提出主交联马铃薯淀粉存在着不同于原淀粉多晶颗粒态的只含无定形结构的非晶颗态。对非晶颗粒态高交联马铃薯淀粉颗粒的粒度分布的进一步研究还表明,此时的淀粉颗粒发生了轻度有限的膨胀。 相似文献
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研究了以三氯氧磷为交联剂的高交联玉米淀粉的制备方法,报道了高交联玉米淀粉颗粒随反应取代度增加而逐渐非晶化的现象.采用偏光显微镜和广角X-射线衍射对其由多晶态向非晶态的渐变过程进行了研究,提出高交联玉米淀粉中存在不同于原淀粉多晶颗粒态的只含无定形结构的非晶颗粒态。对非晶颗粒态高交联玉米淀粉颗粒的粒度分布的进一步研究结果还表明,此时的淀粉颗粒发生了轻度的膨胀。 相似文献
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对肇实淀粉的颗粒形貌、X-射线衍射谱图、直链与支链淀粉含量、糊化温度、溶解度与膨胀度以及糊的透明度、冻融稳定性、凝沉性进行了研究,并与玉米淀粉进行了比较,为肇实淀粉的应用提供了一定的理论基础。 相似文献
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微波作用对木薯淀粉颗粒结晶的影响 总被引:1,自引:0,他引:1
利用物理场中微波对木薯淀粉颗粒进行处理,考察微波作用对木薯淀粉结晶形态的影响,通过偏光显微镜和扫描电镜观察作用后的木薯淀粉颗粒的结晶结构的变化。实验结果表明,微波作用木薯淀粉,以水为溶剂,配置木薯淀粉悬浮液的含量12.5%,微波作用时间60s,功率160W时,木薯淀粉状态最佳,此时的木薯淀粉颗粒不仅保持着原木薯淀粉的颗粒形状,无溶胀变大或者出现淀粉凝胶和糊化的现象,并且木薯淀粉颗粒的偏光十字呈现减弱或消失的状态,木薯淀粉颗粒的结晶结构减弱或消失。微波作用破坏了淀粉的结晶结构,使颗粒表面与反应试剂的接触面积增多,从而提高了反应活性。 相似文献
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Piyarat Noosuk Sandra E. Hill Pasawadee Pradipasena John R. Mitchell 《Starch - St?rke》2003,55(8):337-344
The viscosities of five Thai rice starches with different amylose contents were measured by rotational rheometry and using a Rapid Visco Analyser. The viscosity response was interpreted in terms of the swelling volume and the structural properties of the granule determined by calorimetry, infrared spectroscopy and X‐ray diffraction. It was found that the waxy rice starches had a higher swelling volume resulting in a higher viscosity than the other rice classes. Critical concentrations for close packing, identified from the concentration where the flow behaviour departs from Newtonian, were 2.5%, 1.5% and 1.10% for the high amylose, medium amylose and waxy rice starch, respectively. An exception to this was a commercial high amylose starch that had a critical concentration similar to the medium amylose category. This was ex‐plained in terms of a relatively higher loss of short‐range molecular order on gelatini‐sation as shown by FTIR for this starch. Medium amylose Jasmine rice starch, extracted from rice that had been aged for 5 months, showed differences in granule size, crystallinity, pasting profile and enthalpy of gelatinisation when compared with the results for starch extracted from freshly harvested rice. This was provisionally interpreted in terms of granule damage during the extraction process, though more work would be required to confirm this interpretation. 相似文献
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为提高淀粉的反应活性,采用氢氧化钠尿素法对马铃薯原淀粉进行处理,以处理后的马铃薯淀粉和肉豆蔻酸为原料,Novozyme 435为催化剂,在无溶剂体系中制备了取代度为0.018~0.065的肉豆蔻酸淀粉酯,并对其部分理化性质进行研究。结果表明:与原淀粉相比,预处理淀粉溶解度和透明度显著增加(P0.05),其膨胀度、冻融稳定性、乳化性和乳化稳定性均显著降低(P0.05)。同时,肉豆蔻酸淀粉酯的性质与其取代度密切相关,与原淀粉相比,随着取代度的增加,酯化淀粉冻融稳定性、乳化性和乳化稳定性随之升高,而其溶解度、膨胀度和透明度随之下降。扫描电子显微镜(SEM)、傅里叶红外光谱分析(FTIR)、疏水性测定对预处理淀粉及不同取代度的肉豆蔻酸淀粉酯进行观察、测定、分析,结果表明,淀粉颗粒结构被破坏,酯化淀粉具有较好的疏水性,FTIR验证了预处理淀粉及酯化淀粉的生成。 相似文献
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马铃薯抗性淀粉理化性质的研究 总被引:1,自引:0,他引:1
以马铃薯原淀粉为对照,研究了纤维素酶-压热法制备的马铃薯抗性淀粉的理化性质。结果表明,马铃薯原淀粉颗粒呈椭球形,表面光滑;而抗性淀粉的颗粒状结构消失,形成了连续的致密结构,表面不再光滑。红外光谱分析表明,抗性淀粉分子中未出现新的基团,只较原淀粉形成了更多的氢键。马铃薯原淀粉的分子晶型为A型,整体结晶度为22.82%;抗性淀粉的分子晶型为B型,整体结晶度为29.64%。马铃薯抗性淀粉的溶解度、透明度远远低于原淀粉;膨润度、持水性优于原淀粉。抗性淀粉的沉降速度较快,沉降性比原淀粉强。原淀粉糊化温度为65.8 ℃,峰值黏度可达到10 770 mPa·s;而抗性淀粉其糊化温度高于95 ℃。 相似文献
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In this work the contribution of molecular structures to the swelling behavior of rice starches was investigated. Rice starches with different amylose contents (0 ‐ 23.4 %) were gelatinized to various degrees (approximately 10, 20, and 50 %) with 13 M aqueous LiCl, and the surface‐gelatinized starch and ungelatinized remaining granules were separated and characterized. The native starches were heated at 85 or 95°C for 30 min in excess water, and the granule envelope remnants were recovered by centrifugation for further characterization. The remaining granules after surface removal exhibited a lower gelatinization temperature and enthalpy, and swelled to a greater extent upon heating than the native counterpart. The amylopectin molecules in granule envelope remnants obtained at 95°C had larger Mw (weight‐average molar mass) and Rz (z‐average gyration radius) than those in remnants obtained at 85°C. The chemical composition and structure of granule envelope remnants obtained at 85°C were different from those obtained at 95°C for the same rice starch cultivar. The results imply that starch periphery may not be responsible for maintaining starch granule integrity during gelatinization and swelling. It is proposed that the composition and structure of the granule envelope remnant that maintains granule integrity are not constant but dynamic. The formation of a semi‐permeable membrane‐like surface structure during gelatinization and swelling is proposed to be a result of molecule entanglement after gelatinization. 相似文献