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湿热处理对淀粉性质的影响 总被引:8,自引:0,他引:8
水分含量为30%的高链玉米淀粉在100℃处理12h。通过研究淀粉的性质发现,湿热处理后淀粉的颗粒形状保持不变,但表面出现了凹坑;主要衍射峰强度增加,结晶度为44.65%,比原淀粉大2.51%;To、Tp、Tc分别比原淀粉相应的温度高14.02、18.81、6.87℃,而△H却比原淀粉小1.08cal/g:湿热处理淀粉的膨胀度和溶解度变小;淀粉的Brabender粘度曲线几乎为一直线;酸水解前7d,湿热处理淀粉水解率比原淀粉大,之后水解率小于原淀粉,而酶水解到第3d,原淀粉水解率大于湿热处理淀粉。淀粉性质的变化说明湿热处理使淀粉内部结构发生变化,特别是无定形区的直链淀粉的结合产生了不同稳定性的新的结晶。 相似文献
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本实验研究了湿热处理对蜡质玉米淀粉性质及羧甲基反应活性的影响.结果表明,经湿热处理后,蜡质玉米淀粉的颗粒形貌基本没发生变化,偏光十字未消失,但表面出现了一些裂纹:湿热处理没能改变蜡质玉米淀粉的晶型,但晶体结构变强,糊化温度升高,糊黏度降低.经湿热处理后淀粉中直链淀粉含量增加,羧甲基反应活性降低. 相似文献
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在单因素实验和响应面分析实验的基础上对制备的酶解辛烯基琥珀酸酐玉米淀粉的DSC特性、IR特性及黏均分子量进行了分析研究。结果显示:利用DSC扫描辛烯基琥珀酸酐淀粉和酶解辛烯基琥珀酸酐淀粉,发现二者的To、Tp、Tc较原淀粉都降低。玉米原淀粉经辛烯基琥珀酸酐酯化后引入了OSA基团,而辛烯基琥珀酸酐淀粉经α-淀粉酶水解后,并没有影响分子中的OSA基团,只是淀粉分子链缩短,分子量降低。通过黏均分子量的测定,表明经过α-淀粉酶的水解确实将淀粉分子链缩短,分子量降低。 相似文献
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湿热处理改性淀粉的研究进展 总被引:2,自引:1,他引:2
湿热处理是改性淀粉的一种新的物理方法。本文列举了不同种类淀粉的湿热处理条件,对湿热处理影响淀粉的理化性质如颗粒形貌、糊化性质、以及对酸和酶的敏感性等作了概述。最后阐述了湿热处理对淀粉作用的机理及发展。 相似文献
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以4种不同链/支比含量的玉米淀粉为原料,酸解处理不同时间,以酸解玉米淀粉的形貌特性、冻融稳定性、膨胀度、溶解度、晶体性质为指标衡量不同酸解时间对玉米淀粉结构性质的影响。结果表明:4种玉米淀粉酸水解程度的顺序为:蜡质玉米普通玉米淀粉G50G80。酸解后,同品种的4种玉米淀粉的析水率随着酸解天数的增加而增加;溶解度增加,膨胀度降低。酸解并未改变淀粉的晶型,随着酸解时间的延长,蜡质玉米淀粉和普通玉米的相对结晶度先增大后保持不变,G50和G80的相对结晶度随着酸解时间的增加而增大。表明酸解对低直链淀粉(蜡质玉米淀粉和普通玉米淀粉)的结构、性能影响最大。 相似文献
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Elessandra da Rosa Zavareze Vânia Zanella PintoBruna Klein Shanise Lisie Mello El HalalMoacir Cardoso Elias Carlos Prentice-HernándezAlvaro Renato Guerra Dias 《Food chemistry》2012,132(1):344-350
This study investigated the effects of sodium hypochlorite oxidation and a heat-moisture treatment of potato starch on the physicochemical, pasting and textural properties of potato starches in addition to the water vapour permeability (WVP) and mechanical properties of potato starch films produced from these starches. The carbonyl contents, carboxyl contents, swelling power, solubility, pasting properties and gel texture of the native, oxidised and heat-moisture treated (HMT) starches were evaluated. The films made of native, oxidised and HMT starches were characterised by thickness, water solubility, colour, opacity, mechanical properties and WVP. The oxidised and HMT starches had lower viscosity and swelling power compared to the native starch. The films produced from oxidised potato starch had decreased solubility, elongation and WVP values in addition to increased tensile strength compared to the native starch films. The HMT starch increased the tensile strength and WVP of the starch films compared to the native starch. 相似文献
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The effect of acid hydrolysis on the swelling power of pea starch granules was studied by field emission SEM (FE‐SEM). The swelling power of the native starch granules (g water absorbed/g dry starch) was 13, and this decreased to less than 2 after 1 day of acid hydrolysis. The proportion of the starch that was soluble in hot water increased from 15% for native starch to 75% after 1 day of hydrolysis. The swelling power of the starch decreased further, and solubility increased, with more extended hydrolysis. The decrease in swelling power and increase in solubility were attributed mainly to the disruption of side chains of amylopectin. Observations with FE‐SEM indicated that starch granules were still able to melt and coalesce after 1 day of acid hydrolysis, but after 2 days solubilization of starch chains occurred predominantly rather than swelling when the granules were heated in excess water. The intactness of amylopectin is proposed to play a crucial role in the swelling power of starch granules and in the structure of granule ghosts. 相似文献
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Tsuyoshi Ito Kenji Saito Masayoshi Sugawara Kazumi Mochida Teruo Nakakuki 《Journal of the science of food and agriculture》1999,79(9):1203-1207
High‐amylose corn starch (HAS) is widely known as a resistant starch foodstuff. We developed heat–moisture‐treated high‐amylose corn starch (HMT‐HAS) that was more resistant to enzymatic hydrolysis. Resistant starch contents of HAS and HMT‐HAS using the enzymatic–gravimetric method were found to be 30% and 65% respectively. Rats were given 10% ordinary corn starch (CS), HAS or HMT‐HAS by meal feeding for 10 days. The caecum contents increased and the caecal pH was lower after their diets were supplemented with HAS and HMT‐HAS. Starch contents increased in the upper and the lower small intestine with HAS and HMT‐HAS. Caecal starch with HAS and HMT‐HAS was more than that with CS. Particularly, caecal starch with HMT‐HAS was seven times more than that with HAS. There were no differences in starch content in the large bowel between CS and HAS, but the content increased with HMT‐HAS. These results suggested that HAS and HMT‐HAS were resistant to digestion and absorption in the small intestine, and any indigestible starches reached the caecum. In the caecum, HAS was hydrolysed almost completely by intestinal bacteria; however, some HMT‐HAS escaped bacterial hydrolysis. This escaped HMT‐HAS reached the large bowel and was excreted in the faeces. © 1999 Society of Chemical Industry 相似文献
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采用扫描电子显微镜(SEM)、激光粒度分析仪(LPA)、X射线粉末衍射仪(XRD)和差示扫描量热仪(DSC)研究退火处理对玉米淀粉颗粒形貌、粒径大小、晶体结构和热力学性质的影响。结果显示:退火处理会改变玉米淀粉颗粒的外貌,使其微孔增多,孔径增大;退火处理会增加玉米淀粉颗粒粒径;退火处理不涉及玉米淀粉晶体结构的变化;退火处理会使玉米淀粉糊化温度显著增高,糊化温度范围变窄;原玉米淀粉(NC)和退火处理玉米淀粉(AC)的溶解度和膨胀率都随着温度的升高而增大,在相同温度条件下,退火处理玉米淀粉(AC)溶解度和膨胀率均小于原玉米淀粉(NC)。 相似文献
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淀粉是芡实中含量最高的组分,其结构和性质对芡实的加工和应用至关重要。研究了芡实淀粉的表面结构,冻融稳定性,溶解度,膨胀度,透明度,直链淀粉和支链淀粉的含量,以及淀粉糊特征曲线等理化性质并与马铃薯和玉米淀粉进行比较。结果表明,与马铃薯和玉米淀粉相比,芡实淀粉的溶解度,膨胀度,透明度以及峰值粘度的值较低,糊化温度的值和直链淀粉的含量较高,冻融稳定性与玉米淀粉相近。 相似文献
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Physicochemical,crystallinity, pasting and thermal properties of heat‐moisture‐treated pinhão starch
Vnia Zanella Pinto Nathan Levien Vanier Bruna Klein Elessandra da Rosa Zavareze Moacir Cardoso Elias Luiz Carlos Gutkoski Elizabete Helbig Alvaro Renato Guerra Dias 《Starch - St?rke》2012,64(11):855-863
The effect of heat‐moisture treatment (HMT) on the properties of pinhão starches under different moisture and heat conditions was investigated. The starches were adjusted to 15, 20 and 25% moisture levels and heated to 100, 110 and 120°C for 1 h. The X‐ray diffractograms, swelling power, solubility, gel hardness, pasting properties and thermal properties of the native and HMT pinhão starches were evaluated. Compared to native starch, there was an increase in the X‐ray intensity and gel hardness of HMT starches, with the exception of the 25% moisture‐treated and 120°C heat‐treated starch. HMT reduced the swelling power and solubility of the pinhão starches when compared to native starch. There was an increase in the pasting temperature, final viscosity and setback and a decrease in the peak viscosity and breakdown of HMT pinhão starches compared to native starch. HMT increases the gelatinisation temperature of native pinhão starch and reduces gelatinisation enthalpy. 相似文献
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Mung bean starch was subjected to a range of heat-moisture treatments (HMT) based on different moisture contents (15%, 20%, 25%, 30%, and 35%) all heated at 120 °C for 12 h. The impact on the yields of resistant starch (RS), and the microstructure, physicochemical and functional properties of RS was investigated. Compared to raw starch, the RS content of HMT starch increased significantly, with the starch treated at 20% moisture having the highest RS content. After HMT, birefringence remained at the periphery of the granules and was absent at the center of some granules. The shape and integrity of HMT starch granules did not change but concavity was observed under scanning electronic microscopy. Apparent amylose contents of HMT starch increased and the HMT starch was dominated by high molecular weight fraction. Both the native and HMT starches showed A-type X-ray diffraction pattern. Relative crystallinity increased after HMT. The gelatinization temperatures (To, Tp, and Tc), gelatinization temperature range (Tc–To) and enthalpies of gelatinization (ΔH) increased significantly in HMT starch compared to native starch. The solubility increased but swelling power decreased in HMT starches. This study clearly shows that the HMT exhibited thermal stability and resistance to enzymatic hydrolysis owing to stronger interactions of starch chains in granule. 相似文献
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Elessandra da Rosa Zavareze Cátia Regina Storck Luis Antonio Suita de Castro Manoel Artigas Schirmer Alvaro Renato Guerra Dias 《Food chemistry》2010
The effect of heat-moisture treatment (HMT) on the properties of rice starches with high-, medium- and low-amylose content was investigated. The starches were adjusted to 15%, 20% and 25% moisture levels, and heated at 110 °C for 1 h. The swelling power, solubility, pasting properties, morphology, enzymatic susceptibility and X-ray crystallinity of the starches were evaluated. HMT reduced the swelling power and solubility of the starches. The strongest effect of HMT occurred on the high-amylose starch; the pasting temperature was increased and the peak viscosity, breakdown, final viscosity and the setback were reduced. HMT increased the starch’s susceptibility to α-amylase and promoted a reduction in the starch relative crystallinity. 相似文献