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1.
为进一步探讨韧化处理对淀粉性质的作用机理,通过测定糊化性质、热特性、膨胀力、结晶特性及观察偏光十字现象和微观结构,研究了不同韧化温度和时间对不同直链淀粉质量分数玉米淀粉(普通玉米淀粉(normal corn starch,NCS)和蜡质玉米淀粉(waxy corn starch,WCS))物化性质的影响。结果表明,韧化处理主要作用于NCS和WCS淀粉颗粒的无定形区,对淀粉结晶类型没有影响;但韧化处理能够明显增强NCS和WCS的热稳定性和抗剪切能力,抑制淀粉老化和糊化,显著降低峰值黏度和膨胀力(P<0.05)。韧化温度升高至60 ℃时韧化效果更加明显,糊化焓和相对结晶度明显降低,颗粒表面被明显破坏。但延长韧化时间对NCS和WCS老化的抑制效果和对糊化焓、膨胀力、颗粒形貌等的影响不明显。  相似文献   

2.
韧化处理对不同玉米淀粉理化特性的影响   总被引:3,自引:0,他引:3  
杜双奎  王华  赵佳  徐卯年 《食品科学》2012,33(17):78-81
以不同直/支链比例的普通玉米淀粉和蜡质玉米淀粉为材料,在40、50、60℃进行韧化处理,研究韧化处理对玉米淀粉理化特性的影响。结果表明:韧化处理的两种玉米淀粉颗粒形貌有较小变化。韧化处理后,两种淀粉的溶解度和膨胀度随着处理温度的升高而降低;所有韧化处理过的玉米淀粉黏度低于原淀粉,起糊温度高于原淀粉;韧化处理后淀粉的糊化温度升高,热焓变化不大。  相似文献   

3.
目的 为研究湿热和韧化改性对莜麦淀粉理化性质和消化特性的影响,扩大莜麦淀粉在慢消化主食食品中的应用,方法 分别在体系水分含量为15%、20%、25%、30%,温度为100℃的条件下和料液比为1:5,体系温度为30℃、40℃、50℃、60℃下对莜麦淀粉进行湿热和韧化处理,并采用傅里叶红外光谱(FT-IR)、X-射线衍射(XRD)、扫描电镜(SEM)、差示扫描量热仪(DSC)和酶解实验等分析湿热和韧化处理前后莜麦淀粉的理化性质和消化特性变化。结果 结果表明,湿热和韧化处理均未改变莜麦淀粉原有的A-型结晶结构,但淀粉结晶度表现为下降趋势,且淀粉的糊化焓从1.49J/g分别降低至0.92J/g和0.8J/g。此外,微观结构表明莜麦淀粉颗粒表面结构出现聚集行为。在体外酶解实验中,经过湿热、韧化处理后的莜麦淀粉中慢消化淀粉(SDS)和抗性淀粉(RS)含量均出现不同程度的增加,表现为湿热处理后RS含量增加显著,而韧化处理则显著提高了SDS的含量。结论 结果表明湿热和韧化处理可以通过改变淀粉结构降低莜麦淀粉的消化速率。  相似文献   

4.
为研究湿热和韧化改性荞麦淀粉的消化机制,分别在体系水分含量为15%、20%、25%、30%,温度为100℃的条件和料液比为1:5,体系温度为30℃、40℃、50℃、60℃对荞麦淀粉进行湿热和韧化处理,测定了湿热和韧化处理前后荞麦淀粉的理化性质和消化特性。结果表明:湿热和韧化处理并未改变荞麦淀粉原有的A-型结晶结构,但淀粉的糊化焓显著降低,从7.96J/g分别降低到6.68J/g和2.77J/g。微观结构表明,淀粉颗粒表面出现裂痕和凹陷。同时,经过湿热和韧化处理后的荞麦淀粉中慢消化淀粉(SDS)和抗性淀粉(RS)含量出现不同程度的改变,表现为湿热处理过程中SDS含量增加(HMT-25,HMT-30除外),RS含量减少,而韧化处理只有(ANN-50)提高了RS的含量,SDS含量也出现了增加(ANN-40,ANN-60除外)。结论:荞麦淀粉可以通过湿热和韧化改变理化结构从而改变消化速率。  相似文献   

5.
赵凯  杨春华  张娜  缪铭 《食品科学》2010,31(11):109-112
探讨韧化处理条件下,缓慢消化玉米淀粉的形成过程。分别采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、差示扫描量热仪(DSC)研究韧化处理前后玉米淀粉颗粒形貌、结晶特性、热焓特性的变化情况。结果表明,韧化处理对玉米淀粉的颗粒形貌基本无影响,处理后基本保持原来的A型结晶结构,但结晶结合更为紧密,韧化玉米淀粉和去除快速消化玉米淀粉(RDS)的韧化玉米淀粉相比,DSC图谱的To、Tp、Tc以及Tc-To均较原玉米淀粉有所提高。这表明,韧化处理过程促进缓慢消化玉米淀粉的形成主要是通过调整玉米淀粉的结晶结构,使其结合更为紧密,从而对酶的抵抗作用增强而实现的。  相似文献   

6.
本文研究了等离子体活化水(plasma-activated water,PAW)协同韧化处理对蜡质玉米淀粉(waxy maize starch,WMS)和玉米淀粉(maize starch,MS)结构及性能的影响。结果表明,与常规韧化处理相比,PAW韧化没有改变WMS和MS的结晶类型,但降低了相对结晶度。WMS的相对结晶度从37.1%降低到25.9%,MS的相对结晶度从30.3%降低到27.7%。PAW韧化没有使淀粉分子产生新的官能团,但导致WMS和MS的短程有序性降低。PAW韧化降低了WMS和MS的糊化焓(WMS:13.33~12.10 J/g、MS:10.76~10.26 J/g)、峰值黏度和黏弹性,提高了淀粉糊的凝胶强度。PAW协同韧化处理提供了一种淀粉双重物理改性的新方法,在淀粉基凝胶领域具有潜在的应用。  相似文献   

7.
非晶颗粒态淀粉是一种特殊的淀粉物态形式,具有颗粒性,但不具有结晶性。为了实现对原淀粉颗粒的改性,本文以玉米淀粉为原料,采用乙醇溶液处理法制备非晶颗粒态淀粉。在此基础上,研究了这种非晶化处理方法对玉米淀粉的颗粒形貌、结晶性质、溶解度与膨胀力及体外消化性能的影响。结果表明,原淀粉经非晶化处理后颗粒性仍保持完整,但颗粒表面有较大爆裂孔生成,并出现明显褶皱;非晶颗粒态玉米淀粉呈现V-型衍射结构,其结晶性基本消失,颗粒由多晶颗粒态结构转变为非晶颗粒态结构;与玉米原淀粉相比,其溶解度和膨胀度在相同的测定温度下均明显增加。原淀粉经乙醇溶液处理后,其快消化淀粉含量由92.83%下降到81.64%。而慢消化淀粉和抗性淀粉总含量由7.17%上升到18.36%。因此,采用乙醇溶液处理法对淀粉颗粒进行改性将有助于开发低热量和慢血糖应答的产品。  相似文献   

8.
比较玉米淀粉(A型)、马铃薯淀粉(B型)和锥栗淀粉(C型)韧化处理前后的颗粒形貌、结晶特性和热特性变化,探究韧化处理对3种晶型淀粉消化特性的作用机理。SEM图片显示,韧化处理后玉米淀粉表面出现凹坑,马铃薯淀粉表面出现少许裂痕,锥栗淀粉表面变得光滑,褶皱消失;XRD和FTIR分析表明,3种淀粉经韧化后晶型未有改变,但结晶度均显著提高,分子短程有序性增加,晶体结构更趋稳定;DSC分析表明,韧化处理后3种晶型淀粉的糊化温度显著升高,热焓值无显著变化;韧化处理对不同晶型淀粉消化特性的影响存在差异,3种淀粉经韧化后RS含量均显著增加,水解指数HI和血糖指数GI显著降低;玉米淀粉韧化后RDS含量显著增加,SDS含量显著减少,水解平衡浓度由84.81%降至76.79%;马铃薯淀粉中SDS和RDS含量均显著减少,水解平衡浓度由30.59%降至21.84%;韧化处理对锥栗淀粉的RS、SDS、RDS含量及水解平衡浓度变化影响较小。  相似文献   

9.
该文研究了等离子体活化水(plasma-activated water, PAW)协同韧化处理(annealing, ANN)对小麦淀粉结构及性质的影响。X射线衍射结果表明,与常规韧化处理相比,PAW-ANN没有改变小麦淀粉的结晶类型,但导致相对结晶度增加。傅里叶变换红外光谱和拉曼光谱结果表明,PAW-ANN没有使淀粉分子产生新的官能团,但增强了小麦淀粉的短程有序性。差示扫描量热分析表明,PAW-ANN使小麦淀粉的糊化焓值升高。黏度特性和动态流变特性分析表明,PAW-ANN降低了小麦淀粉的峰值黏度,增强了淀粉糊的凝胶强度。该研究提出了一种PAW协同韧化的双重物理改性新方法,为PAW在淀粉改性中的应用提供了新思路。  相似文献   

10.
针对目前鲜有的韧化和湿热处理对大米淀粉改性效果的对比研究,本文采用韧化及湿热处理大米淀粉,对比分析韧化处理和湿热处理对大米淀粉溶解度、膨胀度、消化性、糊化特性、微观结构及晶体结构的影响。结果显示,经韧化处理后,淀粉溶解度、膨胀度及还原糖释放率上升,凝胶强度升高,淀粉更易于糊化,但热稳定性降低;而经湿热处理后,淀粉溶解度、膨胀度和还原糖释放率明显降低,糊化凝胶强度减小,且更难于糊化,但淀粉的热稳定性提高,回生性降低。X-衍射分析表明,处理后大米淀粉依然为\  相似文献   

11.
    
To improve processability and nutritional properties, normal cornstarch is modified by dry heating treatment (DHT) at different heating temperatures (70, 100, and 130 °C) for different heating times (0, 2, 12, 48 h) after mixing with various amino acid types (aspartic acid and lysine). The combination treatment effectively retards the starch digestibility. Among all samples, the rapidly digestible starch content of lysine–cornstarch mixture after being heated at 130 °C for 12 h is the lowest (14.1%), which decreases by 13% as compared to cornstarch. The gelatinization temperatures, gelatinization enthalpy, and relative crystallization of the combination treated cornstarch increases while no significant changes are observed in the X-ray diffraction and Fourier transform infrared spectroscopy of those starches. With increasing DHT temperature or prolonged DHT time, the viscosity of the heated aspartic acid–cornstarch mixture decreases, while that of the heated lysine–cornstarch mixture increases. Cluster analysis indicates that there are obvious differences between the samples with added aspartic acid and adding lysine. The combination treatment at 130 °C shows a more significant effect on the properties of AA-CS.  相似文献   

12.
  总被引:3,自引:0,他引:3  
BACKGROUND: In recent years, germinated brown rice as a functional food has received great attention with its improved sensory and nutritional properties. Particularly of interest are the high levels of γ‐amino butyric acid (GABA) which can be obtained during germination. However, more studies are needed to fully understand the effect of germination on the physicochemical properties of brown rice. RESULT: Germination altered the chemical composition of brown rice, resulting in an increase in reducing sugar and ash content, and a reduction in amylose. Solubility, paste viscosity, transition temperatures (To, Tp and Tc) and percentage of retrogradation (%Retrogradation) were decreased, while swelling power and turbidity were significantly increased. Scanning electron micrographs indicated that starch granules from germinated brown rice became smaller and less homogeneous. Moreover, germination shortened the chain length of amylopectin and amylose molecules. CONCLUSION: This investigation provides information on changes in the characteristics of rice flour and rice starch during germination, leading to a better understanding on the chemistry of brown rice germination. Copyright © 2011 Society of Chemical Industry  相似文献   

13.
    
Long shelf life is important for industrially packaged cooked chestnut kernel. This study aims to investigate the physicochemical and digestive properties of starch in cooked chestnut stored for varying periods of up to 12 months. Apparent amylose content decreases significantly during the initial storage period of 2 months and then increases gradually in the succeeding 10 months. During storage, the degree of gelatinization decreases, whereas the degree of retrogradation (DR) increases. The relative crystallinity of cooked chestnut starch increases during storage and shows a significant positive correlation with DR. The content of rapidly digestible starch (RDS) decreases significantly during shelf life. Starch retrogradation and relative crystallinity exhibit a significant negative correlation with RDS content, and the short-range molecular order of starch is negatively correlated with the content of slowly digestible starch. The results indicate that the digestibility of cooked chestnut kernel decreases during storage because of an increase in the crystallinity of starch.  相似文献   

14.
    
BACKGROUND: Multicereal/pseudocereal blends based on major and minor seeds with high nutritional profile appear as a promising strategy, hardly explored, to obtain enhanced value grain‐based foods such as bread. RESULTS: In a preliminary stage the suitability of minor/ancient cereals (rye, oat, Kamut® wheat, spelt wheat) and pseudocereals (buckwheat) was assessed in single (100% of wheat flour replacement) and multigrain (from 20 to 44% of wheat flour replacement) matrices. The research allowed identification of the qualitative (oat, rye, buckwheat) and quantitative (up to 75% of wheat flour replacement) grains in the mixed matrices providing enhancement of nutritional quality (higher protein content, higher mineral content, lower digestible starch, higher viscous fibre content, higher resistant starch content, source of antioxidants) and minimisation of techno‐functional impairment and sensory depreciation of the resulting breads. CONCLUSION: The quality profile of associated mixtures of oat, rye, buckwheat and common wheat flours (20:20:20:40 w/w/w/w) endorsed the proposed grain blend as suitable to make highly nutritious, modern and innovative baked goods meeting functional and sensory standards in terms of nutritional added value (improved dietary fibre fractions, minerals and antioxidant activity, slower starch hydrolysis), palatability (high sensory scores), convenience (extended keepability during storage) and easy handling during processing. Copyright © 2011 Society of Chemical Industry  相似文献   

15.
以荔枝核为原料,采用超声辅助的方法提取荔枝核中的淀粉,与马铃薯淀粉和玉米淀粉比较,观察3种淀粉的颗粒形态、溶解率、酶解率、透光率、凝沉性和失重率.结果表明:荔枝核淀粉提取率在34%以上;显微镜下颗粒呈不规则椭圆形,粒径较马铃薯淀粉及玉米淀粉小;60℃时的溶解率为(2.06±0.29)%;酶解率为(27.91±0.18)...  相似文献   

16.
黑麦是制作面包的常用原料,但是关于黑麦的消化特性鲜有报道。作者以黑麦粉为原料,制备了脱脂黑麦粉、脱蛋白质黑麦粉及黑麦淀粉;探究了蛋白质、脂肪、淀粉对黑麦粉理化特性、体外淀粉消化速率及估计血糖生成指数的影响。经不同处理后,样品在化学组成、溶解度、糊化特性等方面均有显著差异,尤以黑麦粉和黑麦淀粉之间的差异最为显著。实验结果表明黑麦粉的淀粉水解速率低于脱脂黑麦粉、脱蛋白质黑麦粉和黑麦淀粉,且脱蛋白质处理对于黑麦粉体外淀粉消化速率的影响较脱脂处理更为显著。血糖生成指数(eGI)从低到高依次为:黑麦(69.19)脱脂黑麦(76.77)脱蛋白质黑麦(79.73)黑麦淀粉(81.08)。  相似文献   

17.

湿热处理因其安全、绿色、环保、高效的特点被广泛应用于淀粉的改性。本研究采用不同含水量的湿热处理(分别为20%、25%和30%,处理温度为120 ℃,处理时间为10 h)对藜麦淀粉进行改性并对其流变性质、体外消化性质和结构进行了测定。结果表明:所有样品均为剪切变稀型非牛顿流体,湿热处理后藜麦淀粉的表观粘度均显著降低,且随着湿热处理含水量的增加而降低。频率扫描实验结果表明随着湿热处理含水量的增加,藜麦淀粉的储能模量G'呈不断降低趋势,而损耗模量G'和损耗因子呈不断增加的趋势。触变实验表明,随着湿热处理含水量的增加样品的触变环面积不断降低。体外消化结果表明,湿热处理能够显著降低藜麦淀粉中的快速消化淀粉含量(P<0.05),且藜麦淀粉中的慢性消化淀粉含量随着湿热处理含水量的增加而显著增加(P<0.05)。在30%含水量下,湿热处理后淀粉所含慢性消化淀粉含量最高,为24.93%,相较原淀粉提高了31.42%。X-衍射结果表明湿热处理后藜麦淀粉的晶型未发生变化,均为A型结晶,但处理后淀粉的相对结晶度显著降低(P<0.05)。傅里叶红外结果表明湿热处理会降低淀粉的整体有序性,但会增加藜麦淀粉中双螺旋结构含量。扫描电镜下观察到相较于原淀粉,改性后的藜麦淀粉出现粘结团聚,部分颗粒表面会出现部分塌陷的现象。本研究结果表明,湿热处理能够显著改变藜麦淀粉的流变学性质,提高藜麦淀粉的慢消化淀粉含量。淀粉的含水量是影响湿热处理改性效果的主要因素。相关结果将为藜麦淀粉的应用提供理论依据。

  相似文献   

18.
    
BACKGROUND: Walnut (Juglans regia L.) is a good source of protein that has potential application in new product formation and fortification. The main objectives of this study were to investigate the effects of high hydrostatic pressure (HHP) treatment (300–600 MPa 20 min) on physicochemical and functional properties of walnut protein isolate (WPI) using various analytical techniques at room temperature. RESULTS: The results showed significant modification of solubility, free sulfhydryl content and surface hydrophobicity with increased levels of HHP treatment, indicating partial denaturation and aggregation of proteins. Differential scanning calorimetry and fluorescence spectrum analyses demonstrated that HHP treatment resulted in gradual unfolding of protein structure. Emulsifying activity index was significantly (P < 0.05) increased after HHP treatment at 400 MPa, but significantly decreased (P < 0.05) relative to the untreated WPI with further increase in pressure. HHP treatment at 300–600 MPa significantly decreased emulsion stability index. Additionally, HHP‐treated walnut proteins showed better foaming properties and in vitro digestibility. CONCLUSION: These results suggest that HHP treatment could be applied to modify the properties of walnut proteins by appropriate of pressure levels, which will help in using walnut protein as a potential food ingredient. © 2012 Society of Chemical Industry  相似文献   

19.
以'海藜'甘南'格尔木'和'静乐'4种藜麦淀粉为实验材料,玉米淀粉和马铃薯淀粉为对照,对其直链淀粉含量、支链淀粉链长分布、质构特性、冻融稳定性、凝沉性等理化性质以及消化特性进行分析.结果表明:相比对照,藜麦淀粉的直链淀粉含量较少,平均为10.10%,藜麦含有大量的短链支链淀粉,约为34.62%.藜麦淀粉凝胶内部结合...  相似文献   

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