红薯/玉米淀粉共混物糊、流变及热力学性质研究

以不同质量比(0100,2575,5050,7525,1000)的红薯/玉米淀粉混合物为原料,用不同试验方法研究其糊化及流变学特征。布拉班德糊化结果表明:玉米淀粉成糊温度(77.7℃)高于红薯淀粉(73.2℃),红薯淀粉峰值黏度(513BU)大于玉米淀粉(281BU),混合淀粉的崩解值及回生值介于单一种类淀粉之间;动态频率扫描结果表明:玉米淀粉的储能模量约是红薯淀粉的4倍,混合淀粉的模量介于单一品种淀粉之间,均为弱凝胶;稳态流变曲线表明:被测样品符合Herschel-Bulkley模型,均为非牛顿型流体,相较于单一淀粉,红薯/玉米淀粉混合物触变性假塑性更强。剪切结构恢复力结果表明:红薯/玉米混合物淀粉凝胶抗剪切能力低于玉米淀粉。差示扫描量热(Differential scanning calorimetry,DSC)测定结果表明:玉米淀粉具有较高的热焓值,红薯/玉米混合淀粉热焓值降低。     

Effect of phytochemical extracts on the pasting,thermal, and gelling properties of wheat starch

Pasting, thermal and gel textural properties of wheat starch were studied in the presence of phytochemical extracts from pomegranate peel (C18), green tea (C53), Chinese hawthorn (C54), and Chinese gall (C46). All the four extracts increased the breakdown values and reduced the final viscosity. C18, C46, and C53 increased the peak viscosity. C18 and C46 reduced peak time and hot paste viscosity. All the four extracts reduced gel hardness. C46 increased gel adhesiveness. C46 facilitated the gelatinization of starch with earlier onset of T_o, T_p and T_c and a higher melting enthalpy whereas C18 and C54 prolonged the T_o, T_p and T_c and decreased the melting enthalpy. All phytochemical extracts caused earlier onset of T_o and T_p of amylose inclusion complex melting without altering the enthalpy. Scanning electron microscopy revealed that phytochemical extracts could cause looser gel matrices of dried wheat starch gels. Colour observation showed phytochemical extracts imparted different colours to wheat starch gels.     

大豆多糖对大米淀粉糊化及凝胶特性的影响

以大米淀粉为材料,研究了大豆多糖对淀粉糊化及凝胶特性的作用.通过布拉班德黏度计,DSC差示量热扫描和质构仪等分析手段,研究分别添加相当于淀粉干基质量分数1.0%、2.5%、5.0%的大豆多糖的影响.结果表明,大豆多糖能有效降低大米淀粉黏度,改善其凝胶品质,且添加量越大,效果越明显,对淀粉基食品的改良有重大意义.     

核桃蛋白对大米淀粉凝胶化及凝胶特性的影响

研究不同核桃蛋白添加量下大米淀粉的糊化特性、流变特性、热特性及凝胶质构和水分子状态.结果表明,核桃蛋白以浓度依赖的方式降低了大米淀粉糊的黏度和相变焓值,而使糊化温度升高,当核桃蛋白添加质量分数达12％时,峰值黏度、谷值黏度、最终黏度分别降低了 30.77％、12.35％和14.65％,糊化温度升高了 8.89％;所有样...     

The effect of rice variety and starch isolation method on the pasting and rheological properties of rice starch pastes

The effect of rice variety and starch isolation method on the pasting and rheological properties of rice starches was evaluated. One waxy and three non-waxy rice varieties from California with a range of amylose contents of 1.6–26.5% and four methods of isolation were evaluated. A rotational rheometer (RR) was used to measure the pasting and rheological properties of starch dispersions (8% w/w). The RR pasting curves had similar shapes to those from a rapid visco-analyzer (RVA). The four treatments used for isolating starch were a protease, NaOH (0.1% and 0.4%), or sodium dodecyl sulfate (SDS) (1.0%). The NaOH (0.4%) and SDS treatments were found to reduce the peak pasting temperatures of the non-waxy starches as compared with the protease and NaOH (0.1%) treatments. The same trend of the treatments was found with the elastic moduli, low shear viscosities, and yield stresses of the non-waxy starch pastes measured at 65 °C, immediately after pasting. The elastic moduli of the waxy starch pastes appeared to be least affected by method of starch isolation, but the low shear viscosity and yield stress of the protease starch paste was significantly higher than the paste from the other three treatments. Overall, the method of rice starch isolation was found to affect the gelatinization and rheological characteristics of hot rice starch paste.     

Effect of wheat germ addition on the microbiological quality,in vitro protein digestibility,and gelatinization behavior of macaroni

Macaroni was produced from semolina blended with 15% raw and microwaved wheat germ. Samples were stored at room temperature and monitored over one year of storage in terms of their sensory attributes, microbial count, in vitro protein digestibility, and gelatinization phenomena. Small but significant differences between the sensory attributes of the blended samples and those of control macaroni samples were found using the triangle test, and these differences didnt change significantly after a year of storage. Supplementing semolina with raw and microwaved wheat germ resulted in macaroni that gave similar results to control macaroni in terms of in vitro protein digestibility. Differential scanning calorimetry (DSC) was used to study the extent of gelatinization of the starch in the macaroni samples. Two endothermic transitions were observed. Significant changes in the gelatinization of the semolina and macaroni were observed after the addition of raw and microwaved wheat germ. Control macaroni had higher onset (T_o1) and peak (T_p1) temperatures, as well as a narrower gelatinization range (T₁), and a lower gelatinization enthalpy (H₁) than the control semolina. Addition of raw and microwaved wheat germ to the macaroni increased T_o1, but lowered the T₁ and H₁ values of the macaroni significantly. The nature of the second endothermic DSC peak indicated an increase in the amylose-lipid complexation (H₂) in the macaroni after enrichment with raw and microwaved wheat germ.     

Effect of damaged starch on the rheological properties of wheat starch suspensions

The influence of damaged starch content on particle size distribution and rheological properties of unheated starch suspensions and pasting properties were investigated. Four samples containing different amounts of damaged starch were studied. Particle size distribution curves shifted toward higher diameters, and a greater overlap of both populations of particles (A- and B-type granules) and a decrease of both peak heights were produced. The flow curves of unheated starch suspensions were fitted using the power law model. The flow behavior indexes were higher than the unit. The consistency coefficient increased with the increment of damaged starch content. Unheated starch suspensions showed time-dependent rheological behavior and were described by the Weltman model. The unheated suspensions exhibited a thixotropic behavior. With regard to the pasting process, the increment of damaged starch content produced gradual reductions in peak viscosity, final paste viscosity, breakdown and setback. Results demonstrated the importance of the presence of physically damaged granules in wheat starch rheological characteristics.     

糯小麦与非糯小麦面粉糊化特性的比较

淀粉是小麦籽粒的重要组成部分,约占小麦粒重的70%～75%。淀粉糊化特性的不同是区分小麦类型、判断小麦淀粉品质特性的重要依据。实验以农大糯麦1号、糯227等5个糯麦品种及非糯小麦品种京411为材料,利用RVA测试其糊化特性,结果表明,糯麦与非糯小麦在峰值黏度、峰值时间、糊化温度等糊化特性参数上存在显著差异,而峰值黏度与小麦的糯性与否无关。     

淀粉糊化及其检测方法

淀粉糊在食品工业具有重要应用价值,淀粉糊性质直接影响食品品质。该文介绍淀粉糊化特性及其检测方法,详述各种检测方法在淀粉糊中应用实例,并指出其中优缺点;提出今后淀粉糊检测方法发展方向,为淀粉糊在食品工业广泛应用奠定基础。     

苦荞淀粉糊化性质的研究

通过使用DV-T2黏度温控一体机测定苦荞淀粉在不同溶剂中黏度的变化曲线.结果 表明,苦荞生粉的热稳定性、凝胶性较早餐粉苦荞强,更易回生;以硬度高的水为溶剂时苦荞淀粉的热稳定性较好,凝胶性较弱,不易回生;以柠檬酸溶液或食盐溶液为溶剂时,苦荞淀粉的热稳定性随浓度的升高而增强,凝胶性随浓度的升高而减弱,不易回生;以蔗糖溶液为...     

芒果皮粉对淀粉糊化与老化特性的影响

采用布拉班德黏度仪、差示扫描量热仪等测定芒果皮粉的添加对玉米淀粉和大米淀粉黏度、热特性、透光率、沉降率、凝胶硬度与色泽的影响。结果表明,随芒果皮粉添加量(0%~15%)的增加,2种淀粉的起糊温度逐渐降低,玉米淀粉糊峰值黏度在添加15%芒果皮粉时显著升高,崩解值增大;大米淀粉糊峰值黏度呈降低趋势,崩解值先降低后升高,2种淀粉回生值都显著降低。芒果皮粉的添加显著降低了2种淀粉的糊化和老化焓值及贮藏中透光率与沉降率的下降程度,减小玉米淀粉凝胶的硬度,降低了2种淀粉凝胶色泽的变化程度。说明芒果皮粉的添加影响淀粉的糊化特性,且影响趋势随淀粉品种不同而异,但能有效抑制2种淀粉的老化。     

甘薯淀粉磷酸酯糊化特性研究

以甘薯淀粉为原料,与三偏磷酸钠反应,制得甘薯淀粉磷酸酯;并采用偏光显微镜、分光光度计、旋转粘度计等现代分析仪器,对所生成不同取代度的淀粉磷酸酯糊化特性进行了较为详细的研究。结果表明:甘薯淀粉磷酸酯糊化温度升高,其冷热粘度稳定性、冻融稳定性、耐盐能力较原淀粉有所提高,但透明度、凝沉性与原淀粉相比无明显优势;取代度的变化对这些性能有显著的影响。      

蛀蚀害虫侵害后小麦粗淀粉含量及其糊化特性变化

为探讨蛀食性害虫玉米象、米象侵害后小麦粗淀粉含量和全麦粉糊化特性的变化,选用河南产储藏3年的商品小麦为材料,按不同虫种分组,设定不同的虫口密度和侵害时间,检测害虫感染后小麦粗淀粉含量和全麦粉的糊化特性。结果表明:玉米象和米象不同程度感染后小麦粗淀粉含量总体呈下降趋势;无论是同一虫口密度随着蛀蚀时间的延长,还是同一蛀蚀时间下随虫口密度增加,其感染后的全麦粉峰值黏度、最低黏度、最终黏度、衰减值和回生值均呈下降趋势;糊化温度呈上升趋势,峰值时间基本无变化;粗淀粉含量与峰值黏度、最低黏度、最终黏度、衰减值和回生值均存在极显著正相关,与糊化温度呈极显著负相关,与峰值时间无相关性。     

Kinetics of cowpea starch gelatinization and modeling of starch gelatinization during steaming of intact cowpea seed

Steaming of cowpea seeds prevents weevil infestation during storage. Physicochemical changes such as starch gelatinization from steaming may lead to seed resistance to weevil penetration and digestion. A kinetics of starch gelatinization was constructed and incorporated in a heat and mass transfer model to quantitatively investigate starch gelatinization in intact seeds during steaming. The outer layers of steamed seeds (0.5 mm thick) were removed by a specially designed grinding device to measure degree of starch gelatinization (DG). The predicted DG in the outermost layer of seeds was found to be in good agreement with experimental data. The average relative error for DG was 14.6%.     

小杂粮淀粉糊化及回生研究进展

荞麦、燕麦、糜子是特色小杂粮,但由于对其糊化特性和老化特性影响因素缺乏系统的研究,对其开发依旧停留在初级加工的水平,制约了甘肃特色杂粮加工产业的发展。该文从淀粉自身特性、外源物质添加和加工方式三个方面综述了近年来促进粉糊化与抑制淀粉回生新技术,为特色小杂粮的高质化利用提供理论支持。     

Effect of the extent of pasting on the dynamic rheological properties of acidified skim milk gels containing normal rice starch

The dynamic rheological behaviour of skim milk gels containing 2% normal rice starch granules pasted to different temperatures was investigated. The extent of swelling of the starch granules was also measured. It was found that the complex modulus G* was maximal when the starch granules were pasted to the temperature of maximum swelling and not to the temperature of maximum viscosity. It is suggested that, in these systems, the starch granules behave as inactive fillers and that their main effect is to increase the milk protein concentration during swelling by absorbing water from the continuous phase. A simple empirical model that agrees qualitatively well with the experimental results is proposed.     

Pasting and rheologic properties of potato starch and maize starch mixtures

This study characterized the pasting and rheologic behavior of potato/maize starch mixtures of various ratios. Pasting analysis using a Brabender Viscograph indicated that most important pasting parameters did not show a linear change that reflected the ratio of starches. A significant effect on final viscosities and setback was evident. The diameter distribution of starch granules that were heated to 70°C was determined by a laser particle size analyzer. The result suggested that the swelling of starch granules in the mixtures was reduced at the onset of gelatinization. Measurement of dynamic viscoelasticity measurement demonstrated that the mixtures showed slightly higher loss modulus than those seen for the control at small measuring frequencies. The mixture pastes with a high proportion of potato starch exhibited more pseudoplasticity and had a more significant thickening effect than either control paste. Nonadditive behavior was found by mixing potato and maize starch. This suggests that an appropriate blend of starches from diverse botanical origins may provide a simple practical avenue for manipulation.     

莲藕淀粉糊化温度的测定

对莲藕糊化温度的三种测定方法展开比较,得出偏光十字消失法测得莲藕淀粉的糊化温度为63.8～71.8℃,差示扫描量热分析法(DSC)测得糊化温度为63.5～74.7℃,动态流变仪法测得糊化温度为60.1～66.2℃。得出结论:在一般的实验室里,品种相同的情况下,应用偏光十字消失法是较为准确且经济的测定方法;如果条件允许,动态流变仪法是相对精确的方法。