淀粉糊化工艺的研究

运用Brabender糊化仪研究了玉米淀粉的糊化特性,比较了玉米淀粉和大米淀粉的糊化特性差异．结合玉米淀粉的糊化特性,研究了糊化料水比、耐高温仅一淀粉酶添加量、耐高温α-淀粉酶的品种等因素对玉米淀粉糊化、液化效果的影响。根据玉米淀粉的糊化性质,优化确定了玉米淀粉的糊化工艺,在大生产中进行了验证和对比。     

部分糊化玉米淀粉浆液的性能

以玉米淀粉为原料,采用蒸汽升温法制备部分糊化淀粉浆液。运用光学显微镜、粒度分析仪、差示热分析仪、X射线衍射仪等对原淀粉和用蒸汽升温法于不同温度下制备的部分糊化淀粉浆液的形态结构、颗粒大小、膨胀势、糊化度、结晶度等进行了测试和比较。结果表明:随着制备温度的提高,部分糊化淀粉浆液的偏光十字逐渐消失,结晶度下降,而糊化度、粒径、膨胀势逐渐增大;64℃时制备的稳定性较好的部分糊化淀粉浆液的大部分偏光十字消失,但仍有结晶峰存在,糊化度为72.22%。     

预糊化淀粉在食品中的应用

本文介绍了预糊化淀粉的性质及其在食品中的应用。糊化度是预糊化淀粉的一个重要质量指标 ,因此同时简要介绍了检测和提高产品糊化度的方法。     

淀粉的不同糊化方法

综述淀粉的不同糊化方法,对目前常用的糊化方法和新型化学糊化方法分别进行概述,阐述了这些方法的原理和应用,探讨将新型化学糊化方法应用于淀粉颗粒结构研究的途径.     

配料对淀粉峰值黏度和糊化温度的影响

采用RVA快速黏度仪研究了食盐、蔗糖和植脂末等配料对普通和高支链玉米淀粉的峰值粘度和糊化温度的影响。结果表明,对于NaCl和蔗糖来说,随着其质量分数的升高,普通和高支链淀粉的峰值黏度和糊化温度均增大;而对于植脂末,普通淀粉在其质量分数小于6%时,其峰值黏度升高,糊化温度基本不变,大于6%时,峰值黏度和糊化温度均降低。高支链玉米淀粉在植脂末质量分数小于4%时峰值黏度和糊化温度均略微降低,而大于4%时均升高。研究结果有助于阐明玉米淀粉糊化的规律,以及为其它谷物淀粉糊化工艺提供借鉴。     

小麦淀粉高压糊化动力学的研究

本文采用差示扫描热分析（ＤＳＣ）法测定了不同压力下处理不同时间的小麦淀粉的糊化度,计算了小麦淀粉压车湖化反应动力学参数,结果表明,科淀偻的加压糊化为一级反应,压力分别在３００ＭＰａ、４００ＭＰａ、４５０ＭＰａ其糊化速率常数０．３６、０．４５和０．５;压力对速率常数的影响可用。     

蒸煮工艺参数对绿豆糊化特性的影响

浸泡和蒸煮是豆类食品加工的必须程序,直接影响产品的品质。通过对不同浸泡时间下绿豆胀豆率以及不同蒸煮时间对绿豆硬度和糊化特性的影响研究,确定了绿豆的最佳泡豆温度为35℃、时间为5h、最佳蒸煮时间为15min;并建立了绿豆硬度和糊化度、糊化度与RVA糊化特性各特征值之间的线性回归方程,证明糊化度和硬度、糊化度和RVA特征值之间存在极显著的线性关系。     

糊化度研究进展及在高粱品控上迁移应用研究

糊化度是衡量谷物食品熟化程度的指标，糊化度的把控对于食品行业意义深远。本文对不同谷物的特性、糊化及现阶段食品加工业常用的糊化方式和糊化检测方法进行概述，并探讨相关技术方法和思路在高粱品控和酱香型白酒生产中的意义和应用。     

酿酒用大米糊化效果的影响因素分析研究

大米是多粮浓香型白酒的重要原料之一,能使酒体净爽、醇厚。蒸粮过程中大米的糊化程度直接影响酒的产量和质量。本实验在比较不同品种大米糊化曲线及糊化时间差异的基础上,进一步探讨大米干燥方式、大米品种、润粮时间、大米粉碎度等因素对多粮浓香型白酒蒸粮过程中粮食糊化程度的影响。结果表明,不同品种大米本身的糊化时间不同,在酿酒过程中的糊化程度也有较大差异;扫描电镜结果表明不同品种稻米的胚乳淀粉体结构不同,蒸煮后稻米的糊化程度差异较小;延长润粮时间、控制大米的粉碎粒度能在一定程度上加快酿酒大米的糊化程度。     

糊化淀粉的研究进展

阐述了淀粉的糊化机理,分析得出影响糊化效果的因素主要有水分、温度、淀粉类型及其它因素;总结了糊化淀粉的特点,介绍糊化淀粉生产的方法主要有热糊化、压力糊化和化学糊化法,且前两种方法适合工业化规模生产;最后介绍糊化淀粉在各行业的应用,并提出展望。     

NaCl和糖对葛根淀粉糊化特性的影响

通过差示扫描量热法（DSC）研究糖和盐对葛根淀粉糊化特性的影响，结果表明葡萄糖，果糖和蔗糖均可使葛根淀粉的糊化温度（包括T0，TP和TC）糊化焓△H升高，不同的糖对提高葛根淀粉糊化温度的顺序依次为蔗糖＞葡萄糖＞果糖。NaCl的添加也可导致葛根淀粉糊化温度（T0,TP,TC）和糊化焓△H升高，其上升的幅度与NaCl的添加量呈正相关性。     

超高压对植物淀粉影响研究进展

非热力处理技术中的超高压处理技术已被认为是目前国际上食品领域的高新技术,其特点是能最大限度地保持食品中营养成分,具有广阔的应用前景。本文主要综述了超高压对植物淀粉的糊化特性、表观粘度、结晶结构以及淀粉酶活性的影响,为超高压淀粉改性技术的深入研究提供有益的借鉴。     

稻米的凝胶特性研究

用拉伸应力法对不同糊化时间、含水量和糊化度的大米的凝胶特性进行了研究。建立了弹性模量与拉伸时间的数学模型。弹性模量具时变性,与拉伸时间成倒数关系。糊化时间和加水量对凝胶断裂强度的响应面分析表明,在糊化时间为7．631min,加水量为56．15％,断裂强度有极小值4．79gf/mm^2。糊化度、糊化时间和加水量都与时间系数成负相关。     

A Small‐scale Spectrophotometric Method for Determining Starch Gelatinisation

The development of a small‐scale spectrophotometric method of determining both onset and peak gelatinisation temperatures of starch is reported. In this assay the changes in absorbance of a dilute starch suspension are measured at 380 nm as the suspension is heated to 95°C. The values obtained from this method for both onset and peak gelatinisation temperatures correlate extremely well with those obtained by DSC, but are generally 5°C to 10°C lower. This method works on both pure and crude starch samples and thus has the potential to be used in a high‐throughput format allowing up to 100 samples per day, making it useful for research and breeding programs in which large numbers of impure starch samples need to be assayed. This allows for earlier selection of the lines of interest, which can then be analysed more comprehensively with techniques such as DSC which provide a greater amount of information, thus saving the researchers' time and money.     

Chemical and Functional Characterization of Products Obtained from Yam Tubers

Aiming to find alternative uses of yam (Dioscorea alata) in the food industry, three products (flour, starch and mucilage) were obtained form yam tubers and characterized. Flours were obtained from peeled fresh tubers, dried at two different temperatures (30 and 55 °C) and then milled. Starch and mucilage were extracted from mashed yam before drying. Products were characterized by their chemical, structural, morphological, rheological and thermal properties. Flours showed differences in pasting, thermal and water absorption properties as a function of drying temperature. Starch contained 30% amylose. The analysis of monosaccharide composition of starch showed traces of mannose, xylose and rhamnose. The onset gelatinization temperature was 74.4 °C for starch, whereas those for flours varied between 71.5 and 74.4 °C. The relatively high gelatinization temperature and the absence of breakdown in the amylograph test evidenced the stable structure of starch when submitted to heat and shear. The mucilagenous material contained 55.36% protein and 43.05% starch, and also an acidic polysaccharide fraction linked to a neutral fraction. Flow curves of 1% mucilage dispersions showed a pseudoplastic behavior with high pH sensitivity. Results demonstrated that yam products have promising applications in the food industry.     

Application of unreacted-core model to in situ gelatinization of chickpea starch

Unreacted-core model for reaction-controlled systems was tested on modeling of starch gelatinization in whole chickpea (in situ) during cooking. Experiments were conducted in deionized water at 50, 60, 70, 80, 90, and 100 °C. The process was followed through images of the flat sides of the chickpea cotyledons. During cooking between 60 and 100 °C, a white core in the original color of the cotyledons and a surrounding opaque yellow zone were observed on the cotyledons. According to birefringence studies starch granules in the yellow zone were gelatinized, and in the white core they remained ungelatinized. The formation of the yellow color was connected to the gelatinization in the peripheral zone. During cooking at 50 °C the color change was not observed because of working below the gelatinization temperature of chickpea starch. The area of the gelatinized zone increased at the expense of the area of the ungelatinized core with the progress of the cooking. The unreacted-core model fitted the process very well, and the estimated gelatinization times were in good agreement with the experimental gelatinization times. The kinetic data for the gelatinization reaction estimated after verifying the unreacted-core model were in agreement with the literature. These findings indicated that the in situ gelatinization of chickpea starch can be modeled using the unreacted-core model, and the process is effectively gelatinization-controlled under the given conditions.     

乳化剂在面包烘烤中的作用

比较了几种乳化剂与面粉中蛋白质和淀粉的作用,并对其不同晶型和复合形式对面包的改良效果进行了比较。结果表明,乳化剂不仅可以提高面团的耐揉性,更重要的是可以提高淀粉糊化温度,延长淀粉糊化时间,保证面团在较长时间内具有可膨胀性,为面团入炉后的进一步膨胀弹起创造条件,从而增大面包烘焙体积;粉状或颗粒状乳化剂不宜直接加入面粉中使用,须处理成a晶型后才能发挥最大效果;将不同种类的乳化剂适当复合,能产生明显的协同增效作用;粘度仪是研究乳化剂对淀粉性质影响的有效手段。     

Effect of damaged starch on wheat starch thermal behavior

The influence of damaged starch (DS) on gelatinization and retrogradation wheat starch properties was investigated. Samples with different content of DS were obtained and evaluated. DSC was used for monitoring the changes in thermal behavior of the starch samples at different water amounts. Starch thermal transitions were affected simultaneously by DS content and water content. The Flory–Huggins parameters were modified by DS. A significant raise in the T°_m, and x_1–2, and a decrease in ΔH_u was recorded. The AP retrogradation kinetics was evaluated by Avrami model. A significant increase of the AP crystallization rate was observed when DS increased. The results demonstrated the importance of the presence of physically damaged granules on wheat starch properties.     

Physicochemical properties of starches obtained from Polish potato cultivars

Selected physicochemical, thermal, and rheological properties of starches isolated from new Polish potato varieties were determined. The starches contained 25.7–30.0 g/100 g d.m. of amylose and 59.5–90.2 mg/100 g d.m. of phosphorus. Gelatinization temperatures were 62.6–64.0, 68.9–69.9, and 73.6–77.0°C for T_O, T_P, and T_E, respectively, whilst enthalpy of gelatinization amounted to 11.1–15.3 J/g. The retrogradation degree of starch was from 52.90 to 78.53%. Pasting curves showed significant differences between the starches. Peak viscosity and final viscosity ranges were 2035–4458 and 1931–2985 mPa · s, respectively. Starch pastes exhibited non‐Newtonian, shear thinning, and thixotropic behavior. After cooling they demonstrated diversified viscoelastic properties, however, all of them were classified as weak gels. Significant linear correlations among selected rheological parameters and amylose and phosphorus content were found. Results of principal component analysis demonstrated an ability to differentiate the starches isolated from different potato varieties.