豌豆淀粉的提取及其理化性质的研究

为了优化豌豆淀粉的碱法提取工艺,采用响应面法研究料液比、提取时间和碱液质量分数对淀粉中蛋白残留量及淀粉得率的影响。并采用扫描电镜、黏度速测仪、离子色谱对豌豆淀粉的表面结构、糊化特性及支链淀粉链长分布进行了研究。结果表明,碱法提取豌豆淀粉的工艺条件为:料液比1:7.26,提取时间18.00 h,NaOH溶液质量分数0.43%,在此工艺条件下制得豌豆淀粉的蛋白残留量为(0.081±0.005)%,淀粉得率为豌豆干基质量的30.5%。豌豆淀粉为表面光滑的椭圆形,与绿豆淀粉、豇豆淀粉和红豆淀粉比较,豌豆淀粉具有较低的峰值黏度和较高的糊化温度。豌豆淀粉的链长主要分布在聚合度9~25,属长链型淀粉,是制备粉丝、粉皮的良好原料。该研究为豌豆淀粉的生产及应用提供参考。     

天然黄酮类化合物含量测定方法研究进展

为大规模地研究、开发和应用天然黄酮类化合物,综述了目前天然黄酮类化合物含量的测定方法,主要有紫外分光光度法(直接测定法、比色法、差示分光光度法及双波长和导数分光光度法)、薄层扫描法、高效液相色谱法、荧光光度法、超临界流体色谱法和毛细管电泳法等几种主要的方法.     

绿原酸分析测定方法研究新进展

为了更准确地检测绿原酸的含量,对绿原酸含量分析的测定方法进行了综述。目前的检测方法主要有:紫外分光光度法、二阶导数光谱法、可见分光光度法、阻抑-催化褪色光度法、差示导数光谱法、二阶导数差示脉冲极谱定量分析法、胶束薄层色谱法、流动注射化学发光分析法、毛细管区带电泳法、薄层色谱扫描法(TLC法)、高效液相色谱法(HPLC法)、反相高效液相色谱法(RP-HPLC法)、系数倍率法、导数极谱法和HPLC法与其它方法的联用等,同时对绿原酸的检测方法进展进行了展望。     

慈菇淀粉分离纯化及其支链淀粉分子结构研究

本研究采用正丁醇法对慈姑支链淀粉与直链淀粉进行分离,Sepharose 2B凝胶层析表明支链淀粉得到纯化。采用酶法分析了慈姑支链淀粉的分子结构,结果表明慈姑支链淀粉的平均链长(CL)为22,其中外链长(ECL)为14,内链长(ICL)为7。异淀粉酶和普鲁兰酶依次作用于慈姑支链淀粉的β-极限糊精,计算得支链淀粉A链与B链比值为1.33:1.0,分支化度为2.33。     

淀粉的支链精细结构与消化性能

采用高效液相排阻色谱技术探索不同淀粉中支链淀粉精细结构与其慢消化性能的关系。结果表明：支链淀粉结构中的链长分布Fr Ⅰ(DP ＞ 30)、Fr Ⅱ(13 ＜ DP ＜ 30)均与慢消化淀粉(SDS)呈极显著正相关(r ＝ 0.909,P ＜0.05;r ＝ 0.847,P ＜ 0.05);Fr Ⅲ(DP ＜ 13)与SDS 呈极显著负相关(r= － 0.869,P ＜ 0.05)。支链淀粉的分支链长分布与淀粉低血糖特性关系密切,可采用基因工程调控淀粉链合成从而开发高营养品质的新淀粉品种。     

双波长法测定糯米粉支链淀粉的含量

研究了双波长分光光度法测定糯米粉中支链淀粉的含量。对最佳波长的选择进行了详细考察、比较。选择支链淀粉的测定波长为534 nm,参比波长为732 nm。并与碘比色法测定糯米粉中支链淀粉的含量进行了比较,结果表明双波长方法重复性和稳定性都好,碘比色法测得支链淀粉含量比双波长法偏大。     

纺织品中荧光增白剂的应用及检测技术现状

荧光增白剂是一种荧光染料,广泛应用于纺织品、皮革等领域,对人体具有潜在的危害性。本文讲述了纺织品中荧光增白剂的增白原理,以及国内外纺织品中荧光增白剂的检测方法,主要包括紫外灯照射检测法、紫外-可见分光光度法、荧光分光光度法、超高效合相色谱法和液相色谱-串联质谱法等。     

食品中柠檬酸的检测方法研究进展

结合国内的研究进展,综述了食品中柠檬酸的各种检测方法。其中重点介绍了比较常用的测定方法,如高效液相色谱法、离子色谱法、气相色谱法、电泳法、分光光度法等,并建议采取有效方法进行检测。     

食品中柠檬酸的检测方法研究进展

结合国内的研究进展,综述了食品中柠檬酸的各种检测方法。其中重点介绍了比较常用的测定方法,如高效液相色谱法、离子色谱法、气相色谱法、电泳法、分光光度法等,并建议采取有效方法进行检测。      

有机五色小米淀粉的精细结构、理化性质和消化性研究

目的 本研究通过从有机红谷小米、绿小米、白小米、金苗小米和黑小米中分别分离纯化制备得到有机五色小米淀粉。方法 利用现代分析仪器测定五色有机小米淀粉的形貌特征、结晶结构、功能特性和消化特性。利用体积排阻色谱分析法(Size exclusion chromatography,SEC)与荧光辅助毛细管电泳法(Fluorescence assisted capillary electrophoresis, FACE)测定五种有机小米的直链淀粉含量和支链淀粉的链长分布。构建有机五色小米淀粉精细结构与理化特性,功能特性和消化性之间的关联。结果 体外斜率对数法(Log of Slop,LOS)消化性结果表明,有机五色小米淀粉的最终消化率(C₁₂₀)差别并不明显,其中黑小米淀粉的C₁₂₀最低(72.23±4.97%),金苗小米淀粉的C₁₂₀最高(78.15±0.40%),其次依次为白小米>绿小米>红谷小米。有机五色小米淀粉中绿小米淀粉最易糊化,与自身支链淀粉的短链分布有关。有机黑小米淀粉糊化峰值温度最高,金苗小米次之,与其结晶度及直链淀粉含量有关。黑小米淀粉的峰值粘度最低,最难糊化,与支链淀粉的平均链长较长难断裂有关。有机五色小米淀粉结晶度整体差异不大,半结晶结构中红谷小米的松散程度最大。结论 研究不同品种有机小米淀粉的差异性,为人们科学饮食搭配及个性化营养提供重要参考价值。     

Chain Length Distribution of Amylopectin and Physicochemical Properties of Starch in Myanmar Rice Cultivars

Three different types of amylopectin: long chain length of amylopectin (L-type), medium chain length of amylopectin (M-type), and short chain length of amylopectin (S-type) were classified in 16 rice cultivars (3 for L-type, 6 for M-type, and 7 for S-type amylopectin) based on chain length distribution of amylopectin by fluorophore-assisted carbohydrate electrophoresis through capillary electrophoresis. Frequency distribution of amylopectin chain ratio and short chain ratio supported three types of amylopectin. Ta Soke Pwa and Thet Nu Saba Net Pyan had high values of transition temperatures in a range from (70.7, 74.0, and 77.6°C) to (71.4, 75.0, and 78.8°C) in differential scanning calorimeter analysis. Alkali spreading values and starch gelatinization characteristics in 4 M urea solution showed the association between chain length distributions of amylopectin in Myanmar rice cultivars. A simple linear regression in Myanmar rice cultivars was observed for fa, fb1, amylopectin chain ratio, and short chain ratio with alkali spreading values, with R² values of 0.68, 0.84, 0.84, and 0.81, respectively.     

纺织品中五氯酚残留量检测方法的研究

概述了纺织品五氯酚(PCP)残留量的检测方法,包括分光光度法、高效液相色谱法(HPLC)、高效液相色谱/质谱联用法(HPLC/MS)、气相色谱法(GC)、气相色谱/质谱联用法(GC/MS)和免疫分析法等,总结了各种检测方法的优缺点,并提出了纺织用PCP残留检测的发展方向.     

双波长法测定南瓜中直链与支链淀粉含量

为建立同时测定南瓜中直链和支链淀粉的双波长比色法。本文采用正丁醇结晶法分离纯化南瓜中直链和支链淀粉并测定其含量。结果表明,分离纯化得到的直链和支链淀粉蓝值分别为0.874和0.196;根据双波长原理和扫描谱图,确定其测定波长为645、565 nm,参比波长为495、730 nm处测定南瓜中直链与支链淀粉含量;南瓜样品中直链淀粉占21.64%,支链淀粉占50.19%,总淀粉含量为71.83%,相对标准偏差分别为0.97%和1.06%,平均回收率分别为98.62%和99.42%,检出限分别为0.0116和0.0644 mg/mL。正丁醇结晶法能有效地分离南瓜直链与支链淀粉,双波长法可同时获得南瓜中3个淀粉含量指标,该方法既节省了样品,又提高了效率。同时,该方法的建立也为南瓜淀粉理化特性的研究提供了技术支持。     

Fine Structure of Mung Bean Starch: An Improved Method of Fractionation

Laboratory isolated mung bean starch was fractionated into its amylose and amylopectin components using a modified procedure. The resulting products were shown to be both homogeneous and more susceptible to the hydrolyzing enzymes commonly used for structural analysis. The fine structure of the fractions was investigated using hydrolytic enzymes, chemical analysis and gel filtration chromatography. Differences in amylose/amylopectin fractions isolated by the modified and conventional extraction procedures were apparent. The unit chain length of amylopectin, DP_n and limiting viscosity number of amylose were all lower for samples isolated by the modified method. In contrast the enzymatic hydrolysis of both the amylose and amylopectin fractions was improved for the material extracted by the modified method, low levels of branching and a unit chain distribution by gel filtration chromatography of the two overlapping populations with average degree of polymerization of 42 and 14 was obtained.     

大豆异黄酮分离及其检测方法研究概述

该文从几个方面论述层析法和高效液相色谱法等分离大豆异黄酮方法,和紫外分光光度法、三波长吸光光度法、高效液相色谱-质谱法、气相色谱法等检测大豆异黄酮方法及其这些分离检测方法特点和操作要点,还简要介绍医学免疫法测定大豆异黄酮方法。     

Orthogonal-function spectrophotometry for the measurement of amylose and amylopectin contents

In this study, orthogonal-function spectrophotometry (OFS) was used for the first time in the determination of amylose and amylopectin contents. A six-point quadratic orthogonal polynomial (QOP) was chosen for amylose determination at an interval of 8 nm, and an inter-wavelength of 596 nm. For amylopectin determination, a ten-point QOP was selected with an interval of 22 nm and an inter-wavelength of 538 nm. OFS was more precise, with a standard deviation (SD) of 0.4–0.7 for both amylose and amylopectin content analyses. Dual-wavelength colorimetry (DWC) showed a SD of 1.3–2.5 and 3.8–4.6 for amylose and amylopectin content analyses, respectively. OFS has an acceptable recovery ratio and hence has an advantage over DWC in determining amylose and amylopectin concentration in solution without prior separation. OFS is an alternative method for the analysis of amylose and amylopectin content.     

橄榄多酚含量测定方法的比较

采用酒石酸铁法、福林酚试剂法和紫外分光光度法3 种方法测定橄榄多酚类物质含量。结果表明： 3 种方法检出限及定量限的顺序为：紫外分光光度法＜福林酚试剂法＜酒石酸铁法,且3 者存在显著性差异 （P＜ 0 . 0 5）。3 种方法回收率顺序为：酒石酸铁法＞福林酚试剂法＞紫外分光光度法,但差异不显著 （P＞0.05）,这3 种方法都具有良好的重复性。利用福林酚试剂法与紫外分光光度法测得的多酚含量显著高于酒 石酸铁法（P＜0.01）,其中福林酚试剂法测得的多酚含量略高于紫外分光光度法,但差异不显著（P＞0.05）。同 时,各方法测得的多酚含量存在良好的线性关系。实验证明紫外分光光度法灵敏度高、重复性好,且操作简单、快 速、经济,是一种较理想的测定橄榄多酚的方法。     

Comparison of the starch properties of Japanese wheat varieties with those of popular commercial wheat classes from the USA,Canada and Australia

The starch properties of four Japanese wheat varieties/breeding lines suitable for both bread and noodles were compared with those of popular commercial wheat classes from the USA, Canada and Australia. All starches were analyzed for amylose content, pasting properties measured by a rapid visco analyzer (RVA), swelling power, thermal properties measured by differential scanning calorimetry (DSC), enzyme digestibility, and chain length distribution of amylopectin (DP 6–17). All starch characteristics studied, except the chain length distribution of amylopectin, were significantly different among the tested wheat classes and varieties/breeding lines. Including Japanese wheat varieties/breeding lines, higher amylose contents and lower peak viscosities were found in hard wheats than in soft wheats. Interestingly, enthalpy, in the amylose–lipid complex measured by DSC, showed significant correlations with the pasting temperature from the RVA and swelling power.