双波长法测定木薯淀粉中直链和支链淀粉的含量

目的：分离纯化木薯淀粉中的直链和支链淀粉,建立同时测定木薯淀粉中直链与支链淀粉含量的双波长法。方法：采用正丁醇结晶法分离纯化直链和支链淀粉,蓝值比较法表征直链与支链淀粉的纯度;根据双波长法原理,分别在测定波长624、538nm,参比波长440、750nm处测定木薯淀粉中直链与支链淀粉含量。结果：分离纯化得到的直链与支链淀粉蓝值分别为0.979和0.144,分别落在0.8～1.2与0.08～0.22范围内,表明纯化后木薯直链与支链淀粉的纯度较高;直链淀粉在0～80mg/L质量浓度范围内其碘复合物与吸光度呈线性关系(r＝0.9992),支链淀粉在0～220mg/L质量浓度范围内其碘复合物与吸光度呈线性关系(r＝0.9995)。结论：正丁醇结晶法能有效地分离木薯直链与支链淀粉;双波长法操作快速、准确,无需分离即可同时测定木薯淀粉样品中直链和支链淀粉含量。     

芭蕉芋直链和支链淀粉纯品的提取及其光谱分析

分离提纯芭蕉芋淀粉中的直、支链淀粉,表征其纯度,建立快速测定芭蕉芋淀粉中直链淀粉含量的双波长法。正丁醇结晶法分离纯化直、支链淀粉;光吸收特性分析法表征直、支链淀粉纯度;根据双波长法原理,在测定波长617nm,参比波长504nm处测定芭蕉芋淀粉中直链淀粉含量。分离提纯得到的直、支链淀粉最大吸收波长分别为630～645nm和548～554nm,蓝值分别为1.167±0.209和0.122±0.001,均处于相应分布范围,表明提纯后直、支链淀粉的纯度较高;直链淀粉在0～80mg/L浓度范围内与吸光度呈线性关系,r=0.9998。正丁醇结晶法能有效地分离纯化芭蕉芋直、支链淀粉;光吸收特性分析法可有效地表征直、支链淀粉纯度;双波长法操作简便、准确,无需分离即可快速测定芭蕉芋淀粉中直链淀粉含量。     

双波长法测定绿豆中的直链和支链淀粉

建立绿豆中直链淀粉和支链淀粉含量同时测定的双波长分光光度法,研究光度测定的影响因素,并对方法精密度和加标回收率进行考察。直链淀粉的测定波长和参比波长分别为610nm和498nm,支链淀粉为553nm和709nm。方法精密度良好,直链和支链淀粉平均回收率分别为94.10%和90.94%。建立回归方程并求得3种绿豆的直链淀粉含量为11.70%~12.67%,支链淀粉含量为32.70%~34.22%。     

双波长法测定籼米中直链淀粉和支链淀粉含量

建立了双波长法测定籼米中直链淀粉和支链淀粉含量的方法.按照双波长测定的等吸收点波长法确定两种淀粉的测定波长和参比波长,直链淀粉的分别为596 nm和449 nm,支链淀粉的分别为533 nm和705 nm.直链淀粉浓度在20～60 mg/L线性良好,R=0.999 8;支链淀粉浓度在100～200 mg/L线性良好,R=0.999 7.籼米中直链淀粉和支链淀粉质量分数分别为24.2％和50.5％.     

双波长法测定山药中直链和支链淀粉含量

使用双波长分光光度法测定不同品种山药中直链淀粉和支链淀粉的含量,根据双波长法的测定原理,确定山药直链及支链淀粉的测定波长和参比波长,直链淀粉分别为624 nm和410 nm,支链淀粉分别为538 nm和758 nm。试验结果表明,该测定方法标准曲线良好。直链淀粉在0~50μg/mL质量浓度范围内其碘复合物与吸光度呈线性关系(R~2=0.999 7),支链淀粉在0~250μg/mL质量浓度范围内其碘复合物与吸光度呈线性关系(R~2=0.998 4)。山药中直链淀粉含量为0.026 mg/mL,回收率在96.72%~98.73%之间;支链淀粉的含量为0.072 mg/mL,回收率在95.74%~97.87%之间,RSD均小于1.5%。     

双波长法测定冰温贮藏西洋参中直链淀粉和支链淀粉的含量

建立同时测定冰温贮藏西洋参中直链淀粉和支链淀粉的双波长法。根据双波长原理和扫描谱图,确定直链淀粉和支链淀粉的测定波长分别为630、520 nm,参比波长分别为423、771 nm,直链淀粉和支链淀粉标准曲线的回归方程分别为y=23.046x+0.0062、y=2.5021x-0.0017,其决定系数R2分别为0.998、0.997,通过方法学验证实验,测定直链淀粉和支链淀粉稳定性的RSD值分别为1.95%、1.85%,精密度的RSD值分别为0.89%、0.42%,准确性的RSD值分别为0.82%、0.62%,平均回收率分别为100.22%、100.19%,因而该方法具有简便、快速、准确等特点;冰温贮藏不同月份西洋参中直链淀粉和支链淀粉含量随着贮藏月份的增加呈现小幅下降的趋势。     

葛根淀粉提取及直链、支链淀粉的双波长测定

以淀粉提取率为指标,采用正交实验研究了葛根淀粉的加工工艺,并确定了最佳工艺参数为:料水比为2:17,浸泡液的pH为8.5,浸泡时间为1h;同时采用双波长分光光度法对葛根中直链淀粉和支链淀粉的显色反应和光度测定的最佳条件进行了详细的考察,根据吸收光谱,确定直链淀粉的测定波长为617nm和476nm,支链淀粉的测定波长为415nm和532nm,建立回归方程并求得葛根淀粉中直链淀粉的含量为18.29%,支链淀粉的含量为77.24%.     

双波长比色法测定不同产地和品种青稞中直链淀粉和支链淀粉的含量

利用一种更简便、准确的双波长比色法来测定不同产地和品种青稞中直链淀粉和支链淀粉的含量,以此代替以往复杂繁琐的样品前处理过程。根据双波长比色原理——若溶液中某溶质在两个波长下均有吸收,则两个波长的吸收差值与该溶质浓度成正比,以及根据直链淀粉和支链淀粉与碘试剂作用分别产生纯蓝色和紫红色的性质,用紫外分光光度计对两种淀粉与碘试剂的反应液进行全波长扫描(450~900nm),用作图法在同一个坐标系里确定其各自的测定波长和参比波长。结果测得直链淀粉的测定波长和参比波长分别为560nm和506nm,支链淀粉的测定波长和参比波长分别为545nm和722nm。青稞中直链淀粉和支链淀粉分别在0.20~0.59mg和0.50~3.00mg范围内具有良好的线性关系(R2=0.9993和R2=0.9995),平均加样回收率分别为91.14%和91.73%,RSD分别为1.70%和2.25%(n=9)。该方法简便、准确、稳定性和重现性好,适用于测定青稞中直链淀粉和支链淀粉的含量,可为青稞的质量控制提供依据。     

粉葛直链淀粉与支链淀粉分离工艺研究

以粉葛为原料,对粉葛中直链淀粉和支链淀粉的分离工艺进行了研究。根据直链和支链淀粉的理化特性及结构的不同,采用正丁醇-异戊醇配合物沉淀法对粉葛直链和支链淀粉进行粗分离,再经正丁醇重结晶得到较纯的直链与支链淀粉,讨论了分离前对淀粉进行预处理、纯化次数、分离过程中离心时间对分离效果的影响。通过对淀粉-碘复合物光吸收特性分析和蓝值比较,表征分离得到的直链与支链淀粉的纯度。结果表明:直链淀粉纯化5次、支链淀粉纯化6次、分离前经过预处理、支链淀粉纯化时离心时间和速度为30min,5 000r/min的条件下,光谱分析测得的最大吸收波长和蓝值都落在直链淀粉与支链淀粉文献报道结果的相应数值范围内,表明此时分离效果最佳,正丁醇结晶法分离的直链和支链淀粉纯度较高。     

优化毛细管电泳法测定山药淀粉中直链/支链淀粉

以市售新鲜怀山药为原料通过石灰水浸泡法制备山药粉,并通过正丁醇反复结晶法分离纯化直链淀粉与支链淀粉。利用碘做显色剂,使用毛细管电泳法测定山药淀粉中直链淀粉与支链淀粉的含量以及比率,本文分别对柠檬酸-磷酸盐缓冲液以及醋酸-醋酸盐缓冲液等不同缓冲液作为流动相进行了对比,实验发现醋酸-醋酸盐缓冲液对于分离测定直链淀粉与支链淀粉的效果较好。随后分析了不同p H条件下的醋酸-醋酸盐缓冲液进行的分离效果进行了比较,并测定其迁移率,当p H 4.8时分离效果最佳且其迁移率达到15.4。利用最佳条件使用纯的马铃薯直链淀粉与支链淀粉标准品,得出支链淀粉的保留时间约为1.8 min,而直链淀粉的保留时间约为2.9 min,对怀山药淀粉进行分析,从而得出怀山药中直链淀粉含量为19.49%。利用重复性试验以及回收率试验该方法的准确性与精确度能达到很好的效果。     

双波长法测定薯芋类农产品中直链淀粉和支链淀粉的含量

目的:建立薯芋类农产品中直链淀粉和支链淀粉的双波长测定法,为品种选育、品质分级、加工应用和标准制定等提供基础数据。方法:研究了直链淀粉和支链淀粉的吸收光谱图,确定二者的最大吸收波长及参比波长。优化了分散剂、乙酸加入量等显色条件及测定条件。结果:直链淀粉标准曲线方程为:y=0.0259x?0.0051,R2=0.9994,线性范围0~33 μg/mL;支链淀粉标准曲线方程为:y=0.0031x+0.0167,R2=0.9965,线性范围0~111 μg/mL。直链淀粉的检出限为0.093 μg/mL,定量限0.28 μg/mL;支链淀粉的检出限为0.079 μg/mL,定量限0.24 μg/mL,直链淀粉回收率为90.0%~100.0%;支链淀粉回收率为88.0%~108.0%。结论:双波长法简单易行,结果准确可靠,适用于薯芋类农产品中直链淀粉和支链淀粉的分析检测。     

Qualitative and Quantitative Determination of Starch by a Colorimetric Method

A method for the qualitative and quantitative determination of low amounts of starch and its components, amylose and amylopectin, was worked out. It combines the extraction of starch with HCI, staining with KJ/J2 and measurement of the absorbancies at two wavelengths, 605 and 530 nm, the absorption maxima of amylose and amylopectin, respectively. The determination of the amylose fraction and the quantification of the starch were done according to two evaluated equations. Phenolic substances did not influence the method. The method proved to be useful for sensitive starch determination and characterisation in plant material.     

双波长分光光度法测定木薯块根淀粉含量的动态变化

以双波长分光光度法测定SC201、SC205、GR891和GR911共4个木薯品种生育期块根中直链淀粉与支链淀粉含量的动态变化.结果表明,4个木薯品种块根直链淀粉的含量是随生育期的延长而逐渐增加的,而支链淀粉的含量却缓慢下降,支链淀粉/直链淀粉的比例呈现下降趋势,到12月份4个品种的这一比例已接近相同;以鲜重计的总淀粉含量,4个品种均呈逐渐增加的趋势;而以干重计的总淀粉含量的变化则4个品种表现不一致.研究初步揭示了木薯块根直链淀粉、支链淀粉和总淀粉含量的积累规律.     

荧光光谱法测定淀粉中的直链淀粉

为了建立一种荧光光谱法测定淀粉中直链淀粉含量的方法,采用荧光光谱法测定了直链淀粉的激发光谱和发射光谱以及直链淀粉与支链淀粉的浓度比对荧光强度的影响。结果表明:直链淀粉的激发波长为370 nm、发射波长为422 nm;在0.10~0.70 μg/mL浓度范围内,直链淀粉荧光强度与其浓度呈良好线性关系,相关系数r=0.9996,检出限为0.026 μg/mL。用该方法测定玉米淀粉和土豆淀粉中直链淀粉的含量,加标回收率为94.5%~121.7%,相对标准偏差(RSD)为2.42%~3.24%。该方法不需加任何生化试剂,不受时间、温度、共存支链淀粉的影响,快速简便,绿色环保,检出限低,结果准确。     

A novel triple‐wavelength colorimetric method for measuring amylose and amylopectin contents

A novel triple‐wavelength colorimetry based on the principle of iodine binding was developed to determine amylose and amylopectin contents. Detection wavelengths of different starch material were different for each method. Comparative trials were carried out by both single‐ and dual‐wavelength colorimetry. We found that single‐wavelength colorimetry could only be used to evaluate amylose content. Correlation coefficient of standard curves for amylopectin content determination was improved by increase of detection wavelength numbers. The precision and recovery coefficient was also improved by triple‐wavelength colorimetry compared to single‐ and dual‐wavelength colorimetry. Percent amylose of cassava, potato, and high‐amylose maize determined by triple‐wavelength were 19.3, 21.8, and 42.3%, respectively, and percent amylopectin were 78.9, 76.9, and 54.5%, respectively. This developed triple‐wavelength colorimetry could provide accurate data for evaluating amylose content and have potential for amylopectin content detection.     

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.