青稞麸皮阿拉伯木聚糖的提取工艺优化及结构分析

以青稞麸皮为原料,利用响应面法优化NaOH溶液提取阿拉伯木聚糖的最佳工艺条件。在单因素试验的基础上,以料液比、提取温度、提取时间、NaOH质量浓度为自变量,以青稞麸皮阿拉伯木聚糖得率为响应值,作四因素三水平的响应面回归分析。得到最佳提取工艺为料液比1∶25（g/mL）、提取温度55?℃、提取时间3?h、NaOH质量浓度15?g/L,在此条件下阿拉伯木聚糖得率为14.31%,与理论值14.27%无显著差异。因此利用响应面优化得到的青稞麸皮阿拉伯木聚糖提取工艺稳定可行。采用高效凝胶渗透色谱、紫外吸收光谱、红外吸收光谱、高效离子交换色谱对提取的多糖进行纯度鉴定及初步结构分析,结果表明青稞麸皮阿拉伯木聚糖均一性较好;多糖中含有微量蛋白质,不含核酸,并且含有α、β-糖苷键结构;其主要单糖组成为阿拉伯糖、半乳糖、葡萄糖和木糖,各单糖对应物质的量比为11.61∶1∶3.62∶18,阿拉伯糖与木糖物质的量比值为0.645。     

不同处理的精制玉米麸皮单糖组分及阿魏酸含量分析

对去除淀粉和蛋白质的精制玉米麸皮进行酸碱处理,得到酸解产物和碱解产物,用高效液相色谱对精制玉米麸皮、酸解产物及碱解产物的单糖组成及阿魏酸进行分析。结果显示:酸解产物含有44.5%的木糖、20.8%的阿拉伯糖和4.57%的阿魏酸,推测其主要成分是阿魏酸阿拉伯木聚糖;碱解产物含有50.3%的木糖、24.5%的阿拉伯糖,阿魏酸基本未检出,推测其主要成分是阿拉伯木聚糖;玉米麸皮含有3.5%的阿魏酸。     

小麦麸皮低聚糖生产中预处理条件研究

该文研究耐高温α–淀粉酶添加量、酶解时间对小麦麸皮去淀粉效果的影响;并研究酸种类、蒸煮温度对木聚糖溶出量的影响。结果表明:耐高温α–淀粉酶添加量0.2%,酶解时间15 min时,小麦麸皮去淀粉效果最好;酸性条件蒸煮的最优工艺:去淀粉麸皮按料液比1∶6,加入0.012mol/L盐酸溶液,120℃蒸煮30 min。HPLC分析结果显示:得到的小麦麸皮低聚糖中,低聚木糖占到52.5%;单糖组分为阿拉伯糖、木糖和葡萄糖,其含量之比1∶3∶0.75。     

玉米芯木聚糖和桦木木聚糖组成成分及结构的研究

本文通过薄层层析、离子色谱和红外光谱及溶解率对玉米芯木聚糖和商品桦木木聚糖的成分及结构进行了研究。研究结果表明:玉米芯木聚糖中的单糖成分主要是木糖、阿拉伯糖和少量的葡萄糖,主要为直链型木聚糖,支链少;醇不溶性玉米芯木聚糖中的单糖成分主要是木糖、阿拉伯糖、少量的葡萄糖和半乳糖,但其阿拉伯糖比前者略高,有直链和支链型木聚糖,支链较多;桦木木聚糖主要是木糖,其它单糖未检出,有直链和支链型木聚糖,支链较多。     

微波处理对小麦麸皮酶法制取低聚木糖的影响

研究一种高效、无污染、低成本的以小麦麸皮为原料酶法制备低聚木糖的方法.分别考察酸法、碱法、双氧水法处理小麦麸皮,比较经微波处理与不经微波处理的小麦麸皮中木聚糖的得率.结果表明:不经微波处理的麸皮的木聚糖提取率最高的是双氧水法处理;经微波处理后木聚糖提取率最高的是碱法处理;TLC(薄层色谱)结果显示小麦麸皮酶解液的主要成分为木二糖.     

水溶戊聚糖分级纯化组分结构初步分析

采用气相色谱(GC)、高效液相色谱(HPLC)、液质联用(LC／MS)、核磁共振(NMR)等分析手段，对小麦麸皮水溶戊聚糖的分级纯化组分——P-WSPIl-S进行组成和结构初步分析．研究表明：P-WSPIl-S组分由木糖和阿拉伯糖两种糖组成，两者的摩尔比为0．98，相对分子质量为831030，其可能的结构为：D-吡喃木糖以β(1→4)连接为木聚糖主链，侧链为α-呋喃阿拉伯糖，D-吡喃木糖残基可在C-2、C-3位被阿拉伯糖单独取代或同时取代，并且该组分中还含有一定量的阿魏酸基团，其通过酯化的形式与阿拉伯木聚糖共价连接．     

酶法制备麸皮中低聚木糖的研究

木聚糖酶酶解小麦麸皮中的木聚糖制备低聚木糖,试验确定了最佳的酶解工艺条件,即酶添加量为800 IU/g,麸皮用量为12%,酶解温度为55℃,酶解时间为4h,总糖得率为61.02%,DP值为3.01,低聚木糖的得率为28.67%。     

不同提取方法对小麦麸皮多糖化学组分及免疫调节活性的影响

目的:以小麦麸皮超微粉为实验材料,分别用酸法、碱法、水提和酶法提取获得多糖,研究不同提取方法对小麦麸皮多糖得率、提取后麸皮残渣微观形态、糖醛酸含量、硫酸根含量、蛋白质含量、单糖组成及免疫调节活性的影响。方法:采用苯酚-硫酸法测定多糖含量,硫酸-间羟基苯酚法测定糖醛酸含量,BaCl₂-明胶法测定硫酸根含量,气相色谱法测定单糖组分;采用MTT检测细胞毒性,Griess法测定细胞上清液中NO含量,Western Blot法检测细胞诱导型一氧化氮合成酶(iNOS)和环氧合酶-2(COX-2)蛋白表达。结果:碱提法获得的粗多糖得率最高,为31.73%,测定提取的粗多糖中多糖含量为57.79%;小麦麸皮多糖中糖醛酸和硫酸根的含量依次为:碱提法>酶提法>酸提法>水提法;不同提取方法的小麦麸皮多糖组分中所含单糖的种类为阿拉伯糖、木聚糖及葡萄糖;MTT法检测四种小麦麸皮多糖对细胞均无毒性,其中水提多糖能促进RAW264.7细胞分泌NO因子并能促进细胞诱导型一氧化氮合成酶和环氧合酶-2蛋白的表达。结论:四种不同提取方法所得到的小麦麸皮多糖的得率、化学组成成分及生物活性各不相同,采用传统水提法工艺提取多糖更利于维持多糖的免疫调节活性。     

超声波辅助提取小麦麸皮酚基木聚糖的研究

以小麦麸皮为原料,研究了超声波超声功率、超声时间、碱液质量分数、碱提时间、碱提温度对小麦麸皮中水溶性酚基木聚糖和总酚基木聚糖得率的影响,同时分析了小麦麸皮水溶性酚基木聚糖的抗氧化特性和总酚含量.结果表明,小麦麸皮中酚基木聚糖提取的最佳工艺条件是超声功率300 W,超声时间30 min,碱液质量分数2％,碱提时间2h,碱提温度55℃,在此条件下,酚基木聚糖得率为38.73％,水溶性酚基木聚糖得率为29.05％.对提取的麸皮水溶性酚基木聚糖的抗氧化性的研究表明,水溶性酚基木聚糖对羟自由基有明显的清除作用,并呈现明显的量效关系.水溶性酚基木聚糖的总酚含量为12.27mg/g.     

发酵法提取青稞麸皮中β-葡聚糖的工艺优化及其理化性质研究

为提高青稞麸皮β-葡聚糖的产量和纯度,选用发酵法提取制备青稞麸皮β-葡聚糖。运用单因素、正交试验确定最优提取条件,并对该条件下得到的青稞麸皮β-葡聚糖进行了分子量、单糖组成等理化分析。结果表明,发酵法提取青稞麸皮β-葡聚糖最佳工艺参数为:料液比1:6,接种0.05%高活性干酵母,在32℃条件下发酵34 h。在最优条件下生产的β-葡聚糖,得率为5.21%±0.02%,与传统水提法相比提高了60.8%,纯度为91.21%。发酵法提取的青稞麸皮β-葡聚糖理化分析特征为单糖组成主要为D-葡萄糖,其平均相对分子质量为1.366×105,水提法提取的青稞麸皮β-葡聚糖单糖组成有D-阿拉伯糖、D-半乳糖、D-木糖、D-甘露糖、D-葡萄糖,平均分子量为7.759×105。     

Effect of Peroxidase on Textural Quality of Dough and Arabinoxylan Characteristics Isolated from Whole Wheat Flour Dough

Effect of peroxidase on arabinoxylans (pentosans) isolated from whole wheat flour and instrumental textural parameters of whole wheat flour dough were studied. Significant increase in dough hardness and decrease in adhesiveness was observed on treatment of dough with peroxidase. Arabinoxylans isolated from peroxidase treated dough had higher molecular weight, viscosity, arabinose to xylose ratio, ferulic acid, and protein contents as compared to that of untreated dough. Arabinoxylans isolated from treated dough had higher absorption at 280 and 320 nm indicating the association of proteins and ferulic acid with arabinoxylans. Thus, the treatment of dough with peroxidase may catalyze the formation of cross-linking between arabinoxylans as well as protein-arabinoxylan that could be responsible for the alteration of the whole wheat flour dough characteristics.     

小麦阿拉伯木聚糖对鲜湿面条品质的影响

从小麦麸皮中提取阿拉伯木聚糖,将其添至鲜湿面条中,通过测定面筋蛋白的流变特性,淀粉的糊化特性,面条的蒸煮及质构特性等,分析添加不同质量分数的小麦阿拉伯木聚糖(WBAX)对鲜湿面条品质的影响。结果表明:添加WBAX对面筋蛋白形成有弱化作用,随着WBAX添加量的增加,面粉中淀粉糊化的峰值黏度和终值黏度增加,糊化过程的崩解值降低,面条干物质损失率降低,吸水率、硬度和咀嚼性增加。高添加量的WBAX(3%和4%)会限制淀粉膨胀,减少其破裂。添加4%WBAX对改善鲜湿面条品质的效果最好。     

Aleurone cells are the primary contributor to arabinoxylan oligosaccharide production from wheat bran after treatment with cell wall-degrading enzymes

Arabinoxylans and in particular arabinoxylan oligosaccharides (AXOS) from wheat are recognised for their prebiotic potential. A high-yield, non-chemical production of AXOS is therefore of interest when producing functional foods. This study investigated the enzymatic production of AXOS from wheat bran with the aim of establishing the main fraction contributing to production of AXOS. Fractions of wheat bran, outer pericarp and aleurone with two different purities were treated with the cell wall-degrading enzymes: xylanase, cellulase and β-glucanase. The yield of solubilised arabinoxylans upon treatment was greatest in the most pure aleurone fraction (164 g kg⁻¹) and lowest in the outer pericarp fraction (15 g kg⁻¹). The yield was mainly recovered as AXOS rather than soluble arabinoxylans and was negatively related to the arabinose/xylose ratio found in the raw material. In conclusion, wheat aleurone cell walls are the main contributor to the production of AXOS from wheat bran and this seems to depend on the A/X ratio of the raw material.     

Antioxidant properties of commercial soft and hard winter wheats (Triticum aestivum L.) and their milling fractions

The total phenolic content (TPC), total antioxidant activity (TAA), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging capacity, inhibition of coupled oxidation in a β‐carotene–linoleate model system, iron(II) chelation activity and inhibition of copper‐induced oxidation of human low‐density lipoprotein (hLDL) cholesterol of 80% ethanolic extracts of soft and hard winter wheat samples and their milling fractions, namely flour, germ, bran and shorts, were investigated. Soft wheat extracts examined demonstrated higher TPC and TAA compared to those of hard wheat extracts. The germ fraction possessed the highest TPC, followed by bran, shorts, whole grain and flour for both wheat types examined. The TAA of both wheat types showed similar results except that shorts performed better than bran in this assay. Free radical scavenging properties of whole grain and milling fractions of both soft and hard wheat samples were examined against DPPH radical. The germ and flour fractions demonstrated the highest and lowest DPPH radical scavenging activity, respectively, among wheat fractions. Wheat extracts were also efficient in preventing bleaching of β‐carotene, which is also known to be free radical mediated. In the iron(II) chelation assay the flour extracts demonstrated excellent activity, while the germ extracts showed a weak activity. The trends were similar in both soft and hard wheat for the iron(II) chelation assay. Wheat extracts also inhibited copper‐induced oxidation of hLDL. In LDL oxidation assay, wheat extracts performed better than the reference antioxidant, ferulic acid. Thus wheat phenolics may serve as effective antioxidative components as measured by in vitro techniques. Copyright © 2005 Society of Chemical Industry     

麦麸对酥性饼干物理性质和淀粉消化性的影响

目的：研究了麦麸对酥性饼干颜色、物理性质以及淀粉消化性的影响；方法：将麦麸按0~50%比例添加到面粉中制作饼干,测定混合粉的溶剂保持力,测定饼干颜色、延展度、硬度以及淀粉消化性；结果：添加麦麸会造成饼干颜色变暗,导致混合粉的水和碳酸钠溶剂保持力值增加,乳酸溶剂保持力值和面筋性能指数降低(4.71%~33.20%和25.73%~34.11%)；麦麸添加量大于20%增加了饼干的延展度和硬度(53.54%~64.31%和135.98%~408.53%)；麦麸在一定程度上抑制了饼干淀粉的消化。麦麸添加量与饼干物理性质呈强正相关性,与消化终点葡萄糖含量呈负相关。通过主成分分析,提取了2个主成分,累计方差贡献率为85.3%；结论：适量添加麦麸有效改善了饼干酥脆性,并在一定程度上抑制了饼干淀粉的消化,增加了饼干的功能性质。     

小麦阿拉伯木聚糖水凝胶结构及流变特性

讨论3种小麦(郑麦9023、矮抗58、周麦27)阿拉伯木聚糖(W9023、W58、W27)水凝胶特性的差异。通过流变学实验、扫描电子显微镜、傅里叶变换红外光谱分析、称质量法对3种水凝胶(Q9023、Q58、Q27)的成胶性及凝胶稳定性、微观结构、溶胀性及色泽进行研究。3 g/100 m L的W9023和W58在漆酶作用下可形成凝胶。Q9023凝胶点为9 min,Q58为19 min。傅里叶变换红外光谱分析结果为典型的AX图谱。扫描电子显微镜观察发现Q9023凝胶孔壁光滑,Q58呈脊状结构。结果表明,不同来源的小麦阿拉伯木聚糖成胶性能有差异。Q9023结构更为稳定,控释能力较强,色泽较浅,更利于后续改善凝胶特性的研究。     

采用浓硝酸和酶处理后麦麸成分的变化规律研究

麦麸是一种典型的木质纤维素类生物质.本文研究了应用85%的浓硝酸和酶对麦麸进行前期处理和糖化处理之后的成分变化规律.结果表明,在50℃以下温度和60 min的处理时间之内,提高浓硝酸处理温度或者延长处理时间均有利于原料水溶部分质量比例的提高;有利于水溶部分中木糖,阿拉伯糖、葡萄糖等糖类成分含量的增加;有利于高分子量的碳...     

麦麸超微粉对面团特性及制品品质的影响

对超微粉碎麦麸粉面团的流变学特性进行研究,分别将超微粉碎麦麸(添加质量分数分别为0%、5%、10%、15%、20%)添加到面粉中并调制成面团,测定并记录其粉质特性和拉伸特性等。结果表明：麦麸超微粉的添加会使面粉的吸水率增大,面团形成时间、弱化度均有所增加,面团的稳定时间呈下降趋势;从粉质特性总体来看,超微麦麸粉的添加能改善面粉的粉质特性。在麦麸超微粉添加量在10% 时,麦麸超微粉馒头样品模糊综合评价结果为良好,其色泽、气味、组织结构、口感都可以被人接受。     

Red–Green–Blue (RGB) colour system approach to study the segregation and percolation in a mixture of white wheat flour and bleached wheat bran

In this work, we applied a nonintrusive measurement method based on the Red–Green–Blue (RGB) image analysis system to study the segregation and percolation in a mixture of white wheat flour and bleached wheat bran. This method intended to quantify the presence of one or several colours in the surface of mixed ingredients. The mixing of flour particles with bleached and unbleached wheat bran was studied using a 90 mm closed rotating cube. This system forced the particles to roll relative to each other so as to favourite the segregation by percolation in order to hide one colour by another. The obtained results showed a possibility of obtaining homogeneous colour when the wheat flour was mixed with the bleached wheat bran at a volume ratio of 20/5%–10%. By increasing to ratio up to 20/15% (flour/bran), the RGB system showed a presence of two colours in the surface of the mixture. Moreover, the RGB method confirmed the presence of two heterogeneous colours when the wheat flour was mixed with the unbleached wheat bran whatever the ratio (20/5%, 10% and 15%).