苦荞茶中黄酮提取工艺优化及不同品牌苦荞茶黄酮含量比较

研究苦荞茶中黄酮提取的最佳工艺,比较不同类型苦荞茶的黄酮含量。通过单因素试验考察乙醇溶液体积分数、料液比、提取时间和提取温度4个因素对黄酮得率的影响。通过正交试验确定最佳提取工艺,并在此基础上对不同类型苦荞茶黄酮含量进行比较。结果表明:各因素对苦荞茶中黄酮类物质得率的影响由大到小分别为温度、提取时间、乙醇溶液体积分数和料液比。优化得到苦荞茶中黄酮类物质的最佳提取工艺条件为:乙醇溶液体积分数70%,料液比1∶25,提取时间4 h,温度70℃,此条件下苦荞茶中总黄酮得率为1.98%;基于该条件下,分析8个品牌19种苦荞茶(11种造粒茶、6种全麦茶、2种全株茶)的黄酮含量,结果表明三类苦荞茶总黄酮含量平均值高低依次是全株茶造粒茶全麦茶;同类型苦荞茶之间,总黄酮含量差异最大的是造粒茶,其次是全麦茶,最小的是全株茶。     

仙人掌皮黄酮提取工艺优化

仙人掌皮黄酮提取可提高废弁物的资源利用和活性成分的开发.采用响应面分析法对乙醇体积分数、提取温度、提取时间和剂料比等提取条件进行了优化.结果表明,曲面回归方程拟合性好;优化工艺为乙醇体积分数67%、提取温度76°C、提取时间5.7 h、剂料比21.4 mL/g时,仙人掌皮黄酮得率为6.45%.经鉴定仙人掌皮中主要黄酮为异鼠李素-3-O-[2-O,6-O-双-α-L-鼠李糖基]-α-L葡萄糖苷、异鼠李素-3-O-(6'-鼠李糖) 葡萄糖苷.     

苦荞籽粒中D-手性肌醇提取工艺的优化

利用单因素试验、正交试验和HPLC检测法,对提取苦荞籽粒中D-手性肌醇的三因素(乙醇体积分数、料液比、提取时间)进行优化。试验结果表明,苦荞籽粒中D-手性肌醇的最佳提取工艺条件为:提取时间25 min,乙醇体积分数30%或40%,料液比1/30(m∶v)。     

仙人掌皮黄酮提取工艺优化(简报)

仙人掌皮黄酮提取可提高废弃物的资源利用和活性成分的开发。采用响应面分析法对乙醇体积分数、提取温度、提取时间和剂料比等提取条件进行了优化。结果表明,曲面回归方程拟合性好;优化工艺为乙醇体积分数67%、提取温度76℃、提取时间5.7 h、剂料比21.4 mL/g时,仙人掌皮黄酮得率为6.45 %。经鉴定仙人掌皮中主要黄酮为异鼠李素-3-O-[2-O,6-O-双-?-L-鼠李糖基]-?-L-葡萄糖苷、异鼠李素-3-O-（6?-鼠李糖）葡萄糖苷。     

油梨皮黄酮提取及大孔树脂纯化

该文研究了油梨皮黄酮的提取及大孔树脂纯化条件.结果表明:油梨皮黄酮的最佳提取条件为乙醇浓度70%、提取温度70℃、提取时间1.5 h、料液比(m/V)1:20.乙醇浓度和提取温度对提取得率有显著性(P<0.05)影响.在此条件下,黄酮的提取得率为1.12%;AB-8型树脂对油梨皮黄酮有较好的吸附和洗脱效果,其纯化油梨皮黄酮的条件为柱体积250 mL,上样量2.03 g,水洗,接着用75%的乙醇洗脱(约500 mL),在此条件下AB-8型树脂可重复使用6次.经纯化后油梨皮黄酮相对纯度为82.37%,纯化后总黄酮回收率为71.65%.     

雪莲果水溶性粗多糖提取分离工艺优化

为了考察雪莲果中粗多糖的较优提取分离工艺,采用水提取法提取雪莲果中多糖,以提取温度、料液比、提取时间、乙醇终浓度为影响因素,在单因素试验的基础上进行四因素三水平的正交试验。正交试验以粗多糖得率为考察指标,优化粗多糖的提取分离工艺。四因素中提取温度对试验结果影响最大,其次是乙醇终浓度和料液比,最后是提取时间。雪莲果粗多糖较优提取分离工艺为提取温度90℃,乙醇终体积分数为80%,料液比1∶20g/L,提取时间2 h。在此条件下粗多糖得率为5.11%,粗多糖的总糖质量分数为46.2%。     

乙醇水溶液提取玉米胚芽油的工艺优化

为了解决水酶法提取玉米胚芽油生产成本高、提取时间长的缺点,该文采用乙醇水溶液作为提取剂提取玉米胚芽油。通过对粒径、料液比、温度、乙醇体积分数、p H值和时间等条件对油在油相、水相和渣相中分布的研究发现,物料粒径和乙醇体积分数对提高清油得率具有显著(P0.05)的影响,而提取时间对清油得率的影响最小(P0.05)。在单因素试验的基础上通过正交试验,得出乙醇水溶液提取玉米胚芽油的最佳工艺参数为:物料细粉4次(此时粒径为49.18μm)、料液比1∶7 g/m L、温度70℃、乙醇体积分数30%、p H值9.0、提取时间2 h。在该条件下,清油的得率为94.05%±0.32%,水相含油量为3.49%±0.77%,渣相含油量为2.55%±0.82%。分析乙醇水溶液提取的玉米胚芽毛油酸价、过氧化值和含水率等指标发现,该毛油的质量优于国标规定的玉米原油,并且和压榨一级成品油指标接近,只需要经过简单精炼就可以达到食用油要求。研究结果为乙醇水溶液工业化生产玉米胚芽油提供参考。     

超声波辅助提取木薯皮活性物质工艺

木薯皮乙醇提取物同时具有抗乙酰胆碱酯酶（AChE）和抗丁酰胆碱酯酶（BuChE）的活性,为了能充分提取和利用其抗胆碱酯酶活性物质,研究了超声波提取木薯皮活性物质的工艺。通过单因素试验和Box-Behnken Design法设计的响应面优化试验确定了超声波辅助乙醇提取木薯皮中抗胆碱酯酶活性物质的最优工艺条件,并比较了超声波提取与传统溶剂浸提的提取效果。试验结果表明：超声波辅助乙醇提取木薯皮中抗胆碱酯酶活性物质的最优工艺条件为：乙醇体积分数为95%,超声波功率550W,提取时间90min,提取温度60℃,液料比12mL/g,在此工艺条件下,木薯皮活性物质的平均得率为8.97%,质量浓度为0.5mg/mL时的AChE抑制率为54.62%,BuChE抑制率为45.7%;影响木薯皮活性物质得率的4个主要因素的显著程度排列顺序为：超声波提取功率＞提取温度＞提取时间＞液料比;与传统溶剂浸提法相比,超声波提取法具有提取速度快,得率高,提取物活性好,溶剂用量少等明显优势。     

闪式提取油茶枯饼中茶皂素的工艺优化

为了研究闪式提取油茶枯饼中茶皂素的工艺,在单因素试验基础上,选取乙醇体积分数、提取时间、液料比3个因素,利用Box-Benhnken中心组合试验和响应面分析法对提取工艺进行优化。结果表明,闪式提取茶皂素的较佳工艺条件为：乙醇体积分数78%、提取时间40 s、液料比20 mL/g。在此条件下,茶皂素得率为21.09%±0.26%,与模型预测值基本相符。与传统乙醇热回流提取方法相比,闪式提取方法茶皂素得率略有提高,提取时间由6 h缩短为40 s,提取温度由70℃降到20～25℃。该方法是一种较为理想的茶皂素提取方法。     

苹果渣多酚提取工艺的优化

为优化苹果渣中多酚提取工艺,并得到提取工艺和多酚组成之间的关系,利用微波辅助提取法设计了由物料颗粒、液料比、乙醇浓度、微波功率和微波提取时间5个因素构成的多酚提取优化试验流程,构建了涵盖黄酮、原花青素2种典型多酚物质和抗氧化能力的提取工艺评价指标体系。采用证据理论对不同工艺在评价指标下的焦元进行识别,并基于信度函数和似真函数得到了不同提取工艺的效用区间和优化方案。优化结果为：物料颗粒60目,液料比30?mL/g,乙醇体积分数60%,微波功率600?W,提取时间70?s,此条件下苹果渣多酚的提取量为213.83?mg/100g,黄酮提取量为83.21?mg/100g,原花青素提取量为52.79?mg/100g,抗氧化的EC50值为3.71?mg/100mL,验证了采用证据理论进行苹果渣多酚提取工艺优化的有效性。     

Tartary buckwheat (Fagopyrum tataricum Gaertn.) as a source of dietary rutin and quercitrin

Two samples of tartary buckwheat (Fagopyrum tataricum Gaertn.) from China and one from Luxembourg were studied by high-performance liquid chromatography (HPLC) to reveal the possibilities of growing tartary buckwheat herb as a possible source of rutin, quercetin, and quercitrin. The content of rutin was determined as up to 3% dry weight (DW) in tartary buckwheat herb. Quercitrin values were in the range of 0.01-0.05% DW. Only traces of quercetin were detected in just some of the samples. Tartary buckwheat seeds contained more rutin (about 0.8-1.7% DW) than common buckwheat seeds (0.01% DW). Rutin and quercetin content in seeds depends on variety and growing conditions. Tartary buckwheat seeds contained traces of quercitrin and quercetin, which were not found in common buckwheat seeds.     

Antioxidant activity of tartary (Fagopyrum tataricum (L.) Gaertn.) and common (Fagopyrum esculentum moench) buckwheat sprouts

This study compared the differences of two types of buckwheat sprouts, namely, common buckwheat ( Fagopyrum esculentum Moench) and tartary buckwheat ( Fagopyrum tataricum (L.) Gaertn.), in general composition, functional components, and antioxidant capacity. The ethanol extracts of tartary buckwheat sprouts (TBS) had higher reducing power, free radical scavenging activity, and superoxide anion scavenging activity than those of common buckwheat sprouts (CBS). As for chelating effects on ferrous ions, CBS had higher values than TBS. Rutin was the major flavonoid found in these two types of buckwheat sprouts, and TBS was 5 fold higher in rutin than CBS. The antioxidant effects of buckwheat sprouts on human hepatoma HepG2 cells revealed that both of TBS and CBS could decrease the production of intracellular peroxide and remove the intracellular superoxide anions in HepG2 cells, but TBS reduced the cellular oxidative stress more effectively than CBS, possibly because of its higher rutin (and quercetin) content.     

Application of near-infrared reflectance spectroscopy to the evaluation of rutin and D-chiro-Inositol contents in tartary buckwheat

Tartary buckwheat [Fagopyrum tataricum (L.) Gaench] is rich in rutin and D- chiro-inositol (DCI), which have beneficial effects in the treatment of hemorrhagic diseases and insulin-resistant diseases, respectively. The current methods of extraction and detection of rutin and DCI are complex and time-consuming; a simple way of analyzing these compounds in the native matrix would be desirable. In this work, near-infrared reflectance spectroscopy (NIRS) was applied to determine the contents of rutin and DCI in tartary buckwheat. The spectral data were compared with those determined from high-performance liquid chromatography (HPLC) methods. Models for predicting rutin and DCI contents in buckwheat were developed using a partial least-squares algorithm. Cross-validation procedures indicated good correlations between HPLC data and NIRS predictions (R2 = 0.76 for rutin and R2 = 0.86 for DCI). The rutin content ranged from 0.998 to 1.75%, while the DCI content covered 0.179-0.200%. The results showed that NIRS, a well-established and widely applied technique, could be applied to determine rutin and DCI in tartary buckwheat rapidly and nondestructively.     

硒对苦荞硒、总黄酮和芦丁含量、分布与累积的影响

采用盆栽试验探讨土壤施硒对苦荞硒、总黄酮和芦丁含量、分布与累积的影响。结果看出,在土壤施硒0.5～2.0 mg/kg范围,苦荞根在苗期（40 d）大量吸收并累积硒,全生育期各器官硒含量极显著提高;在生长中后期(60～80 d) 硒的累积最快,累积量最多。硒在苦荞各器官中的分布为:在40 d时,根＞叶＞茎;60 d时Se0.0处理为叶＞根＞花＞茎,施硒各处理则为花＞根＞叶＞茎;80 d时Se0.0处理以花＞根＞叶＞茎＞子粒,Se0.5处理以花＞叶＞子粒＞茎＞根,施硒≥1.0 mg/kg的处理则为花＞叶＞茎＞根＞子粒。土壤施硒≤1.0 mg/kg促进苦荞生长,提高地上部各器官干重和植株总干重以及各器官总黄酮和芦丁含量与累积量,不改变总黄酮和芦丁的器官分布,增加苦荞中后期对总黄酮的累积;以Se0.5处理效应最佳,各差异达显著水平。过量的硒（Se1.5～2.0 mg/kg）显著抑制苦荞生长,降低各器官干重、总黄酮和芦丁含量与累积,不利于硒在子粒中富集和总黄酮在子粒中分布。表明在低硒土壤上栽培苦荞,土壤施硒以不超过1.0 mg/kg为宜,既能最大限度的提高苦荞各器官硒、总黄酮和芦丁含量和累积量,又可降低施用硒肥的成本和减少硒肥对环境的影响。     

苦荞芽期黄酮合成关键酶和MYB转录因子基因的表达分析

苦荞(Fagopyrum tataricum)作为一种药食两用植物,富含以芦丁为主的黄酮类化合物.苦荞芽期芦丁含量较高,其分子机制尚不清楚.本研究选用西荞2号,采用AlCl3法测定了苦荞芽期6～10 d胚轴和子叶中的总黄酮,采用半定量RT-PCR分析其黄酮合成途径中主要关键酶基因苯丙氨酸氨裂解酶基因(Pal)、查尔酮异构酶基因(Chi)和黄酮醇合酶基因(Fls),以及MYB转录因子基因FtMyb1、FtMyb2和FtMyb3的相对表达水平,并对三者之间的相关性进行了统计学分析.结果表明,以相关系数绝对值大于0.75为阈值,子叶中,总黄酮的积累与FtMyb3表达显著正相关(0.9625),与FtMyb2表达显著负相关(-0.8572); Chi与FtMyb2表达显著正相关(0.8468),与FtMyb3表达显著负相关(-0.8010):Pal、Chi和Fls表达彼此显著正相关,相关系数分别为0.9119、0.8920和0.7584.子叶中总黄酮含量在4.58％～5.54％之间,且随芽期递增.Pal、Chi和Fls整体表达趋势相似,均呈现先升高后降低的趋势,且Fls的表达水平明显高于前二者.FtMyb2和FtMyb3整体表达趋势相反,FtMyb2呈下降趋势,FtMyb3呈上升趋势.胚轴中,总黄酮含量与Chi显著负相关(-0.8989); Fls与Chi显著负相关(-0.7498).结果提示,苦荞芽期黄酮合成的分子机制较为复杂,但部分基因表达仍存在显著相关性联系,为进一步选择苦荞分子操作靶位点提供参考.     

Determination of D-chiro-Inositol in tartary buckwheat using high-performance liquid chromatography with an evaporative light-scattering detector

A simple method for rapid determination of d- chiro-inositol (DCI) (a potent mediator of insulin metabolism) contained in tartary buckwheat ( Fagopyrum tataricum L. Gaench) was developed on the basis of high-performance liquid chromatography coupled to an evaporative light scattering detector (ELSD). DCI was separated from an extract of tartary buckwheat on an Alltech Prevail Carbohydrates ES 5 mum column. During postcolumn detection, DCI was detected by ELSD. The detection limit was 100 ng. This method was sensitive enough for determining DCI in tartary buckwheat and its related products.     

Fagopyritols, D-chiro-inositol, and other soluble carbohydrates in buckwheat seed milling fractions

Fagopyritols are mono-, di-, and trigalactosyl derivatives of D-chiro-inositol that accumulate in seeds of common buckwheat (Fagopyrum esculentum Moench) and may be important for seed maturation and as a dietary supplement. Fagopyritols and other soluble carbohydrates were assayed in mature groats and 11 milling fractions of common buckwheat seed. Because fagopyritols are in embryo and aleurone tissues, differences in fagopyritol concentrations reflect varying proportions of these tissues in each milling fraction. Bran milling fractions contained 6.4 g of total soluble carbohydrates per 100 g of dry weight, 55% of which was sucrose and 40% fagopyritols. Flour milling fractions had reduced fagopyritol concentration [0.7 g/100 g of dry weight total fagopyritols in the dark (Supreme) flour and 0.3 g/100 g in the light (Fancy) flours]. Fagopyritol B1 was 70% of total fagopyritols in all milling fractions. Fagopyritols were 40% of total soluble carbohydrates in groats of two cultivars of common buckwheat but 21% in groats of tartary buckwheat [Fagopyrum tataricum (L.) Gaertn.], probably a reflection of environment and genetics. A rhamnoglucoside present in tartary buckwheat was not detected in common buckwheat.     

Physicochemical Properties of Common and Tartary Buckwheat Starch

Physicochemical properties of starch of three common (Fagopyrum esculentum) and three tartary (F. tataricum) buckwheat varieties from Shanxi Province, China, were compared. Starch color, especially b*, differed greatly between tartary (7.99–9.57) and common (1.97–2.42) buckwheat, indicating that removal of yellow pigments from tartary buckwheat flour may be problematic during starch isolation. Starch swelling volume in water of reference wheat starch (2.8% solids and 92.5°C) was 20.1 mL; for the three common buckwheat starches it was 27.4–28.0 mL; and for the three tartary buckwheat starches it was 26.5–30.8 mL. Peak gelatinization temperature (T_p) in water was 63.7°C for wheat starch, 66.3–68.8°C for common buckwheat and 68.8–70.8°C for tartary buckwheat. T_p of all samples was similarly delayed (by 4.0–4.8°C) by 1% NaCl. Enthalpy of gelatinization (ΔH) was higher for all six buckwheat starches than it was for wheat starch. However, one common buckwheat sample had significantly lower ΔH than the others. Starch pasting profiles, measured by a Rapid Visco-Analyzer, were characteristic and similar for all six buckwheat starches, and very different from the reference wheat starch. A comparison of pasting characteristics of common and tartary buckwheat starches to wheat starch indicated similar peak viscosity, higher hot paste viscosity, higher cool paste viscosity, smaller effect of NaCl on peak viscosity, and higher resistance to shear thinning. Texture profile analysis of starch gels showed significantly greater hardness for all buckwheat samples when compared to wheat starch.     

Social and environmental influences on tartary buckwheat (<Emphasis Type="Italic">Fagopyrum tataricum</Emphasis> Gaertn.) varietal diversity in Yunnan,China

Effective conservation strategies aimed to protect crop genetic resources require multiple sources of information. We used a combination of AFLP genotyping and farmer surveys to understand the extent, distribution and management of tartary buckwheat (Fagopyrum tataricum Gaertn.) diversity in its center of origin in Yunnan Province, China. We found genetic evidence of gene flow in tartary buckwheat throughout the study area, with small but statistically significant regional and village-level components. We also found genetic differentiation by seed color. Although most farmers reported exchanging seed in localized kinship networks, our results imply homogenizing gene flow is occurring. Yi ethnic farmers tend to plant more buckwheat than non-Yi farmers, and we found that in some communities, Yi farmers serve as seed sources for farmers of other ethnicities. Different tartary buckwheat varieties did not have different end uses; rather farmers maintained varietal diversity in order to protect crop yield and quality. Individual farmers’ seed exchange practices reflect their ideas about components of seed quality, as well as priorities in protecting buckwheat yield. From the standpoint of genetic resources conservation, the presence of a culturally rich farmer exchange network and hierarchical structuring of tartary buckwheat genetic diversity demonstrates the importance of maintaining an interlinked community of tartary buckwheat farmers in Yunnan.