黑米中黄酮类化合物的稳定性分析

以黑龙江五常黑米为原料,研究利用超声波辅助水浴浸提黑米中黄酮类化合物的稳定性。对黑米黄酮浸提液在不同温度、pH值、光照、氧化剂、还原剂、金属离子等条件下的稳定性进行测定。结果表明:温度在20℃~60℃时黄酮类化合物含量基本不变;长时间的光照对黄酮的稳定性影响较大;在弱酸性条件下比较稳定;对氧化剂H_2O_2具有较好的抗氧化性,但对还原剂Na_2SO_3显示出很大的不稳定性;K~+和Na~+两种金属离子对黑米黄酮稳定性无明显影响,Al~(3+)、Ca~(2+)、Mg~(2+)、Fe~(3+)对其影响较大。     

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.     

天然黄酮类化合物含量测定方法研究进展

黄酮类化合物的含量在植物化学活性成分的开发、评价等方面有非常重要的意义,其测定方法众多．该文综述了目前天然黄酮类化合物含量的测定方法,旨在为黄酮类化合物的进一步研究、开发、应用提供借鉴。     

竹叶中黄酮类化合物的研究

竹叶是一味传统中药，含有丰富的黄酮类化合物，黄酮类化合物是优良的生物抗氧化剂，本文概述竹叶中黄酮类化合物的研究进展。     

芦笋中黄酮类化合物的研究进展

芦笋是一种营养价值丰富的药食兼用型蔬菜,在加工处理过程中产生大量的老茎、根、叶等废弃物。芦笋废弃物中含有丰富的黄酮类化合物,其具有抗炎、抑菌、抗氧化等多种生物活性,具有很大的开发应用价值。本文综述了芦笋中黄酮类化合物的提取分离方法、化学组成、含量测定方法及药理作用等方面的研究进展,为芦笋的进一步开发利用提供参考。     

食用菌中黄酮类物质的研究进展

食用菌作为人类可食用的大型真菌,种类多达2000种。食用菌产业近几年在全球发展很快,特别是在我国发展更为迅猛,产量已达3000多万吨,占世界比重70%~80%。食用菌营养丰富,富含蛋白质、多糖、维生素和矿物质,具有低脂肪、低热量的特点,且具有增强免疫力、抑制肿瘤、抗衰老和降血压等多种生物活性。大量研究表明,食用菌多酚中的黄酮类化合物具有抗氧化功能,在食用菌生物活性中起重要作用,另有研究认为食用菌不含黄酮类化合物。本文对食用菌中黄酮类化合物的提取方法、含量、活性作用进行综述,针对食用菌是否含有黄酮类化合物的研究思路进行展望。     

陈皮中黄酮类化合物的研究进展

陈皮为芸香科植物橘及其栽培变种的干燥成熟果皮,含有丰富的黄酮类化合物,具有抗氧化性、抗肿瘤、抗炎、抗过敏等生理功能。主要对陈皮中黄酮类化合物的提取方法、化学组成、生理作用等进行综述。为进一步研究和利用陈皮中的黄酮类化合物提供参考。     

芦笋中黄酮类化合物的研究进展

芦笋是一种营养价值丰富的药食兼用型蔬菜,在加工处理过程中产生大量的老茎、根、叶等废弃物。芦笋废弃物中含有丰富的黄酮类化合物,其具有抗炎、抑菌、抗氧化等多种生物活性,具有很大的开发应用价值。本文综述了芦笋中黄酮类化合物的提取分离方法、化学组成、含量测定方法及药理作用等方面的研究进展,为芦笋的进一步开发利用提供参考。      

分光光度法测定火龙果茎中黄酮类化合物的含量

火龙果是仙人掌三角柱属多年生植物,其果具有丰富的营养价值,可作为水果直接食用,花也可以作为蔬菜,而火龙果茎却未被利用.本文研究了火龙果茎中黄酮类化合物的分离提取和测定方法.采用单因素实验和正交试验对黄酮类化合物的分光光度法测定条件和火龙果茎中黄酮类化合物的分离提取条件进行优化.实验结果表明,以芦丁为标样,黄酮含量在6.6444.8mg/L范围内服从比尔定律,回归方程为A=0.333ρ-5.14×10-3,相关系数R=0.9999;火龙果茎中黄酮类化合物的分离提取条件为:70%的乙醇溶液为提取溶剂,料液比为1 : 40,提取温度为75℃,提取时间3h.方法回收率为96.1%102.2%,相对标准偏差(RSD)为3.3%(n=5).火龙果茎干品中黄酮类化合物的含量为0.49%.     

黄酮类化合物生物活性及食品中应用的研究

本文介绍了黄酮类化合物的抗自由基、抗氧化、抗病毒、抗肿瘤、抗糖尿病及其并发症、抗衰老等生物活性，以及黄酮类化合物在食品中的应用。     

Levels of some trace elements in edible fungi

A number of common edible fungi were analysed for their contents of Pb, Cd, Cr, Ni, Co, Zn, Cu, Mn and Se. The results indicate that the Cd level in the speciesRozites caperata can be as high as several mg/kg fresh weight. InLycoperdon perlatum andMacrolepiota procera the Pb level was found to be up to 2.5 mg/kg. The Ni level was at or below 0.1 mg/kg in all species, with the exception ofAlbatrellus ovinus, which had a mean concentration of 0.72 mg/kg. The level of Cr was highest inM. procera with a mean of 0.091 mg/kg. In a single sample of the speciesAgaricus augustus, the concentration of Co was found to be exceptionally high at 0.28 mg/kg. Zn and Cu levels were highest inL. perlatum andM. procera. Mn levels were fairly similar in the different species. The results of several surveys show that there can be large differences in the concentrations of the same metal (e.g. Pb) in the same species. The Se level was found to be very high in the speciesBoletus edulis, as has been shown by others. In the other species analysed the level of Se was low.     

Concentrations of trace elements in wild edible mushrooms

The concentrations of Cu, Cd, Co, Ni, Mn, Pb, Zn and Fe in 66 samples of mushroom fruiting bodies, representing seven species, mainly all edible, were determined by atomic absorption spectrophotometry. The mushrooms were collected from near roads and inner parts of forest and lawns in Balıkesir in the north western part of Turkey. The results indicate that the Fe level in the species Volvariella speciosa (Fr.) Sing. from near the road was the highest with a mean of 6990 mg/kg. The level of Ni was the highest in Clitocybe flaccida (Sow.: Fr.) Kummer, from near road with a mean of 3.32 mg/kg. Cu levels were almost similar for both areas within a range of 35–89 mg/kg in the different species. The Cd was accumulated mostly by Lactarius sanguifluus (Paulet: Fr.) Fr. and V. speciosa from near road with a mean of 1.60 mg/kg. Concentration of Mn, Pb, Co and Zn in L. sanguifluus from near road were the highest with means of 63.6, 7.66, 6.03 and 149 mg/kg, respectively.     

食用菌富集微量元素的研究进展

微量元素是一类人体所必需的营养素,在自然界中多数以无机态形式存在,且分布不平衡,不易被人体吸收利用。近年来许多研究显示,食用菌对微量元素锌、硒、碘、铁等都具有富集和将无机态微量元素转化成有机态的功能。本文对食用菌富集微量元素的机理进行了归纳总结,概述了灵芝、香菇和金针菇等各类食用菌对微量元素的富集作用的研究进展。      

ICP-AES法同时测定食用盐中微量元素的研究

采用电感耦合等离子体原子发射光谱(ICP—AES)法测定食用盐中微量元素。讨论了影响因素，优化了操作参数。     

药食两用食品中微量元素和重金属含量的测定

建立了微波消解电感耦合等离子体发射光谱法测定药食两用食品中微量元素的方法,并用该法分别测定了14种药食两用食品中Mn、Fe、Zn、Cu、Ni、Cr、Cd和Pb等元素的含量。结果表明,该方法的加标回收率在95.0%~104.0%之间,RSD≤4.35%。药食两用食品中Zn含量高于其它可食性花卉,Fe含量比普通叶菜类蔬菜更高,而其Cu/Zn比值较低,重金属含量普遍较低。此测定结果可为探讨药食两用食品的保健作用与微量元素含量的相关性提供科学数据。      

ICP-MS法测定食用明胶中重金属元素

利用电感耦合等离子体质谱法(ICP-MS)测定食用明胶中Cr、Mn、Ni、As、Cd、Sb、Hg、Pb等8种重金属元素的分析方法。通过优化仪器的工作参数、选择适宜待测元素的同位素以及选用干扰元素校正方程可以克服质谱干扰,以Sc、Rh、Bi为内标元素,样品的基体效应和仪器漂移得到了很好地校正。结果表明,8种重金属元素的检出限在0.002～0.091μg/L之间,RSD<2.11%,回收率在91.5%～109.0%之间,方法与其他分析对照,结果一致。     

Macro and trace elements in edible tissues of Carcinus maenas and Necora puber

BACKGROUND: Macro and trace elements have significant impacts on human health. Yet, information of elemental content in seafood is still scarce. Green crab Carcinus maenas and velvet crab Necora puber are mainly caught off English, Scottish and French coastal waters and live transported to Southern Europe, where they are consumed. During transportation, mortalities can reach 50% and dead animals are regularly commercialized for human consumption. The present study characterises the elemental composition of both species. RESULTS: C. maenas exhibited higher K, Fe and Br contents than N. puber, and lower Mn, Cu, As, Hg and Pb levels. Hepatopancreas was the most distinct tissue, with higher Ca, Mn, Fe, Cu, Br, Sr, Cd and Pb levels compared to muscle and gonads. Differences between live and dead crabs were species and tissue dependent, though live C. maenas had higher Fe content and lower Mg and Se levels, whereas live N. puber exhibited higher As content and lower Na, Mg, Cl, Br, Sr and Cd values. CONCLUSION: Both species were considered as safe food items since toxic elements were always below the maximum level or action level. In addition, they are good sources of Na, Cl, Ca, Cu, Zn and Se. Copyright © 2008 Society of Chemical Industry     

Levels of eight trace elements in edible mushrooms from a rural area

Eight trace elements were determined using ICP-MS in 78 fruiting body samples of 22 edible mushroom species. The mushrooms were collected from four sites in a rural area, unpolluted by human activity. Median values (dry matter) were as follows: Arsenic (As) 1.45 mg kg^-1, barium (Ba) 1.41 mg kg^-1, cobalt (Co) 0.28 mg kg^-1, copper (Cu) 47.0 mg kg^-1, rubidium (Rb) 130 mg kg^-1, silver (Ag) 2.95 mg kg^-1, thallium (Tl) 0.02 mg kg^-1 and vanadium (V) 0.25 mg kg^-1. Higher trace element accumulation was observed in samples of Macrolepiota procera, Macrolepiota rhacodes, Lycoperdon perlatum, Lycoperdon gigantea and Xerocomus chrysenteron for As and Cu, and in samples of Cantharellus cibarius and of genera Boletus and Suillus for Rb.     

Levels of eight trace elements in edible mushrooms from a rural area

Eight trace elements were determined using ICP–MS in 78 fruiting body samples of 22 edible mushroom species. The mushrooms were collected from four sites in a rural area, unpolluted by human activity. Median values (dry matter) were as follows: Arsenic (As) 1.45?mg?kg^–1, barium (Ba) 1.41?mg?kg^–1, cobalt (Co) 0.28?mg?kg^–1, copper (Cu) 47.0?mg?kg^–1, rubidium (Rb) 130?mg?kg^–1, silver (Ag) 2.95?mg?kg^–1, thallium (Tl) 0.02?mg?kg^–1 and vanadium (V) 0.25?mg?kg^–1. Higher trace element accumulation was observed in samples of Macrolepiota procera, Macrolepiota rhacodes, Lycoperdon perlatum, Lycoperdon gigantea and Xerocomus chrysenteron for As and Cu, and in samples of Cantharellus cibarius and of genera Boletus and Suillus for Rb.     

干态青岛大花花和叶的营养成分分析

采用国标和农业部颁布的标准方法对新疆产青岛大花花和叶中的营养成分进行了测定。结果显示,青岛大花花和叶营养成分丰富,其中蛋白质含量分别为16.9%和18.1%,粗纤维含量分别为14.8%和12.7%,总糖含量分别为3.26%和5.44%;花和叶中均含有17种氨基酸,氨基酸总量分别为7.75%和9.65%,其中必需氨基酸占各自氨基酸总量的34.32%和43.94%,药效氨基酸占各自氨基酸总量的68.26%和63.52%;花和叶中矿质元素丰富,且钾含量分别为钠含量的147.5和84.8倍,具有典型的高钾低钠特征。结果表明,新疆产青岛大花花和叶均具有较高的营养价值和保健价值,且叶的总体营养品质略优于花。