桦褐乳菌多酚清除自由基作用的稳定性研究

利用紫外分光光度法研究了桦褐孔菌多酚对羟自由基和超氧自由基清除作用的稳定性.结果表明.pH、温度、紫外线照射时间对桦褐孔菌多酚清除羟自由基作用的影响小于对其清除超氧自由基作用的影响,桦褐孔菌多酚对羟自由基的清除较对超氧自由基的清除更稳定.添加蔗糖、食盐和柠檬酸对桦褐孔菌多酚清除羟自由基的能力影响不大,但对桦褐孔菌多酚清除超氧自由基的能力影响较大.     

桦褐孔菌乙醇粗提物对朊病毒复制的抑制作用

优化桦褐孔菌乙醇粗提物提取工艺并初步探究其对朊病毒复制的影响。采用醇提方法,利用正交试验方法,确定最佳提取工艺。使用CCK-8试剂盒对桦褐孔菌乙醇粗提物处理细胞的安全性进行评价,确定其安全质量浓度;根据安全性评价结果,使用蛋白免疫印记（Western blot）方法检测桦褐孔菌乙醇粗提物对朊病毒复制的影响;通过测定过氧化氢及抗氧化因子等对桦褐孔菌乙醇粗提物的抗氧化活性进行研究。桦褐孔菌乙醇粗提物的最佳提取工艺为：料液比（桦褐孔菌生粉:乙醇）1:10（g/mL）,乙醇体积分数75%,提取时间2 h,提取温度80 ℃,在此条件下,得率为6.32%。桦褐孔菌乙醇粗提物的最大安全质量浓度为6.25×10-4 mg/mL;在此浓度下,处理细胞24 h后,桦褐孔菌乙醇粗提物对朊病毒的复制有抑制作用（p<0.01）,可减少H2O2的含量,增加SOD和抗氧化因子GCLM、GCLC的含量,且具有统计学意义。本试验表明桦褐孔菌乙醇粗提物对朊病毒的复制具有抑制作用,且这种作用可能与其抗氧化活性有关。     

发酵桦褐孔菌对果蝇寿命及抗氧化能力的影响

研究桦褐孔菌深层培养条件以及培养基。并将培养得到的桦褐孔菌加入果蝇饲料,以基础饲料为对照,研究桦褐孔菌对果蝇寿命及抗氧化能力的影响。用加入不同剂量的桦褐孔菌饲料喂养果蝇,每3天记录果蝇死亡数,绘制生命曲线。通过测定不同饲养天数的果蝇体内主要抗氧化酶活力及脂质过氧化产物丙二醛含量,评价深层培养桦褐孔菌对果蝇抗氧化能力的影响。结果表明深层培养获得的桦褐孔菌可有效延长果蝇平均寿命,显著提高果蝇体内超氧化物岐化酶(SOD)及过氧化氢酶(CAT)活力,抑制丙二醛(MDA)的生成。可见,深层培养桦褐孔菌具有抗氧化能力和抗衰老的功能。     

桦褐孔菌多糖的乙酰化修饰及其抗氧化活性

采用乙酰化修饰方法对桦褐孔菌多糖进行结构修饰,并评价其抗氧化活性,为桦褐孔菌多糖结构修饰提供新的思路和方向。以桦褐孔菌为原料,采用水提醇沉法提取桦褐孔菌多糖,过AB-8大孔吸附树脂,得纯化后的桦褐孔菌多糖。在氢氧化钠水溶液中以不同体积的乙酸酐制备乙酰化桦褐孔菌多糖,盐酸羟胺比色法测定其取代度。在此基础上,对3种不同取代度的乙酰化桦褐孔菌多糖进行抗氧化活性研究。结果表明,桦褐孔菌多糖经纯化后,通过乙酰化修饰得到三个取代度分别为0.2810、0.3136、0.4072的乙酰化产物,随着乙酰化试剂的体积增加,多糖取代度逐渐增大;三个不同取代度的乙酰化产物对DPPH自由基最大清除率分别为71.8%、74.9%、78.5%;对超氧阴离子的最大清除率分别为71.8%、74.9%、78.5%;对羟基自由基的最大清除率分别为74.5%、79.9%、81.1%。随着取代度的增加,乙酰化桦褐孔菌多糖抗氧化活性逐渐增强。桦褐孔菌多糖经乙酰化修饰后,可显著提高体外抗氧化活性,且抗氧化活性的强弱与乙酰基取代度有关。     

桦褐孔菌黄酮类化合物的提取工艺优化及抗氧化活性

以桦褐孔菌为试材,采用乙醇热回流进行黄酮类化合物的提取,研究了单因素(料液比、提取温度、乙醇浓度以及提取时间)对桦褐孔菌中黄酮类化合物提取率的影响,通过正交实验对其提取工艺进行优化,利用FRAP、DPPH·、ABTS+·三种方法测定其抗氧化活性。结果表明:桦褐孔菌黄酮类化合物提取率影响因素为提取温度>乙醇浓度>提取时间>料液比,最佳工艺为提取温度75℃,乙醇浓度60%,提取时间2.0 h,料液比1:25 g/mL,在此工艺下提取桦褐孔菌黄酮类化合物含量为53.25 mg/mL,提取率为10.66%。桦褐孔菌黄酮类化合物浓度为200 μg/mL时,其总抗氧化能力相当于464.53 μmol/L FeSO₄。对DPPH自由基清除率的EC₅₀为36.44 μg/mL;对ABTS+自由基清除率的EC₅₀为299.89 μg/mL。研究表明桦褐孔菌中黄酮类化合物对DPPH·和ABTS+·的清除率接近V_C,具有较强的抗氧化活性,有潜力作为天然抗氧化剂推广应用。     

桦褐孔菌多酚的抗氧化性及其在食用油脂中的应用

本实验研究了桦褐孔菌多酚的抗氧化性及对食用油脂的抗氧化效果。结果表明,桦褐孔菌多酚具有较强的抗氧化能力且对食用油脂具有较好的抗氧化效果,0.2%的桦褐孔菌多酚对羟自由基和超氧自由基的清除率分别为69.58%和82.01%。     

发酵时间对桦褐孔菌主要活性成分的影响

该文主要研究桦褐孔菌在液体发酵过程中主要活性成分多糖、三萜甾醇的累积与代谢变化。采用液体发酵法培养桦褐孔菌获得不同发酵时间的发酵产物,分别采用苯酚硫酸法及HPTLC分析法检测不同培养时间的菌丝体中多糖、三萜和甾醇的含量,DPPH与硫酸香草醛显色法检测抗氧化活性。结果显示,随发酵时间的延长,桦褐孔菌菌丝体生物量越来越高,经HPTLC法分析可见发酵后的菌丝体与桦褐孔菌子实体中的三萜和甾醇成分相似。且多糖、三萜甾醇的含量均呈现先增高后降低的趋势,而通过显色反应,发现菌丝体中含有子实体未发现的抗氧化三萜成分。通过研究确定了桦褐孔菌液体发酵过程中主要活性成分变化,确立最佳发酵时间,为桦褐孔菌的工业化生产提供参考。     

液体发酵桦褐孔菌胞内多糖提取及抗氧化活性测定

桦褐孔菌(Inonotus obliquus)多糖因具有良好的功能性调味特性，引起了食品行业的广泛关注。然而，目前对液体纯化培养桦褐孔菌胞内多糖的研究较少，缺乏系统的提取工艺优化和性质分析。该研究旨在比较热水浸提法和超声波辅助提取法对桦褐孔菌胞内多糖的提取效果，并利用Design Expert 13.0软件构建超声波提取以及热水浸提桦褐孔菌胞内多糖的响应面模型。结果表明，超声波辅助提取法优于热水浸提法，其最佳提取工艺条件为超声功率508.25 W、料液比1∶19.38、超声时间18.40 min。在此条件下，桦褐孔菌胞内多糖的最佳理论预测值为43.81 mg/g。此外，该研究还探讨了超声波辅助提取法得到的桦褐孔菌胞内多糖的抗氧化活性，发现其对DPPH自由基和羟基自由基(·OH)均有较强的清除能力，其IC₅₀值分别为1.70,1.98 mg/mL。该研究为桦褐孔菌胞内多糖的工业化生产以及其在食品风味物质的开发利用中的应用提供了依据。     

桦褐孔菌多糖磷酸化修饰工艺研究

桦褐孔菌多糖是桦褐孔菌中主要的生物活性成分,在抗氧化、提高免疫力等方面具有重要作用和广泛的药用价值。该文以桦褐孔菌为研究对象,以桦褐孔菌多糖溶液中磷酸根含量为指标,通过单因素试验及响应面法对桦褐孔菌多糖磷酸化修饰工艺条件进行优化,以提高其多糖的生物活性。结果表明,桦褐孔菌多糖磷酸化修饰最佳工艺条件：三聚磷酸钠与三偏磷酸钠质量比为6∶1、反应温度为75℃,反应时间为4 h,pH值为8.6,修饰后的桦褐孔菌多糖溶液中磷酸根含量为9.58%。该结果为桦褐孔菌多糖磷酸化衍生物的开发提供参考依据。     

桦褐孔菌水提粉的抗氧化性及对人体经络电压的作用初探

桦褐孔菌,常称为白桦茸,又叫作西伯利亚灵芝,是一种具有良好的抗氧化功效的保健食品。为了研究桦褐孔菌的抗氧化性和归经作用,测定桦褐孔菌水提粉的SOD活力、总抗氧化力和氧化还原电位值。召集30名志愿者并分为两组,分别服用桦褐孔菌水提粉制备的菌汤和添加SOD蛋白的菌汤,志愿者每日服用100 mL,连续服用24 d,记录左、右两侧的24条经络电压的变化。试验结果表明:桦褐孔菌水提粉有很强的抗氧化性,当志愿者服用桦褐孔菌粉和SOD桦褐孔菌粉24 d后,能够显著提高心经、心包经和肺经电压,而且添加SOD蛋白的桦褐孔菌粉能够显著提高脾经、膀胱经、肝经的电压。以上结果与已报道的桦褐孔菌的功效描述基本吻合。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press