玛咖与酒浸玛咖的成分分析与比较

以云南种植玛咖为试验材料,对酒浸玛咖与玛咖中的蛋白质、粗纤维、糖类、矿质元素分别进行分析和比较。结果表明:两者各成分的含量间存在极显著差异;酒浸玛咖中的多糖和粗纤维明显高于玛咖中的含量,分别为玛咖含量的158.10%和178.70%;所测定的矿质元素,酒浸玛咖中均高于玛咖中的含量,其中Zn和Ca分别是玛咖中含量的144.64%和210.47%。从而说明酒浸玛咖存在开发利用的潜在价值。     

响应面法优化玛咖多糖运动饮料配方及其抗疲劳研究

本研究探讨了玛咖多糖运动饮料的最佳工艺配方。选取玛咖多糖添加量、木糖醇添加量、柠檬酸添加量为实验因子进行单因素试验,并基于单因素试验结果,以玛咖多糖运动饮料感官评审得分为响应面值,应用响应面设计方法建立数学模型并进行分析。结果表明,三个实验因子对感官评审得分的影响依次为：玛咖多糖添加量>柠檬酸添加量>木糖醇添加量。玛咖多糖运动饮料的最佳工艺配方为：玛咖多糖添加量为25%、木糖醇添加量为9%、柠檬酸添加量为0.3%。在此条件下,实际感官评审得分为92。通过抗疲劳实验发现,玛咖多糖运动饮料能够延长大鼠游泳时间,延缓血液中血清尿素氮含量的增加,有助于缓解大鼠机体疲劳,提高运动能力。     

玛咖多糖-Fe（Ⅲ）配合物的制备与表征

采用热水浸提和超声辅助法制得玛咖多糖,通过检测玛咖多糖-Fe（Ⅲ）配合物在不同pH值、反应温度和时间的吸光度来优化玛咖多糖-Fe（Ⅲ）配合物的试验条件。结果表明：玛咖多糖-Fe（Ⅲ）配合物制备的最佳条件为pH9,反应温度70℃,反应时间150 min。采用铁盐的特殊反应、红外光谱及紫外-可见吸收光谱对玛咖多糖-Fe（Ⅲ）配合物进行定性表征;采用邻菲罗啉分光光度法测得产品中Fe（Ⅲ）含量为13.31%,精密度为0.46%。     

黑玛咖多糖超声辅助提取研究

以黑玛咖为原料,多糖得率为指标,研究提取温度、超声时间、料液比对玛咖多糖得率的影响,采用苯酚–硫酸法测定玛咖多糖的含量。以单因素试验和正交试验优化提取条件,最佳提取工艺条件为提取温度50℃、超声时间30 min、料液比1∶40(g/mL),利用方差分析表明影响多糖提取的主次因素为提取温度超声时间料液比,在最佳条件下多糖得率为9.03%。     

羧甲基玛咖多糖制备及抗氧化性研究

通过水提醇沉淀法从玛咖粉末中提取了玛咖多糖,采用氢氧化钠-氯乙酸反应体系,以异丙醇为溶剂对玛咖多糖进行羧甲基化,经Sevage法脱除蛋白、透析得到固体羧甲基玛咖多糖,产物有良好的水溶性。紫外光谱显示羧甲基玛咖多糖水溶液在260～280nm处未见核酸和蛋白质的特征吸收峰;红外光谱表明羧甲基玛咖多糖在1600cm-1出现-COO特征吸收,并具有典型的多糖吸收峰,结构中存在β-型糖苷键;灰度法测定羧甲基玛咖多糖的取代度DS为0.618。同时抗氧化能力测定结果表明玛咖多糖羧甲基化前后均可清除利用Fenton反应由Fe2+-H2O2体系产生的羟自由基,且羧甲基化后玛咖多糖对羟自由基的清除能力增强。     

三相萃取法提取玛咖多糖的工艺研究

以玛咖为实验原料,利用三相萃取法优化玛咖多糖的提取工艺,并对其抗氧化性进行研究。玛咖多糖提取工艺中,对(NH_4)_2SO_4添加量、叔丁醇添加量、萃取温度、水提次数等因素进行单因素实验,在此基础上进行响应面优化设计,得到最佳工艺条件为(NH_4)_2SO_4添加量30%、叔丁醇添加量10 mL、萃取温度37℃、水提次数1次,多糖提取率达到45.3%。玛咖多糖的抗氧化性研究发现,玛咖多糖对·OH自由基和DPPH·自由基的半数清除率值分别达到2.5 mg/mL和11.6 mg/mL,说明具有很较高的抗氧化性,三相萃取法工艺很好的保留玛咖多糖的活性。     

超声波提取玛咖多糖的工艺研究

研究了超声波、热水和微波方法提取玛咖多糖的效果和液料比、温度、时间、功率等因素对提取玛咖多糖的影响,通过正交实验得出了超声波提取的最佳工艺条件。结果表明,不同提取方法对玛咖多糖的提取效果为超声波>微波>热水;超声波提取的影响因素顺序为温度>功率>时间,其最佳提取条件为料液比1:20、时间20min、温度50℃、功率200W,此条件下玛咖多糖的提取率为74.4%。     

玛咖多糖抗氧化保健作用研究

探讨南美药食两用植物玛咖多糖成分的体外抗氧化保健作用。采用邻苯三酚自氧化法、H2O2诱导红细胞氧化溶血以及CCl4致豚鼠肝脏脂质过氧化的方法,观察体外给予玛咖多糖对这些氧化反应的影响。结果表明,玛咖多糖对邻苯三酚的自氧化有微弱的抑制作用,对H2O2诱导红细胞氧化溶血有显著的抑制作用,最大抑制率达76.9%,显著减少CCl4所致豚鼠肝脏脂质过氧化代谢产物丙二醛的产生。玛咖多糖体外具有一定的抗氧化保健作用。     

玛咖多糖的提取条件及体外活性研究

优化玛咖多糖的提取条件,并通过体外实验对其抗氧化活性和降血脂功效进行研究.采用超声波辅助热水浸提并结合响应面法对玛咖多糖提取条件进行优化,通过自由基清除率评价玛咖多糖的抗氧化活性,基于玛咖多糖与胆酸钠的结合能力评价其降血脂功效.在提取温度50℃,提取时间42 min,超声功率220 W,料液比(g/mL)1:32的条件...     

正交试验优化喷雾干燥法制备玛咖精粉工艺

以玛咖块根为原料,经过醇提、浓缩后采用喷雾干燥法制备玛咖精粉,对进料液固形物质量分数、进风温度和热风流速3 个因素进行单因素和正交试验分析,结果表明：进料液固形物质量分数5%、进风温度120 ℃和热风流速0.4 m3/min时制得的玛咖精粉质量最佳,此时玛咖精粉水分含量为21.2 mg/g（含水率2.12%）,生物碱含量为15.87 mg/g,水溶性蛋白质含量为1.64 mg/g,VC含量为6.03 mg/g,总糖含量为554.50 mg/g。对优化条件下得到的玛咖精粉超微结构、吸湿性的实验研究表明,优化后的喷雾干燥工艺使得玛咖中的有效成分得以保留,所制备的玛咖精粉可作为玛咖深加工产品的优良原料。     

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.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

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