响应面超声波法提取藤茶多酚工艺优化

为提高得率,采用超声波法提取藤茶多酚。以藤茶多酚得率为评价指标,在单因素试验的基础上,设计Box-Behnken响应面试验优化提取工艺。结果表明:藤茶多酚最佳工艺条件为超声功率300 W、超声温度50℃、超声时间25 min、乙醇体积浓度60%。在此工艺条件下,茶多酚得率为614.64 mg/100g。     

超声波-酶解辅助提取火龙果皮色素的工艺优化

以火龙果皮干粉为原料,采用超声波-纤维素酶法辅助乙醇提取火龙果色素,通过单因素试验和正交试验考察纤维酶添加量、乙醇浓度、超声功率和提取时间对红龙果皮中的色素甜菜红素提取率的影响。结果表明最佳提取工艺条件为:纤维酶添加量为1 %、乙醇浓度为30 %、超声功率50 W和提取时间20 min,在此条件下火龙果皮中的甜菜红素提取率达70.06 %,制备的火龙果皮色素粉末的色价为2.071。     

两种火龙果果皮红色素提取工艺优化及其抗氧化活性

以红肉红皮(RP)和白肉红皮(WP)火龙果果皮为原料,采用超声波辅助乙醇浸提法提取火龙果果皮红色素,并对其粗提物进行鉴定,通过单因素与正交试验优化提取工艺,同时测定两种果皮红色素提纯物质的总还原能力和自由基抗氧化活性。结果表明,经光谱法和HPLC-MS/MS联用法双重检测,火龙果果皮红色素为甜菜红素。WP中甜菜红素的最佳提取条件为:40%乙醇、料液比1:40 (g/mL)、超声时间25 min、超声温度40 ℃,色素最大得率为0.856%。RP中甜菜红素的最佳提取条件为:40%乙醇、料液比1:30 (g/mL)、超声时间15 min、超声温度30 ℃,色素最大得率为0.915%。RP以其纯化工艺流程获得的提纯物产量是WP的1.232倍。在一定浓度范围内,WP和RP火龙果果皮甜菜红素都有较强的总还原能力,但略低于V_C,清除DPPH·自由基、羟自由基(·OH)的IC₅₀分别为1.15和0.95 mg/mL、5.95和4.57 mg/mL,两者对亚硝酸根(NO₂-)最大清除率分别为22.90%和25.10%,红肉火龙果果皮甜菜红素的综合抗氧化能力优于白肉红皮品种。     

酸木瓜总黄酮提取工艺的优化

以酸木瓜为原料,采用超声波乙醇辅助法对其果皮、果肉和籽中的总黄酮进行提取,探讨酸木瓜果皮、果肉和籽中总黄酮得率情况,选取总黄酮得率最高的部位进行正交试验,以得到酸木瓜中总黄酮最佳提取工艺条件。单因素试验结果表明:在酸木瓜果皮、果肉和籽中,随着乙醇体积分数的增大,总黄酮得率均逐渐增大,但当乙醇体积分数大于60%时总黄酮得率均下降;总黄酮得率随超声提取时间的增加先呈现上升趋势,当超声时间超过30min后总黄酮得率均下降;总黄酮得率均在料液比1∶25(g/mL)时达到最大;总黄酮得率均随超声功率的变化呈现先升后降的趋势,当超声功率达到198W时总黄酮得率最大。不同提取条件下酸木瓜果皮中的总黄酮得率明显高于果肉和籽,因此选择酸木瓜果皮进行正交试验。正交试验结果显示超声时间25min,超声功率231W,料液比1∶25(g/mL),乙醇体积分数60%是超声波乙醇辅助法提取酸木瓜果皮中总黄酮的最佳提取工艺条件,此条件下总黄酮得率为7.31%。     

超声波分级提取玫瑰精油和色素的工艺优化

目的研究超声波技术分级提取玫瑰精油与色素的最佳工艺条件,在提取玫瑰精油的同时,增加色素的得率。方法以平阴玫瑰花瓣为原料,超声波辅助乙醇水溶液提取玫瑰中的精油与色素。通过pH示差法测定玫瑰色素的粗得率,气相色谱法确定精油的相对含量。采用乙醚-石油醚混合液萃取玫瑰精油,并使用大孔树脂纯化色素。结果最佳工艺参数:超声功率130 W超声时间20 min,液料比4:30(g/mL),乙醇浓度50%,此时玫瑰精油得率为(0.22±0.02)mg/g,粗提液中色素得率为(0.83±0.02)mg/g。经大孔树脂纯化后的色素得率为(0,74±0.02)mg/g。结论利用超声技术实现了玫瑰花精油提取,同时获得较高得率的色素。     

响应面分析法优化黄蜀葵花中金丝桃苷、异槲皮苷、槲皮素提取工艺的研究

采用响应面优化黄蜀葵花中金丝桃苷、异槲皮苷、槲皮素的提取工艺。在超声功率、提取时间、乙醇浓度、提取温度、料液比的单因素实验基础上,固定提取温度50℃、料液比0.1∶15 g/m L,利用响应面分析法优化,建立二次多项式回归方程模型,确定最佳提取工艺为:超声功率340 W、提取时间60 min、乙醇浓度为60%。经工艺验证,金丝桃苷得率为4.97 mg/g,异槲皮苷得率为4.84 mg/g、槲皮素得率为2.02 mg/g,与理论值的相对误差分别为2.5%、4.5%、6.9%。采用响应面设计分析得到最佳提取工艺条件具有较高的实用价值,可为工业化提取提供理论参考。     

超声波辅助提取火龙果皮中水溶性膳食纤维工艺研究

采用超声波辅助提取火龙果皮中水溶性膳食纤维(SDF),通过单因素实验和响应面分析,探讨提取时间、提取温度、p H、液料比、超声波功率五个因素对SDF得率的影响,并对提取工艺条件进行优化。结果表明,超声波辅助提取火龙果SDF的最佳工艺条件为超声波功率400 W、提取温度67℃、提取时间50 min、p H3.3、液料比20∶1(m L/g),然后采用95%的乙醇沉淀2 h,4000 r/min离心20 min后用75%乙醇洗涤沉淀,SDF得率达26.45%。该工艺可以有效地从火龙果皮中提取水溶性膳食纤维。     

响应面法优化超声辅助提取山药多糖工艺的研究

以山药为原料,通过单因素试验,结合响应面法优化超声辅助提取山药多糖的工艺。分别研究了乙醇浓度、超声功率、超声时间和提取温度对山药多糖提取得率的影响。结果表明:对山药多糖得率的影响顺序为提取温度超声时间超声功率乙醇浓度;确定最佳工艺参数为乙醇浓度60%、超声功率803 W、超声时间61 min、提取温度49℃,在此条件下,山药多糖得率为1.30%。     

火龙果皮原花青素提取及凝胶软糖的开发研究

目的：开发和利用火龙果皮的生物活性成分,研制一种富含火龙果皮原花青素提取物的无糖凝胶糖果配方。方法：以红肉火龙果果皮为原料,通过超声波辅助浸提果皮中的原花青素。探究提取温度、乙醇浓度、超声功率、提取时间等因素对其提取率的影响,以正交试验优化提取工艺;同时以山梨糖醇、木糖醇、明胶以及火龙果果皮原花青素提取物、叶黄素酯等为主要原料制备无糖凝胶软糖,通过正交试验探究胶糖比、加水量、柠檬酸添加量等对凝胶软糖品质的影响。结果：在料液比为1:20 (g/mL)、提取剂乙醇体积分数50%、超声功率180 W、超声时间30 min、恒温水浴提取温度40℃、提取2.5 h的条件下提取效果最优。根据感官评分和质构测定,最优糖果配方为木糖醇与山梨糖醇的比例为4:6,胶糖比例为0.3,加水量为28%,柠檬酸添加量为0.1%,火龙果皮原花青素提取物添加量0.4%,叶黄素酯添加量0.024%。结论：在超声波辅助浸提法的最佳条件下,提取火龙果皮中的原花青素的得率为79.2 mg/100 g。该提取物能作为色素及营养物质添加到凝胶糖果中,优化配方下制得的软糖产品具有较好的弹韧性,感官评分有所增加,具有一定的市场价值。     

灵芝发酵粉中三萜化合物提取与测定

试验采用超声波辅助提取灵芝发酵粉中三萜类化合物,运用分光光度法测定其得率。通过单因素和BoxBenhnken设计研究乙醇浓度、浸泡时间、料液比、超声时间、超声功率、超声温度对灵芝三萜类化合物得率的影响。研究结果表明,灵芝三萜化合物提取的最佳工艺参数为:料液比为1∶42(g/m L),95%乙醇溶液中浸泡100 min后,超声功率为210 W下43℃超声提取17 min。在最优工艺条件下进行3次验证试验,测得三萜化合物平均得率为0.612 8 mg/g。研究结果为灵芝发酵类产品的在线监测提供理论依据。     

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