速溶鹧鸪茶粉真空冷冻干燥工艺及品质分析

通过研究3种不同真空冷冻干燥工艺对速溶鹧鸪茶粉含水率、色泽、多酚含量、湿润性、分散性的影响,确定真空冷冻干燥工艺条件;以速溶普洱茶粉为辅料拼配,结合电子感官和人为感官评分筛选最佳配比,采用顶空固相微萃取-气质联用技术比较拼配前后风味差异。结果表明:预冻温度-20±2℃、预冻7 h,一次干燥温度80℃,干燥3 h,二次干燥温度55℃,干燥6 h,速溶粉各理化指标最佳;速溶鹧鸪茶粉与速溶普洱茶粉拼配比为7∶3,风味最佳。拼配后复合茶粉中醛类物质含量增加了0.34%,酸类物质含量减少了0.18%,滋味醇和,口感顺滑。该研究为鹧鸪茶综合利用及产品研发提供理论参考和技术支持。     

普洱茶多糖的提取工艺及抗氧化活性研究

用单因素实验研究茶多糖(TSP)提取工艺条件,并进一步通过连苯三酚自氧化测定所得普洱茶茶多糖的抗氧化活性.研究结果表明:普洱茶多糖的适宜提取条件为料液比1:30、浸提温度70℃、浸提时间40min,提取次数4次,所得普洱茶多糖具有一定的抗氧化活性,其抗氧化活性与Vc的抗氧化活性相近.     

酶解法生产工艺对速溶普洱茶产品得率的影响

速溶茶是国内外当前最为流行的一种饮料.酶在普洱茶工艺中的应用尚无资料报道.本实验利用单因素实验、正交实验确定酶解法制备速溶普洱产品的最佳工艺参数.通过测定速溶普洱茶产品得率,研究最佳生产速溶普洱茶的工艺条件.结果显示,酶解法最佳工艺参数为复合纤维素酶:果胶酶:蛋白酶=1∶1∶1,酶添加量为0.75％,酶解温度为45℃,酶解60min,茶水比为1∶12,浸提2次,产品平均得率为26.23％.所得产品干粉呈砂红色泽,冲溶性为易溶,冲调后的汤色为红褐明亮,无沉淀,具有陈香香气,其滋味醇和.     

普洱茶风味口香糖的研制

以普洱茶为原料,通过浸提、浓缩、干燥等工艺制成普洱茶粉,与产品胶基混合制成普洱茶风味口香糖.本文主要探讨普洱茶汁浓缩、干燥的最佳工艺,以及茶粉用量对口香糖品质的影响.实验结果表明,普洱茶汁最佳浓缩条件为:β-环糊精3.0%、蒸发温度55℃,真空度-0.08MPa,最佳干燥条件为:3倍原茶叶重量的蔗糖、蒸发温度55℃、真空度-0.09MPa、7h.口香糖生产工艺中荼粉最佳添加量为50g/300g胶基.     

基于单宁酶处理原料制备的高茶黄素速溶红茶品质分析

目的 研究基于单宁酶发酵加工的红茶原料,制备高茶黄素含量的速溶红茶。方法 以速溶红茶中的茶黄素含量为主要评价指标,对红茶原料进行两种提取溶剂处理和不同茶叶状态,即茶叶和茶叶磨碎样处理,同时分析其感官品质及其它化学成分含量。结果 本研究发现用60%乙醇提取工艺制备的速溶红茶中,茶黄素含量显著高于水提取工艺,茶叶状态则是茶粉原料浸提效果显著高于茶叶原料浸提效果,且速溶红茶中茶黄素含量达到2.3%,是传统红茶原料中茶黄素的3倍,速溶红茶得率达到了38%。结论 以高茶黄素茶叶为原料,并将其磨成粉,用60%乙醇提取作为提取剂制备速溶红茶,其制备的速溶红茶富含茶黄素,为速溶茶的生产加工提供了一定的理论依据,也可以为夏秋茶资源的开发利用提供新方法。     

速溶藏茶制备工艺优化、功能性成分及抗氧化性分析

为制备速溶藏茶,本研究以速溶藏茶得率、藏茶多糖提取量和藏茶茶多酚提取量为指标,通过单因素实验和响应面试验优化了速溶藏茶浸提工艺,并进一步研究了冷冻干燥和喷雾干燥对速溶藏茶中功能性成分和体外抗氧化活性的影响。结果表明,藏茶最佳浸提条件为料液比1:53 （g/mL）,温度98.5 ℃,浸提时间1.5 h,浸提次数3次,此时速溶藏茶得率为29.72%±0.13%,藏茶多糖提取量为6.06±0.03（g/100g）,藏茶茶多酚提取量为6.27±0.05（g/100g）利用UHPLC-QqQ-MS/MS检测出冷冻干燥和喷雾干燥的速溶藏茶中均有10种功能性成分,EGCG、GA、GCG、ECG为速溶藏茶主要功能性成分,且冷冻干燥的速溶藏茶中EGC、EGCG和槲皮素含量更高（P<0.05）。冷冻干燥速溶藏茶对DPPH自由基和ABTS自由基清除能力的IC₅₀分别为0.247、0.417 mg/mL;喷雾干燥速溶藏茶对DPPH自由基和ABTS自由基清除能力的IC₅₀分别为0.339、0.443 mg/mL,可见,速溶藏茶具有较好的抗氧化活性。     

普洱茶茶色素提取工艺条件的响应面分析及其抗氧化性活性研究

目的：优化普洱茶茶色素的提取工艺及研究其抗氧化性活性。方法：以与蒸馏水的色差作为普洱茶茶色素提取的评价指标,在单因素试验基础上,利用Box-Behnken中心组合试验和响应面分析法,对普洱茶茶色素提取工艺参数进行优化;以清除1,1-二苯基-2-苦基肼自由基(DPPH自由基)的能力评价普洱茶茶色素的抗氧化性活性。结果：普洱茶茶色素提取的最佳工艺条件为液料比45:1(mL/g)、提取温度100℃、提取时间150min、色差52.97,高出单因素试验和Box-Behnken组合中的最高色差4.73%;普洱茶茶色素清除DPPH自由基的IC50值30.83μg/mL。结论：采用响应曲面法对普洱茶茶色素提取条件进行优化可行;普洱茶茶色素具有良好的抗氧化作用,可作为天然抗氧化剂进一步开发和利用。     

普洱茶中茶多糖提取工艺的研究

目的建立一种普洱茶中茶多糖的提取工艺。方法以普洱茶为材料,采用水提醇沉法,研究了浸提温度、浸提时间、浸提次数、乙醇浓度4个因素对普洱茶中茶多糖提取率的影响,并通过正交实验确定茶多糖的最佳提取工艺。且用此提取工艺测定市售不同级别普洱茶中茶多糖含量。结果普洱茶中茶多糖的最佳提取工艺为:浸提温度90℃,浸提时间40 min,浸提次数3次,乙醇浓度80%。该提取工艺重复性好,吸光度与葡萄糖含量呈良好的线性关系(n=5),线性范围0.02~0.10 mg/L(r2=0.9999)。实验也发现,普洱茶的嫩度越低,茶多糖的含量越高。结论本方法简便、快捷、重复性好,可作为茶叶多糖原材料和产品质量控制的方法。     

速溶绿茶粉浸提工艺参数优化

目的:优化绿茶速溶茶粉的浸提工艺。方法:在单因素试验基础上,采用L16(43)正交试验设计优化绿茶速溶茶粉的浸提工艺,研究各因素对绿茶速溶茶粉提取的影响,并确定最佳工艺条件。结果:影响速溶绿茶得率的主要因素依次为浸提温度>水茶比>浸提时间;经正交试验确定茶多酚最佳提取工艺条件为浸提水温80℃、水茶比(浸提用水量与茶叶质量之比)20:1、浸提时间80min,在此最佳工艺条件下,绿茶速溶茶粉的得率为(25.1±0.1)%。结论:正交试验设计可以优化速溶茶浸提工艺,所得到的最佳工艺条件高效、可行。     

超声波法提取焙焦油莎豆粕速溶粉的工艺研究

以油莎豆粕为原料,采用均匀试验法进行焙焦工艺优化,同时采用超声波辅助水提法,并结合单因素试验设计及正交试验法优化速溶粉提取工艺参数.研究结果显示,最佳提取条件为超声时间60 min、超声功率20％,超微粉碎时间40 min和料液比1:30,此时油莎豆粕固形物提取率最高为35.47％.试验成果为进一步开发油莎豆速溶咖啡提...     

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