双歧杆菌菊芋复合汁增菌培养基的优化筛选

以菊芋为主要原料,以两歧双歧杆菌(Bifidobacterium bifidus,Bbm)和长双歧杆菌(Bifidobacteriu.longum,Blm)为试验菌株,研究了菊芋汁基础培养基中添加单一营养因子对Bbm细胞生长量的影响.利用正交试验优化筛选出Bbm菊芋复合汁增菌培养基;利用优选的菊芋复合汁增菌培养基对Blm进行验证性增菌试验.结果表明大豆蛋白胨、牛肉浸膏、酵母膏、玉米浆可显著促进Bbm的细胞增殖(P＜0.01),而磷酸氢二钾既能促进Bbm生长,又有缓冲培养基pH值的作用;利用L934筛选出Bbm菊芋复合汁增菌培养基的最佳配比是在10 Brix菊芋汁中添加0.6%大豆蛋白胨、0.9%牛肉浸膏、0.3%酵母膏、0.4%玉米浆、0.2%磷酸氢二钾.在菊芋复合汁增菌培养基中,经37℃培养12 h,Bbm活菌数6.80×109 cfu/mL,Blm活菌数6.65×109 cfu/mL,较时照菊芋汁培养基的活菌数分别提高了13.5倍和7.63倍;较实验室常用的改良MRS培养基的成本降低了2770元/t.     

菊芋汁双歧杆菌培养基的筛选优化

本文研究了双歧杆菌在菊芋汁中的生长状况,考察了添加不同物质对双歧杆菌生长的影响。结果表明,双歧杆菌在菊芋汁中能够良好生长,在菊芋汁中添加胰蛋白胨、牛肉膏、玉米浆、半胱氨酸盐、大豆蛋白胨对双歧杆菌促进生长作用极显著。采用正交试验法确定了菊芋汁双歧杆菌培养基的配方:菊芋汁+0.3%玉米浆+0.5%大豆蛋白胨+0.025%半胱氨酸盐酸盐,双歧杆菌在其中的活菌数可以达到109以上。     

响应面法优化乳双歧杆菌Z-1高密度发酵培养基

采用响应面法优化乳双歧杆菌Z-1发酵培养基。以改良MRS为基础培养基,通过单因素试验、PB试验、最陡爬坡试验得到影响乳双歧杆菌Z-1菌量的显著因素及最优响应值区间。试验结果表明,乳糖、胰蛋白胨和玉米浆为乳双歧杆菌最适宜碳源、氮源和生长因子;磷酸氢二钾、硫酸镁、L-半胱氨酸盐酸盐和玉米浆对菌量影响显著。经响应面设计优化得到最优高密度培养基为:乳糖2%、胰蛋白胨1%、酵母膏0.5%、牛肉膏1%、磷酸氢二钾0.322 8%、柠檬酸铵0.26%、硫酸镁0.097 2%、硫酸锰0.005%、吐温80 0.15%、L-半胱氨酸盐酸盐0.245 1%、玉米浆8.129 8%。     

嗜热链球菌与保加利亚乳杆菌麦芽复合汁增菌培养基的优化筛选

研究了在麦芽汁中添加不同的营养因子对嗜热链球菌S.t-3的细胞生长量的影响,进一步采用正交试验优化筛选出S.t-3的麦芽复合汁增菌培养基,并对保加利亚乳杆菌L.b-DR和L.b-S1进行了验证性增菌试验。结果表明,S.t-3、L.b-DR和L.b-S1在麦芽汁中能进行正常的产酸代谢,大豆蛋白胨、牛肉膏、酵母膏可显著促进S.t-3的细胞生长(P<0.05);K2HPO4不仅可以促进菌体增殖,而且还可缓冲基质pH值的变化,避免了低pH值对乳酸菌的伤害;利用L9(33)正交试验,筛选出S.t-3的麦芽复合汁增菌培养基最佳配比为:在10%的麦芽汁中添加0.5%大豆蛋白胨、0.5%酵母膏、1%牛肉膏、0.2%K2HPO4;在麦芽复合汁增菌培养基中,S.t-3、L.b-DR和L.b-S1,37℃恒温培养16 h,活菌数分别为2.42×109cfu/mL、2.85×109cfu/mL和4.81×109cfu/mL,与液体MRS培养基的活菌数相当,成本较MRS培养基降低1 000元人民币/t。     

婴儿双歧杆菌增菌培养基优化的研究

本研究针对婴儿双歧杆菌的营养需要 ,采用正交实验优化基础培养基及增殖因子的用量。得出最佳基础培养基配比是 :大豆蛋白胨 1.2 % ,胰蛋白胨 0 .6 % ,酪蛋白水解物 0 .6 % ,牛肉浸膏 0 .6 % ,葡萄糖 0 .5 % ,低聚糖 1.0 % ,乳糖 0 .5 % ,酵母浸出粉 0 .5 %。最佳增殖因子添加量是 :胡萝卜汁 15 % ,西红柿汁 10 % ,肝浸液 5 % ,胱氨酸 0 .0 5 %。最后使用优化出的增菌培养基配比测定生长曲线 ,同时测定pH和滴定酸度的变化 ,确定增菌培养终止时间为 10h,通过平板菌落计数 ,此时菌数可达 8.78×10 9cfu/mL     

双歧杆菌酸奶冻干发酵剂不同菌株特性的研究

研究了不同来源的4株双歧杆菌在乳中的生长与发酵特性、冷藏期间的存活力和后酸化活性以及抗冷冻干燥特性。结果表明:4菌株在乳中42℃发酵的凝乳时间均为6.0h,Blm和Bbm凝乳后的活菌数高,均在1×109cfu/mL以上,而其pH值均在5.0左右,滴定酸度70～80°T,且无显著差别;4菌株在发酵后的酸乳中冷藏期间,Blm和Bbm的存活力高,Blm、Bbm和Blr均表现出较低的后酸化活性;4℃冷藏21d,Blm和Bbm活菌数下降至不足1个log数量级,Blm、Bbm和Blr的酸度上浮不足10°T,pH值下降仅0.2～0.3;4菌株在以脱脂乳为保护剂的冷冻干燥试验中,Blm和Bbm抗冻干性强,其冻干存活率均在30%以上。     

两株低温乳酸菌增殖培养基的优化

10℃条件下,以两株源于四川泡菜的耐低温乳酸菌3m-1(Lactobacillus plantarum)和8m-9(Leuconostoc mesenteroides)为研究对象,在白菜汁基础培养基中,研究添加不同氮源、碳源及缓冲剂对其生长的影响,并通过正交实验对增殖因子进行优化,确定了菌株3m-1和8m-9增殖的改良白菜汁培养基配方分别为:白菜汁基础培养基中添加蛋白胨1.0%、牛肉膏0.5%、乳糖1.0%、葡萄糖1.5%、磷酸氢二钾0.2%;白菜汁基础培养基中添加蛋白胨1.5%、牛肉膏1.0%、乳糖0.5%、葡萄糖1.5%、磷酸氢二钾0.2%。10℃条件下,菌株3m-1和8m-9在相应改良白菜汁培养基中培养72h,活菌数分别为6.05×109cfu/mL和7.35×109cfu/mL,较白菜汁基础培养基提高了6.1倍和10.4倍,而与MRS培养基培养相比,活菌数相近,研究结果为制备低温乳酸菌发酵剂具有指导意义,同时也为低温发酵泡菜的生产奠定了基础。     

促双歧杆菌生长培养基的优化

为了促进双歧杆菌更好地生长,根据双歧杆菌的营养需求,采用正交试验,优化MRS培养基中的碳源、氮源和增殖因子。试验结果显示,优化MRS培养基的最佳配比是:大豆蛋白胨0.37%、胰蛋白胨1.13%、葡萄糖1.0%、酵母浸出粉0.7%、胡萝卜汁7.5%、番茄汁7.5%、玉米浆5.0%。双歧杆菌在优化MRS培养基中所得菌数是普通MRS培养基中的10倍。     

菊芋在体外对双歧杆菌生长的影响研究

目的:研究菊芋在体外对双歧杆菌生长的影响,为进一步开发菊芋资源和生产双歧杆菌制品提供理论依据。方法:以菊芋汁为试验材料,以长双歧杆菌(Blm)和两歧双歧杆菌(Bbm)为试验菌株,采用Hungate厌氧培养技术。结果:菊芋汁在基础培养基中对双歧杆菌具有促进生长作用,表现为生长速率提高,最大生长量增加,并且对不同菌种的促进生长作用存在差异。结论:菊芋在体外对双歧杆菌有促进生长作用。     

保加利亚乳杆菌菊芋复合汁增菌培养基的优化筛选

以菊芋为主要原料,以自行分离选育的高活力保加利亚乳杆菌(Lactobacillus bulgaricus)L.b-DR为试验菌株,研究了在菊芋汁培养基中添加单一营养因子对保加利亚乳杆菌L.b-DR细胞生长量的影响;利用正交试验优化筛选出保加利亚乳杆菌L.b-DR的菊芋复合汁增菌培养基。试验结果表明:在菊芋汁基础培养基中添加番茄汁、乳糖、蛋白胨、碳酸钙,可显著促进试验菌株的细胞生长(P<0.01);利用L934正交试验筛选出菊芋复合汁增菌培养基的最佳配比是:在菊芋汁培养基中添加7.5%番茄汁,1.5%乳糖,1%蛋白胨,0.3%碳酸钙。保加利亚乳杆菌L.b-DR经过复原脱脂乳培养基和液体MRS培养基活化后,以1%(约1×106cfu/mL)接入菊芋汁复合增菌培养基中,37℃培养16h,活菌数可达1.50×109cfu/mL,较对照菊芋汁培养基的活菌数提高23.96倍,与实验室常用的MRS培养基的活菌数相当,而其成本较实验室常用的液体MRS培养基的成本降低了2400元/t。     

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