粘红酵母H810产油脂培养基、发酵条件优化及其油脂组分的分析

以粘红酵母（Rhodotorula glutinis）H810为实验菌种,探讨了不同碳源、氮源、碳氮比（C／N）、培养温度、培养pH值和接种量等因素对粘红酵母菌体生物量和油脂含量的影响,在此基础上优化了粘红酵母H810产油脂发酵条件。结果表明,产油脂培养基的最佳工艺条件为：碳氮比C／N 40,接种量5％,培养温度28℃和培养初始pH值6．8,在此条件下粘红酵母油脂含量达N56．88％。利用气相色谱分析菌株H810在该条件下的油脂组分,主要包括油酸47．95％、亚油酸12．96％、棕榈酸12．34％、α-亚麻酸11．76％和γ-亚麻酸7．30％。采用该工艺发酵粘红酵母生产微生物油脂具有一定的应用价值,也为进一步大规模生产微生物油脂和研究油脂的不饱和性能提供了研究基础。     

常压室温等离子体诱变粘红酵母筛选高产油脂菌株及发酵条件优化

以粘红酵母(Rhodotorula glutinis)为出发菌株,采用常压室温等离子体对其进行诱变。得到最佳诱变条件为120 W功率下处理60 s,致死率达90%。诱变后,采用苏丹黑B染色法筛选出1株高产油脂突变株LA1,与出发菌株相比较,其油脂产量、油脂含量分别较出发菌株提高了17.59%和46.08%。对LA1发酵培养条件进行优化,得到最佳条件为初始葡萄糖质量浓度70 g/L,氮源为(NH4)2SO4,C/N值53。在最佳发酵条件下,LA1的油脂产量、生物量、油脂含量及油脂得率较优化前分别提高了123.9%、56.6%、43.0%和43.5%,其油脂脂肪酸组成与植物油相近。     

发酵荔枝渣制备微生物油脂

利用粘红酵母发酵荔枝渣水解液对制备微生物油脂,为综合利用荔枝加工下脚料提供参考。通过摇床培养确定粘红酵母种子液的最佳培养时间及最适装液量,通过单因素试验及正交试验优化发酵工艺参数,获得产油脂最优发酵条件,并对所得微生物油脂理化性质进行分析。结果表明:(1)粘红酵母种子液的最佳培养时间为24 h;发酵液最适装液量为40 m L/250 m L;最佳工艺条件为初始糖度8°Brix、初始p H值5.5、接种量10%、发酵时间96 h。在此基础上测得微生物平均油脂浓度、生物量和油脂含量分别为:0.378 g/L、15.670 g/L和2.414%,产脂能力为378.3 mg/L。(2)对得到的微生物油脂进行理化指标分析,所得微生物油脂呈黄色透明液体,无特殊气味,平均相对密度为1.104 4 g/m L,折光指数为1.459 0,酸价为5.39(mg/g),碘价为101.8(g I2/100 g),过氧化值为9.44(mmol/kg)。     

利用粘红酵母生产微生物油脂研究进展

粘红酵母是一种良好的产油微生物,其油脂可用来生产生物柴油。本文介绍了粘红酵母生产油脂的情况,包括其常用基本培养基,廉价工农业废弃物培养基,以及促进粘红酵母生长和产油的方法和培养条件,并对粘红酵母生产微生物油脂方面存在的问题和未来的发展方向进行了概述。      

双菌混合发酵丢糟生产微生物油脂的研究

探索利用假丝酵母和皮状丝孢酵母混合发酵丢糟生产微生物油脂的最佳工艺条件.在对假丝酵母和皮状丝孢进行驯化培养的基础上,设定假丝酵母和皮状丝孢酵母的比例、接种量、培养温度、培养时间为4个因素,进行L9(34)正交试验,通过测定油脂含量,获得油脂生产的最佳工艺条件.研究结果表明,双菌发酵丢糟生产微生物油脂的最佳工艺条件:假丝酵母和皮状丝孢酵母的比例为1:1,接种量为9％,培养温度为32℃,培养时间为4d,在该条件下测得每1000g丢糟发酵物中油脂含量为21.14g.     

利用木糖产油脂酵母的筛选、鉴定及发酵条件优化

采用磷酸香兰素比色法从环境中筛选分离得到1株能够利用木糖产油脂的114号酵母菌株,通过生理生化特性实验及分子生物学实验对该菌株进行鉴定,并对该菌株的发酵条件进行优化,考察了培养时间、接种量、装液量和发酵温度对菌株产油能力的影响,通过GC-MS对该菌株最优发酵条件下所产油脂进行脂肪酸组成分析。结果表明:该菌株为胶红酵母(Rhodotorula mucilaginous),在啤酒糟酶解液中培养状况良好;最优发酵条件为培养时间5 d,接种量12%,装液量30m L/250 m L,培养温度32℃。在最优发酵条件下,生物量、油脂产量和油脂含量分别为16.92、4.44g/L和26.22%。所产油脂中不饱和脂肪酸含量76.923%,油酸含量59.087%,与植物油类似。     

高产油脂菌株的筛选及其利用柠檬酸废水发酵的工艺优化

文中采用了高效的常压室温等离子体(ARTP)诱变技术,结合流式细胞仪对经过尼罗红染色后的细胞进行了高通量筛选,获得了一株高产油脂的粘红酵母菌株,油脂含量较出发菌株提高了69.4%。将分选得到的菌株利用柠檬酸废水进行微生物油脂的生产。研究了废水稀释比例、初始pH值、初始补糖浓度对粘红酵母生长、油脂积累和COD降解率的影响。结果表明,最适的发酵条件为使用废水原液,pH值为5.5,初始补糖浓度为20g/L。此时,粘红酵母的生物量、油脂含量、油脂产量和COD降解率分别达到9.18g/L、37.66%、3.27g/L和63.3%。并且利用气相色谱-质谱分析了脂肪酸的组成。所产菌体的油脂成分中,不含和脂肪酸的含量较基础培养基提高了10.5%,可达88.32%,主要成分是油酸和亚油酸。表明柠檬酸废水适于粘红酵母进行微生物油脂的生产,并进一步用于生物柴油的制备。     

红酵母生物合成类胡萝卜素的培养条件优化

采用红酵母(Rhodotorula mucilaginosa)发酵生产类胡萝卜素,对其培养基及培养条件进行了研究。得到2组适合红酵母生长的培养基,其中葡萄糖组各组分最佳添加量:3%葡萄糖,2.0%蛋白胨,1.5%酵母膏,生物量、色素含量和产量分别为11.38g/L、120.63μg/g、1.37mg/L,最佳培养条件为pH值为6.0,温度30℃,转速160r/min,培养时间168h,此条件下的生物量、色素含量和产量分别为14.38g/L、176.6μg/g、2.54mg/L,其中产量提高了85.4%。最后优化了蔗糖组各组分的最佳添加量:4%蔗糖,1.5%磷酸氢二铵,1%酵母膏,产量为2.53mg/L。     

玉米秸秆水解液发酵产生物油脂试验研究

对发酵性丝孢酵母IFFI01368发酵玉米秸秆水解液产脂的培养基组成和发酵条件进行了探索,并对油脂的脂肪酸组成进行了鉴定.结果表明最佳条件为:补加4%的蔗糖,酵母膏、硫酸铵为氮源,碳氮比100:1,pH 5.5,发酵摇瓶装液量为300 mL三角瓶装玉卷秸秆水解液50 mL,时间4d.在最佳条件下于27℃、150 r/min振荡发酵培养,所得生物量为23.5 g/L,油脂含量42.7%,产脂能力为10.03 g/L.所产生物油脂的脂肪酸主要为棕榈酸、油酸和硬脂酸.     

多菌种混合发酵玉米秸秆生产微生物油脂的研究

利用绿色木霉、烟曲霉与皮状丝孢酵母共酵玉米秸秆,采用正交试验进行微生物油脂发酵.结果表明,多菌种混合发酵玉米秸秆生产微生物油脂的最佳条件:绿色木霉、烟曲霉与皮状丝孢酵母配比为1:1:1,接种量为l0%,培养温度为28℃,培养时间为7d.在最佳条件下每l00g玉米秸秆发酵产物中可获得1.247g油脂.研究表明,利用多菌种发酵玉米秸秆生产微生物油脂具有一定的可行性.     

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