固定化酵母细胞在鼠曲草啤酒中的应用

探讨了固定化啤酒酵母在鼠曲草啤酒中的应用，采用正交试验确定了固定化酵母的最佳条件和鼠曲草啤酒的发酵工艺条件。固定化酵母细胞的最佳条件为海藻酸钠浓度为6％，氯化钙浓度为0．5％，固化时间为1h；鼠曲草啤酒的发酵工艺为主发酵前添加3．0％的鼠曲草提取液，发酵时间为8d。     

固定化酵母发酵制备菠萝酒

以菠萝为原料，采用酒用酵母、面包酵母、啤酒酵母和葡萄酒酵母发酵制备菠萝酒实验比较，结果表明，酒用酵母发酵过程酒精度最高，达8．8％(V／V)；固定化酵母比游离酵母发酵快；固定化酵母发酵过程中起始糖度、温度、pH值对发酵产酒精都有影响；通过正交实验得出固定化酵母发酵制备菠萝酒的最佳工艺条件为：温度20℃。初始糖度20％，酸度pH为5。     

固定化酵母生产蜂蜜酒的研究

对固定化酵母生产蜂蜜酒的工艺条件进行了研究，通过L9(3^4)正交试验确定了最适固定化条件为Na-Alg 1．0％，CaCl2 1．0％，固定化时间1h，7#针头凝胶球；最佳发酵条件为底物浓度18％，pH4．2，32℃，接种量1．4％。(丹妮)     

固定化猕猴桃酒酵母发酵条件的研究

采用混合材料作为载体将猕猴桃酒酵母固定化。通过温度、pH、起始糖度、填充量对固定化酵母发酵影响的分析；采用L9(3^4)正交试验对固定化酵母发酵工艺条件进行研究。结果表明，最佳发酵条件为温度25℃，pH3．3，起始糖浓度270g／L，填充量0．4g／ml。在此条件下发酵速度快，发酵的酒果香味浓郁，Vc保存率高。(孙悟)     

海藻酸锰固定化酵母在木薯淀粉酒精发酵工艺中的应用研究

利用Mn2+对Ca2+呈换后形成的海藻酸锰固定化酵母细胞对木薯淀粉双酶法水解后的糖化液进行发酵.正交试验对海藻酸锰固定化细胞的固化条件和发酵条件进行了优化,固定化最佳条件为CaCl2浓度0.2mol/L,海藻酸钠浓度2.0％,MnSO4浓度1.2％.发酵最佳条件为初还原糖浓度20％,颗粒填充率30％,发酵液pH值为5.0.强度实验表明,海藻酸锰固定化酵母细胞的耐磷酸盐能力是海藻酸钙固定化酵母细胞的3倍左右.对海藻酸锰、海藻酸钙固定化酵母细胞进行13批次发酵对比试验,表明第3批次后海藻酸锰固定化酵母细胞的糖利用率和酒精度都比海藻酸钙固定化酵母细胞要高.     

固定化酵母发酵蟠桃酒的工艺研究

以蟠桃为原料采用活性干酵母,固定化酵母发酵制备桃酒试验比较,结果表明,固定化酵母比游离酵母发酵速度快,固定化酵母发酵过程中桃液起始糖度、温度、pH、亚硫酸钠添加量对发酵产酒均有影响,通过试验得出固定化酵母发酵制备桃酒的最佳工艺条件为：温度20℃,初始糖浓度20％,pH5．0,亚硫酸钠添加量30g／L。     

固定化多菌种发酵海藻酒的研究

采用PVA固定化酿酒酵母和产香酵母发酵海带，酿造海藻酒。对游离细胞与固定化细胞的分批发酵和连续发酵的动力学进行了研究并建立了相应的发酵动力学方程。实验结果表明：酿酒酵母和产香酵母最佳配比为4：1，发酵温度20℃，固定化细胞分批发酵和连续发酵凝胶粒的充填系数分别为0．25和0．5，游离混合细胞的发酵时间为7d，固定化细胞连续发酵稀释速率0．12/h，发酵时间为0．5d左右。经160d连续发酵实验，PVA固定化细胞粒子的机械强度良好。     

固定化酵母应用于酵母工序大生产试验研究

介绍了固定化酵母应用于酵母工序大生产的试验过程。结果表明，酒固定化酵母具有传统酵母的发酵能力，其含酒精高于传统酵母0．05％加．1％；以麦芽、玉米为混合原料的发酵周期为40h-50h，以瓜干为原料的发酵周期为45h-50h，产酒精能力8%-11％。并提出了该技术的优点和不足之处。     

固定化多菌种发酵苦瓜酒的研究

以苦瓜为主要原料，采用固定化酿酒酵母和产香酵母酿造苦瓜酒。对游离细胞与固定化细胞的分批发酵和连续发酵的动力学进行了研究，并建立了相应的发酵动力学方程。结果表明，酿酒酵母和产香酵母2种菌种菌量的最佳配比为4：1，发酵温度25℃，共固定化细胞分批发酵和连续发酵凝胶粒的充填系数分别为0．25和0．5，游离混合细胞的发酵时间为7d，共固定化细胞连续发酵稀释速率0．12／h，其发酵时间为0．5d左右。经60批次连续发酵实验，固定化细胞粒子的机械强度良好．     

酿酒酵母细胞固定化研究

初步研究了海藻酸钙固定化技术在酿酒酵母上的应用。分析在不同条件下固定化酵母的发酵性能、机械强度，并对固定化酵母与游离酵母的发酵力进行了分析。结果表明，酵母细胞固定化后，其使用寿命、发酵周期均有大幅度提高。海藻酸钠的浓度3％，氯化钙浓度为2．0mol／L，固定化温度20℃，酵母细胞的固定化效果最为理想。     

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