混菌发酵对苹果酒香气物质及发酵效率的影响

本文研究通过法尔皮有孢汉生酵母(Hanseniasporavalbyensis)和酵母属酵母(Saccharomycescerevisiae)顺序混菌发酵增加苹果酒的风味酯含量和保证苹果酒发酵的发酵效率。方差分析表明两种酵母接种量及该两种接种量的交互因素对混菌发酵效率有显著性影响;对接种量、苹果汁营养条件进行正交试验确定了一种适宜条件,在该条件下,混和酵母具有法尔皮有孢汉生酵母高产酯能力特性和酵母属酵母高发酵效率特性:在15℃下,发酵时间为31d,发酵完毕时苹果酒中总酯浓度为酵母属酵母发酵苹果酒的1.60倍,残余总糖低于4.0g/L。     

苹果酒发酵条件的研究

选择了一种适宜苹果酒生产的酵母,利用单因子和正交实验法对苹果酒的发酵条件进行了优化,得到理想的发酵条件为:温度20℃、糖度22°Bx、酸度2g/L(pH=4.06)和接种量0.5g/L.研究结果对苹果酒的酿造有一定的帮助.     

甜苹果酒的发酵工艺优化

发酵工艺对苹果酒品质有重要影响.以感官质量为评价指标,以发酵温度、糖度、酸度、接种量为试验因素,进行四因素三水平正交试验,对甜苹果酒主发酵工艺进行优化.甜苹果酒主发酵的最佳工艺条件是:发酵醪调至糖度20°Bx、酸度(按苹果酸计)6g/L,按接种量为0.25g/L接入酵母,在18℃温度下发酵7d,前1～2d对发酵醪进行通...     

苹果酒主发酵工艺研究

通过进行正交试验分析,研究接种量、温度、SO2添加量、起始糖度四个因素对苹果酒主发酵的影响。试验结果表明:最适反应温度为50℃,酶解时间3~4h。通过响正交试验优化的最适发酵条件为:苹果汁接种量2.0g/L、发酵温度28℃、SO2添加量100mg/L、起始糖度24%。     

肠膜明串珠菌肠膜亚种Z_25在苹果酒中发酵特性的研究

从发酵温度、接种量、酒精度、起始苹果酸浓度等方面研究了肠膜明串珠菌肠膜亚种Z25的苹果酸乳酸发酵（MLF）能力,确定了肠膜明串珠菌MLF适宜条件为温度20℃、接种量6%、酒精度10%（v/v）以及起始苹果酸浓度4.0g/L。按此工艺酿制,发酵时间12d后苹果酒中的乳酸含量由0.99g/L提高到了3.5g/L,苹果酸含量从4g/L下降到0.25g/L,且苹果酸降解发生在菌株Z25的对数生长阶段。显然,辅助肠膜明串珠菌肠膜亚种Z25到苹果酸乳酸发酵中,可以改善苹果酒的品质。     

短乳杆菌发酵苹果汁工艺优化及有机酸变化

该研究利用短乳杆菌发酵苹果汁,生产能够调节人体肠道功能的乳酸菌苹果汁。通过单因素实验确定最适碳源、氮源以及缓冲因子;并以总酸、还原糖的变化为依据,进行响应面优化,确定最适发酵工艺条件,采用高效液相色谱法测定苹果汁发酵过程中有机酸组成及含量变化。结果表明,优化后发酵苹果汁的最佳培养基条件为:葡萄糖质量浓度50 g/L,蛋白胨质量浓度9 g/L,K₂HPO₄质量浓度4 g/L;菌种接种量为8%,发酵温度为36℃,发酵时间为6 d。在该条件下测得苹果汁的总酸为2. 61 g/100 g、还原糖为5. 027 g/100 g;经短乳杆菌发酵后苹果汁的品质明显优于发酵前。发酵后乳酸、富马酸、乙酸、奎宁酸含量显著增多;苹果酸、琥珀酸含量均持续减少,酒石酸含量无明显变化。     

苹果酒酿造工艺的研究

苹果酒是一类市场发展前景良好的低酒精度饮品,由于其风味与口感极佳且富含多种营养成分,因此受到国内外消费者的喜爱。但是,国内苹果酒的生产工艺尚待成熟,因此对苹果酒的酿造工艺做进一步研发十分必要。本文以山东省日照市所产苹果汁为原料,研究苹果酒酿造的工艺条件,并对其进行优化,选择最佳参数;研究内容包括确定酵母的添加量、苹果汁初始糖度和pH值对发酵的影响,确定了苹果汁发酵前的糖度和pH值应分别调整为Brix值15和pH值3.3～3.7;通过单因素实验对苹果酒发酵工艺中发酵温度、酵母添加量、营养盐的用量、初始苹果汁pH值进行考察;采用正交实验进行发酵条件的优化。结果表明,在发酵温度25℃、酵母添加量0.20‰、营养盐添加量0.20‰、初始pH值3.7时,苹果酒的感官评定结果最佳,最终理化指标为pH值3.629、总酸0.47%、二氧化碳含量1.72V/V、Brix7.21%、酒精度6.95%。     

杏鲍菇液态发酵培养的初步研究

杏鲍菇是一种珍贵的药食皆宜的真菌.为在较短时间内大量获得杏鲍菇菌体,该试验探讨了液态发酵方法制备杏鲍菇.试验以杏鲍菇菌丝体干重为指标,通过单因素试验和正交试验,对杏鲍菇液态发酵培养基和液态发酵条件进行了优化.试验结果表明,杏鲍菇液态发酵的最佳碳源为葡萄糖,最佳氮源为蛋白胨,当培养基配方为葡萄糖30g/L、蛋白胨5g/L、KH2PO40.8g/L、MgSO41.2g/L、VB110mg/L时杏鲍菇菌丝体生物量较高.在摇瓶培养条件中研究了种龄、装液量、初始pH值、接种量、温度、转速、培养时间等对液态发酵杏鲍菇菌体生物量的影响.得出最佳培养条件:种子培养6d,装液量20％ (v/v),接种量为10％ (v/v),培养基的初始pH值为自然,培养温度为25℃,摇瓶转速为140r/min,发酵8d,杏鲍菇菌丝产量可达8.23g/L.     

棕色蘑菇液体菌种培养基和培养条件的优化

为了缩短棕色蘑菇的栽培周期,该文采用L16 (45)正交试验对棕色蘑菇液体菌种培养基配方和培养条件进行了优化,确定发酵培养基为:菜园土700g/L、麦粒120g/L、蛋白胨6g/L、葡萄糖15g/L、七水硫酸镁1.5g/L、磷酸二氢钾1.0g/L.发酵条件为转速100r/min,装液量75mL/250mL,接种量12％ (w/v).在此条件下,棕色蘑菇的菌丝量由1.657g/L提高到17.028g/L.     

添加肠膜明串珠菌后的苹果酒苹果酸乳酸发酵工艺优化研究

以苹果酒风味的柔和指数为指标,对添加肠膜明串珠菌后的苹果酒苹果酸乳酸发酵(MLF)工艺条件进行优化。结果表明,发酵温度、pH和肠膜明串珠菌接种量等因素会影响MLF后的苹果酒柔和指数;采用二次正交回归旋转实验确定了苹果酒MLF的适宜工艺参数为:发酵温度21.78℃,pH 3.53,肠膜明串珠菌接种量4.65%(v/v),按该工艺生产柔和指数从2.73提高到3.54,苹果酒的风味得到了明显改善。     

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