富硒乳酸菌发酵条件的研究

通过单因素试验和L27(313)正交试验,确定了乳酸菌富硒的最佳发酵条件.正交试验结果表明,影响乳酸菌总硒量的主要因素是培养温度、接种量、亚硒酸钠浓度和培养温度与接种量的一次交互作用.最佳发酵条件为培养基初始pH为6.6,亚硒酸钠浓度为18 μg/mL,装液量为150 mL/250 mL三角瓶,接种量5.5%,培养温度 42 ℃,培养时间45.5 h.在此优化条件下,富硒乳酸菌生物量可达6.85 g/L,细胞硒含量达1100 μg/g,硒总含量可达7536 μg/L,细胞硒含量的92.15%为有机硒.     

富锗酵母培养条件优化及分析

该研究通过向麦芽汁培养基中添加GeO2培养啤酒酵母的方法来制备富锗酵母.测定富锗酵母的生物量及锗含量来评价其品质.对培养条件进行了优化.确定培养条件为:培养温度28℃,摇床转速200r/min,培养基锗离子添加浓度为100mg/L,培养基的装液量80mL/250mL三角瓶,种子液接种量10％(v/v),培养基初始pH值为为6.0,培养时间60h.优化培养条件制备所得的富锗酵母生物量可以达到(3.85+0.17)g/L,而其锗含量可以达(758.6+31.6)μg/g,其中有机锗含量为92.8％.采用红外光谱法分析空白酵母粉和富锗酵母粉,比较酵母富集Ge元素前后红外吸收峰的变化.     

高生物量富硒酵母的选育和培养条件的初步研究

对富硒酵母进行了选育并进行了条件优化，得到了摇瓶培养时富硒酵母的最适发酵条件：温度30℃，10％接种量，转速200r／min，发酵培养基最适初始硒浓度为25μg／ml，初始pH为4．0，发酵培养时间48h，经测定成品硒酵母生物量达到10g／L，硒含量超过1500μg／g，硒总含量超过15000μg／L，其中有机硒含量超过90％。     

硒对啤酒酵母细胞生长的影响

目的研究不同硒浓度对啤酒酵母细胞生长的影响，确定适宜的硒添加量。方法用分光光度计测定不同硒浓度时酵母细胞培养液在不同时间的吸收度，绘制生长曲线，比较硒浓度不同时酵母细胞的生长情况。结果亚硒酸钠的添加浓度小于20μg／mL时，有促进酵母菌生长的作用；亚硒酸钠浓度高于30μg／mL时，对酵母菌生长有明显的抑制作用；亚硒酸钠浓度在20μg／mL时酵母菌可以正常生长。结论亚硒酸钠的添加浓度应在20μg／mL左右。     

响应面法优化富硒米曲霉的培养条件的研究

文章首先用单因素法分别对富硒米曲霉发酵的培养条件:转速、接种量、装液量进行了考察.确定了最佳培养条件为:转速180 r/min,接种量10%,装液量320 mL/L.在此基础上,采用中心组合试验设计结合响应面分析法(Response Surface Methodology,RSM)对影响富硒米曲霉的发酵条件进行进一步优化.结果表明,主要影响因素的最佳条件为:转速180 r/min,接种量10.5%,装液量364 mL/L,米曲霉的胞内硒产量为2.512 mg/g,与理论值2.529 mg/g,相差0.67%.因此,利用响应面分析法对米曲霉富硒的培养条件进行优化合理可行.     

富硒乳酸菌的筛选及其富硒能力的初步研究

从黄水中筛选到一株富硒乳酸菌，经鉴定为布氏乳杆菌（Lactobacillus buchneri）。通过亚硒酸钠抗性筛选和MRS液体培养基发酵培养，初步确定其富硒条件为：接种量10％（v／v），亚硒酸钠添加量46μg／mL，pH6．2，37℃，培养36h，富硒能力为56．52％。     

富铬酵母培养条件优化及分析

通过在培养基中添加Cr3 制备富铬酵母,测定富铬酵母生物量及铬的含量进行培养条件优化实验,结果表明,培养温度28℃,摇床转数220r/min,培养基CrCl3·6H2O添加量为20mg/L,装液量50mL/250mL三角瓶,接种量5%(v/v),pH值为6.0,培养时间72h,获得的富铬酵母生物量可达(12.11±0.14)g/L,铬含量可达(184.68±0.07)μg/g,铬总含量达到了(2236.48±26.62)g/L。其中有机铬含量为88.9%。对空白酵母和富铬酵母进行红外光谱分析,比较了酵母富集Cr3 前后吸收峰的变化,并对空白酵母和富铬酵母中的17种氨基酸的组成进行了分析。     

啤酒酵母富铬条件的初步研究

本文研究了培养温度、摇瓶时间、接种量,培养基中添加铬盐和营养成分对啤酒酵母富铬作用的影响;比较啤酒酵母、异常汉逊氏酵母、假丝酵母、热带假丝酵母和粉状毕赤酵母的富铬能力。取得啤酒酵母富铬作用的优化条件:麦芽汁培养基中,添加2.0μg/mLCrCL_3·6H_2O、2.0μg/mL的尿素,每瓶(500 mL)接种2 ml啤酒酵母菌母液(3.2×10~6酵母细胞/mL)、30℃、140往返/min摇瓶48 h,可制得总铬含量和有机铬含量较高的铬酵母。     

荷叶离褶伞菌丝体富硒条件的研究

为获得荷叶离褶伞富硒菌丝体,以菌丝体干重和富硒率为评价指标,研究灭菌条件、培养时间、硒添加量和硒添加时间对荷叶离褶伞菌丝体生长及其富硒效果的影响.采用L9(34)正交实验优化荷叶离褶伞菌丝体富硒条件,结果表明当灭菌条件为115℃、20min,于发酵至第5d在发酵液中加入4.μg/mL Na2Se03,待发酵至13d时,菌丝体干重量和富硒量分别为0.8232g/100mL和0.7040mg/g,由此确定上述条件为荷叶离褶伞菌丝体的最优富硒发酵条件.     

富硒益生菌的筛选及其富硒条件的优化

为了获得能耐受较高亚硒酸钠质量浓度和具有富硒能力的益生菌菌株,对7株酵母菌和12株乳酸菌进行了筛选。结果表明,所有菌株均能在亚硒酸钠质量浓度为20~80μg/m L的平板上生长,乳酸菌YQRS菌株和酵母菌FJYJM3菌株具有较高的耐受性和富硒能力。对它们进行发酵条件的优化,表明YQRS菌株在亚硒酸钠添加量为15μg/m L、添加硒的时间为对数期前期时,富硒效果最好,菌体生物量为2.66 g/L,总硒含量能达到2 300.26μg/L。而FJYJM3菌株在亚硒酸钠添加量为20μg/m L,添加硒的时间为对数期前期时,富硒效果最显著,生物量能达到4.86 g/L,总硒含量能达到5 790.99μg/L。     

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.     

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     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.