乳酸菌在牡蛎酶解液中的生长特性及发酵条件优化

以牡蛎酶解液为原料,通过测定培养液中OD值及乳酸菌数,探讨保加利亚乳杆菌、嗜热链球菌及干酪乳杆菌的生长特性。以滴定酸度、p H值为指标,通过神经网络平台建立这3株乳酸菌混合发酵牡蛎酶解液的神经网络模型,拟合确定发酵的最适宜条件。试验结果表明:3种乳酸菌被驯化后延滞期缩短,稳定期延长;保加利亚乳杆菌和嗜热链球菌的最适生长温度均为40℃,而干酪乳杆菌在36℃时生长繁殖最快。通过神经网络模型优化的这3株乳酸菌发酵牡蛎酶解液的条件:保加利亚乳杆菌、嗜热链球菌和干酪乳杆菌混合比例4∶2∶1,接种量(体积分数)7%,发酵温度40℃,发酵时间7 h。按此条件接种乳酸菌混合发酵7 h,牡蛎酶解液的滴定酸度为51.8°T,p H 4.41。     

两种乳酸菌协同发酵冷鲜调理牛肉的工艺优化

为了优化冷鲜调理牛肉发酵工艺,选用乳酸乳球菌乳亚种、植物乳杆菌协同发酵冷鲜调理牛肉。采用单因素试验和L_9(3~4)正交试验设计,以pH、剪切力、感官评价、TVB-N、TBA为指标,优化2种益生菌协同发酵冷鲜调理牛肉的工艺条件。结果表明:乳酸乳球菌乳亚种和植物乳杆菌分别发酵调理牛肉的最佳工艺均为接种量4%,发酵时间18 h,发酵温度36℃;2株菌有协同增效作用;2种乳酸菌发酵工艺条件为菌种接种量3%,菌种配比1:1,发酵温度36℃,发酵时间12 h。     

乳酸菌降低发酵烤肠中亚硝酸盐残留量的研究

本实验针对乳酸菌降低发酵烤肠亚硝酸盐残留量进行了研究,以发酵烤肠的亚硝酸盐的残留量、pH值为指标,并兼顾产品的品质。针对影响发酵烤肠的四个主要因素：发酵菌种(植物乳杆菌、嗜热乳链球菌:保加利亚乳杆菌=1:1混合菌、德国科汉森乳酸菌)、接种量、发酵温度和发酵时间进行了单因素试验;在确定较优工艺参数的基础上,以产品的亚硝酸盐残留量的降解率和感官评分为指标,进行了正交试验,最终确定最优化的工艺参数为：发酵菌种是德国科汉森复合乳酸菌,接种量为2.0%,发酵温度为30℃,发酵时间为22h。     

大豆乳酸发酵的菌种筛选

以大豆为原料,通过乳酸菌发酵制备功能性食品过程中,探讨5株不同乳酸菌的发酵性能测试并筛选出合适的菌种.试验结果表明:保加利亚乳杆菌(Lactobacillus bulgarious)、嗜酸乳杆菌(Laerobacillus aci-dophilus)和两岐双岐杆菌(Bifidobacterium bifidum)为最佳菌种组合,最佳种间比2:1:1,多菌株大豆发酵最佳工艺条件为:接种量3%,发酵温度39℃,豆浆添加量为3.0%,碳源(蔗糖:葡萄糖为1:1)使用量为3%,发酵时间24 h.     

甜瓜发酵饮料的研究

以甜瓜为原料,研究具有甜瓜特殊风味的乳酸菌发酵饮料.采用驯化的保加利亚乳杆菌和嗜热链球菌(1:1)为发酵菌种,通过正交试验确定最佳发酵条件为:白砂糖4%,奶粉5%,发酵温度42℃,接种量4%,发酵时间48h.稳定剂选用CMC+黄原胶1:1混合,用量为0.2%.研制的产品口感细腻酸味可口,风味独特,是营养保健型发酵饮品.     

高效水解乳糖乳酸菌的筛选及发酵条件优化

我国新疆地区传统酸马奶中乳酸菌资源丰富,为获得高效降解乳糖的乳酸菌及其发酵条件,本实验从分离自新疆酸马奶的14 株乳酸菌中,筛选出1 株高效水解乳糖的发酵乳杆菌RB-6,其乳糖水解率达37%。进一步利用单因素试验和正交试验对发酵乳杆菌RB-6的发酵温度、接种量和发酵时间进行优化,获得其乳糖水解率最高的发酵条件为：发酵温度39 ℃、接种量3%、发酵时间8 h。发酵乳杆菌RB-6在该条件下发酵酸奶的乳糖水解率达47%,比优化前提高了10%。     

芸豆酵素复合发酵工艺优化

利用乳酸菌和酵母菌复合菌系制备酵素,通过多菌种单因素试验优化发酵菌种条件并确定复合发酵接种顺序及发酵时间。结果表明:最优发酵方式为先接种酵母菌预发酵后再接种乳酸菌,最佳复合发酵条件为装瓶量30mL(250mL)、pH 5.0、接种0.20%酵母菌、30℃振荡培养24h;再接种3.0%复合乳酸菌(植物乳杆菌嗜酸乳杆菌为11),37℃培养24h;4℃低温静置发酵24h,酵素产香。该条件得到的芸豆酵素上清液色泽通透呈黄色,气味清冽,活菌数显著增加,超氧化物歧化酶活力(SOD)达224.09U/mL。     

黄瓜、胡萝卜发酵果蔬汁的工艺研究

以黄瓜、胡萝卜为原料,用乳酸链球菌、干酪乳杆菌、4号酵母为发酵菌种,采用4因素3水平正交试验,确定了发酵果蔬汁的最佳制作工艺。其最佳工艺参数为：乳酸链球菌：干酪乳杆菌：酵母菌=1：2：3、接种量5%、发酵温度30℃、发酵时间6h、冷藏温度4℃、冷藏时间20h。该果蔬汁最佳配方为：蔗糖6%、明胶0.03%、耐酸性CMC-Na0.02%、抗坏血酸3mg/1000g。     

益生乳酸菌发酵苹果汁的研究

研究益生乳酸菌对苹果汁发酵的适应性和最优工艺条件。以发酵酸度为考核指标,考察保加利亚乳杆菌、嗜酸乳杆菌和植物乳杆菌单一菌株发酵和混合菌株发酵苹果汁的能力,筛选获得最佳的发酵菌株组合。通过正交实验优化了乳酸菌发酵的最佳工艺条件。结果显示,嗜酸乳杆菌与植物乳杆菌按1:1混合的复合乳酸菌对苹果汁发酵产酸作用较好,其发酵的最佳工艺参数是:苹果汁添加量35%、蔗糖添加量3%、发酵剂接种量4%、发酵温度40℃。在最优条件此时,苹果汁的发酵酸度达到0.952%。冷藏4周后,乳酸菌活菌数为1.12×10~9 cfu/mL,说明采用嗜酸乳杆菌与植物乳杆菌混合发酵苹果汁可行。     

真空包装鲤鱼肉干发酵工艺参数优化

以鲤鱼肉为主要原料,人工添加乳酸菌进行发酵,通过单因素试验和L9(34)正交试验,以感官评分和pH值为指标,确定了鲤鱼肉干植物乳杆菌发酵最佳工艺参数。结果表明:乳酸菌发酵鱼肉制品最佳发酵工艺参数为植物乳杆菌接种质量分数3%、白砂糖添加质量分数2%、食盐添加质量分数4%、发酵温度35℃、发酵时间20 h。在此条件下制成的发酵鱼制品表面有光泽、酸味适中、肉质弹性好、韧性好、口味独特。     

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