羧甲基纤维素钠与几种胶体复配对双蛋白活性乳酸菌饮料稳定性的影响

研究了羧甲基纤维素钠(CMC-Na)分别与黄原胶、魔芋胶、瓜尔豆胶复配对双蛋白活性乳酸菌饮料稳定性的影响,结果表明,CMC-Na分别与黄原胶、魔芋胶复配时体系的稳定性较好,其中CMC-Na与黄原胶复配时,优化用量为CMC-Na0.3%、黄原胶0.1%;CMC-Na与魔芋胶复配时,优化用量为CMC-Na0.3%、魔芋胶0.15%;相较之下,优化用量的CMC-Na与魔芋胶复配时体系的稳定性最好;而CMC-Na与瓜尔豆胶复配不利于该体系的稳定.     

交联淀粉黄原酸酯

一、概述交联淀粉黄原酸酯,即不溶性淀粉黄原酸酯(ISX),这里定义为经用交联试剂交联后再黄原酸酯化的淀粉。黄原酸酯化是在强碱(通常是氢氧化钠)存在下进行的,黄原酸基团具有一元酸的性质,因制备时在强碱性介质中,产品呈现以盐的形式,可以用下列通式来表示。     

酯化蜡质玉米淀粉对糯米粉团冷冻特性的影响

目的评价酯化蜡质玉米淀粉和预糊化酯化蜡质玉米淀粉对糯米粉团冷冻特性的影响。方法测定酯化蜡质玉米淀粉与预糊化酯化蜡质玉米淀粉的冻融稳定性;分别往糯米粉中添加1%、2%、3%、4%(m:m)4个比例的酯化蜡质玉米淀粉和预糊化酯化蜡质玉米淀粉制作速冻糯米粉团,检测速冻糯米粉团的失水率、裂口率、煮熟时间、糊汤率、感官评价等指标。结果预糊化酯化蜡质玉米淀粉与酯化蜡质玉米淀粉均具有良好的冻融稳定性,能有效降低速冻糯米粉团的失水率和裂口率,同时改善速冻糯米粉团的蒸煮和食味品质;预糊化酯化蜡质玉米淀粉在改善糯米粉团冷冻特性斱面效果更优,但两者差距不大,当预糊化酯化蜡质玉米淀粉的添加量为1%时,速冻糯米粉团的失水率为11.8%,裂口率为22.5%,煮熟时间为229 s,吸光度为0.823,感官及外观评分分别为79.3分、23.1分。结论添加1%预糊化酯化蜡质玉米淀粉制成的糯米粉团冷冻特性最好。     

几种食品添加剂对蔬菜杂粮方便面品质影响的研究

研究了几种食品添加剂对蔬菜杂粮方便面品质的影响,结果表明,随着羧甲基纤维素钠(CMC-Na)、瓜尔豆胶、黄原胶添加量的增加,方便面的断条率减少,吸水率增大.当CMC-Na添加量在0.5%以下时,方便面烹煮损失随其添加量的增大变化不明显.烹煮损失随瓜尔豆胶、黄原胶添加量的增大呈现先减小后增大的趋势,当其添加量为0.3%时,面条烹煮损失达到最小值.在减少方便面烹煮损失、断条率方面,单甘酯比蔗糖酯更加有效,马铃薯变性淀粉优于马铃薯原淀粉.     

木薯淀粉与黄原胶共混干热改性研究

研究了干热反应的温度、时间及共混物pH对木薯淀粉及黄原胶共混物的影响,对改性产物的交联度、淀粉糊粘度及透明度进行测定,用X-射线衍射仪(XRD)对淀粉结构进行分析。结果表明,干热处理能有效抑制淀粉糊化,降低透明度,证明木薯淀粉和黄原胶发生了交联反应,且淀粉与黄原胶在碱性条件下混合有利于交联反应的进行,交联程度随反应温度和时间的增加而增加。     

魔芋基材可食用蔬菜包装纸生产工艺的研究

以莲花白、魔芋作为可食用蔬菜纸的基料,添加红薯淀粉作为交联剂以增强纸的强度,调节CMC-Na和黄原胶提高蔬菜纸的成膜性。以抗张强度、伸长率和透水率为主要检测指标,确定蔬菜纸的最佳工艺参数:红薯淀粉添加量12.5%,黄原胶/CMC-Na的比例3.5∶1,加工温度45℃。     

稳定剂对枸杞果汁稳定性的影响

选用果胶、羧甲基纤维素钠(CMC-Na)、卡拉胶、黄原胶、结冷胶共5种稳定剂,进行单因素实验,通过感官评定、离心沉淀率及黏度的测定,分析稳定剂对枸杞果汁稳定性的影响。并从中筛选出果胶、CMC-Na、黄原胶进行复配稳定剂优化组合实验,通过响应面分析得出:果胶添加量为0.21%、CMC-Na添加量为0.24%、黄原胶添加量为0.059%时,枸杞果汁的稳定性最好。     

不溶性阳离子交联淀粉黄原酸酯的制备研究

以天然淀粉为原料,氢氧化钠为催化剂、环氧氯丙烷为交联剂制备交联淀粉,以制备得到的交联淀粉为原料、2,3-环氧丙基三甲基氯化铵为醚化剂,采用微波辅助半干法制备交联醚化淀粉,在此基础上,以交联醚化淀粉为原料,二硫化碳为酯化剂,在碱性条件下制备阳离子交联淀粉黄原酸酯。实验结果表明,制备阳离子交联淀粉黄原酸酯的最佳工艺参数为:Na OH的加入量为24 m L,二硫化碳用量7 m L,反应温度为50℃,反应时间2.5 h。     

交联淀粉黄原酸酯的制备及其处理废水的研究

以淀粉为原料,环氧氯丙烷为交联剂,二硫化碳为酯化剂,制备不溶性交联淀粉黄原酸酯。结果表明交联淀粉的最佳操作工艺条件为:玉米淀粉20 g、0.2 g/m L Na OH溶液5.0 m L、环氧氯丙烷4.0 m L、反应温度30℃、反应时间2.5 h。交联淀粉黄原酸酯的最佳合成工艺条件为:交联淀粉10 g,0.2 g/m L的Na OH溶液20 m L,5 m L CS2,温度50℃,反应时间1.0 h。交联淀粉黄原酸酯净化生活废水试验结果表明:在10 m L生活废水中,投加0.7 g淀粉黄原酸酯时,废水吸光度达到最小;当其他条件一定时,生活废水p H约为7、反应时间为40 min时,吸附效果较佳。     

添加剂对速冻水饺品质的影响

速冻水饺常常出现冻裂、蒸煮后韧性差、耐煮性差等品质问题,通常采用添加改良剂的方法改善品质.研究了抗坏血酸(VC)、马铃薯淀粉、羧甲基纤维素钠(CMC-Na)、蔗糖脂肪酸酯(SE)、黄原胶、分子蒸馏单甘酯和复合磷酸盐对速冻水饺冻裂率及蒸煮品质的影响,结果表明添加量为0.15%的黄原胶的抗冻裂效果最好,羧甲基纤维素钠(CMC-Na)和黄原胶的使用可以有效提高速冻水饺的蒸煮品质.     

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