面包中丙烯酰胺调控方法研究

研究食品添加剂和天然提取物对面包中丙烯酰胺含量的影响,结果表明,柠檬酸、硫酸钙、大蒜粉、藤黄果提取物均能降低面包中的丙烯酰胺含量,其抑制率分别是30.1%,35.8%,36.1%,38.9%。正交试验结果表明,在柠檬酸添加量0.55%、硫酸钙添加量0.90%、大蒜粉添加量2.5%、藤黄果提取物添加量3.5%条件下,面包中丙烯酰胺形成量降低78.0%。     

馍干中丙烯酰胺的抑制工艺及添加剂配方

研究降低馍干中丙烯酰胺含量的方法,包括馍干加工工艺和食品添加剂两方面。结果表明,采用高温（230 ℃）烘烤馍干,与低温（190 ℃）烘烤相比,馍干中丙烯酰胺含量下降10.9%;降低馍干坯水分（从41.7%降到9.6%）,馍干中丙烯酰胺含量下降31.7%;添加复合食品添加剂（硫酸钙添加量为1.0%,茶多酚添加量为0.04%）,馍干中丙烯酰胺含量下降56.5%。通过优化工艺条件和添加复合添加剂,馍干中的丙烯酰胺含量从177.2 μg/g下降到46.8 μg/g,总共下降了73.5%。因此,采用高温短时烘烤、降低馍干坯烘烤前水分含量和添加复合添加剂,能有效降低馍干中丙烯酰胺含量。     

部分含金属离子的食品添加剂对茶多酚抗氧化活性的影响

研究了部分含金属离子的食品添加剂对茶多酚抗氧化活性的影响。结果表明:不同处理浓度的茶多酚,在添加含金属离子的食品添加剂苯甲酸钠、山梨酸钾、亚硝酸钠、氯化钙、硫酸钙、硫酸亚铁和硫酸锌后,TP含量均有不同程度的下降,降低率依次为38%~72%、25%~49%、35%~59%、34%~49%、38%~69%、31%~47%和13%~51%;各处理丙二醛生成量均低于只添加茶多酚的对照(除亚硝酸钠外),表明这些含金属离子的食品添加剂对茶多酚抗氧化活性有增效作用,即这些食品添加剂可降低TP使用量和提高TP的使用安全性。添加苯甲酸钠和山梨酸钾可提高茶多酚的还原力。     

面包加工工艺对其丙烯酰胺含量影响

面包在加工过程中会产生丙烯酰胺,对食品安全带来一定危害。该文研究了面包加工工艺对其丙烯酰胺含量影响,包括烘烤温度、烘烤时间、水分含量、发酵方法四方面。研究结果表明,烘烤温度、烘烤时间、面包水分含量及发酵方法对面包中丙烯酰胺含量具有一定影响,在保证面包品质的前提下,采用高温短时烘烤、降低面包坯水分含量、延长发酵时间有利于降低面包中丙烯酰胺含量。该论文研究对降低面包中丙烯酰胺含量具有理论和技术参考意义。     

几种食品添加剂对挤压即食食品丙烯酰胺形成的抑制效果研究

以马铃薯-小麦混合粉为原料,通过在挤压膨化即食食品中,添加不同种类、不同浓度的食品添加剂,研究不同添加剂对产品中丙烯酰胺含量的影响。结果表明:海藻糖、大豆多肽、茶多酚、竹叶提取物、氯化钙等食品添加剂的添加对挤压产品中丙烯酰胺含量的影响显著(p<0.05)。其中当氯化钙添加量达到0.5%时,产品中丙烯酰胺含量比对照减少了80%;大豆多肽添加量达到3%以上或竹叶提取物含量达到0.3%时,产物中丙烯酰胺含量对比对照组减少了50%。     

面包中丙烯酰胺抑制技术研究

高温焙烤食品中产生的丙烯酰胺是食品安全研究的热点。研究如何抑制食品中丙烯酰胺的产生,具有十分重要的现实意义。以面包为研究对象,探索面包中丙烯酰胺产生的抑制技术,筛选出抑制效果良好的添加剂甘氨酸,并将其应用在面包中,对其抑制效果、外观和质构的影响进行研究,寻找出理想的丙烯酰胺抑制剂,研究其最佳抑制工艺条件,初步探讨其抑制机理。研究发现,烘烤时间和烘烤温度分别在10 min~25 min,160℃~220℃范围变化时,对丙烯酰胺含量影响不显著(p≤0.05)。甘氨酸能显著降低面包中丙烯酰胺的含量。     

茶多酚对面包品质及面包酚类物质抗氧化能力的影响

研究了不同茶多酚添加量对面包比容以及品质的影响,通过ABTS~+自由基清除率(ABTS法)和DPPH~+自由基清除率(DPPH法)探讨了茶多酚对面包总酚含量的影响及其抗氧化性变化。研究结果表明,茶多酚的添加对面包比容无显著性影响(P0.05),通过对面包质构分析,添加0.15%茶多酚对面包品质有一定改善,此时面包口感较好、呈有弹性;茶多酚的添加使面包总酚含量显著增加(P0.05),增强了ABTS~+自由基清除率和DPPH~+自由基清除率。当茶多酚添加量为0.15%,面包皮的ABTS~+自由基和DPPH~+自由基清除率分别增加了26.68%、69.85%,面包芯的自由基清除率分别提高了29.06%、61.18%。此外,面包皮相比于面包芯的抗氧化能力高,这是由于面包皮中美拉德产物具有抗氧化性。研究为通过日常饮食预防退行性疾病提供一定指导。     

茶多酚对面包纹理结构的影响

为明确茶多酚对面包纹理结构的影响,应用感官评分法对不同茶多酚添加量面包的纹理结构进行评判,运用图像分析技术检测不同茶多酚添加量对面包芯气孔特性的影响,采用扫描电镜观察面包微观结构的变化,并利用红外光谱研究其对面包蛋白质二级结构的影响。结果显示,随着茶多酚添加量的增加,面包纹理结构感官评分呈先上升后下降趋势;面包芯气孔的个数、表面分率、稠密度呈先增加后降低趋势,而气孔平均半径呈先缩小后增大趋势;面筋网络结构的有序性和紧密度呈先增加后降低趋势;面包蛋白质二级结构中β-折叠和α-螺旋的含量呈先增大后减少趋势,而无规则卷曲和β-转角的含量呈先减少后增大趋势。当茶多酚添加量为0.4%时,面包纹理结构感官评分最高;面包芯气孔的个数、表面分率、稠密度最大,气孔平均半径最小;面筋网络结构最为紧密有序;β-折叠和α-螺旋含量最高,无规则卷曲和β-转角含量最低。由此可见,适量添加茶多酚可改变面包蛋白质二级结构,促进面筋网络结构形成,使面包内部纹理结构得到改善。     

低分子添加剂法抑制焙烤食品中丙烯酰胺的研究现状

丙烯酰胺属于对人可能致癌物质,其主要产生于食品加工过程中的Maillard反应。目前,关于丙烯酰胺的研究主要集中于油炸食品,但关于焙烤食品如面包、饼干、蛋糕等方面的研究较少,而且由于工艺的不同,油炸食品中可行的方法并不能直接应用于焙烤食品。使用低分子添加剂是目前较为新兴的抑制丙烯酰胺的方法,其在油炸食品及焙烤食品中均具有良好的效果,且对产品风味的影响较小。本文总结了近些年学者们通过使用低分子添加剂降低焙烤食品中丙烯酰胺含量的实践及研究。     

牛乳（活性肽）及加工工艺对面包品质的影响

为了增加乳制品的消费量,研究了牛乳和牛乳活性肽添加量及加工工艺对面包品质影响。面包中添加6.0%(m/m)的牛乳或0.014%(m/m)的牛乳活性肽能提高面包的营养价值和弹性,降低面包的硬度,增加面包的比容和感官品质。牛乳面包和牛乳活性肽面包的弹性、硬度和比容分别为0.784、0.931;901.46 g、1466.25 g和6.3 mL/g、6.9 mL/g。虽然面包的品质优于馒头,但用面包的配方加工馒头的工艺也是可行的;面包的丙烯酰胺含量高达92.6±8.4μg/kg,极显著高于蒸烤结合的馒头,而同样配方加工的馒头的丙烯酰胺含量未检出(p0.01),因此在丙烯酰胺含量方面馒头较面包安全。消费者选用那种面包或馒头要根据自身需要,将美味和安全结合起来考量。     

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