海洋微藻多不饱和脂肪酸生物合成机制的研究进展

为了开发营养丰富的多谷物面包预拌粉，本研究以杂粮粉为主要原料，添加谷朊粉构建面包网络结构，通过评价混合粉黏度特性，面团发酵流变特性和面包加工品质，研究多谷物粉含量对面团加工特性和面包品质的影响。结果表明：随着多谷物粉含量的增加，多谷物预拌粉的糊化黏度呈显著性上升，糊化温度呈显著性下降，面团的最大发酵高度和最终发酵高度显著降低（p<0.0.5）。当多谷物粉添加量从50%增加到80%时，面包的比容从5.10 mL/g降低到1.83 mL/g，体积降低，弹性下降，硬度和耐咀性增加。多谷物粉含量、糊化特性、部分发酵流变特性与面包质构特性、比容和颜色L*、a*之间均呈显著或极显著相关。当多谷物粉添加量在50%~60%之间，面包品质良好；添加量≥65%时，所制成的面包品质较差。     

菊糖对面团流变学特性及面包品质的影响

添加不同比例的菊糖于面包粉中,对面包面团特性及面包品质变化进行研究。结果表明,添加菊糖能够明显影响面包粉的粉质和拉伸等流变特性。随着菊糖添加量的增加,面团吸水率显著下降,面团形成时间和面团稳定时间延长,弱化度减小;添加菊糖可增加面团的延伸度、拉伸面积和拉伸阻力;面粉的峰值黏度、最终黏度、衰减值和回生值也显著降低,其淀粉老化速度得到延缓;弹性模量和黏性模量显著增加,面团的网络结构得到改善;但面团发酵体积显著减小,使得面包的比容减少,面包初始硬度显著性增加,在面包贮藏过程中,添加2.5%、5%、7.5%的菊糖面包硬度明显低于未添加菊糖的面包硬度,说明适宜添加量的菊糖能够改善面包内部结构,降低其贮藏过程中的硬度和老化速率,延长面包货架期。     

挤压糙米粉对糙米面团及面包品质的影响

将糙米粉（生粉）与挤压糙米粉（熟粉）分别按照生熟比10 ∶ 0,9 ∶ 1,8 ∶ 2,7 ∶ 3,6 ∶ 4比例混合制备成混合粉,然后将糙米混合粉与谷朊粉按照8 ∶ 2的比例混合制备糙米面团及面包。研究挤压糙米粉添加量对糙米面团及面包品质的影响。结果表明：随着挤压糙米粉添加量的增加,糙米面团网络结构越疏松,孔隙越大,黏弹性均比未添加挤压糙米粉的面团低,糙米面包比容先减小后增大。添加挤压糙米粉后,糙米面包的硬度降低,感官评分值升高。放置1～4 d,糙米面包的硬度增加值随着挤压糙米粉添加量的增加而降低,面包弹性均比未添加挤压糙米粉面包的高。挤压糙米粉的添加有利于面包延缓老化,提升品质,当生熟比为6 ∶ 4时,面包品质最好。     

挤压膨化玉米粉对小麦粉面团特性及馒头质构特性的影响

对比研究不同添加量的挤压膨化玉米粉和玉米粉对小麦面团粉质特性、糊化特性以及对馒头质构特性的影响。结果表明:挤压膨化玉米粉添加量增加到25%时,面团吸水率升高6.72%、稳定时间下降82.64%、蛋白质弱化度升高60.78%、形成时间下降88.37%、峰值黏度降低55.60%、低谷黏度降低60.91%、最终黏度降低58.41%、崩解值降低34.07%、回生值降低50.43%;膨化玉米粉添加量为10%时,馒头的弹性、内聚性和回复性最大,硬度显著的低于对照(p<0.05),馒头的口感柔软、筋道,爽口不黏牙,品质最好。玉米粉添加量、面团的粉质特性、糊化特性与馒头的质构特性显著相关,可通过混合粉面团的粉质特性和糊化特性对馒头的质构特性进行预测。与玉米粉相比,挤压膨化玉米粉能够提高面团的吸水率,增强小麦粉的热稳定性,延缓面团的老化,改善了馒头的品质。     

乳酸菌对酵母菌发酵多谷物杂粮面包品质的影响

目的:探讨添加乳酸菌粉对酵母菌发酵多谷物杂粮面包品质的影响。方法:检测添加不同比例（0、0.03%、0.06%、0.09%、0.12%）乳酸菌粉发酵多谷物杂粮面团的pH、发酵体积和流变特性指标变化,同时检测添加乳酸菌粉后杂粮面包硬度、胶黏性、咀嚼性指标,以及面包比容、感官品质和风味指标的变化。结果:添加乳酸菌发酵使多谷物杂粮面团pH降低;添加0.03%~0.12%混合乳酸菌粉发酵60 min面团体积增加50.00%~88.12%,均高于单一酵母菌发酵（增加48.51%）;添加乳酸菌粉降低了面团储能模量（G'）和损耗模量（G"）值,添加量0.06%时G'和G"值分别降低33.33%和30.00%,降低幅度最小;添加0.06%乳酸菌粉,可显著降低面包硬度、胶粘性和咀嚼性（P<0.05）,显著提高面包弹性（P<0.05）,改善面包质构特性,面包比容比单一酵母菌发酵增加24.88%,面包形态、质地、纹理结构、风味和口感均具有较好的改善,感官品质显著提高（P<0.05）,感官评分超过80分。酵母菌联合乳酸菌发酵复配杂粮面包,共检测出65种挥发性风味物质,化合物种类多于小麦面包43种,风味物质强度高于单一酵母菌发酵杂粮面包。结论:添加乳酸菌粉对酵母菌发酵多谷物复配杂粮面包品质改善具有积极作用。     

挤压改性绿豆粉对小麦粉加工及其面条品质特性的影响

研究了添加挤压改性绿豆粉对挤压改性绿豆-小麦混合粉粉质特性、面团流变特性和所制备面条品质的影响。首先采用双螺杆挤压机处理绿豆粉,随后将挤压改性绿豆粉以不同添加量(10%~60%)添至小麦粉中,制备面条。然后采用粉质拉伸仪、RVA黏度仪、流变和质构仪对混合粉的粉特性、面团流变性能以及面条的质构特性进行分析。结果表明,随着挤压改性绿豆粉添加量的增加,绿豆-小麦混合粉面团的形成时间、稳定时间、粉质质量指数急剧下降,混合粉的粉质特性明显降低,且与小麦粉相比,混合粉的起始糊化温度、峰值黏度、谷值黏度、最终黏度、崩解值及回生值呈明显的下降趋势;随着挤压改性绿豆粉添加量的增加,混合粉面团的G'和G″降低,面团的网络结构受到破坏;对于挤压改性绿豆-小麦混合面条,随着挤压改性绿豆粉添加量的增加(<40%时),其干物质吸水率和损失率有所提高,蒸煮面条的硬度、弹性、胶粘性、咀嚼性和回复性有所降低,综合感官评分降低,当挤压改性绿豆粉添加量≤ 20%时,整体可接受度接近小麦面条。最后分析三者之间的相关性发现,挤压改性绿豆粉的添加量、挤压改性绿豆-小麦混合粉的粉质特性、黏度特性与其制作面条的品质有明显的相关性。综上所述,挤压改性绿豆粉的添加改变了小麦面团的特性和面条的品质,其添加量不宜超过20%。     

百合粉添加量对面团特性及面包品质的影响

为拓宽百合的应用渠道,提高面包的营养价值,研究了百合粉添加量(0%,5%,10%,15%,20%)对面团的微观结构、糊化特性、流变学特性以及面包品质的影响。结果表明:随着百合粉添加量增大,混合粉的持油性先降低后增加,持水性显著增加(P<0.05)。添加了百合粉后,面团的糊化温度升高,回生值和峰值黏度下降,面团的弹性模量和黏性模量均呈上升趋势。百合粉的添加,破坏了面筋蛋白原本均匀致密的微观结构;使面包的硬度显著增大(P<0.05),弹性、内聚性、胶黏性、咀嚼性、回复性、比容和感官评分显著降低(P<0.05);改变了小麦面团的特性和面包的品质,在小麦粉中添加5%~10%的百合粉,能保证面包较高的感官品质。     

松茸粉对面团流变特性及饼干品质的影响

为研究添加松茸粉对面团流变特性和饼干品质的影响,对不同添加量松茸粉面团的热机械学特性、淀粉糊化特性和动态流变学特性进行分析,同时测定松茸曲奇饼干的物理特性、感官评价及营养品质。结果表明,添加松茸粉使得面团的稳定时间、最大黏度指数、峰值黏度、谷值黏度、最终黏度显著降低,蛋白弱化度增加,面团面筋蛋白结构被破坏。随着松茸粉添加量的增加,tan δ先升高后降低,面团弹性先降低后升高,曲奇饼干的硬度和感官评分先升高后降低。当松茸粉添加量达到6%时,松茸曲奇的风味和口感更易被接受。与普通曲奇相比,松茸曲奇的蛋白质和膳食纤维含量分别提高了58.08%和191.24%,必需氨基酸含量升高了32.77%,氨基酸评价更接近联合国粮食及农业组织/世界卫生组织标准,营养价值更优。     

不同杂粮对面粉品质特性的影响研究

本文以谷物杂粮为研究对象,通过将不同质量的红豆粉、绿豆粉、玉米粉和燕麦粉混合于小麦粉中,观测其对面粉的品质特性和面包质量的影响。试验结果表明：除玉米粉外,随着其他杂粮添加量的增加,其蛋白质、面筋和灰分含量呈增加趋势;而混合粉的峰值黏度、最低黏度、衰减值、最终黏度和回生值均有所下降;添加绿豆粉和红豆粉的小麦粉在添加量12%时其峰值黏度最低,而添加12%燕麦粉的小麦粉峰值黏度突然增大;峰值时间和糊化温度明显降低。杂粮的添加改变了面团的品质特性。综合评价后认为最佳添加比为不超过12%。     

黑米粉对面团热机械学特性及面包烘焙品质的影响

将黑米粉添加到小麦粉中,研究了不同比例黑米粉对面团热机械学特性、面包品质和贮藏特性的影响。结果表明,随着黑米粉添加量的增加,面团的C1形成时间、稳定时间呈下降趋势,而蛋白质弱化度呈上升趋势;此外黑米粉的添加降低了淀粉的回生值C5-C4,黑米粉添加量为15%时,C5-C4值降低了34.0%。焙烤制得的面包比容下降,感官品质下降,硬度增大,面包的弹性先增加后降低,在添加量为7.5%时弹性最大,添加量在5%~10%均大于对照样品。综合面包比容、色泽、质构与营养而言,黑米粉添加量7.5%时制作的面包品质良好。黑米粉的添加对面包的老化有一定的抑制作用。     

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