赖氨酸复合盐在小麦粉及馒头和面条中的适用性研究

在小麦粉中分别强化901.45、1802.9和2704.35mg/kg的L-赖氨酸-L-谷氨酸盐(一种赖氨酸复合盐产品,简称为“LG”),与对照组比较,作了基础分析并制作了馒头和面条。研究表明:LG的强化对粉质特性没有明显影响,而对面团的拉伸特性有一定的改善作用;各试验组馒头在体积、高度、质量及感官评分方面没有显著性差异,适度添加LG不会对馒头感官品质产生不良影响;各试验组面条在感官评分方面没有显著性差异,所制作的面条色泽、气味都很正常,无异味和变色现象,适度添加LG不会对面条感官品质产生不良影响。因此,L-赖氨酸-L-谷氨酸盐作为营养强化剂在小麦粉及馒头和面条中是适用的。     

营养强化玉米馒头粉的研究

在玉米馒头粉中添加（强化）复合营养素：维生素B，3．5mg／kg，B2 3．5mg／kg，尼克酸35mg／kg，叶酸2．0mg／kg，钙1000mg／kg，铁20mg／kg，锌25mg／kg，赖氨酸复合盐1．8g／kg，与对照组比较．对其流变学特性、营养品质做了基础分析，并进行了馒头和面条制作试验。研究表明：强化复合营养素使玉米馒头粉面团的稳定时间有所降低，但对面团的拉伸特性有一定的改善作用；玉米馒头粉强化复合营养素对馒头和面条的感官品质及内部质构没有产生明显的不良影响；玉米馒头粉营养强化后，其维生素、矿物质和赖氨酸等营养素含量明显提高。     

强化赖氨酸复合盐的小麦粉混合均匀度及营养成分分析

以GB14880-1994中规定谷物食品的L-赖氨酸(Lys)和公众营养与发展中心规定的锌(Zn)的强化标准为依据,设计了在小麦粉中强化两种L-赖氨酸复合盐(L-赖氨酸锌(LZn) L-赖氨酸-L-谷氨酸盐(LG))的配方(mg/kg小麦粉),配方一是LZn584.8 LG2072.1,配方二是LZn443.5 LG1592.1。测定了强化L-赖氨酸复合盐的小麦粉的混合均匀度和营养成分。结果表明:赖氨酸复合盐强化剂在小麦粉中混合分散的变异系数(CV)为7.63%,混合均匀度符合要求,利用面粉公司生产线定量添加赖氨酸复合盐在工艺上是完全可行的,不会对原有工艺流程和设备造成不利影响。与普通小麦粉比较,中试生产的强化L-赖氨酸复合盐的小麦粉在外观、气味和色泽等方面无不良变化。使用该复合强化剂可显著增加小麦粉中的锌含量,提高小麦粉赖氨酸含量及蛋白质的赖氨酸分,营养价值得到显著提高。     

滚揉时间和添加赖氨酸对低盐蒸煮火腿品质的影响

研究不同滚揉时间和添加0.8%赖氨酸对于低盐蒸煮火腿保水性、质构特性和色泽等食用品质的影响。结果表明：随着滚揉时间的延长,火腿的蒸煮损失率逐渐降低,而赖氨酸的添加可进一步提高火腿的保水性,低场核磁共振结果显示这可能是由于火腿中不易流动水相对含量的增加;延长滚揉时间或添加赖氨酸对火腿质构有一定的改善作用,滚揉时间的延长会造成火腿红度值下降,同时,长时间滚揉或添加赖氨酸会引起蛋白质中的α-螺旋向β-折叠转变以及总巯基含量增加,这间接表明延长滚揉时间和添加0.8%赖氨酸可能有利于蛋白凝胶的形成。因此,延长滚揉时间至40 min和添加0.8%赖氨酸可以开发低盐蒸煮火腿,改善其品质特性。     

混合菌株和外源赖氨酸对鱼酱发酵品质的影响

研究中度嗜盐菌混合菌株及外源赖氨酸对鱼酱发酵品质的影响。通过对pH值、总酸、氨基酸态氮、挥发性盐基氮、游离氨基酸、挥发性风味物质分析及感官评定,探讨发酵60 d混合菌株（Halobacillus campisalis、Halobacillus faecis、Bacillus aquimaris、Bacillus hwajinpoensis）和外源赖氨酸对鱼酱品质的影响。以鮰鱼碎鱼肉为原料,4 种处理：第1组只添加15%食盐（鱼酱a）,第2组添加15%食盐和0.1%赖氨酸（鱼酱b）,第3组添加15%食盐和混合发酵剂（鱼酱c）,第4组添加15%食盐、0.1%赖氨酸和混合发酵剂（鱼酱d）。结果表明：发酵60 d时,4 组不同处理鱼酱的总酸质量分数分别为0.382 5%、0.63%、0.607 5%和0.585%,与鱼酱a相比,鱼酱b、c、d均能显著提高总酸含量（P＜0.05）;与鱼酱a相比,鱼酱c中的氨基酸态氮含量无显著变化（P＞0.05）,鱼酱b和d中的氨基酸态氮含量显著上升（P＜0.05）;与鱼酱a相比,b、c和d三组鱼酱的挥发性盐基氮含量显著下降（P＜0.05）,氨基酸的种类和含量更加丰富,挥发性风味物质更加丰富,鱼酱的感官评分和风味更好。     

“营养强化小麦粉生产技术开发研究”项目通过了科技成果鉴定

2006年9月29日由陕西省科技厅组织，宝鸡市科技局主持，组织有关专家，在陕西眉县对陕西老牛面粉有限公司等单位完成的“营养强化小麦粉生产技术开发研究”项目进行了科技成果鉴定．2006年10月19日进行了成果登记，登记号为961200640431。该项目采用赖氨酸复合盐和复合维生素强化小麦粉，具有一定的创新性和先进性，对全面提高我国民众的健康营养水平具有重要意义，预期社会效益和经济效益显著，市场前景广阔，研究成果达到国内领先水平，其中L-赖氨酸复合盐在面粉中应用研究处于国际先进水平。     

L-赖氨酸对低盐鱼糜凝胶特性的影响

为提高低盐鱼糜制品的品质,研究了L-赖氨酸(L-Lys)添加量对低盐鱼糜凝胶的质构、色泽、持水性、水分流动性和流变特性的影响。结果表明鱼糜凝胶强度随着L-Lys添加量的增加呈现先增加后降低的趋势,添加0.1% L-Lys能够使低盐鱼糜凝胶(1.0% NaCl)达到与对照鱼糜凝胶(2.5% NaCl)相当的凝胶强度;随着L-Lys添加量的增大,鱼糜凝胶的pH和持水性增大,而L-Lys添加量对鱼糜凝胶色泽的影响不显著;添加L-Lys使鱼糜凝胶不易流动水的比例提高,易流动水比例降低。动态流变结果表明,G'达到第一个峰值的温度随着L-Lys 添加量的增加而下降,且显著低于对照组(p<0.05);G'达到最低点的温度随着L-Lys 添加量的增加而增大,且显著高于对照组(p<0.05)。添加0.1% L-赖氨酸能够提高鱼糜制品的凝胶特性,为生产低盐鱼糜凝胶制品提供理论依据。     

L-赖氨酸和L-组氨酸对低盐乳化肠品质特性的影响

为了探究氨基酸对低盐乳化肠品质的影响，以猪肉乳化肠为载体，在40%氯化钾替代食盐的条件下，设置6组氨基酸替代组：0.4%、0.8%L-赖氨酸，0.4%、0.8%L-组氨酸，以及0.6%、1.2%的混合氨基酸（L-赖氨酸质量∶L-组氨酸质量=1∶1）。通过对乳化肠pH、色差物理指标测定，采用电子鼻、电子舌和TPA仪器测定（硬度、弹性、内聚性、咀嚼性、回复性）的测定，研究L-赖氨酸、L-组氨酸和混合氨基酸对低盐钠乳化香肠出品率、pH、色泽、质构、感官、滋气味等品质的影响。结果表明：这两种氨基酸及其混合氨基酸均能显著提高低盐乳化肠产品的出品率、pH、红度和黄度，并对质构指标有显著影响（P <0.05）。     

响应面法优化低钠香猪培根的复合盐配方

为开发一种低钠复合盐香猪培根的加工技术,以从江香猪肉为原料,通过单因素实验探究氯化钾、氯化钙和L-赖氨酸的不同替代量对香猪培根感官评分、质构特性和水分含量的影响。经过单因素实验后进行响应面优化,以感官评分作为响应值,结果表明,香猪培根低钠复配盐的最佳配方为氯化钾29%、氯化钙9%、L-赖氨酸10%,此时香猪培根的感官得分为76.1分,与模型理论值接近,钠离子含量比对照组降低了42.03%。该条件下制作的香猪培根不仅钠离子含量低,而且质地良好,咸淡适中,滋味纯正,综合品质较好,为低钠香猪培根生产提供一定的理论参考。     

营养强化对速冻馒头品质影响规律研究

研究以普通小麦面粉为原料,考察了挤压改性大豆分离蛋白、营养素强化剂以及两者复配对速冻馒头品质特性的影响。结果表明,普通面粉的质量指数为72.00,添加改性蛋白后面粉的质量指数上升为75.00,添加营养素后面粉的质量指数下降为65.00,复配强化面粉的质量指数为70.50,复配强化对面粉粉质特性无显著性影响。同时通过面团拉伸试验表明:与普通面团的拉伸特性相比,改性蛋白强化面团和营养素强化面团其拉伸特性具有一定程度的降低,而复配强化面团其拉伸特性变化不显著。普通馒头、改性蛋白强化馒头、营养素强化馒头以及复配强化馒头的硬度与咀嚼性随着冷冻时间的增长呈现逐步下降的趋势,但馒头弹性无明显变化。不同营养强化面团经冷冻贮藏后所做馒头的比容、外观、色泽、口感和总评分均降低,但改性蛋白强化馒头的品质最好。添加改性蛋白可以提高馒头的感官品质特性,同时添加改性蛋白和营养素对馒头的感官品质无显著性影响,但可以增加其营养价值。研究结果可为营养强化速冻馒头的生产提供一定的理论基础。     

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