天然色素和人工色素对肉仔鸡皮肤和脚胫颜色影响的研究

研究在日粮中添加含天然色素的玉米和人工色素的加丽素红对AA肉仔鸡皮肤和脚胫颜色的影响。结果表明:AA肉仔鸡饲喂含天然色素的玉米和含人工色素的加丽素红的日粮都能改善AA肉仔鸡皮肤、脚胫颜色。人工色素组,随着加丽素红添加量的提高,各处理的RCF值提高,30mg/kg、60mg/kg组RCF值较对照组提高显著(P<0.05)。天然色素组,试验前期随着玉米添加量的提高,各处理的RCF值提高,50%、70%玉米组较对照组提高显著(P<0.05)。人工色素组加丽素红添加量为60mg/kg时,AA肉仔鸡皮肤和脚胫的RCF值与天然色素组日粮中玉米添加量为50%的着色程度一致。试验后期,人工色素组玉米添加量均为30%的处理1、处理2与天然色素组玉米添加量为30%的处理6AA肉仔鸡皮肤和脚胫的RCF值保持一致。     

涂膜保鲜对不同蛋龄鸡蛋贮藏品质的影响

选用0,3,6,10 d蛋龄鸡蛋,经涂膜处理,对比不同蛋龄组贮藏品质的变化.结果表明：各组鸡蛋失重率差异不显著（P＞0.05）;蛋黄系数差异显著（P＜0.05）;蛋白系数和蛋白pH值差异极显著（P＜0.01）.贮存60,0 d蛋龄全部为新鲜蛋,失重率1.95%,蛋黄系数为0.32,蛋白系数为0.61,蛋白pH值仅为8.79;3 d蛋龄次鲜蛋占84%,散黄蛋占16%;6 d蛋龄次鲜蛋占50%,散黄蛋占50%;10 d蛋龄全部散黄.     

壳聚糖涂膜对鸡蛋品质的影响

通过对新鲜鸡蛋涂擦不同质量浓度的壳聚糖溶液,旨在研究壳聚糖对鸡蛋品质的影响。试验将300 枚新鲜鸡蛋随机分成6 组,分别涂上0、0.5、1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖溶液,25℃条件下贮存5周。每周从每个处理中取10 枚鸡蛋测定鸡蛋失重率、哈夫单位、蛋黄指数和蛋清pH 值。结果表明,第5 周与第1 周相比,不涂壳聚糖的鸡蛋失重率和蛋清pH 值显著升高(P ＜ 0.05)、哈夫单位和蛋黄指数显著低(P ＜ 0.05) 。5 周时,与不涂壳聚糖的鸡蛋相比,所有涂壳聚糖的鸡蛋失重率显著降低(P ＜ 0.05),蛋黄指数显著升高(P ＜ 0.05);涂1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖的鸡蛋哈夫单位显著升高(P ＜ 0.05),蛋清pH 值显著降低(P ＜ 0.05);涂1.5、2.0g/100mL 和2.5g/100mL 壳聚糖的鸡蛋间比较,蛋质量损失率、哈夫单位、蛋黄指数和蛋清pH 值差异均不显著(P ＞ 0.05)。用0.5g/100mL 壳聚糖涂擦的鸡蛋5 周时降到C 级,相当于不涂壳聚糖的鸡蛋3 周时的级别;用1.0、1.5、2.0g/100mL 和2.5g/100mL 壳聚糖处理的鸡蛋5 周时降到B 级,相当于不用壳聚糖处理的鸡蛋2 周时的级别。该实验证明壳聚糖能够延长鸡蛋货架期。     

宁都黄鸡蛋与常见市售鸡蛋品质比较分析

测定并比较了宁都黄鸡蛋(36枚)、白壳蛋(15枚)、褐壳蛋(23枚)和土鸡蛋(14枚)的蛋重、哈氏单位等10项蛋品质指标。结果表明:宁都黄鸡蛋与其他3种鸡蛋的蛋品质存在着差异,其中蛋形指数、蛋壳比率差异不显著(P0.05);在蛋重方面,除与土鸡蛋差异不显著外,与白壳蛋、褐壳蛋差异极显著(P0.01);在蛋的密度方面,与白壳蛋、褐壳蛋差异不显著(P0.05),与土鸡蛋差异显著(P0.05);在蛋壳厚度方面,与其他3种鸡蛋均差异极显著(P0.01);在蛋壳质量方面,与白壳蛋、褐壳蛋差异极显著(P0.01),与土鸡蛋差异显著(P0.05);在浓蛋白高度、哈氏单位、蛋黄比率、蛋白比率方面,与白壳蛋差异不显著(P0.05),与褐壳蛋、土鸡蛋差异极显著(P0.01)。     

青壳鸡蛋与褐壳鸡蛋品质及营养成分比较分析

为了比较青壳鸡蛋和褐壳鸡蛋品质的差异,以苏禽青壳蛋鸡和海兰褐壳蛋鸡2个鸡种为试验素材,采用笼养饲养方式,测定苏禽青壳蛋鸡和海兰褐壳蛋鸡鸡蛋的常规蛋品质和营养成分含量。结果表明:在常规蛋品质方面,苏禽青壳蛋鸡鸡蛋的哈氏单位和蛋黄色泽极显著高于海兰褐蛋鸡鸡蛋(P0.01),蛋黄比率显著高于海兰褐蛋鸡鸡蛋(P0.05),蛋重极显著小于海兰褐蛋鸡鸡蛋(P0.01),蛋形指数、蛋壳厚度和蛋壳强度差异不显著。在营养成分方面,苏禽青壳蛋鸡鸡蛋的干物质、脂肪、胆固醇和卵磷脂含量均极显著高于海兰褐蛋鸡鸡蛋(P0.01),蛋白质和氨基酸含量差异不显著。钙、镁、铜含量两者差异不显著,但苏禽青壳蛋鸡鸡蛋的铁、锌、锰、硒、磷含量均极显著高于海兰褐蛋鸡鸡蛋(P0.01),可见鸡种对鸡蛋常规品质和营养成分均具有一定的影响。     

鸡蛋内部品质与其呼吸强度的关系

贮藏期鸡蛋品质的变化与呼吸作用息息相关,为了进一步明确鸡蛋内部品质与其呼吸强度之间的关系,本研究选取同一品种的鸡蛋作为实验样本,利用呼吸测定仪测定鸡蛋的二氧化碳呼吸强度,通过SPSS 19.0软件分别分析鸡蛋哈夫单位、蛋白高度、pH值、黏度、蛋黄指数、蛋黄比例以及蛋黄色度与呼吸强度间的关系。结果表明：鸡蛋哈夫单位、蛋白高度及黏度与呼吸强度之间呈极显著正相关（P＜0.01）;pH值与呼吸强度之间呈极显著负相关（P＜0.01）;蛋黄指数、蛋黄色度与呼吸强度之间呈极显著正相关（P＜0.01）;而蛋黄比例与呼吸强度间相关性较小;此外,pH值与黏度、蛋黄指数、蛋黄色度间均存在极显著负相关（P＜0.01）;黏度与蛋黄指数、蛋黄色度之间呈极显著正相关（P＜0.01）;蛋黄比例与其他参数相关性较小。总之,在鸡蛋内部品质参数中,鸡蛋哈夫单位、蛋白高度、蛋黄指数、pH值、黏度及蛋黄色度对呼吸强度影响较大。     

桑叶饲料添加剂对鸡蛋黄品质的影响

分析在蛋鸡饲料中分别添加2.5%、5.0%、7.5%、10.0%桑叶对鸡蛋黄品质的影响,结果表明：随桑叶添加量增加,蛋黄颜色加深;添加桑叶对蛋黄胆固醇含量影响不大;5.0%和7.5%桑叶组的蛋黄磷含量显著高于对照组(P＜0.05);添加桑叶各组的饱和脂肪酸含量比对照组显著降低(P＜0.05),单不饱和脂肪酸与多不饱和脂肪酸含量比对照组极显著提高(P＜0.01);5.0%和7.5%桑叶组的7种必需氨基酸总量显著高于对照组(P＜0.05);蛋黄VE含量随桑叶添加量增加而极显著增加(P＜0.01),其中10.0%桑叶组比对照组提高了近3倍。桑叶组蛋黄在气味和口感上都优于对照组,其中5.0%、7.5%桑叶组较其他桑叶组好(P＜0.05)。总之,饲料中添加桑叶能改善鸡蛋黄的品质,添加量在5.0%～7.5%比较合适。     

饲喂银杏叶超微粉对鸡蛋胆固醇含量的影响

实验旨在研究银杏叶超微粉对鸡蛋胆固醇含量的影响。选择健康55周龄的罗曼白商品蛋鸡192羽,随机分为对照组和实验组共4组,每组3个重复,每个重复16羽,对照组饲喂基础日粮,实验组在基础日粮中分别添加0.60%、0.80%、1.00%的银杏叶超微粉,预试期7d,正试期28d。结果表明:在第7、28d时,添加银杏叶超微粉对蛋重和蛋黄重、蛋黄相对重影响不显著(p>0.05);第14d时,0.60%、0.80%银杏叶超微粉添加组蛋黄重较对照组差异显著(p<0.05),蛋重和蛋黄相对重差异不显著(p>0.05);第21d时,0.80%、1.00%银杏叶超微粉添加组蛋黄重和蛋黄相对重较对照组差异显著(p<0.05),蛋重差异不显著(p>0.05)。整个实验期,蛋黄胆固醇含量和鸡蛋胆固醇含量较对照组差异显著(p<0.05),在第21d时,0.80%银杏叶超微粉添加组呈现极显著差异(p<0.01),实验至28d时,银杏叶超微粉对鸡蛋胆固醇含量的影响趋于平稳。本实验表明银杏叶超微粉对降低鸡蛋胆固醇具有一定的促进作用,且以0.80%添加量为效果最佳。      

泰和乌鸡蛋与普通鸡蛋维生素含量差异分析

比较分析了泰和乌鸡蛋与普通鸡蛋外观品质及维生素含量差异,以期为当地乌鸡蛋资源的综合开发利用提供数据参考。选取泰和乌鸡蛋、市售普通鸡蛋各120枚,对其外观指标(蛋重、蛋黄比率)以及维生素含量(全蛋、蛋黄中的β-胡萝卜素、V_A、V_E、V_(B1)、V_(B2)、烟酸含量)进行测定。结果表明:泰和乌鸡蛋平均质量为40.23 g,为普通鸡蛋平均质量的66%;蛋黄比率为32.32%,较普通鸡蛋低7.13%。泰和乌鸡蛋全蛋、蛋黄中的β-胡萝卜素含量分别为2.27、7.83μg/100 g;V_(B1)含量分别为46.80、139.08μg/kg,VB2含量分别为433.11、461.39μg/kg,均显著高于普通鸡蛋(P0.05)。VE含量均显著低于普通鸡蛋(P0.05);烟酸含量差异不显著(P0.05)。     

饲喂银杏叶超微粉对鸡蛋胆固醇含量的影响

实验旨在研究银杏叶超微粉对鸡蛋胆固醇含量的影响。选择健康55周龄的罗曼白商品蛋鸡192羽,随机分为对照组和实验组共4组,每组3个重复,每个重复16羽,对照组饲喂基础日粮,实验组在基础日粮中分别添加0.60%、0.80%、1.00%的银杏叶超微粉,预试期7d,正试期28d。结果表明:在第7、28d时,添加银杏叶超微粉对蛋重和蛋黄重、蛋黄相对重影响不显著(p>0.05);第14d时,0.60%、0.80%银杏叶超微粉添加组蛋黄重较对照组差异显著(p<0.05),蛋重和蛋黄相对重差异不显著(p>0.05);第21d时,0.80%、1.00%银杏叶超微粉添加组蛋黄重和蛋黄相对重较对照组差异显著(p<0.05),蛋重差异不显著(p>0.05)。整个实验期,蛋黄胆固醇含量和鸡蛋胆固醇含量较对照组差异显著(p<0.05),在第21d时,0.80%银杏叶超微粉添加组呈现极显著差异(p<0.01),实验至28d时,银杏叶超微粉对鸡蛋胆固醇含量的影响趋于平稳。本实验表明银杏叶超微粉对降低鸡蛋胆固醇具有一定的促进作用,且以0.80%添加量为效果最佳。     

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