猪骨明胶的提取工艺研究

本实验对猪骨明胶的提取工艺进行了研究。通过单因素实验探讨了提取pH值、提取温度对猪骨明胶提取率、凝胶强度和粘度的影响,通过SDS-PAGE电泳观察胶原蛋白水解情况,判断最适pH值及提取时间,确定猪骨明胶最佳提取条件为提取pH值10.5,提取温度70℃,提取时间5h。结果表明:在该条件下明胶的提取率可达到54%,6.67%的明胶溶液的凝胶强度为576g,60℃下的粘度为11.2mPa·s。     

鱼皮明胶的超高压辅助提取工艺

为建立鱼皮明胶清洁生产工艺,对超高压辅助提取鱼皮明胶进行系统研究,考察超高压处理压力、超高压作用时间、提取温度、提取时间对凝胶强度和提取率的影响。结果表明,较优提取工艺为处理压力300MPa、超高压时间10min、提取温度50～60℃、提取时间4h,在此条件下明胶凝胶强度可达274g,得率可达75.03%,溶解温度和凝胶温度分别为23.6℃和16.4℃。     

草鱼鱼鳞明胶的提胶工艺及特性研究

探讨草鱼鱼鳞明胶的提胶条件及其特性。采用正交试验研究pH值、温度和时间对鱼鳞明胶品质的影响,利用物性仪、高效液相色谱仪和红外光谱仪等对制备的明胶特性进行分析研究。得到最佳提胶条件:提胶液pH值为6、提胶温度为55℃和时间为6h。得到的明胶提取率为35.56%,黏度为6.04mPa·s,凝胶强度为478.58g,等电点为pH值7.6,亚氨基酸(脯氨酸和羟脯氨酸)含量达21.6%。所得鱼鳞明胶结构稳定,为较高品质的明胶。     

鱼鳞明胶的提胶工艺

根据单因素试验结果,利用正交试验,考察了提胶温度、pH值和时间对鱼鳞明胶品质的影响。并得到提胶条件为:提胶温度为55℃,pH值为6,时间为5h。在该条件下明胶的提取率达到58%,6.67%的明胶溶液在60℃时的黏度为8.16mPa·s,7℃下保温18h后凝胶强度为1 202.65g,约290Bloom,凝胶温度和熔化温度分别为20.8℃,26.9℃,等电点约为pH 7,可达到高品质明胶的要求。     

斑点叉尾鮰鱼皮明胶的制备

目的以斑点叉尾鮰鱼皮为原料,采用酸碱法制备鱼皮明胶;方法选用NaOH溶液和H2SO4溶液进行明胶的提取,通过单因素试验和正交试验,确定斑点叉尾鮰鱼皮明胶最佳制备工艺;结果NaOH质量分数为0.3%,H2SO4质量分数为0.4%,处理时间均为120 min,提取温度45℃,提取时间6 h,此时,所得明胶的凝胶强度和黏度分别为672.2 g和9.46 mPa·s,明胶提取率为65.21%.     

辣木提取物的制备、抗氧化活性及其在饮料中的应用

通过考察乙醇浓度、温度、料液比、提取时间4个因素对总黄酮提取率的影响获得提取苦荞麦米黄酮的最佳工艺。利用单因素试验和正交试验确定超声波法辅助提取苦荞麦米中总黄酮的最佳工艺为:乙醇浓度70%,料液比1∶70(g/mL),温度为80℃,提取时间为50 min。在此条件下,苦荞麦米中总黄酮的提取率为4.128%;恒温水浴法提取苦荞麦米中总黄酮的最佳工艺为:乙醇浓度80%,料液比1∶70(g/mL),温度为70℃,提取时间为80 min。在此条件下,苦荞麦米中总黄酮的提取率为4.477%。通过比较发现,两种方法提取的黄酮含量相差不大,超声法辅助提取的时间相对较短,节能。因此,超声法辅助提取苦荞麦米中的黄酮比恒温水浴法的效果好。     

提取pH对鳙鱼鱼鳞明胶功能性质的影响

研究了制备过程中pH值(3.0~7.0)对鳙鱼鱼鳞明胶组成、得率和功能性质(凝胶强度、胶融温度和浊度)的影响,并对鱼鳞明胶的分子量分布进行了探究。结果表明,pH值在3.0~7.0时均能得到高品质的鱼鳞明胶(高蛋白质含量、低灰分含量)。随着pH值的增加,鳙鱼鱼鳞明胶得率逐渐降低,浊度逐渐增加,凝胶强度和胶融温度先增加后减小。此外,鳙鱼鱼鳞明胶的凝胶强度与分子量分布具有一定的相关性。上述研究结果可为特定用途的鱼明胶制备提供技术支撑。     

杨梅叶中花色苷提取工艺优化

以乙醇作提取剂,恒温水浴震荡器为辅助仪器,利用单因素试验及正交试验确定花色苷的最佳提取工艺。结果表明:当乙醇含量为80%、料液比为1∶70、温度为60℃、提取时间为60min时,杨梅叶中的花色苷的提取率最高。     

酸碱法提取鱼鳞胶的工艺研究

以鳙鱼鱼鳞为原料,采用酸碱法与热水浸提相结合的方法提取鱼鳞明胶,分析酸处理过程中浸酸浓度、料液比、浸酸时间对水溶性胶原蛋白提取率的影响,同时分析浸碱过程中Ca(OH)2浓度、料液比、浸碱时间对明胶提取率、明胶黏度和凝胶强度的影响,从而得到最佳的酸碱处理条件,以获得较高的提取率和较高品质的明胶.结果表明,浸酸过程浸酸浓度3%、料液比1:20、浸酸时间6 h可得到较高的提取率;浸碱过程Ca(OH)2浓度3%、料液比1:20、浸碱时间12 h可得到品质最佳的鱼鳞明胶.     

基于鱼鳞贮藏方式改善鳙鱼鱼鳞明胶的功能特性

鱼鳞的贮藏方式会影响鱼鳞明胶的品质,本实验研究了太阳晒干后室温贮藏、4 ℃贮藏、－20 ℃贮藏和 60 ℃热风干燥后室温贮藏对鳙鱼鱼鳞明胶凝胶强度、乳化活性和起泡能力的影响,并通过傅里叶变换红外光谱、 十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和扫描电子显微镜表征经不同方式贮藏后制备得到的鱼鳞明胶的结构特性。 结果表明：4 种贮藏方式不会破坏明胶的分子质量分布（α链、β链和高分子聚合物）和傅里叶变换红外光谱的特征 性吸收峰（酰胺A带、酰胺I带、酰胺II带和酰胺III带）。4 种贮藏方式都能提升鱼鳞明胶的乳化活性和起泡能力, 其中,－20 ℃贮藏鱼鳞1 个月改善明胶乳化活性和起泡能力的效果最佳。除60 ℃热风干燥之外,其他贮藏方式均 能改善鱼鳞明胶的凝胶强度,这可能与其相应的结构特征变化有关。相比新鲜鱼鳞和60 ℃热风干燥鱼鳞,太阳晒 干和低温方式（4 ℃和－20 ℃）贮藏鱼鳞使得鱼鳞明胶α链、β链和高分子聚合物含量增加,酰胺A带吸收峰的波数 降低,鱼鳞明胶网络结构的致密性增加。     

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