鳕鱼皮明胶-Ca~(2+)复配止血粉的止血活性研究

利用超滤技术制备三个不同分子量段(Mr50 ku、10 kuMr50 ku、Mr10 ku)的鳕鱼皮明胶,分别与Ca~(2+)复配为明胶-Ca~(2+)复配止血粉。通过液体吸收倍率、大鼠体内、外止血实验,探究了不同分子量鳕鱼皮明胶-Ca~(2+)复配止血粉的止血性能,并对其止血机制做初步探讨。结果表明:高分子量鳕鱼皮明胶-Ca~(2+)复配止血粉的液体吸收倍率最大,且能显著(p0.05)缩短体外凝血时间(24 s),降低大鼠股动脉出血时间(114 s)和肝创面出血时间(97 s)。高分子量鳕鱼皮明胶-Ca~(2+)复配止血粉能显著(p0.01)缩短活化部分凝血活酶时间(activated partial thromboplastin time,APTT),主要影响内源性凝血途径;并能促进血小板聚集,通过促进大鼠血小板第四因子(Rat Platelet Factor 4,PF4)、P-选择素(Rat P-Selection)和血栓素B2(Rat Thromboxane B2,TXB2)的释放来缩短凝血时间。高分子量明胶-Ca~(2+)复配止血粉可以作为一种有效的止血材料投入到止血产品的工业化生产中。     

薯莨提取物止血效果及化学成分的初步研究

以薯莨乙醇提取物对小白鼠的止血作用进行研究,并初步鉴定了其化学成分类型,以期利用薯莨的乙醇提取物生产止血药物,提高薯莨的利用价值.本实验以80％的乙醇水溶液为溶剂,提取得到薯莨的乙醇提取物；实验分为空白组、阳性对照组、低剂量组和高剂量组对小白鼠进行灌胃,给药10d后,对小白鼠的出血时间、凝血时间和血小板数量进行了测定.结果表明,薯莨的乙醇提取物能有效缩短小鼠的出血时间和凝血时间,并可提高血小板数量,具有良好的止血效果；其化学成分包括了酚类、苷类、黄酮、蒽醌、三萜、甾醇、有机酸等.     

狭鳕鱼皮明胶提取工艺的研究

为了充分利用水产品加工废弃物狭鳕鱼皮,优化狭鳕鱼皮明胶提取工艺,通过单因素试验和响应曲面法对鱼皮明胶提取工艺进行优化。结果表明：狭鳕鱼皮明胶提取的最佳工艺条件为：氢氧化钠浓度0.10%、硫酸浓度0.21%、浸提时间12.1h,此条件下明胶的提取率为17.52%。     

鳕鱼皮胶原蛋白肽的功能特性及抗氧化活性

以鳕鱼皮胶原蛋白肽为实验材料,研究其吸水性、保水性、乳化性等功能特性,并且进行了体外抗氧化实验。结果表明鳕鱼皮胶原蛋白肽具有较好的吸水性、保水性、吸油性和起泡性,具有一定的乳化性和较弱的泡沫稳定性。体外抗氧化实验结果显示,鳕鱼皮胶原蛋白肽对DPPH自由基、羟自由基和超氧阴离子自由基均有一定的清除效果,且清除率与样品溶液的浓度存在剂量依赖关系;浓度为30mg/mL时,胶原蛋白肽对DPPH·、·OH和O2-·的抑制率分别可达到73.84%、85.76%、64.09%。分级后,分子量1ku以下的胶原蛋白肽对DPPH·和·OH的清除能力最强,30mg/mL时清除率达到84%和90.97%;分子量5ku以上的胶原蛋白肽对O2-·清除能力最强,30mg/mL时清除率达到74.02%。     

响应面法优化酶法提取鳕鱼皮中胶原蛋白条件

利用响应分析法考察了酶浓度、酶解反应时间和酶解温度3个因素对提取鳕鱼皮中胶原蛋白提取率的影响。研究发现,胶原蛋白的最佳提取条件为水解时间10.43h、水解温度16.32℃、酶浓度0.054%,提取率27.53%,比单因素试验最高的提取率高22.3%。并通过对所提取的鳕鱼皮的胶原蛋白的SDS-PAGE电泳分析,确定了所提取的蛋白质制品是纯度较高的胶原蛋白,经电泳测定鳕鱼皮胶原蛋白α1与α2链的分子量分别为113kDa和110kDa。     

鳕鱼皮明胶肽硒复合物的制备及结构表征

以新西兰鳕鱼皮为原料，提取鳕鱼皮明胶并酶解获得鳕鱼皮明胶肽，以亚硒酸钠为硒源，制备并筛选出硒结合量较高的肽硒复合物，对其进行结构表征。结果显示，鳕鱼皮明胶胃蛋白酶酶解物的硒结合含量最高（13.61 μg/mg），因此将其用于制备鳕鱼皮明胶肽硒复合物；鳕鱼皮明胶肽与硒结合后，紫外光谱吸收峰强度增大且红移，荧光光谱吸收峰由波长311 nm迁移到355 nm且荧光强度减弱，表明鳕鱼皮明胶肽与硒结合产生新的物质；基于粒径分布、原子力显微镜、扫描电子显微镜、X射线衍射分析，鳕鱼皮明胶肽硒复合物呈现为纳米晶体结构，主要是由于鳕鱼皮明胶肽上的羧基和氨基与硒发生了结合反应，使得β-折叠结构转变为α-螺旋结构和β-转角结构，从而使得结构更加紧凑有序。本研究制备了一种新型的肽硒复合物，为实现鱼皮高值化利用提供了新途径。     

氧化绿原酸改性鳕鱼皮明胶功能特性的研究

该试验研究经不同浓度氧化绿原酸(2.5%、5.0%、10.0%和20.0%)改性后鳕鱼皮明胶的抗氧化能力和乳化性。测定氧化绿原酸改性的鳕鱼皮明胶游离氨基的含量、表面疏水性、浊度、抗氧化活性以及硫代巴比妥酸值。结果表明,经氧化绿原酸改性的明胶抗氧化活性提高,但游离氨基含量和表面疏水性降低。5.0%氧化绿原酸改性明胶的浊度最高,较高浓度的氧化绿原酸会影响明胶的乳化性能。氧化绿原酸能够增强供氢能力,并作为金属螯合剂增强明胶的抗氧化活性。此外,氧化绿原酸改性的明胶能够增加乳状液的氧化稳定性。     

罗非鱼皮明胶酶解物及其模拟消化产物的抗氧化活性

以罗非鱼皮为原料提取罗非鱼皮明胶,选用风味蛋白酶和胰蛋白酶制备罗非鱼皮明胶酶解物,采用ABTS自由基、DPPH自由基、羟基自由基及亚油酸过氧化体系,初步评价罗非鱼皮明胶酶解物的抗氧化活性,再通过模拟体外胃肠道消化实验,结合分子质量分布测定,进一步考察罗非鱼皮明胶酶解物的抗氧化活性。结果显示,在酶解过程中,风味蛋白酶及胰蛋白酶酶解的水解度逐渐升高,在3 h时达到最高,分别达到5.8%和25.36%。在酶解60 min时其TCA可溶性肽得率最高,风味蛋白酶、胰蛋白酶酶解物分别达56.82%和54.44%。通过比较半抑制浓度(IC_50),确定了酶解60 min时风味蛋白酶酶解物的清除DPPH自由基及抑制亚油酸过氧化能力较胰蛋白酶酶解物强。模拟体外胃肠道消化后,酶解物羟基自由基清除活性均显著提高(p0.05),亚油酸脂质过氧化活性明显降低,消化前后样品分子量分布范围均主要集中于3000~5000 Da,消化后风味蛋白酶及胰蛋白酶酶解物3000~5000 Da组分的含量分别提高了45%及13%。以上研究结果表明,罗非鱼皮明胶酶解后制备的明胶水解物具有一定的抗氧化能力,具有潜在的开发价值。     

花生凝胶软糖工艺研究

以花生仁、白砂糖、葡萄糖、卡拉胶与狭鳕鱼皮明胶复配凝胶剂为原料制作花生凝胶软糖,采用正交实验确定花生凝胶软糖的配方。实验结果表明花生凝胶软糖的最佳配方为：白砂糖添加量为20％、葡萄糖添加量为60％、卡拉胶与狭鳕鱼皮明胶的比例为3：2、凝胶剂（卡拉胶与狭鳕鱼皮明胶的混合物）添加量为4％。     

海洋生物胶原蛋白的制备及比较

利用鳕鱼皮、鲽鱼皮、马哈鱼皮、鱼骨作为原料,分别用化学方法和酶法提取胶原蛋白,并对提取的胶原蛋白的性质、各种原料的前处理时间和提取率进行了比较,同时用鲤鱼鳞、猪骨为对照.结果发现酶法提取的胶原蛋白纯度高,灰分少;鳕鱼皮、鲽鱼皮胶原蛋白提取率高,适合工业化生产;鳕鱼骨与猪骨、鲤鱼鳞一样可以进行综合利用.     

胶原止血性能的研究进展

探讨了胶原的止血机理,介绍了胶原止血海绵、胶原止血纤维以及胶原复合止血材料的止血作用、止血性能及临床应用现状,提出了胶原止血材料的未来发展方向。     

可溶性止血医用棉纱布的性能分析及制备

说明可溶性止血医用棉纱布的重要性,对可溶性止血医用棉纱布的性能进行分析,阐述可溶性止血医用棉纱布应用及发展现状。将国内外技术和价格进行对比,提出了一种可溶性止血医用棉纱布的制备方法:首先,准备必要的制备材料,打散纤维;其次,与氢氧化钠水溶液反应、静止碱化和醚化反应等;再次,用相关化学制剂洗涤,将得到的羧甲基化溶剂纺纤维素纤维进行风干、织布、包装、消毒等;最后,加工得到成品。     

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.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.