辅酶Q10纳米脂质体配方与工艺优化研究

采用乙醇注入-超声法制备辅酶Q10纳米脂质体,以包封率、保留率、平均粒径以及平均粒径的变化程度作为响应指标,应用正交试验法优选辅酶Q10纳米脂质体的配方和制备工艺。最佳配方为磷脂:胆固醇:吐温80:辅酶Q10=2.5:0.4:1.8:1.2(W/W),水相为0.01mol/L磷酸盐缓冲液(pH7.4);最佳制备工艺条件为乙醇用量1ml,搅拌时间10min,水化温度45℃,超声功率450W。以优化配方和工艺制得的脂质体形态均匀,粒径分布范围在20～300nm之间,平均粒径为68nm,包封率高于95%,4℃下贮存四个月,粒径分布无显著变化,平均粒径的变化程度小于10%,保留率高于90%。经优化得到的辅酶Q10纳米脂质体配方合理、工艺简便可行、包封率高、稳定性好。     

全因子试验设计优化他克莫司纳米混悬滴眼液的制备工艺

目的制备一种他克莫司纳米混悬滴眼液,并优化他克莫司纳米微粒的制备工艺。方法采用溶剂-反溶剂法制备他克莫司纳米微粒混悬液,离心除去有机溶剂和表面活性剂,收集沉淀微粒,再分散后得到他克莫司纳米混悬液,将辅料配制成辅料溶液,灭菌后与他克莫司纳米混悬液合并,制成滴眼液。以聚乙烯醇为稳定剂,以药物-溶剂比、溶剂-反溶剂比、搅拌速度、搅拌时间为考察因素,以粒径和沉降体积比为评价指标,采用全因子法优化制备工艺。结果最优制备工艺参数为:药物溶剂比1:4,溶剂-反溶剂比1:40,搅拌速度1500 r/min、搅拌时间6 h。最优工艺制得的他克莫司纳米混悬滴眼液的中值粒径(D50)0.3μm;沉降体积比0.9。加速试验考察结果显示,6个月样品的D50和沉降体积比均未见显著变化。结论优选的他克莫司纳米混悬滴眼液制备工艺可行,产品质量可控,稳定性良好。     

GA-zein-cur核壳结构分散体系的构建及工艺条件优化

采用反溶剂法制备GA-zein-cur分散体系,探讨不同的操作条件(反溶剂加入方式和速度、搅拌速度、溶剂类型以及浓度、溶剂和反溶剂的体积比)对GA-zein-cur分散体系形成的影响。研究结果表明:在1 000 r/min条件下采用正加入法快速加入反溶剂,以80%乙醇-水溶液为溶剂,溶剂和反溶剂体积比为1∶2.5时制得的GA-zein-cur分散体系粒径较小,粒度分布较窄。同时姜黄色素的包埋率大幅度的提高,随着溶剂-反溶剂体积比的减小,制备的分散体系的平均粒径和PDI值均变小,制得的分散体系更均一、稳定、透明。     

辅酶Q_(10)前体脂质体的制备及其质量评价

采用高压均质结合冷冻干燥法制备辅酶Q10前体脂质体,并通过正交实验设计对处方及工艺进行优化。经红外光谱、X射线衍射等手段对优化后的产品质量进行分析,同时,对其稳定性进行评价。结果显示本研究制备的辅酶Q10前体脂质体经重建后的平均粒径为241 nm,包封率67.31%,贮存90 d后质量无明显变化。本实验制备的前体脂质体,质量可靠,稳定性好,工艺便捷,适于工业生产及食品中应用。     

罗非鱼肝脏中辅酶Q10的研究

辅酶Q10是一种重要的类维生素有机物,是促进生物氧化的酶类生化药物.通过L16(45)正交实验,研究皂化法提取辅酶Q10的工艺条件;用硅胶柱层析及制备硅胶板分离纯化;用薄层色谱、紫外光谱对提纯样品进行定性及定量分析.结果表明皂化法提取罗非鱼肝脏辅酶Q10的最佳工艺条件是皂化温度70℃、皂化时间30 min、萃取4次.经硅胶柱层析,每100 g罗非鱼肝脏可以提取纯化辅酶Q103.39mg.     

人参淀粉微粒的制备工艺及性质

为了探究人参淀粉微粒的制备工艺及性质,采用醇沉法制备人参淀粉微粒。利用单因素试验分析淀粉质量浓度、无水乙醇体积、搅拌速度等工艺条件对人参淀粉微粒性质的影响;利用扫描电子显微镜和激光粒度分布仪研究人参淀粉微粒的形貌、粒径尺寸及粒度分布情况,研究发现,人参淀粉微粒是表面具有块状结构的不规则的形貌,其粒径尺寸及粒度分布受淀粉质量浓度、无水乙醇体积和搅拌速度的影响;当淀粉质量浓度增加或无水乙醇体积减少时,均会导致人参淀粉微粒粒度增加及粒度分布不均匀的现象;搅拌速度对人参淀粉微粒粒度分布的影响不是单一的。以人参淀粉微粒质量浓度为2%、无水乙醇体积为40倍、搅拌速度为150 r/min的工艺条件制得的人参淀粉微粒具有相对较小的粒径尺寸,粒径主要集中在1～4μm,粒度分布均匀,适合作为食品原料进行加工使用。     

发酵法制备L-鸟氨酸苯乙酸盐的结晶工艺

L-鸟氨酸发酵液经膜分离、离子交换处理,再加入苯乙酸进行反应,制备结晶型L-鸟氨酸苯乙酸盐(OP)。采用单因素试验考察了晶种加入时机、晶种投加量、乙醇滴加速率及搅拌速率等因素对所得平均粒径及纯度的影响。确定起始质量浓度为800 g/L结晶液的较优结晶工艺条件为:乙醇与起始结晶液体积比为0.4时投加4wt%晶种,乙醇滴加速率0.8 m L/min,搅拌速率200 r/min。所得OP晶体平均粒径为614.7μm,纯度为98.3%,总收率为72%;将其X-射线粉末衍射图谱与文献图谱比对,确定所制备的晶体为OP晶体。     

三元淀粉纳米颗粒的制备及特性表征

研究制备由直链淀粉、棕榈酸和β-乳球蛋白组成的三元淀粉纳米颗粒工艺并对制得的三元淀粉纳米颗粒结构性质进行分析。以马铃薯淀粉为原料,采用水浸法制备直链淀粉,将制得的淀粉溶液加入棕榈酸和β-乳球蛋白溶液以制备三元淀粉纳米颗粒。通过考察棕榈酸浓度、β-乳球蛋白浓度、反应温度、搅拌速率对生成的三元淀粉颗粒粒径大小的影响,采用场发射扫描电镜(FE-SEM)、X射线衍射(XRD)、傅立叶变换红外光谱(FTIR)表征其结构并测其吸附性。结果表明,最适工艺参数:β-乳球蛋白浓度为8mg/mL,棕榈酸浓度为10mg/mL,反应温度90℃,搅拌速率200r/min,得到的三元淀粉纳米颗粒粒径在200-300nm范围内。FE-SEM、XRD、FTIR表明直链淀粉、棕榈酸和β-乳球蛋白之间发生了作用,结晶结构由B型转变成V型。吸附性也增强。     

金磁微粒的制备及其催化性能

采用水热法快速制备Fe_3O_4纳米粒子,并通过表面氨基化与金纳米粒子自组装方法构建金磁微粒(Fe_3O_4@Au),优化金磁微粒的制备工艺,并表征其性能。结果表明,1%浓度的葡萄皮浸泡液制备金纳米粒子,其粒子平均粒径为7 nm,氨基化的Fe_3O_4纳米粒子可以有效固载金纳米粒子,最优制备工艺为:Fe_3O_4混悬液添加量2 m L,温度60℃,时间60 min。金磁微粒饱和磁化强度为61 emu/g,且具有良好的催化性能。     

辅酶Q10纳米脂质体强化运动饮料超高压杀菌工艺的研究

以强化辅酶Q10纳米脂质体的运动饮料为研究对象,利用单因素和响应面实验研究了不同压力和保压时间对微生物存活率的影响,确定了超高压杀菌工艺条件。结果表明,当温度为20～25℃,压力在300～500MPa的范围,保压时间5～15min,超高压杀菌对运动饮料中的微生物杀灭作用显著。处理后该饮料中菌落总数低于10cfu/mL,其中辅酶Q10纳米脂质体平均粒径仍可维持在100nm以下,包封率在90%以上。最终确定压力394MPa,保压时间8.44min为辅酶Q10纳米脂质体运动饮料超高压杀菌工艺。4℃贮存6个月后运动饮料中辅酶Q10的保留率高于90%。     

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.     

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.     

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.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

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