龙蒿精油纳米胶囊制备工艺优化及结构表征研究

以龙蒿精油为芯材,壳聚糖为壁材,采用离子凝胶法制备龙蒿精油纳米胶囊。通过单因素试验考察芯材与壁材质量比、壳聚糖溶液的pH、三聚磷酸钠与壳聚糖的质量比对龙蒿精油包埋率的影响。采用Box-Behnken试验设计和响应面分析优化纳米胶囊制备工艺,建立影响因素的二次回归模型。采用透射电镜、傅里叶红外光谱仪、差示扫描量热仪对所制备的纳米胶囊进行表征分析。结果表明:响应面优化得出龙蒿精油纳米胶囊的最佳制备工艺为芯壁比2∶1、pH 3.5、三聚磷酸钠与壳聚糖的质量比0.4∶1.0,该条件下龙蒿精油纳米胶囊的包埋率为43.67%。傅里叶红外光谱分析证实龙蒿精油被成功包埋;透射电镜观察纳米胶囊呈较规则圆形,平均粒径约为40nm;差示扫描量热分析表明龙蒿精油纳米胶囊具有良好的热稳定性。     

丁香精油纳米胶囊对冷藏调理猪肉饼品质的影响

本实验采用离子凝胶法,以壳聚糖为壁材制备丁香精油纳米胶囊,主要研究了丁香精油纳米胶囊的物理特性及其对调理猪肉饼（4±1）℃冷藏期间菌落总数、脂肪氧化、色泽、pH值、高铁肌红蛋白质量分数以及感官品质的影响。结果表明：丁香精油纳米胶囊的平均粒径为254.7?nm,ζ-电势为35.4?mV,多分散指数为0.33;精油的释放曲线呈现初始的快速增加阶段,随后累积释放率缓慢增加,直到108?h才停止释放;丁香精油可以抑制猪肉饼脂质氧化和微生物腐败,但具有较强烈的精油味道且对猪肉饼护色效果不佳,随着冷藏时间的延长,其抗氧化和抗菌活性下降;添加丁香精油纳米胶囊显著抑制了猪肉饼脂质氧化和微生物生长,并使猪肉饼具有较高的红色稳定性,且对猪肉饼冷藏期间的感官指标没有不良影响。结论：丁香精油纳米胶囊可作为新型纳米保鲜剂延长猪肉饼冷藏期间的货架期。     

不同壁材丁香精油微胶囊保鲜剂性能研究

采用饱和水溶液法,以β-环糊精和壳聚糖为壁材,丁香精油为芯材与壁芯比为4∶1制备3种丁香精油微胶囊保鲜剂,并对三种组合壁材微胶囊保鲜剂的表面形态、光照稳定性、包埋率、缓释效果以及抑菌效果进行测定,结果表明β-环糊精丁香精油微胶囊的包埋率最高,为67%;β-环糊精-壳聚糖丁香精油微胶囊1的光照稳定性最好,丁香精油损失率仅为32.67%;β-环糊精-壳聚糖丁香精油微胶囊1的缓释效果最好;β-环糊精-壳聚糖丁香精油微胶囊1的抑菌圈直径最大(38.5±0.40 mm)。综合考量得β-环糊精-壳聚糖1为壁材制得的丁香精油微胶囊性能最好。     

丁香精油微胶囊工艺优化及其对冰温猪肉保鲜效果的影响

为克服丁香精油在保鲜应用中易挥发、难溶于水的缺点,采用复凝聚法制备丁香精油微胶囊,以包埋率为评价指标,采用Box-Behnken中心组合试验和响应面分析法优化包埋工艺,并将丁香精油微胶囊应用于冰温猪肉的保鲜。结果表明,所得回归模型具有高度显著性(p<0.0001),方程对试验拟合较好,在CaCl₂浓度12 g/L,壁芯比7:1 (m/m),复合壁材比(海藻酸钠-壳聚糖)0.8:1 (m/m),包埋时间47 min的条件下,制得的丁香精油微胶囊包埋率最高为84.20%,与预测包埋率相对误差小于5%;用该条件制备的丁香精油微胶囊处理冷却猪肉,冰温下对照组猪肉可保鲜9 d,空芯组可保鲜21 d,精油组可保鲜27 d,表明丁香精油微胶囊可显著延长冰温猪肉的保鲜期(p<0.05)。     

肉桂精油纳米胶囊制备表征及体外抗菌抗氧化能力

以壳聚糖(chitosan,CS)为壁材,采用离子凝胶法制备肉桂精油-壳聚糖纳米胶囊(cinnamon ssential oilloaded chitosan nanocapsules,CIEO-MPS),研究制备条件对纳米胶囊粒径及ζ-电势的影响,并对所制备纳米胶囊的物理特性进行表征;同时采用抑菌圈法和DPPH法测定肉桂精油纳米胶囊的体外抗菌和抗氧化性能。结果表明:肉桂精油纳米胶囊平均粒径为178 nm,ζ电位为33. 72 m V;拉曼光谱表明肉桂精油已经被封装到纳米胶囊中;此外,肉桂精油纳米胶囊具有良好的缓释性能和良好的抗菌、抗氧化活性。肉桂精油纳米胶囊有望成为一种潜在的天然抗菌抗氧化剂从而在食品和医药领域中应用。     

Fmoc-F多肽水凝胶对丁香精油的控释作用研究

探讨Fmoc-F(Phe)多肽形成的凝胶对丁香精油的包埋和控制释放作用。结果表明,Fmoc-F形成的凝胶对丁香精油的包埋率可达98.69%;在pH6.5时,Fmoc-F凝胶的分解率低于9.0%,该条件下凝胶可有效降低丁香精油的挥发损失;当pH=6.0时,3hFmoc-F—丁香精油分解率接近36.0%,当pH=5.0时,Fmoc-F凝胶迅速分解,3h分解率达到100%,该条件下丁香精油被快速释放到大肠杆菌的菌液中可有效抑制大肠杆菌的生长。说明Fmoc-F凝胶可以有效防止丁香精油常温下的挥发,并控制精油在酸性条件下有效释放并发挥抑菌效果。     

壳聚糖基纳米氧化锌—丁香精油抗菌复合膜对

将抗菌效果良好且不会产生耐药性的无机抗菌剂纳米氧化锌和具有广谱抗菌性、无毒健康的天然抗菌剂丁香精油加入壳聚糖—魔芋葡甘聚糖复合膜中,研究复合膜对鲜肉的保鲜效果。结果发现：添加质量分数6%纳米氧化锌和体积分数0.6%丁香精油的复合膜对大肠杆菌和金黄色葡萄球菌的抑菌率分别为99.78%,99.06%,具有强抗菌效果;红外光谱分析结果表明壳聚糖官能团和丁香精油中存在的酚反应基团之间有效地发生了键合,且扫描电镜结果表明丁香精油在一定程度上可改善纳米氧化锌的分散效果;添加纳米氧化锌和丁香精油的复合膜对鲜肉的保质期可提高6~8 d。     

壳聚糖基纳米氧化锌—丁香精油抗菌复合膜对鲜肉保鲜效果

将抗菌效果良好且不会产生耐药性的无机抗菌剂纳米氧化锌和具有广谱抗菌性、无毒健康的天然抗菌剂丁香精油加入壳聚糖—魔芋葡甘聚糖复合膜中,研究复合膜对鲜肉的保鲜效果。结果发现:添加质量分数6%纳米氧化锌和体积分数0.6%丁香精油的复合膜对大肠杆菌和金黄色葡萄球菌的抑菌率分别为99.78%,99.06%,具有强抗菌效果;红外光谱分析结果表明壳聚糖官能团和丁香精油中存在的酚反应基团之间有效地发生了键合,且扫描电镜结果表明丁香精油在一定程度上可改善纳米氧化锌的分散效果;添加纳米氧化锌和丁香精油的复合膜对鲜肉的保质期可提高6～8d。     

缓释型茶树精油-壳聚糖微胶囊的制备、表征及体外释放规律

以三聚磷酸钠（sodium tripolyphosphate,TPP）为交联剂,采用离子凝胶法制备茶树精油-壳聚糖（chitosan,CS）微胶囊,研究茶树精油微胶囊的结构和功能特性,并分析茶树精油微胶囊在不同食品模拟体系中的释放规律。结果表明,茶树精油添加量和CS与TPP质量比对微胶囊粒径和茶树精油包埋率有显著影响,通过优化得到CS与TPP质量比5.3∶1、茶树精油添加量11.30 mg/mL时,茶树精油微胶囊的粒径最小为（0.74±0.03）μm,包埋率最大为（53.15±0.32）%。该条件下微胶囊的粒径范围在0.2～2.3 μm之间,且呈正态分布;并且可以明显提高茶树精油的稳定性,表现为与茶树精油相比,茶树精油微胶囊在0～15 d时,有更稳定的体外杀菌性和抗氧化性。另外,茶树精油微胶囊在不同的食品模拟体系中均能快速释放,并在30 min后逐渐稳定。说明该工艺可以用于对茶树精油的微囊化包埋,从而提高茶树精油的稳定性。     

基于凹凸棒稳定的姜精油纳米乳的性质表征和结肠靶向研究

为提高姜精油（Ginger essential oil, GEO）的稳定性和利用度,本实验室以酸改性凹凸棒为稳定剂、亚麻籽胶作为乳化剂、壳聚糖盐酸盐做壁材制备了姜精油纳米乳。本研究对姜精油纳米乳进行性质表征（包括形貌与形态、粒径分布、流变性、红外光谱、包埋率）并评价其结肠靶向和缓释性能。研究结果表明姜精油纳米乳粒径呈正态分布,液滴平均粒径为329.6 nm,PDI为0.259,包埋率为91.26%±0.03%;通过荧光显微镜和扫描电镜观察,表明所制备姜精油纳米乳分散度良好,呈表面光滑的球形;红外光谱结果表明,姜精油被包封进纳米乳中且化学组成未被破坏,纳米乳中各组分的结合方式为物理结合;姜精油纳米乳在4、25、40℃贮藏28 d稳定性良好;通过体外模拟消化试验及动力学分析结果表明,姜精油纳米乳具有结肠靶向和缓释的性能。本研究为食品功能因子结肠递送体系的建立、以及后期姜精油纳米乳作为食品功能因子改善肠道健康中的应用提供了理论依据。     

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