植物蜡及液态植物油构建油凝胶的物性研究

以米糠蜡、棕榈蜡、蜂蜡3种食品级植物蜡为凝胶剂,葵花籽油、油茶籽油、亚麻籽油、棉籽油为基料油,构建了植物油基油凝胶,系统分析了油凝胶的外观形态、持油能力、微观结构、硬度、晶型及熔化结晶行为。结果发现,棕榈蜡基油凝胶涂抹性能优良,蜂蜡基油凝胶在三者中具有最高的持油能力。微观分析表明,米糠蜡形成的油凝胶晶体结构较为清晰,呈细长的针状;蜂蜡形成的油凝胶晶体结构最为细小,呈细小的针状;棕榈蜡形成的油凝胶,针型细密,并呈絮状结晶。晶体密度及样品硬度均随凝胶剂质量分数增加而增加。油凝胶的晶型与凝胶剂质量分数、基料油的种类无太大关系,主要取决于凝胶剂的种类。熔化结晶行为表明,凝胶剂种类相同时,随着其质量分数的增加,油凝胶的结晶/熔化峰值温度均升高。     

葵花籽油凝胶油的制备及其在冰淇淋中的应用

以葵花籽油为原料,添加一定量的蜂蜡或蜂蜡与谷维素混合物制备葵花籽油凝胶油,研究不同添加量的凝胶因子对葵花籽油凝胶油的硬度值、黏度值、持油性和微观形态的影响;将得到的凝胶油代替黄油制备冰淇淋,研究其在冰淇淋中的应用。结果表明:蜂蜡添加量对凝胶油的质构特性、持油性和微观形态影响较为显著,并确定5%蜂蜡添加量为凝胶油制备的最优条件;添加5%复合凝胶油(5%蜂蜡+1%谷维素)和5%黄油制备的冰淇淋营养丰富、抗融性好、色泽均匀、组织细腻、滑润爽口,与添加10%黄油制备的冰淇淋较为相近,表明可以通过进一步的优化代替饱和脂肪在冰淇淋中应用。     

油茶籽油基复合油凝胶的制备工艺研究

以油茶籽油为基料油,通过添加单甘酯与蜂蜡制备复合油凝胶,探讨复合凝胶剂添加量、单甘酯与蜂蜡质量比、加热温度以及加热时间对油茶籽油基复合油凝胶持油性的影响。在单因素试验的基础上,采用Box-Behnken试验设计方法优化试验条件,并对复合油凝胶体系的性质进行分析。结果表明,油茶籽油基复合油凝胶的最优制备工艺条件为:复合凝胶剂添加量9.9%,单甘酯与蜂蜡质量比4∶6,加热温度71℃,加热时间47 min。在最优工艺条件下,复合油凝胶持油性为98.70%,体系中存在α、β、β'3种晶型,并且与单一凝胶剂油凝胶相比,油茶籽油基复合油凝胶具有较好的持油性和适中的硬度。     

巴西棕榈蜡和单甘酯复配比对高油酸葵花籽油凝胶油结构和特性的影响

以高油酸葵花籽油为基料油,通过向其添加不同质量比的凝胶剂巴西棕榈蜡（carnauba wax,CW）与单甘酯（monoglyceride,MG）制备凝胶油。固定凝胶剂浓度为5%,探讨不同CW与MG的复配比对制备的高油酸葵花籽油凝胶油微观形态、凝胶晶型、热力学性质、硬度、持油性以及固体脂肪含量（solid fat content,SFC）的影响。结果表明:MG没有影响CW的熔化行为,二者没有形成共结晶,出现了偏晶现象,当CW与MG复配比为9:1时,MG晶体的存在促进了CW的结晶,同时CW的存在会抑制MG晶体的多晶态转变,提高体系的储藏稳定性;少量MG的加入显著降低了CW凝胶油的硬度（P<0.05）,当二者复配比为5:5并随着MG含量的增多和CW含量的减少,体系硬度显著增大（P<0.05）,在1:9时达到最大硬度137.33 g;MG的加入显著提高了CW凝胶油的持油性（P<0.05）,二者复配比为5:5时体系持油性最佳达到100%;CW与MG复配比为3:7时凝胶油在30~37.5 ℃的SFC明显低于CW和MG凝胶油,此时MG的加入对体系口感的改善起到了正向作用。     

基于三种植物蜡构建大黄鱼鱼油凝胶体系及其微观结构的研究

以食品级蜡米糠蜡、蜂蜡、巴西棕榈蜡为凝胶剂,以大黄鱼鱼油为基料油,构建了3种油凝胶体系,系统地分析了3种凝胶体系的外观形态、持油率、流变行为、凝胶晶型及熔化结晶曲线,并对微观结构进行了表征。结果表明：3种凝胶剂临界凝胶浓度为3%。蜂蜡持油率98%以上,棕榈蜡最差;油凝胶的储能模量(G′)大于损失模量(G″),但G′随着角频率的增加而增加;3种油凝胶均存在α、β、β′晶型结构,并以α和β′型为主;熔化结晶曲线显示,随着凝胶剂质量分数的增加,其结晶过程中结晶温度和熔化过程中熔化峰值温度均提高;结构表征发现,米糠蜡的小晶体以簇状结构形式存在,蜂蜡形成的晶体在一维方向上形成少量的“絮状”结构,棕榈蜡油凝胶中晶体以“放射状”形态聚集成小球状结构。该研究结果表明在鱼油中添加适量的天然蜡可以形成结构稳定性、热稳定性良好的油凝胶。     

大豆油基凝胶油储藏过程中结晶结构及物理性能变化研究

以大豆油为原料,添加玉米蜡制备玉米蜡基凝胶油,研究储藏温度及时间对凝胶油微观结构及物理性能的影响。结果表明,储藏不会改变凝胶油晶型,凝胶油形成的结晶呈长纤维针状,在20℃下12周的储藏中结晶的生长呈现生长-聚集-生长的趋势,而4℃下结晶的生长趋势为重组-生长-聚集-生长;4℃下凝胶油SFC变化不显著,凝胶油质量分数为1%、3%时硬度和持油性(OBC)随时间延长逐渐减小,而凝胶油质量分数为7%、10%、15%时硬度变化呈现先增后减,OBC储藏中变化不显著(P0.05);20℃下凝胶油SFC储藏6周后出现下降趋势,而硬度与OBC变化与4℃时储藏相似;4℃下凝胶油的SFC、硬度与持油性均要高于20℃,5%的凝胶油在4、20℃储藏中表现出不同的变化趋势。     

单甘酯与蜂蜡复配制备五步蛇蛇油基凝胶油的研究

以五步蛇蛇油为基料油,通过向其添加不同质量比的蜂蜡与单甘酯制备凝胶油。探讨不同蜂蜡与单甘酯的质量比对五步蛇蛇油基凝胶油流变性、持油性以及硬度的影响,并对其结晶型态、结晶形状进行分析。结果表明:少量单甘酯的存在(蜂蜡与单甘酯质量比8∶2)降低了五步蛇蛇油基凝胶油的黏度恢复值及硬度,促进凝胶油长枝状结晶的生成,增加α、β以及β'型晶体;随着单甘酯比例的进一步增加(蜂蜡与单甘酯质量比8∶2～0∶10),五步蛇蛇油基凝胶油析油率和黏度恢复值增加,长枝状结晶逐渐变短至消失,α型晶体逐渐消失;确定蜂蜡与单甘酯质量比4∶6为最佳比例,此时五步蛇蛇油基凝胶油的析油率为1. 8%,硬度为242 g,黏度恢复值为37%。     

米糠蜡添加量对亚麻籽油基油凝胶结构及性质的影响

为探究亚麻籽油基油凝胶作为替代传统塑性脂肪的潜力,以米糠蜡为凝胶剂,探究不同米糠蜡添加量对亚麻籽油基油凝胶外观形态、微观结构、持油率、理化性质及热力学性质的影响。结果表明：在室温条件下,米糠蜡添加量不小于6%时才会使亚麻籽油凝胶化;随着米糠蜡添加量的增加,油凝胶的结晶网络结构由簇状逐渐转变为针状,结晶密度增大;油凝胶的持油率、酸值以及熔融峰/结晶峰峰值温度均随着米糠蜡添加量的增加而增大;油凝胶的过氧化值随着米糠蜡添加量的增加呈现先增后减的趋势。综上,在亚麻籽油中添加适量的米糠蜡可形成热塑性好、结构稳定、理化性质良好、持油率高的油凝胶。     

羟丙基淀粉颗粒形貌和结晶结构的研究

本文应用扫描电镜、X-光衍射和偏光显微等现代分析技术，观察和研究了不同取代度羟丙基淀粉和原淀粉的颗粒形貌及其结晶结构。结果表明：淀粉羟丙基化反应首先发生在淀粉颗粒中结构较薄弱的非结晶区。随着取代度增大，淀粉颗粒表面发生凹凸不平变化，出现洞穴和裂痕，使淀粉易于糊化，糊化温度降低。     

小烛树蜡和日本木蜡对高油酸葵花籽油凝胶油结晶行为的差异比较北大核心CSCD

将小烛树蜡和日本木蜡分别添加到高油酸葵花籽油中制备凝胶油,分析其在凝胶油形成过程中结晶行为的差异。结果表明:在添加量为5%时,两种蜡均表现出低频率依赖的“强凝胶”行为,小烛树蜡具有更强的热稳定性和表观黏度,日本木蜡则具有更高的触变回复性;热力学性质进一步证实凝胶油性能的差异与天然蜡的成分有关。在微观层面上,小烛树蜡凝胶油和日本木蜡凝胶油分别呈现簇状和针状的晶体形态;小烛树蜡晶型为β′型,而日本木蜡则在形成凝胶油的过程中发生晶体排列堆积方式的改变,晶型由β′型转为β型。日本木蜡具有与高熔点蜡不同的特殊结晶性质,在塑性脂肪开发中具有潜在应用价值。     

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