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1.
对影响乳状液稳定性的因素如乳化剂种类、乳化剂浓度、阿拉伯胶浓度、混合温度及混合时间等进行了研究。试验结果表明 ,香料乳状液稳定的优化条件是 :吐温 - 80用量 0 .8%、阿拉伯胶用量9.0 %、室温下混合搅拌 7min。  相似文献   

2.
小桐子油不溶于水,若将小桐子油制备成杀虫剂,必须先将小桐子油乳化,制备稳定的小桐子油乳状液。研究复配乳化剂、乳化温度、乳化方式及增溶水量对小桐子油乳状液稳定时间的影响,并研究复配乳化剂对小桐子油乳状液杀虫活性的影响。结果表明,小桐子油乳状液制备的最佳工艺条件为复配乳化剂Tween-20/Span-60(0.12/0.88),乳化温度20~30℃,乳化方式为先将复配乳化剂加入油相,再将水加入油相后搅拌均匀,增溶水量27.5%。在最佳工艺条件下,小桐子油乳状液的稳定时间为55 d,在小桐子油乳状液质量浓度为0.10 mg/mL时,试虫72 h的死亡率为99.06%。小桐子油乳状液的杀虫活性随稳定时间的延长而增强。  相似文献   

3.
微胶囊技术制备粉末荆芥精油的研究   总被引:1,自引:1,他引:0  
以荆芥油为芯材,以大豆分离蛋白为壁材,利用乳化和喷雾干燥相结合的方法制备粉末荆芥油.确定的最佳制备工艺条件为:采用单甘酯加吐温-60(HLB=8.0)为乳化剂,添加量为1.5%,乳化温度80℃,明胶添加量2%,荆芥油与壁材大豆分离蛋白的比例为0.5:1,乳状液总固形物浓度为30%.喷雾干燥进风温度210℃,出风温度85℃.该条件下制备的荆芥油粉末微胶囊化效率迭88.1%,表明该法是一种适宜的粉末荆芥油制备方法.  相似文献   

4.
高分子乳化剂对VE的微乳化研究   总被引:1,自引:0,他引:1  
选用明胶、改性淀粉为表面活性剂,采用溶剂扩散法对VE进行微乳化实验.研究乳化剂、助乳化剂的种类及用量,乳化剂溶液浓度以及乳化温度对乳化效果的影响.  相似文献   

5.
为了了解在水包核桃油乳状液中乳化剂类型、浓度及水相p H对其物理稳定性的影响,考察四种乳化剂即乳清分离蛋白(WPI)、十二烷基磺酸钠(SDS)、十二烷基三甲基溴化铵(DTAB)以及失水山梨醇聚氧乙烯酯(Tween20)在p H3.0和p H7.0条件下形成稳定的水包核桃油乳状液所需要的最低浓度。结果表明,p H对阳离子表面活性剂DTAB、非离子表面活性剂Tween20乳化效果影响较大,在p H3.0和7.0条件下形成稳定乳状液所需DTAB最低浓度分别为0.8%、2.0%,而Tween20最低浓度分别为0.6%、0.3%;p H(等电点除外)对两性大分子表面活性剂WPI和阴离子表面活性剂SDS的乳化效果影响较小。研究结果表明不同类型乳化剂在不同p H条件下对水包核桃油乳状液的物理稳定性影响差异较大。  相似文献   

6.
温度、pH和盐对乳清蛋白乳状液稳定性的影响   总被引:2,自引:0,他引:2  
乳清蛋白具有一定的乳化能力,在食品工业中常作为乳化剂使用.以乳清浓缩蛋白(WPC)、乳清水解蛋白(WPH)和乳清分离蛋白(WPI)为乳化剂,经高压均质制备O/W型乳状液,以平均粒径和分层系数为稳定性指标,研究了温度、pH和盐对乳状液稳定性的影响.结果表明:WPI乳状液具有最小的平均粒径.各环境因素对乳状液稳定性的研究表明,pH是影响乳状液稳定性最显著的因素,当pH在蛋白质等电点(4~6)附近时,各乳状液中粒子均发生絮凝或聚合,乳状液发生脱稳,受环境因素影响,WPC乳状液具有最好的稳定性.这些结果为乳清蛋白作为乳化剂用于食品工业提供了重要依据.  相似文献   

7.
粉末化猪油工艺的研究   总被引:1,自引:0,他引:1  
猪油与油溶性乳化剂、水溶性乳化剂及壁材等在一定条件下混合均匀、乳化、均质,经喷雾干燥得粉末化猪油.单因素试验表明,最佳乳化条件为:壁材为大豆分离蛋白、β-环状糊精和可溶性淀粉复合使用,亲油乳化剂为单甘酯,亲水乳化剂为Tween 60,HLB值为6~8,乳化剂用量2%~3%,稳定剂明胶用量1.6%~2.0%,加水量10~15倍于基料,乳化温度70℃,乳化时间20min.在其他条件不变的情况下,通过正交试验研究了乳化剂用量、HLB值、明胶用量和壁材对粉末化猪油的溶解度、产品结块状态的影响.研究结果表明,制备40%含油量的粉末化猪油的最佳配方为:乳化剂用量3%,HLB值6,明胶用量2.3%,大豆分离蛋白、β-环状糊精和可溶性淀粉复合作壁材.  相似文献   

8.
食品乳状液是不稳定的体系,贮藏过程中会发生分层,食品加工中需要寻找一些有效的成分来稳定乳状液,因此天然乳化剂的应用是目前发展的趋势。主要介绍了天然食品级乳化剂(如蛋白质、多糖、磷脂和皂苷)的鉴别、特征以及应用的进展,特别论述了这些乳化剂本身的特性及结构对形成稳定的乳状液的影响,并对一些环境条件(pH、离子强度和温度)对于天然乳化剂乳化能力的影响进行了讨论。该论文的论述,有助于选择适当天然乳化剂,并将其合理应用于以乳状液为基础的食品,化妆品和医药产品中。  相似文献   

9.
废食用大豆油的新用途研究   总被引:1,自引:0,他引:1  
以废食用大豆油为原料,在它与氯化钙和氢氧化钠之比为30:5:3(v/m)、反应时间为120min、反应温度为75℃的工艺条件下进行皂化反应,制得乳化剂。利用该乳化剂和废食用大豆油制备W/O乳状液,测定乳状液流变性、滤失性、稳定性及抗高、低温能力等性能,以此评价乳化剂的乳化能力,并与新大豆油和柴油配制的乳状液比较。结果表明,用废食用大豆油制得的乳化剂乳化效果好于新大豆油在相同条件下制备的乳化剂,用废食用大豆油制备的乳状液具有优良的悬浮性和流变性,滤失量低。可在-20~120℃范围内稳定,性能优于柴油基W/O乳状液,具有开发乳化钻井液潜力。  相似文献   

10.
吕兵  陈洁  夏文水 《粮油加工》2007,(3):53-55,58
以过氧化值(POV)为指标,研究了乳化剂类型、油浓度及油滴粒径对O/W乳状液中油脂氧化稳定性的影响.以用十二烷基硫酸钠(SDS)和Tween-80为乳化剂制备的含红花籽油的乳状液为研究对象,结果表明,乳化剂类型和油浓度对乳状液体系中油脂氧化有较显著的影响.用阴离子型表面活性剂SDS稳定的乳状液中的油脂氧化速率明显大于用非离子型Tween-80稳定的乳状液;随着油浓度下降,油脂氧化速率增大.油滴粒径和油脂氧化速率没有显著的相关性.  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
18.
Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH3CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH2PO4-20.6 mM Na2B4O7 buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.  相似文献   

19.
An investigation is described in which various polyfunctional compounds were applied to wool in attempts to stabilize the temporary improvements in wrinkle-recovery brought about by ‘annealing’. Several reactive systems involving formaldehyde were found to produce the desired permanently improved wrinkle-recovery.  相似文献   

20.
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.  相似文献   

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