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1.
超声波处理提取葵花籽油的研究   总被引:12,自引:5,他引:7  
研究了超声波强度,处理时间,溶剂用量,提取次数对葵花籽油提取率的影响,得出最佳提取参数为:超声波强度为200KW/m2,处理15min,样品与溶剂比(g押mL)1:7,提取2次,提取效果理想。  相似文献   

2.
以烤核桃保质期内的过氧化值和酸价变化为评价指标,研究了特丁基对本二酚单体、复合抗氧化剂(特丁基对苯二酚、柠檬酸、异抗坏血酸钠、单双甘油酯)和木瓜蛋白酶处理在烤核桃产品保质期内抗氧化活性,并通过正交试验确定复合抗氧化剂比例。研究结果表明,同等条件下,木瓜蛋白酶处理比特丁基对苯二酚单体具有更强的抗氧化作用,复合型抗氧化剂在保质初期优于木瓜蛋白酶的抗氧化活性,在保质期后期,复合抗氧化剂和木瓜蛋白酶处理的效果接近;复合抗氧化剂最佳比例为:特丁基对苯二酚0.045%,异抗坏血酸钠0.02%,柠檬酸0.02%,单双甘油酯0.025%,该组合在保质期内抗氧活性最高。  相似文献   

3.
超声波处理提取葵花籽油研究   总被引:7,自引:0,他引:7  
该文介绍超声波强度、处理时间、溶剂用量、提取次数对葵花籽油提取率影响,并得出最佳提取 参数为:超声波强度200KW/m2,处理15min,样品与溶剂比(g:ml)1:7,提取2次,提取效果理想。  相似文献   

4.
采用Schaal烘箱耐热试验法,以人工合成抗氧化剂二叔丁基羟基甲苯、丁基羟基茴香醚和特丁基对苯二酚等为阳性对照,研究茶多酚、苹果多酚、葡萄多酚、野葡萄多酚、牡丹籽多酚、生育酚、脂溶性迷迭香提取物和水溶性迷迭香提取物等8种天然抗氧化剂及2种增效剂(维生素C和柠檬酸)对牡丹籽油氧化稳定性的影响。研究以过氧化值为评价指标。结果表明,在国家允许添加量范围内,几种天然抗氧化剂均能提高牡丹籽油的氧化稳定性,但单独使用的效果要弱于人工合成抗氧化剂特丁基对苯二酚。其中脂溶性迷迭香提取物抗氧化效果较为理想,与合成抗氧化剂特丁基对苯二酚效果接近。维生素C与柠檬酸是抗氧化剂的良好增效剂,协同抗氧化作用显著,且维生素C的效果优于柠檬酸。复合抗氧化剂的抗氧化效果优于同等质量浓度的单一抗氧化剂,复合添加0.01%脂溶性迷迭香+0.01%茶多酚+0.02%维生素C、0.01%牡丹籽多酚+0.01%苹果多酚+0.02%维生素C和0.01%脂溶性迷迭香+0.01%茶多酚+0.02%柠檬酸均能显著减缓牡丹籽油的氧化速度,可使牡丹籽油的贮藏时间明显延长。  相似文献   

5.
研究对芝麻素在大豆油中的抗氧化活性进行了研究,采用过氧化值和共轭双烯值作为指标,将芝麻素的抗氧化活性与VE、TBHQ(特丁基对苯二酚)进行了比较,并研究了芝麻素与VE、增效剂CA(柠檬酸)及EDTA的协同抗氧化作用。研究结果表明,芝麻素具有较强的热稳定性和抗氧化活性,其抗氧化活性随芝麻素浓度的增加而增加;芝麻素在大豆油中的抗氧化活性略高于同浓度的VE,但明显低于同浓度的TBHQ;增效剂CA(柠檬酸)对芝麻素的抗氧化活性增效明显。  相似文献   

6.
松籽油的抗氧化稳定性研究   总被引:6,自引:2,他引:4  
松籽油富含不饱和脂肪酸,营养价值很高,但易氧化,难保藏。影响油脂氧化的因素很多,主要为温度、光线。本文以过氧化值(POV)作为油脂稳定性的评价指标,采用Schaal烘箱法研究了抗氧化剂特丁基对苯二酚(TBHQ)、没食子酸丙酯(PG)及复合抗氧化剂的抗氧化性能。实验结果表明,复合抗氧化剂比单一抗氧化剂单独使用时对松籽油有更显著的抗氧化作用,其抗氧化性能依次为TBHQ 柠檬酸>TBHQ>PG 柠檬酸>PG。  相似文献   

7.
利用对比试验和强制氧化方法研究了茶多酚和特丁基对苯二酚(TBHQ)等抗氧化剂对压榨一级花生油、花生大豆调和油的抗氧化作用。  相似文献   

8.
特丁基对苯二酚(TBHQ)应用与检测   总被引:11,自引:1,他引:10  
本文综述特丁基对苯二酚(TBHQ)应用与检测。TBHQ对大豆油、鱼油等食用油具有良好抗氧化作用,在油中其抗氧化能力优于叔丁基对羟基茴香醚、2,6-二叔丁基对甲苯和没食子酸丙酯。柠檬酸对TBHQ抗氧化作用具有一定增效作用。在高温环境中(如160℃),TBHQ抗氧化效果不好,要使用微胶囊抗氧剂才能获得较好效果。可采用气相色谱配氢火焰离子化检测器和液相色谱配紫外检测器定量分析TBHQ。  相似文献   

9.
枳椇子乙醇提取物对猪油抗氧化能力研究   总被引:1,自引:0,他引:1  
以猪油为试验材料,采用烘箱法评价不同添加量枳椇子乙醇提取物对猪油的抗氧化能力,并与抗坏血酸棕榈酸酯、维生素E、特丁基对苯二酚进行比较分析。结果表明:在猪油氧化诱导期,0.1%乙醇提取物与0.02%特丁基对苯二酚有相当的脂质抗氧化能力,说明枳椇子乙醇提取物具较强油脂抗氧化能力;在猪油氧化的发展期,不同添加量乙醇提取物有不同程度的促进氧化的作用。同时对各抗氧化剂的抗氧化机理进行了探讨。  相似文献   

10.
几种抗氧化剂对核桃油抗氧化性能的研究   总被引:26,自引:1,他引:25  
用schhal烘箱法研究了几种不同的抗氧化剂及增效剂对核桃油的抗氧化性能,结果表明:特丁基对苯二酚(TBHQ)的抗氧化性能最好,抗坏血酸和柠檬酸均是TBHQ和BHT(2,6-二叔丁基对-甲酚)的良好增效剂,二者都能显著提高TBHQ和BHT的抗氧化性能,选用TBHQ和柠檬酸复合,TBHQ与抗坏血酸复合作为核油的抗氧化剂,可使核桃油在20℃下的贮藏时间从1.9个月分别延到19.9个月和25.9个月。研究结果还表明效果较好的抗氧化剂与效果较差的抗氧化剂复合时具有牵制作用。  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.
17.
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   

18.
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   

19.
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   

20.
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