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1.
辣椒红色素的提取工艺及稳定性研究 总被引:10,自引:0,他引:10
红辣椒中含有纯天然辣椒红色素,研究了辣椒红色素的几种提取方法。用有机溶剂从辣椒中提取红色素,同时对不同温度、不同时间下的色素提取率进行测试,以确定最佳提取条件;研究发现,乙酸乙酯法可以有效地去除辣椒中的辣味,使产品应用于更广泛的领域。本文还研究了辣椒红色素对pH值、光照、温度、金属离子的稳定性。 相似文献
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以钛酸丁酯为前驱物,在离子液体([Bmim]BF_4)中采用微波辐射加热法合成了TiO_2/PS-PEMA复合材料。通过测试复合材料在乙酸乙酯中的吸光度以及对甲基橙溶液的降解率,考察了离子液体用量、微波功率、反应温度和反应时间等因素对复合材料分散性和光催化活性的影响。结果表明,制备TiO_2/PS-PEMA复合材料的最佳条件为:离子液体用量2.0 mL,微波功率700 w,反应温度70℃,反应时间45 min和引发剂过硫酸钾用量0.10 g。制得的复合材料亲油性大大提高,在乙酸乙酯中有较好的分散性,对甲基橙具有较高的光催化降解活性。 相似文献
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Preparation of an Acid Butanol Standard from Fresh Apples 总被引:1,自引:0,他引:1
Chunmei Li John D. Trombley Michael A. Schmidt Ann E. Hagerman 《Journal of chemical ecology》2010,36(5):453-460
We have developed a simple method for preparing and verifying suitable standards for the acid butanol assay from a readily
available source. Phenolics were extracted from fresh apples with methanol, and sugars were removed from the crude extract
by treatment with Amberlite resin before fractionating the proanthocyanidins into ethyl acetate. The ethyl acetate fraction
was chromatographed on Toyopearl TSK HW-50F to yield about 50 mg of procyanidin dimer and 35 mg of trimer from 1 kg fresh
apple fruit. The purity and identity of the standards was easily confirmed by using ESI-MS. In the acid butanol assay, the
pure dimer, trimer and purified Sorghum procyanidin had similar color yields on a mass basis, and produced about three times more color than purified quebracho tannin.
This new standard overcomes problems associated with overestimation of tannin due to use of the unreactive quebracho tannin
standard. Use of the new standard will enable accurate comparisons of tannin levels between laboratories and will standardize
comparisons between species, thus promoting our understanding of the role of condensed tannins in plants. 相似文献
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在离子液体([Bmim]BF_4)中采用微波辐射加热法合成了TiO_2/PEMA复合材料,用XRD、SEM和IR对其进行表征。通过测试复合材料在乙酸乙酯中的吸光度及对甲基橙溶液的降解率,考察离子液体用量、微波功率、反应温度和反应时间等因素对复合材料分散性和光催化活性的影响。结果表明,制备TiO_2/PEMA复合材料的最佳条件:离子液体2.0 mL,钛酸丁酯3.4 mL,甲基丙烯酸乙酯1.0 mL,微波功率600 W,反应温度70℃,反应时间45 min。制备的复合材料亲油性大大提高,在乙酸乙酯中有较好的分散性,该复合材料不需要高温焙烧就具有较高的光催化活性,紫外光照射1.5 h,甲基橙降解率为99.4%。 相似文献
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The mass transport of ethyl acetate in syndiotactic polystyrene (sPS) has been studied. Two groups of specimens were prepared using press‐cooling and water‐quenching. The press‐cooled and water‐quenched specimens were identified as crystalline and amorphous structures, respectively, by X‐ray diffraction. The weight gain of ethyl acetate in sPS was monitored at temperatures from 50°C to 70°C. The crystallinity of a press‐cooled specimen prior to solvent sorption was greater than that after solvent sorption. However, solvent‐induced crystallization was observed in the water‐quenched specimen. The transport of ethyl acetate in both press‐cooled and water‐quenched specimens was anomalous and consisted of two stages. Each stage of the sorption curves was well fitted with Harmon's model. Both the diffusion coefficient and velocity component satisfy Arrhenius behavior. For the press‐cooled specimen, fluxes of Case I and Case II transport flow from the outer surface to the center, but for the water‐quenched specimen, the solvent is squeezed out. Pure Case II transport did not appear in the water‐quenched specimen. 相似文献
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In this study, intercalation of dimethylsulphoxide (DMSO) in a Cameroonian kaolinite is used to achieve weakening of the interlayer hydrogen bonds, in the perspective of dispersion or even exfoliation of the clay within polymer composite materials. Displacement of intercalated DMSO by ethyl acetate and ammonium acetate is studied in order to simulate the interactions with the polymer matrix. The exfoliation of the kaolinite is well evidenced by X-ray diffraction and SEM observations. The disruption of the interlayer bonds is shown by the displacement of the FT-IR vibration modes of both Al–OH and Si–O functions, and by the decrease of the dehydroxylation temperature recorded by Controlled Rate Thermal Analysis. Complete displacement of DMSO by ethyl acetate is achieved and the crystalline structure is deeply disordered as a result of interlayer bonds weakening. The displacement of DMSO by ammonium acetate leads to a ternary composite of DMSO/ammonium acetate with respective intercalation ratio of 62.4% and 57.7%. 相似文献
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以MAA(甲基丙烯酸)和PVA(聚乙烯醇)为主要原料,以BPO(过氧化苯甲酰)为引发剂,以乙酸乙酯、丙酮和废弃橙皮精油作为废EPS(聚苯乙烯泡沫塑料)的混合溶剂,制备了清香型废EPS改性胶粘剂。研究结果表明:当混合溶剂中V(乙酸乙酯)∶V(废弃橙皮精油)∶V(丙酮)=5∶3∶2时,其对废EPS的溶解力(8.20 g/10 mL)最强;采用正交试验法优选出制备废EPS改性胶粘剂的最佳工艺条件为w(EPS中MAA)=8%、w(EPS中BPO)=3%、反应温度70℃和w(胶液中PVA)=10.0%,此时改性胶粘剂胶接实木单板的剪切强度可达到0.825 MPa,并且其对织物纤维、纸张等胶接性能良好。 相似文献
11.
Tadamichi Inoue Ken Ando Kiyomi Kikugawa 《Journal of the American Oil Chemists' Society》1998,75(5):597-600
Reactivity of a commercially available test kit (LPO-586), based on N-methyl-2-phenylindole, toward aldehydes was characterized and compared with that of thiobarbituric acid (TBA). In hydrochloric
acid, LPO-586 produced a violet pigment with malonaldehyde (MA) but not with other tested aldehydes. In methane sulfonic acid,
LPO-586 produced the violet pigment with MA and 4-hydroxynonenal (HNE), but not with other tested aldehydes. Pigment formation
with MA was not inhibited by other aldehydes, but that with HNE was inhibited by alka-2,4-dienals. TBA produced a red pigment
with MA but not with other tested aldehydes in hydrochloric acid or in acetate with ethylenediaminetetraacetic acid (EDTA).
Both the LPO-586 test in hydrochloric acid and the TBA test in hydrochloric acid or in acetate with EDTA can be used for specific
measurement of MA in oxidized lipid samples. 相似文献
12.
Effect of Solvent on Nanoparticle Production of β‐Carotene by a Supercritical Antisolvent Process
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Hazuki Nerome Siti Machmudah Wahyudiono Ryuichi Fukuzato Takuma Higashiura Hideki Kanda Motonobu Goto 《化学工程与技术》2016,39(10):1771-1777
Production of micro‐ to nano‐sized particles of β‐carotene was investigated by means of solution‐enhanced dispersion by supercritical fluids (SEDS). β‐Carotene was dissolved in dichloromethane (DCM), N,N‐dimethylformamide (DMF), n‐hexane, or ethyl acetate, and supercritical CO2 served as an antisolvent. The effects of the organic solvents, operating pressure, and temperature were examined. The morphologies of the particles produced by the SEDS were observed by field emission‐scanning electron microscopy and particle sizes were determined by image analysis. Irregularly shaped microparticles were produced in the system with DCM and DMF solution. Plate‐like microparticles were generated by using n‐hexane solution and irregular nanoparticles by ethyl acetate solution. The optimum operating conditions were found to be ethyl acetate as solvent in a defined pressure and temperature range. 相似文献
13.
Thiobarbituric acid reaction of aldehydes and oxidized lipids in glacial acetic acid 总被引:1,自引:0,他引:1
Thiobarbituric acid (TBA) reaction of several aldehydes and oxidized lipids in glacial acetic acid was performed. All the
samples were freely soluble in the solvent used. Saturated aldehydes produced a stable yellow pigment with an absorption maximum
at 455 nm, a red pigment derived from malonaldehyde at 532 nm, and an orange pigment due to dienals at 495 nm. The absorbance
maximum was 7–9 per μmol for saturated aldehydes, 27.5 per μmol for malonaldehyde and about 2 per μmol for dienals. Autoxidation
of unoxidized lipids increased progressively in glacial acetic acid. When the TBA test was performed under nitrogen, autoxidation
of unoxidized lipids was inhibited completely. While saturated aldehydes produced no yellow pigment under nitrogen, oxidized
lipids produced a considerable amount of stable yellow pigment. The value for absorbance at 455 nm as a function of autoxidation
time paralleled those of peroxide values. The absorbance of most oxidized lipids at 455 nm was higher than at 532 nm. Yellow
pigment formation in the TBA test under nitrogen could not be ascribed to free saturated aldehydes but rather to unspecified
closely related substances. The stable yellow pigment was found to be an excellent indicator of lipid oxidation. 相似文献
14.
Diana De Santis Mauro Moresi Anna Maria Gallo Maurizio Petruccioli 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(9):1072-1079
Monascus purpureus C322 was cultivated on well‐established production media to yield prevailingly red or orange pigment‐rich ethanolic extracts. Once these extracts had been diluted by an overall factor of 50, they were used as such to dye raw wool standard specimens differently premordanted using alum or stannic chloride. Independently of the mordant used, the specimens dyed with the red pigment‐rich extracts showed a pale red colour tending to pink, whereas the specimens dyed with the orange pigment‐rich extracts exhibited a more definite orange colour. By carrying out a few colourfastness standard tests (manual washing at 40 °C, acid and basic perspiration and hot pressing), stannic chloride‐premordanted wool specimens dyed with the red pigment‐rich extracts were found to be less resistant to acid and basic perspiration than their orange counterparts. Since the production of the orange pigment‐rich ethanolic extracts appeared to be more cost‐effective than that of their red counterparts, the former might support the present demand for colorants of natural origin in the textile sector. Copyright © 2005 Society of Chemical Industry 相似文献
15.
David Villanueva Bermejo Pilar Luna Marina S. Manic Vesna Najdanovic-Visak Guillermo Reglero Tiziana Fornari 《Food and Bioproducts Processing》2013,91(4):303-309
This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very suitable and environmental benign solvent for food industrial applications.Static extraction assays (one step during 10 min) were carried out in an Accelerated solvent extraction (ASE) system at three different extraction temperatures, namely 100, 150 and 200 °C. Extraction yield and caffeine recovery were determined and compared with those obtained when using other liquid solvents, such as ethyl acetate or ethanol. High recovery of caffeine (≈60%) was found in the extracts produced using ethyl lactate, which demonstrates the potential use of this green solvent for the extraction of caffeine from different vegetable sources. 相似文献
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Azidodinitromethyl compounds represent a new highly energetic class of propellant ingredients. Preparation of these materials was accomplished by means of electroxidative coupling of azide ions to dinitromethyl carbanions. Thus, anodic coupling of sodium azide with ethyl 4,4-dinitrobutyrate produced ethyl 4-azido-4,4-dinitrobutyrate. Similarly, 4-azido-4,4-dinitrobutyl acetate was prepared from 4,4-dinitrobutyl acetate and converted by way of the corresponding alcohol to the nitrate ester, 4-azido-4,4-dinitrobutyl nitrate. 相似文献
19.
Guanghua Li Junho Chu Eun-Seok Song Kyung Ho Row Kyong-Hwan Lee Youn-Woo Lee 《Korean Journal of Chemical Engineering》2006,23(3):482-487
Fine particles of acetaminophen were produced by Aerosol Solvent Extraction System (ASES). The experiments were conducted
to investigate the effects of various temperatures, pressures, solvents, solution concentrations and solution feed volume
rates on particle size and morphology. The choice of solvent appears to be very important for getting specific particle shape
and size. The result shows that when ethyl acetate is used as a solvent, the irregular and acicular morphology of raw material
is recrystallized to be regular and monoclinic. The average particle size of recrystallized acetaminophen from ethyl acetate
solution has been measured to be 3–4 Μm, which was about 1/20th of raw acetaminophen in size. The particle size distribution
range also became narrow from 82 Μm to 4.9 Μm. 相似文献
20.
建立了液相色谱-串联质谱法(LC-MS/MS)测定印染废水中碱性橙2、碱性橙21、碱性橙22三种碱性染料的检测方法。采用乙酸乙酯-环己烷混合溶液(体积比1:1)萃取碱性染料,经凝胶渗透色谱净化浓缩,液相色谱-串联质谱仪测定,结果表明:3种碱性染料在5.0~100.0 ng/m L范围内,线性关系良好,相关系数(R~2)大于0.999 6;检出限在2.5~5.0mg/L之间;回收率在88.6%~98.4%之间,相对标准偏差(RSD)在1.3%~2.7%之间。该方法自动化程度高、样品前处理简单、灵敏度高、检出限低、结果准确可靠、回收率和重现性良好,可用于印染废水中三种碱性染料残留量的同时测定。 相似文献