共查询到20条相似文献,搜索用时 171 毫秒
1.
2.
3.
目的:为了提高薄荷醇的稳定性和水溶性.以β-环糊精为包合壁材,制备薄荷醇β-环糊精包合物。方法:采角饱和水溶液法翩备薄荷醇β-环糊精包合物.通过正交试验,确定最佳工艺条件,并用紫外分光光度法分别测定了包合物薄荷醇量,并计算了薄荷醇的包合率。结果:以包合率为指标,确定最佳工艺条件为:表明薄荷醇与β-环糊精的摩尔比为1:1o.反应温度5O℃.反应时间2小时.在此条件下.表面薄荷醇量最低且包合率最大。结论:包合物 相似文献
4.
5.
6.
茶树油β-环糊精包合物的制备工艺研究 总被引:1,自引:0,他引:1
采用L9(34)正交试验,以包合物产率和包合率为筛选指标,以茶树油与β-环糊精的配比、包合时间、包合温度和无水乙醇与茶树油的体积比为考察因素,采用正交试验对茶树油β-环糊精包合物的制备工艺进行优选出最佳工艺条件是茶树油:β-环糊精为1∶8(mL∶g),包合时间为4 h,包合温度为50℃,无水乙醇:茶树油为1∶1(mL∶mL)。经紫外分光光度法和薄层色谱法鉴定,确实形成了茶树油环糊精包合物。 相似文献
7.
8.
9.
10.
11.
12.
研究芝麻油的挥发性风味成分.采用顶空固相微萃取(HS-SPME)和气质联用(GC-MS)技术,对水代法白芝麻油、水代法黑芝麻油、压榨法白芝麻油和压榨法黑芝麻油4类共18个市售芝麻油中的挥发性风味成分进行检测,比较不同芝麻品种和不同制油工艺对风味成分中含量较高的20种物质及其相对含量的影响.结果表明:压榨法芝麻油中冰醋酸和己醛含量高于水代法芝麻油,而5-甲基-2-呋喃甲醛、2-甲氧基-苯酚和1-(5-甲基-2-吡嗪基)-1-乙酮含量低于水代法芝麻油.压榨法白芝麻油中的甲基吡嗪,水代法黑芝麻油中的2,6-二甲基-4-吡啶胺都比其他类别的芝麻油高,而压榨法黑芝麻油中的2,5-二甲基吡嗪含量比其他3类芝麻油低.余下的12种挥发性风味成分在4类芝麻油中含量没有明显差别. 相似文献
13.
Three methods for the isolation of volatile compounds from oils and fats were compared using small concentrations (approximately 1 ppm) of added C3-12 n-alkan-2-ones and C2-10 n-alkan-1-ols in commercial butter oil. These were : high vacuum degassing, cold-finger molecular distillation and reduced pressure steam distillation. Several modifications were incorporated. The highest yields of all compounds were obtained by cold-finger molecular distillation but difficulties were encountered in subsequent analysis. It was more convenient to recover compounds boiling below 150C by either high vacuum degassing or reduced pressure steam distillation. The latter was more efficient for the higher boiling compounds. Extraction with organic solvents was not required in any of these techniques. The combination of high vacuum degassing and cold-finger molecular distillation was found to be the best method of analyzing the complete range of model compounds. 相似文献
14.
15.
16.
J. S. Pai S. S. Lomanno W. W. Nawar 《Journal of the American Oil Chemists' Society》1979,56(4):494-497
Fresh coconut oil was heated under different conditions for 48 hr at 180 C. The heat treatments included heating in vacuo,
heating in air and heating in air and water. The samples were distilled under high vacuum and the volatiles thus obtained
were analyzed by combined gas chromatography-mass spectrometry. In all heated samples, a series of n-alkanes and I-alkenes,
n-alkanals, methyl alkanones, alkenals, gamma-and delta-lactones, methyl and ethyl esters and free fatty acids were identified.
The relative amounts of these compounds varied with the type of heat treatment to which the coconut oil was subjected. 相似文献
17.
A simple and sensitive method for the quantitative determination of volatile isothiocyanates in canola oil has been developed. The method is based on the specific absorbance of isothiocyanates in the infrared region. The results obtained were confirmed by gas liquid chromatography using a flame photometric detector. The various volatile isothiocyanates isolated from the oil were allyl isothiocyanate, 3-butenyl isothiocyanate, 4-pentenyl isothiocyanate and 2-phenethyl isothiocyanate. Their identities were confirmed by mass spectroscopy and by retention times. The recoveries of sulfur from volatile sulfur compounds by this method ranged from 93.6% to 101.1% when compared to the amount determined by gas liquid chromatography. The coefficients of variability of volatile sulfur compounds in canola oils ranged from 1.7% to 3.2%. The sulfur content represented by the volatile sulfur compounds comprised 21.7% of the sulfur determined by the Raney nickel method for crude oil, 36.6% for refined oil and 22.7% for refined, bleached and deodorized oil. 相似文献
18.
19.
对桦甸油页岩(OS-R)采用HCl/HF/HNO3处理,分别得到去碳酸盐样品(OS-C)、去碳酸盐及硅酸盐样品(OS-F)以及有机质样品(OS-N),用XRD鉴别其矿物组成,然后通过TG-FTIR-MS研究有机质脱挥发分机理及不同矿物质对挥发分不凝气释放过程的影响。结果表明:黄铁矿的存在使挥发分不凝气体释放的初始温度明显降低,反应更易进行,且使生成的不凝气产量更高,尤其是对不凝气中H2O生成促进作用更显著;硅铝酸盐的存在使不凝气体产量明显减少,提高了不凝气释放的初始温度,减少了不凝气释放的过程时间。然而碳酸盐的存在能增加不凝气产量,使CO2脱出的初始温度更低。 相似文献
20.
主要研究了甲醛、乙醛和苯在有机硅烷KH560和1706改性活性炭(AC)表面的脱附活化能,并通过透过曲线实验测定了不同湿度对三者在改性活性炭上吸附的影响,最后用光电子能谱(XPS)分析材料表面的亲水基团和憎水基团比例的变化。结果表明,采用有机硅烷改性活性炭可提高材料的憎水性,在较高湿度下(RH60%),三者在未改性活性炭固定床穿透时间减少得最多,1706/AC固定床次之,KH560/AC固定床最小;程序升温脱附(TPD)实验表明,用有机硅烷改性活性炭可以削弱水和活性炭表面的结合力,增强与甲醛、乙醛和苯的结合力。通过XPS分析,与未改性活性炭相比,经有机硅烷改性的活性炭,其憎水性得到提高。 相似文献