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1.
Seed oils of S. emarginatus Vahl, Z. jujuba, A. excelsa and Delomix regia have been analysed. All the four oils are of semi drying nature and have a higher percentage of unsaturation. S. emarginatus and Z. jujuba are very similar in the composition of the unsaturated acids (67.0% and 65.6%). Oleic content is 56.5% and 53.0% respectively. The iodine value of S. emarginatus (93) is higher than the reported value of a closely related species S. trifoliatus (60.4). The composition of A. excelsa and D. regia are very much similar. A. exelsa has a high oleic acid content (65%) whereas higher fatty acids have not been found. In D. regia the peak for stearic acid is not present in our gas-liquid chromatogram.  相似文献   

2.
Glycerolysis of palm and palm kernel oils were carried out using commercial lipases from Candida antarctica (Novozym 435) and Mucor miehei (Novozym 388) as catalyst (500 units lipase/g oil) at 40°C and with an oil:glycerol molar ratio of 1:2 in a solvent-free system. Novozym 435 catalyzed the glycerolysis of palm and palm kernel oils giving reaction products in similar compositions. Partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils were 64% (wt) and 66% (wt), respectively. However, partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils conducted with Novozym 388 as catalyst at the same conditions were 44% (wt) and 56% (wt), respectively. On the other hand, free fatty acid contents of the glycerolysis products of palm and palm kernel oils obtained using Novozym 388 were higher, 25–30% (wt), than those obtained by Novozym 435, 4–5% (wt). The monoacylglycerols fraction with the highest content of oleic acid, 62.7% (wt), was obtained from the palm kernel oil glycerolysis reaction catalyzed by Novozym 435.  相似文献   

3.
Glycerolysis of palm and palm kernel oils were carried out using commercial lipases from Candida antarctica (Novozym 435) and Mucor miehei (Novozym 388) as catalyst (500 units lipase/g oil) at 40°C and with an oil:glycerol molar ratio of 1:2 in a solvent-free system. Novozym 435 catalyzed the glycerolysis of palm and palm kernel oils giving reaction products in similar compositions. Partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils were 64% (wt) and 66% (wt), respectively. However, partial acylglycerols contents of the glycerolysis products obtained from palm and palm kernel oils conducted with Novozym 388 as catalyst at the same conditions were 44% (wt) and 56% (wt), respectively. On the other hand, free fatty acid contents of the glycerolysis products of palm and palm kernel oils obtained using Novozym 388 were higher, 25-30% (wt), than those obtained by Novozym 435, 4-5% (wt). The monoacylglycerols fraction with the highest content of oleic acid, 62.7% (wt), was obtained from the palm kernel oil glycerolysis reaction catalyzed by Novozym 435.  相似文献   

4.
Differential scanning calorimetry and pulsed nuclear magnetic resonance were used in the estimation of crystallization kinetics of palm oil and modified palm oils. Differential scanning calorimetry was found to be more sensitive and could differentiate between crystallization during cooling and crystallization during isothermal conditions. Hydrogenated palm oils crystallized quickly and completely when cooled from 60° to 20°C, while palm oil and fractionated palm stearin continued to crystallize when held isothermally at 20°C.  相似文献   

5.
用顶空吸着萃取HSSE(Head Space Sorptive Extraction)-GC-MS联用技术分析亚泰果冻棕的香气成分,检测出139种成分,鉴定出占总成分95.231%的79种成分,分别由酯(85.716%)、醇(3.900%)、烃(1.614%)、酸(1.350%)、醛(1.009%)、酮(0.593%)等化合物组成。主要成分为己酸乙酯,占总成分的58.062%。  相似文献   

6.
Several epidemiological studies have demonstrated that high vitamin E intakes are related to a reduced risk of non-communicable diseases, while other dietary antioxidants are not, suggesting that vitamin E exerts specific healthy functions in addition to its antioxidant role. In this regard, tomato (Solanum lycopersicum), one of the most consumed vegetables of the whole world population, is an important source of both tocopherols and tocotrienols. However, vitamin E content may strongly depend on several biotic and abiotic factors. In this review we will debate the elements affecting the synthesis of tocopherols and tocotrienols in tomato fruit, such as environmental conditions, genotype, fruit maturity level, and the impact of classical processing methods, such as pasteurization and lyophilization on the amount of these compounds. In addition we will analyze the specific vitamin E mechanisms of action in humans and the consequent functional effects derived from its dietary intake. Finally, we will examine the currently available molecular techniques used to increase the content of vitamin E in tomato fruit, starting from the identification of genetic determinants and quantitative trait loci that control the accumulation of these metabolites.  相似文献   

7.
The steryl ester fraction of coconut and palm kernel oils has been separated and analysed by gas chromatography (GC) and high performance liquid chromatography (HPLC). The gas chromatograms of the steryl ester fractions of the oils are rather similar, but the liquid chromatograms show important differences which may represent a basis for distinguishing between the two oils.  相似文献   

8.
目的:从新鲜蔬果中提取酪氨酸酶,对得到的酪氨酸酶提取液分别进行动力学研究,计算酶的活性。方法:从苹果、马铃薯、紫茄子、雪梨中提取酪氨酸酶,以邻苯二酚溶液为底物,测定不同浓度的酪氨酸酶活性,建立动力学方程。结果:在最大吸收波长λmax为409 nm处,不同蔬果中,苹果、马铃薯、紫茄子及雪梨的酪氨酸酶活性分别为194.62 U/g、135.39 U/g、156.81 U/g及239.12 U/g。结论:以邻苯二酚为底物,以pH=6.8磷酸盐缓冲溶液测定酪氨酸酶的活性,效果好。  相似文献   

9.
随着人类社会不断的发展,社会对能源的需求也逐渐增加,而常规能源无法满足快速增长的经济的需求,所以近年来石油界对高酸值原油等非常规能源投入很高的兴趣。原油酸值是表示原油中酸性物质总含量的参数,即中和1g原油所需要的KOH的数量。对世界大量原油酸值进行了调研,并根据酸值的大小将原油划分为正常原油、含酸原油、高酸值原油和特高酸值原油。其中将酸值高于1 mg/g的原油称为高酸值原油,其化合物组成复杂。根据高酸值原油的成因,进一步划分出原生高酸值原油和次生生物降解型高酸值原油。  相似文献   

10.
Since the nutritional value of farm‐raised fish fillets is directly related to the diet provided, we supplemented the diet of Tilapia (Oreochromis niloticus) with a blend of chia (Salvia hispanica L.) oil, tung (Aleurites fordii) oil, and conjugated linoleic acid (CLA) to evaluate the effects on the fatty acid composition. Vitamin E was also added to the diet to improve the antioxidant capacity of tilapia fillets. We observed an increase in α‐linolenic acid content (from 6.56 to 19.03 mg g?1 of total lipids), as well as the incorporation of CLA and conjugated linolenic acid (CLnA) isomers in the fillets. The addition of vitamin E resulted in the antioxidant capacity improvement of the fillets and higher values were found after 15 feeding days (39.25 µmol TE g?1 in the Ferric Reducing Ability Power assay). Supplementation proved to be an excellent tool to improve the nutritional value of fish fillets.  相似文献   

11.
The supercritical CO2 fluid extraction process was used to obtain seed oils. The compositional analyses of the seed oils of Amorpha fruticosa L., Caragana microphylla Lam and Elaeagnus angustifolia L. were performed by GC–MS, from which 18–22 fatty acid compositions were identified, and their main components were linoleic acid (49.10–66.39 %) and oleic acid (11.95–41.10 %). The seed oils were rich in unsaturated fatty acids, which accounted for 79.75–91.19 %. The in vitro anti‐oxidant activities of the seed oils were measured by the DPPH, ABTS and phosphomolybdenum complex assays. The IC50s of the seed oils were 6.5110–12.6599 mg/mL tested by DPPH assay, and the IC50s were in the range of 0.6872–1.9310 mg/mL tested by ABTS assay. The anti‐oxidant activities of seed oils decreased in the order of A. fruticosa > C. microphylla > E. angustifolia (A) > E. angustifolia (D). In vitro antimicrobial activities of seed oils against five bacteria were tested by microdilution method. The MIC values of the oils against Bacillus subtilis, E. coli, S. aureus, P. solanacearum and B. thuringiensis were in the range of 26–36, 30–38, 58, 56–58 and 56–58 mg/mL, respectively, while the MBC values were in the range of 30–40, 34–42, 58, 56–58 and 58 mg/mL, respectively. In vitro antifungal properties of the seed oils against four plant pathogenic fungi were tested by the mycelial growth rate method. The EC50s of seed oils against V. mali, C. gloeosporioides, F. graminearum and B. cinerea were in the range of 17.51–19.25, 15.58–19.12, 8.00–17.12 and 18.76–19.14 mg/mL, respectively. The seed oils showed moderate anti‐oxidant and antimicrobial activities.  相似文献   

12.
Production of High Oleic Palm Oils on a Pilot Scale   总被引:1,自引:0,他引:1  
Refined, bleached and deodorized palm olein (RBD POo) with an iodine value (IV) of 62 was chemically interesterified with methyl oleate (MO) at a ratio of 50:50 (w/w). The reaction was carried out at 110 °C in the presence of sodium methoxide as a catalyst using a 100-kg pilot scale reactor. Randomization between 15 and 30 min resulted in less free fatty acid (FFA) formation and higher oleic content in the interesterified product as compared to longer reaction time of 60–90 min. Sodium methoxide-catalyzed ester interchange increased the oleic content of the interesterified product to more than 57% from its initial content of 45%. The product obtained also has an IV of more than 75. The interesterified oil was then subjected to dry fractionation in a 200-kg De Smet jacketed crystallizer at 8 °C to further enhance the oleic content of the liquid olein fraction. The resulted olein had an improved cloud point and higher IV of 81. The solid stearin had a slightly higher IV and oleic content as compared to normal palm stearin. The solid fat content was comparable to normal palm oil. The pilot scale study has proven a successful conversion of laboratory findings to a larger scale production and gave the most realistic information for possible commercialization.  相似文献   

13.
14.
赤桉和本泌桉叶精油的化学成分研究   总被引:4,自引:0,他引:4  
用水蒸气蒸馏法提取了赤桉叶和本泌桉叶精油,通过气相色谱-质谱(GC-MS)联用法分析鉴定了二者的化学成分及质量分数。赤桉叶精油共鉴定出57种化合物,占总离子流出峰面积的94.81%,主要成分为w(1,8-桉叶油素)=50.17%,其后依次是w(α-蒎烯)=8.53%、w(蓝桉醇)=5.65%、w(乙酸松油酯)=3.69%、w(α-松油醇)=3.58%;本泌桉叶精油共鉴定出45种化合物,占总离子流出峰面积的90.93%,主要成分为w(α-蒎烯)=31.00%、w(蓝桉醇)=15.34%、w(香树烯)=13.80%和w(表蓝桉醇)=4.86%。  相似文献   

15.
The physicochemical properties and chemical composition of oils extracted from two varieties of mature seeds of Allanblackia gabonensis and A. stanerana were assessed. The physicochemical properties of oils from Allanblackia gabonensis and A. stanerana were respectively 5.35 and 22.023 % for the water content; 68.15 and 69.87 % for the extraction yield on a dry basis; 0.35 and 0.30 mg KOH/g oil for the acid index; 35.57 and 29.75 g of I2/100 g oil for the iodine index; 1.3740 and 1.4150 for the refractive index. The fatty acid profile of those oils showed respectively four saturated fatty acids 60.61 and 70.94 %, two monounsaturated fatty acids 37.46 and 28.22 %, two polyunsaturated fatty acids 0.82 and 0.81 % for Allanblackia gabonensis and A. stanerana oils respectively. In both cases, fatty acids C18:0 and C18:1 were dominant. Most of the physicochemical properties showed significant variation (P < 0.05) from one oil to other, the difference being insignificant (P > 0.05) between the two chemical compositions. The analysis of these characteristics showed interesting application features for these oils.  相似文献   

16.
迷迭香叶油与花油成分的分析与比较   总被引:1,自引:0,他引:1  
分别提取迷迭香叶与迷迭香花的精油,并用气相色谱和质谱联用技术分析其组成及含量,共识别出30个成分,鉴定出20个。含量测定结果表明花油中α-蒎烯、莰烯、β-蒎烯、α-水芹烯和β-月桂烯等低沸点成分含量分别为 17.58 %、13.19%、1.13%、2.03%、1.02%,比叶油低;而樟脑、龙脑和乙酸龙脑酯等高沸点成分的含量分别为 11.97 %、8.48%、4.29%,比叶油高。  相似文献   

17.
Standard methods for the determination of iodine values of oils involve direct addition of halogen elements to the double bond. Since the reaction proceeds slowly there is a risk of substitution. A direct coulometrical titration method has been investigated.  相似文献   

18.
谷雪贤 《广东化工》2010,37(7):98-98,106
蔬菜、水果中维生素C的测定方法有很多,如间接原子吸收分光光度法、分光光度法、高效液相色谱法等,各种方法各有特点。文章对近年来有关维生素C的测定方法进行了综述。  相似文献   

19.
Abstract

In this study antifungal activities of essential oils from wood and leaf and their constituents of Cunninghamia konishii against four wood decay fungi and six plant pathogenic fungi were investigated. GC and GC-MS analyses show that the major compounds of wood essential oil were cedrol and α-pinene, while those of leaf essential oil were α-pinene and p-cymene. Antifungal tests demonstrated the wood oil from C. konishii used against Trametes versicolor, Lenzites betulina, Laetiporus sulphureus, and Gloeophyllum trabeum and leaf oil from C. konishii used against L. sulphureus had strong antifungal activities. Moreover, wood oil used against Rhizoctonia solani, Fusarium solani, Pestalotiopsis funereal, and Ganoderma australe also had strong antifungal activities. Among the seven constituents of wood oil, cedrol displayed the best antifungal properties, indicating that it may be used as potential antifungal agents for the control of fungal diseases in plants.  相似文献   

20.
分析了美国汽、柴油价格的形成机制和价格水平、构成。介绍了美国对成品油的税收政策和对成品油价格的监管措施。  相似文献   

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