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1.
Studies were carried out to assess the extraction yield of carotenoids from the African boxthorn (Lycium ferocissimum Miers, Solanaceae) fruits with different solvents and solvent mixtures, to optimize the extraction conditions for maximum recovery and to improve the extraction efficiency. Among other solvents, a mixture of hexane and acetone gave the highest carotenoid extraction. Extraction conditions, such as hexane percentage in hexane/acetone solvent mixture, solvent-solid ratio, and extraction time were optimized using a statistically designed experiment. A regression equation for predicting the carotenoid yield as a function of three extraction variables was derived by statistical analysis. The optimized conditions for maximum carotenoids yield were 45 % hexane in solvent mixture, solvent-solid ratio of 70 (ml/g) and extraction time 70 min. The dyeability of cotton with carotenoids extract has also been studied. Unmordant and postmordanted bleached cotton fabric with alum and ferrous sulphatewas dyed. Color measurements and fastness properties as light, rubbing and wash were tested.  相似文献   

2.
Rye and wheat brans are valuable sources of bioactive compounds, which could be used for the development and commercialization of high added value functional ingredients such as dietary antioxidants. The aim of this study was to evaluate antioxidant potential of rye and wheat bran using different polarity solvents. Cereal brans were ground to four different particle size fractions and extracted at 10.3 MPa pressure and 80 °C temperature by consecutive application of hexane, acetone and methanol:water (80:20%). The highest extract yield was obtained from rye bran using methanol-water; particle size in most cases had a significant effect. Antioxidant potential of extracts was assessed by ABTS+•, DPPH scavenging, ORAC and total phenols content (TPC) assays. Extraction solvent had a major influence on TPC and antioxidant activity of the extracts. The most active extracts were obtained using methanol:water; rye bran extracts, in general, were stronger antioxidants than wheat bran extracts. For the majority of assays, reduction of particle size resulted in higher antioxidant activity values. However, ABTS+• scavenging was found to decrease by decreasing particle size of rye bran used for extraction.  相似文献   

3.
One of the most important global problems is protecting food from insect pests. The negative effects of synthetic insecticides on human health led to a resurgence of interest in botanical insecticides due to their minimal ecological side effects. Therefore, the insecticidal potential of hexane, acetone, and methanol extracts of Gnidia kraussiana Meisn roots at 1 and 5g/kg, and neem seed oil (NSO), used as standard insecticide, were evaluated. Ovicidal and larvicidal toxicity was tested by treating freshly laid eggs and larvae at different immature stages of Callosobruchus maculatus (F.). Cowpea (Vigna unguiculata) (L.) Walp seed damage and weight loss were assessed after a storage period of 4 mo. Repellency effects were detected in choice test using a linear olfactometer. All the fractions were toxic to C. maculatus; however, their bioactivities were inversely correlated with products polarity. Extracts proved to be more toxic than the commercial NSO. The acetone extract was more effective against immature stages of C. maculatus than the methanol extract; eggs, first-, and second-instar larvae being the more susceptible. No cowpea seed damage and weight loss were recorded from the seeds treated with hexane and acetone extracts at the dosage of 5 g/kg, after 4 mo of storage. Extracts evoked stronger repellency effects compared with the tested standard insecticide. According to the above, hexane and acetone extracts are good candidates for incorporation in integrated pest management programs for the control of C. maculatus in stored cowpea seeds.  相似文献   

4.
为了给青海高原春小麦改良提供资料。分析了青海育成和国内外引进的125个春小麦品种(系)的HMW—GS等位基因变异。并测定了其中58个品种(系)在青海高原环境下的面团流变学特性。结果表明:(1)参试春小麦品种(系)的HMW—GS存在广泛的变异。Glu—A1位点出现3个等住基因,Glu—B1住点出现5个等住基因,Glu—D1位点出现4个等位基因;共出现了22种HMW—GS组合形式。其中1.7 8.2 12和N,7 8,2 12组合类型出现频率最高。并发现了个别罕见的变异类型,如2 10,10。(2)亚基组合类型对沉淀值、形成时间、稳定时间、评价值等品质性状影响较大,对籽粒蛋白质含量、出粉率和面粉吸水率的影响不显著。试验还表明,HMW—GS组成与面粉的筋力有密切关系。  相似文献   

5.
Bioactive compounds in foods have been shown to maintain human health. However, the relative amounts of bioactive compounds and the variation in the amounts are still poorly understood. In this study, the efficacy of different extraction solvents (hexane, ethyl acetate, acetone, methanol, and a methanol:water mixture), as well as the levels of certain bioactive compounds in non-pungent pepper cultivars (TMH, TMJ, PA137, and B58) were investigated using high-performance liquid chromatography (HPLC). Antioxidant activities were determined using 2,2,-diphenyl-1-picrylhydrazyl (DPPH), reducing power, and deoxyribose degradation. Hexane extracts had the highest level of carotenoids (47.2-628.8 μg/g), and methanol extracts contained maximum flavonoids (24.9-152.2 μg/g) in four different cultivars. Higher DPPH scavenging activity was found in the hexane extracts from TMH, TMJ, PA137, and B58 (IC?? value: 0.67, 0.74, 0.55, and 0.48 μg/ml, respectively), whereas the reducing power was high in ethyl acetate and acetone extracts. Inhibition of deoxyribose degradation was highest in methanolic extracts from TMH, TMJ, PA137, and B58 (51.2, 49.5, 52.6, and 47.4 %, respectively). These data demonstrate that solvent chemical properties such as polarity can differentially impact the efficiency with which different bioactive compounds are recovered from foods, and this could lead to differences in estimated biological activity such as antioxidant capacity.  相似文献   

6.
Various two-step extraction procedures with and without application of ultrasound in the first extraction step were used to isolate the xylan component of corn cobs in polymeric form. The obtained immunogenic water-soluble (ws-X) and the biologically inactive water-insoluble (wis-X) xylan fractions were characterised by yield, composition, structural and molecular properties. The yield of ws-X was strongly affected by the alkali concentration and extraction temperature, particularly in the ultrasound-assisted procedures. The results indicate a higher efficiency of the ultrasonic extraction procedures expressed in the shortening of extraction time, and lowering of the alkali concentration and extraction temperature. In contrast to the molecular properties, there were no significant differences between the sugar composition and main structural features of the ws-X fractions obtained by extraction in 5% NaOH with and without application of ultrasound. At similar levels of yield, the biological activity of the ultrasonically extracted ws-X preparations was higher.  相似文献   

7.
酚抽法已经逐渐成为植物蛋白质组研究中通用的蛋白质提取方法,但在各种改进酚抽法中,应用到的沉淀试剂各不相同,致使蛋白沉淀得率、纯度和沉淀时间也各异,本研究以热带植物橡胶树叶片、胶乳和海马齿叶片为研究材料,在过饱和硫酸铵甲醇溶液、醋酸氨甲醇溶液和丙酮溶液沉淀剂下对比蛋白提取的效果,通过单向电泳检测、胶图质量分析、质谱鉴定、蛋白沉淀时间和得率比较,发现3种沉淀剂提取的蛋白样品1-DE图谱显示的蛋白条带数量均较多,但醋酸铵沉淀法提取蛋白图谱有条纹不清晰现象。得出结论:丙酮沉淀法对橡胶树叶片和胶乳蛋白质的提取率较高,硫酸铵沉淀法对海马齿叶片蛋白质提取率较高。过饱和硫酸铵甲醇溶液和丙酮沉淀剂提取的蛋白质质量较高,所得蛋白图谱背景清晰,质谱鉴定蛋白质信息量大。研究结果可优化提取高质量植物蛋白质的方法,并有望为顽拗类植物蛋白质组学研究提供参考。  相似文献   

8.
The total plant sterol, steryl ferulate and steryl glycoside contents in wheat and rye milling fractions show that there are significant differences in both sterol content and composition between various milling fractions collected from a commercial mill. Total sterols were analysed by gas chromatography after acid and alkaline hydrolyses. The steryl conjugates were first extracted with acetone, fractionated on solid phase extraction (SPE) cartridges and then analysed individually (steryl glycosides by gas chromatography and steryl ferulates by reverse phase-high performance liquid chromatography with UV detection. Differences in sterol contents of the wheat samples were greater than in the rye samples. The highest total sterol content was found in wheat germ, but surprisingly high sterol contents, that were comparable to bran, were found in some flour fractions. Contents of steryl ferulates were high in the bran fractions contributing up to 17% of total sterols. The variation in the content of steryl glycosides in the samples was lower and contributed less than 10% of total sterols. These results show that much of the bioactive components may be lost when certain flour fractions produced in common flour milling procedures are discarded. However, some of these fractions with significantly high sterol contents could possibly be introduced into milling products used in breadmaking and the food industry without greatly compromising consumer acceptability.  相似文献   

9.
In previous aqueous enzymatic oil extraction (AEOE) experiments we reported a best free oil yield of 49% of the hexane extracted yield of dry fractionated corn germ. In the current experiments, a dispersion of 10% cooked, dry-fractionated germ in water was treated with α-amylase, glucoamylase and a cellulase complex. Free oil was collected by centrifuging a foam fraction of the dispersion. Several dispersion treatments were tried to evaluate their release of free oil and effect on the production of foam. The foam contained up to 8% free oil (dispersed from germ containing 26% oil) and fines oil (not centrifugally separable), protein and germ particles. Treatment with α-amylase and glucoamylase prior to treatment with the commercial cellulase used in previous AEOE studies increased the free oil yields about 25-61% of the hexane-extractable yield. A preliminary cost analysis indicates that oil separation with the amylase enhanced AEOE appears to be preferable to AEOE alone and profitable if crude corn oil cost exceeds $1.1/kg ($0.50/lb).  相似文献   

10.
Zein was recovered from corn distiller's dried grains with solubles (DDGS) by a modified method using 70% (w/w) aqueous 2-propanol (70-IPA) or 70% (v/v) aqueous ethanol (70-EtOH) solvents, and a commercial method using 88% (w/w) aqueous 2-propanol (88-IPA). Yield, purity, and film properties of the isolated zein were determined. The modified procedure extracted two fractions of zeins: a mostly α-zein fraction, and a mostly γ-zein fraction. The modified method increased α-zein yield from 4% to 14%. Enzyme cellulase pretreatment did not improve zein yield, but grinding did. The α-zein fraction showed electrophoretic bands at 40, 22, 19, and 10 kDa, corresponding to α-zein dimer, α1-zein, α2-zein, and δ-zein, respectively. The α-zein of DDGS retained its film forming capability. The α-zein film of unmodified DDGS was cloudy and rough, unlike the clear and smooth films of α-zeins isolated from corn gluten meal and enzyme-treated DDGS.  相似文献   

11.
The reduction of particle size can facilitate the extraction of phytochemical compounds. In this study was evaluated the effect of rice bran particles size in the yield and characteristics of γ-oryzanol compound. The γ-oryzanol extraction was realized with hexane and isopropanol solvents and quantification by spectrophotometric method. The γ-oryzanol extracts were characterized in relation of theirs majority components in HPLC-UV and the antioxidant capacity verified by the free radical DPPH consumption. The γ-oryzanol yield varied of 0.10–1.54 mg/g of bran, and the highest yield was obtained in particles smaller than 0.39 mm. The γ-oryzanol majority components presence (cycloartenyl ferulate, 2,4-methylenecycloartanyl ferulate, campesteryl ferulate e β-sitosteryl ferulate) in the extracts was confirmed and verified differences in the profile of this components in function of different particles sizes. The γ-oryzanol extract obtained from particle sizes between 0.73 and 1.67 mm demonstrated most specific inhibition of DPPH radical (6.7%) and IC50 6.63 μg/mL. When the particle size is reduced, the access surface to the extraction solvent is increased resulting in more γ-oryzanol extraction, however the extract from larger particles was more efficient as antioxidant.  相似文献   

12.
高纯度大豆黄苷及大豆黄素的制备   总被引:10,自引:1,他引:9  
使用不同的溶剂从大豆异黄酮粗品中提取大豆黄苷.通过溶剂回流萃取及不同溶剂组合萃取实验确定了最佳的提取条件.结果表明,丙酮和乙酸乙酯的组合萃取可以将原料中大豆黄苷的含量提高2.5倍以上.最终可以得到纯度为90%的大豆黄苷产品,收率40%.产品再通过盐酸水解可以得到其相应甙元.  相似文献   

13.
采用丙酮萃取法从新鲜水化大豆油脚中提取粉末大豆磷脂。提取时第一次油脚:丙酮=3∶1,第2—6次原料:丙酮=1∶1。第1—3次离心后的提取液用于油和丙酮的回收,第4—6次离心后的提取液贮存,用来代替下一次生产1—3次的纯丙酮.从油脚提取的磷脂颜色(淡黄色)好于从浓缩磷脂中提取的(淡棕色),前者酸值,过氧化值较后者低.  相似文献   

14.
脱脂椰子种皮提取物抗氧化活性研究   总被引:1,自引:0,他引:1  
以脱脂椰子种皮为试验材料,分别用异丙醇、正己烷和乙醚提取其中的酚类化合物,采用Folin-Ciocalteu比色法测定3种提取物的总酚含量,并对3种提取物的总抗氧化活性及对猪油的氧化稳定性进行评价.结果表明,正己烷提取物的总酚含量最高,其次是异丙醇提取物,乙醚提取物最低;异丙醇提取物的抗氧化能力最高,正己烷提取物和乙醚提取物次之.3种溶剂提取物对猪油的氧化均有一定的抑制作用,其中异丙醇提取物对猪油的氧化抑制效果最明显.  相似文献   

15.
We report for the first time the antioxidant and antimutagenic activities of fractions from Randia echinocarpa fruit, which is a Rubiaceae plant native to Sinaloa, Mexico. This fruit has been traditionally used in the prevention or treatment of cancer, among other diseases. The pulp of the fruit was sequentially extracted with solvents of different polarity (i.e. hexane, chloroform, methanol and water). A high extraction yield was obtained with methanol (72.17% d.w.). The aqueous extract showed the highest content of phenolics (2.27 mg/g as ferulic acid equivalents) and the highest antioxidant activity based on the β-carotene bleaching method (486.15). The commercial antioxidant BHT was used as control (835.05). Antimutagenic activity of the aqueous extract (0–500 μg/tube) was evaluated using the Salmonella microsuspension assay (YG1024 strain) and 1-NP as the mutagen (50 and 100 ng/tube). The aqueous extract was neither toxic nor mutagenic and the percentage of inhibition on 1-NP mutagenicity was 32 and 53% at doses of 50 and 100 ng/tube, respectively. The results of the double incubation assay suggest that the extract inhibited the mutagenicity of 1-NP by a combination of desmutagenic and bioantimutagenic effects.  相似文献   

16.
为建立固相萃取-气相色谱法测定香蕉中多种残留有机磷农药敌敌畏、乐果、毒死蜱、辛硫磷、丙溴磷的方法,采用氮磷检测器(NPD)气相色谱法对经无水丙酮提取、Na2SO4脱水、固相萃取净化、氮吹仪浓缩后,用丙酮定容的样品进行测定。结果显示,敌敌畏、乐果、毒死蜱、辛硫磷、丙溴磷的最低检出浓度分别为0.010、0.008、0.012、0.002、0.008 mg/kg,加标回收率在78.82%~101.5%,相对标准偏差为3.7%~6.2%。表明该方法线性良好,回收率、精密度好,灵敏度高,符合检测要求,可用于香蕉中多种残留有机磷农药的测定。  相似文献   

17.
几种不同提取方法对小麦叶片总蛋白双向电泳的影响   总被引:1,自引:0,他引:1  
为探索小麦叶片蛋白质提取的最优方法,以普通小麦品种石4185的叶片为材料,研究了三氯乙酸/丙酮法、裂解液法、尿素/硫脲法、KCl-醋酸铵甲醇法等四种不同蛋白质提取方法对小麦叶片蛋白双向电泳图谱的影响.结果表明,三氯乙酸/丙酮法获得的蛋白点形状规则、清晰,且重复性好;裂解液法拖尾现象较轻,但蛋白点数少且欠清晰,重复性也不如前者;尿素/硫脲法的蛋白点数很少,也较为弥散,且有明显的拖尾现象;KCl-醋酸铵甲醇法使大量蛋白丢失,蛋白点数非常少,且上部竖纹干扰较重.因此,三氯乙酸/丙酮法是提取小麦叶片蛋白的较优方法.  相似文献   

18.
The bioactive materials in brown seaweeds hold great interest for developing new drugs and healthy foods. The oil content in brown seaweeds (Saccharina japonica and Sargassum horneri) was extracted by using environmentally friendly supercritical CO2 (SC-CO2) with ethanol as a co-solvent in a semi-batch flow extraction process and compared the results with a conventional extraction process using hexane, ethanol, and acetone mixed with methanol (1:1, v/v). The SC-CO2 method was used at a temperature of 45 °C and pressure of 250 bar. The flow rate of CO2 (27 g/min) was constant for the entire extraction period of 2 h. The obtained oil from the brown seaweeds was analyzed to determine their valuable compounds such as fatty acids, phenolic compounds, fucoxanthin and biological properties including antioxidant, antimicrobial, and antihypertension effects. The amounts of fucoxanthin extracted from the SC-CO2 oils of S. japonica and S. horneri were 0.41 ± 0.05 and 0.77 ± 0.07 mg/g, respectively. High antihypertensive activity was detected when using mixed acetone and methanol, whereas the phenolic content and antioxidant property were higher in the oil extracted by SC-CO2. The acetone–methanol mix extracts exhibited better antimicrobial activities than those obtained by other means. Thus, the SC-CO2 extraction process appears to be a good method for obtaining valuable compounds from both brown seaweeds, and showed stronger biological activity than that obtained by the conventional extraction process.  相似文献   

19.
以黑胡椒为主要原料,研究热回流提取、索氏抽提、超声波提取、微波提取、超声波-微波辅助提取等不同提取方法对胡椒油树脂得率的影响,并用HPLC分析测定胡椒粉和不同提取方法所得胡椒油树脂中的胡椒碱含量。结果表明,不同提取方法所得胡椒油树脂及其胡椒碱含量有显著性差异;索氏抽提法所得胡椒油树脂的得率最低,超声波-微波协同萃取的得率最高,可达17.23%;胡椒油树脂中的胡椒碱含量最高为42.20%;在相同提取条件下,温度对黑胡椒油树脂得率及其胡椒碱含量影响较大。  相似文献   

20.
The objective of this work was to study the effect of the extraction of phenols by methanol/acetone/water and proteolysis (pepsin 1 hour; trypsin 2 hours) on the nutritional characteristics of unheated rapeseed protein as measured by weight gain, protein intake, net protein ratio, apparent digestibility and absorbed protein. The effect of proteolysis of the methanol/acetone/water extracted rapeseed protein, and the effect of mixing the methanol/acetone/water extract back with the extracted rapeseed protein was also studied. Extraction of phenolic compounds from rapeseed flour significantly improved weight gain, protein intake, net protein ratio and absorbed protein value. However, the mixing of phenolic extract with the extracted rapeseed protein did not appear to have a significant effect.Enzymatic hydrolysis (1 hour with pepsin and 2 hours with trypsin) of the raw material significantly improved the weight gain and protein intake. The combined methanol/acetone/water extraction and protein hydrolysis treatments were beneficial on all nutritional quality parameters of rapeseed protein. These results suggest that the protein-bound phenolic compounds, rather than the free phenolic compounds contribute mainly to the decrease in the nutritional values of proteins associated with phenolic compounds in raw flour before extraction.  相似文献   

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