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1.
Pumpkin seed oils from naked and husk pumpkin seeds, produced by an industrial process and by laboratory extraction, were evaluated for fatty acid composition, tocopherol, sterol and squalene content. The major fatty acids in the oils from both varieties were oleic, linoleic and palmitic acid, followed by stearic acid. The ratios of monounsaturated to polyunsaturated fatty acids for husk and naked seed oils were about 0.60 and 0.75, respectively. Analysis of tocopherols in industrially pressed and laboratory‐extracted oils showed that husk seed oils had higher amounts of total tocopherols than naked seed oils. Oils extracted in the laboratory had higher amounts of tocopherols than industrial oils. Pumpkin seed oil, in general, had a high level of squalene, which was higher in husk seed oils than in naked seed oils and in extracted than in pressed oils. The total amount of sterols was higher in husk than in naked seed oils and in extracted oil samples. The main sterols were Δ7‐sterols and their content was similar in all samples, but the content of Δ5‐sterols was higher in oil samples of husk pumpkin seed and in extracted than in pressed oils.  相似文献   

2.
The effect of gas turbine lubricant oil soaking, thermal cycling and their combination on morphology and tension and flexure properties of pultruded composite was studied. Two types of lubricant oils were used: Mil‐L‐7808 and Mil‐L‐23699. Composite samples were oil soaked for 720 h and microscopic analysis and mechanical tests were conducted. Samples were thermal cycled for 600 cycles (RT to 315°C) and measured tension and flexure properties. Samples were oil soaked, thermal cycled and then tested. Results of these three groups of environmentally aged samples were compared with non‐aged samples. The significance of aging effect is discussed in the article. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

3.
In this study, roasted and unroasted (control) tomato seeds were cold pressed and the seeds, oils, and seed presscakes (meals) were analyzed. Some physicochemical properties, total phenolic content and antioxidant capacity, thermal properties, mineral contents, fatty acids, sterols and tocopherols compositions, volatile compounds and sensory evaluation of the tomato seed oils were determined. The tomato seeds contained 3.3 % of ash, 17.3 % of oil and 27.2 % of protein. The cold press oil recovery rate was 7.2 and 10.28 % for control and roasted seeds, respectively. There were eight sensory terms defining the oils together with 34 different aromatic compounds quantified. The volatile compounds furfural, hexanal, benzaldehyde and 2‐isobutylthiazole were found with the highest frequency in the samples. Roasted, green and tomato were defined as characteristic sensory terms for tomato seeds oils. Fifteen different minerals, melting and crystallization temperatures and enthalpies of the oil samples were also quantified. This study provides important data for the tomato seed oils, and proves that pre‐roasted tomato seed oils are high quality, nutritious and aromatics oils with higher levels of consumer acceptability.  相似文献   

4.
The aim of this study was to investigate the effects of different essential oils (from Thymus haussknechtii Velen and Origanum acutidens Hand.‐Mazz. Letswaart; endemic species in Turkey) on butter stability. These essential oils were added to butter at two concentrations (0.1 and 0.2 wt‐%). The antioxidant activities of the essential oils were compared with control samples (without antioxidant) and containing butylated hydroxytoluene (BHT). All samples were stored at 4 ± 1 °C for 90 days and their peroxide values (PV), thiobarbituric acid (TBA) values, % titratable acidity and some microbiological properties were analyzed. As a result, the lowest PV and TBA values were determined in the samples containing BHT and 0.2% essential oils; however, TBA and PV were at the highest levels in the control samples during storage. The amount of 0.2% of essential oils exhibited strong antioxidant activity, which was almost equal to that of BHT. T. haussknechtii essential oil showed a stronger antioxidant effect as compared to O. acutidens. None of the essential oils showed remarkable antifungal activity. However, the antimicrobial activity of O. acutidens on coliform bacteria was found to be higher than that of T. haussknechtii. Sensory analysis of the butter showed that the samples containing 0.2% essential oils had lower flavor scores than those with 0.1% essential oils. The present results indicate that these essential oils can be considered as an alternative source of natural antioxidants in the manufacture of butter.  相似文献   

5.
Samples of oil from whole and dehulled sunflower seed were solvent winterized. The solvent mixture, 85% acetone, 15% hexane (v/v), was used at solvent-in-oil concentrations of 20, 40, and 70% by wt and the samples winterized at 0, −5, −10, and −15 ± .01 C for 4 hr. Generally, sunflower oils from whole seed remained free from cloud formation longer on refrigeration when the oils were winterized at lower temperatures and at lower solvent-in-oil concentrations. With oil from the dehulled samples, no winterization condition produced an oil with a predictable clouding time. However, correlations were significant between residual wax content after winterization and clouding time of the oils from whole seed. Oils from dehulled seed were not as highly correlated with wax content as oils from whole seed. This study indicates that crude sunflower seed oil might be winterized with the aid of solvents and that decortication prior to extraction might not be necessary for effective winterization.  相似文献   

6.
Summary Processing of cottonseed by the hydraulic press method has been carried out at two mills, one located about 100 miles farther south than the other. The varieties of seed processed and conditions during processing, which included cooking of moistened seed, were essentially the same at both mills. Seed was also processed at the more southerly mill by the screw press method for which seed was cooked without added moisture. The crude hydraulic- and screw-pressed oils produced at the two mills were stored at different temperatures for a total of ten months, and samples of the oils were periodically refined and bleached. Seed was also stored at the two mills, and was periodically processed for comparison of the oils produced from stored seed with the stored oils. The absorption spectra of the crude, refined, and bleached oils were determined. The rate of increase of bleach color in the oils during storage of the seed and crude oils has been correlated with temperature of storage and changes in the absorption spectra of the oils. Presented before the 38th Annual Meeting of the American Oil Chemists' Society, New Orleans, Louisiana, May 20–22, 1947. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.  相似文献   

7.
We aimed at investigating oxidative stability and changes in fatty acid and tocopherol composition of extra virgin olive oil (EVOO) in comparison with refined seed oils during short‐term deep‐frying of French fries, and changes in the composition of the French fries deep‐fried in EVOO. EVOO samples from Spain, Brazil, and Portugal, and refined seed oils of soybean and sunflower were studied. Oil samples were used for deep‐frying of French fries at 180 °C, for up to 75 min of successive frying. Tocopherol and fatty acid composition were determined in fresh and spent vegetable oils. Tocopherol, fatty acid, and volatile composition (by SPME–GC–MS) were also determined in French fries deep‐fried in EVOO. Oil oxidation was monitored by peroxide, acid, and p‐anisidine values, and by Rancimat after deep‐frying. Differential scanning calorimetry (DSC) analysis was used as a proxy of the quality of the spent oils. EVOOs presented the lowest degree of oleic and linoleic acids losses, low formation of free fatty acids and carbonyl compounds, and were highly stable after deep‐frying. In addition, oleic acid, tocopherols, and flavor compounds were transferred from EVOO into the French fries. In conclusion, EVOOs were more stable than refined seed oils during short‐term deep‐frying of French fries and also contributed to enhance the nutritional value, and possibly improve the flavor, of the fries prepared in EVOO.  相似文献   

8.
Monodisperse polymer particles composed of polystyrene (PS) and poly(1,6‐hexanedioldiacrylate) were prepared via one‐step seeded polymerization using PS as seed particles. For the study, the effects of the molecular weight of seed polymer particles, the ratio of the absorbed hexanediol dimethacrylate (HDDA) to the seed polymer particles (swelling ratio), and the seeded polymerization rate on the surface morphology of poly(St‐HDDA) particles were investigated. It was observed that the crater‐shaped defect was at the surface of poly(St‐HDDA) particles, independent of the molecular weight of seed polymer, and swelling ratio. But its surface morphology could be controlled by changing the rate of the seeded polymerization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2385–2394, 2007  相似文献   

9.
Phytosterols are natural compounds that contribute to lower serum cholesterol in humans. Sunflower seeds and oils are rich sources of phytosterols. Breeding for phytosterol content in sunflower has been scarce thus far, mainly because of the lack of analytical methods suitable for use in plant breeding. The objective of this research was to validate a method for the analysis of phytosterols in small seed samples of sunflower. Samples consisting of six seeds were analyzed for phytosterol content in a set of 87 inbred lines using a method adapted to small samples. The accuracy of the method was evaluated through the standard error of the analysis of replicates of ground samples, which was 72.12 mg/kg compared to average values of 1665.3 and 1887.2 mg/kg seed in the samples. Sunflower inbred lines showed ranges of variation from 1426.0 to 4710.0 mg/kg seed and from 2855.2 to 9752.0 mg/kg oil. The method correlated strongly with the conventional method based on the analysis of extracted oils (r = 0.85). The results indicated that analysis of phytosterols on samples consisting of sunflower seeds is an accurate approach for breeding and genetic studies, in which extraction of the seed oil is not feasible. Practical applications : Phytosterols are usually analyzed in extracted oils. However, studies in plant breeding and plant sciences often require a direct analysis of phytosterols in seeds, without previous oil extraction (e.g. large‐scale screening of germplasm in breeding programs or genetic studies). Our results will be useful for plant scientists interested in the analysis of phytosterols in small samples of plant tissues.  相似文献   

10.
Information on stability of edible oils is important for predicting the quality deterioration of the oil during storage and marketing. Stripping of crude oils removes most of non‐triacylglycerol components, including polar lipids and phenolics. Oxidative stability of black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.) and niger (Guizotia abyssinica Cass.) crude and stripped seed oils was investigated and compared. The factors influencing the oxidative stability of different seed oils were also discussed. Oil samples were stored under accelerated oxidation conditions for 21 d. The progress of oxidation at 60 °C was followed by recording the ultraviolet absorptivity and measuring the formation of oxidative products (peroxide and p‐anisidine values). Inverse relationships were noted between peroxide values and oxidative stabilities and also between secondary oxidation products, measured by p‐anisidine value and stabilities at termination of the storage. Absorptivity at 232 nm and 270 nm increased gradually with the increase in time, due to the formation of conjugated dienes and polyenes. In general, oxidative stabilities of crude oils were stronger than their stripped counterparts and the order of oxidative stability was as follows: coriander > black cumin > niger seed. Levels of polar lipids in crude oils correlated with oxidative stability. Thus, the major factor that may contribute to the better oxidative stability of crude oils was the carry‐over of their polar lipids.  相似文献   

11.
In this study, the concentrations of three lignans in 100 sesame seeds and 56 sesame oils were determined using a newly developed method based on high‐performance liquid chromatography coupled with a UV/Vis detector. Total lignan contents in sesame seed and oil samples ranged from 2.52 to 12.76 and 3.38 to 11.53 mg/g, respectively. Black sesame seeds showed higher sesamin content (range 1.98–9.41 mg/g, mean 4.34 mg/g) and sesamolin content (range 1.06–3.35 mg/g, mean 1.92 mg/g) than the other three varieties of sesame seeds. Black sesame oils had higher contents of lignans than the white sesame oils, although remarkable differences were not observed. Hot pressed and small mill sesame oils expressed higher contents of sesamol, sesamin, and total lignans than the cold pressed and refined sesame oils. The results revealed that there is extensive variability in lignan concentration in sesame oils and seeds.  相似文献   

12.
Monodisperse polymer particles were prepared via one‐step seeded polymerization using polystyrene, poly(methyl methacrylate), or styrene/methyl methacrylate copolymer [poly(ST‐co‐MMA)] as seed particles and 1,6‐hexanedioldiacrylate or divinylbenzene as crosslinking monomer. For the study, the effects of the combination of seed polymer and crosslinking monomer, the ratio of the absorbed monomer to the seed polymer particles (swelling ratio: S/R), and the seeded polymerization rate on the variation of surface morphology and mechanical properties of polymer particles, such as recovery rate, K‐values, breaking strength, and breaking displacement were investigated by using microcompression test. It was observed that the surface morphology could be controlled by changing polymerization rate or combination of seed polymer and crosslinking monomer, and it had a great influence on mechanical properties, especially the breaking strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2350–2360, 2007  相似文献   

13.
Essential Oils as Allelochemicals and Their Potential Use as Bioherbicides   总被引:4,自引:0,他引:4  
Essential oils were extracted from 32 aromatic plants and evaluated for allelopathic properties. The major components of the oils were identified by gas chromatography and GC-MS. Extracts from Origanum syriacum, Micromeria fruticosa, and Cymbopogon citratus were selected for further study. The germination of several species, including wheat, was strongly inhibited by essential oils when applied at 20–80 ppm. Essential oils mixed with the top 0.5 cm of soil inhibited germination of wheat and Amaranthus seeds. This effect depended on the type of soil. The possible use of essential oils as herbicides is discussed.  相似文献   

14.
Fish oil with 33% long‐chain polyunsaturated fatty acids was microencapsulated in a matrix of n‐octenylsuccinate‐derivatised starch and glucose syrup and stored at varying temperatures (5, 20 and 40 °C) and relative humidities (11, 33, 48–59 and 75%). Development of lipid oxidation parameters upon storage depended to a certain extent on temperature, but to a much greater extent on relative humidity. Temperature had no significant effect on the development of lipid oxidation parameters when samples were stored at 11 or 33% relative humidity. Hydroperoxide concentration doubled over the storage period and reached from 88 to 146 mmol/kg oil in the samples stored at 11 and 33% relative humidity, respectively. An increase in hydroperoxide concentration with increasing storage temperature was observed at 48–59% relative humidity. In all samples, the increase in the lipid oxidation parameters was not linear or exponential and significantly differed from the course as it is described in the literature for bulk oils and emulsions. Based on data for colour measurement, moisture sorption and extractable fat, the course of lipid oxidation is discussed. Finally, the use of silica derivatives and tricalciumphosphate efficiently improved the flowing properties of microencapsulated fish oil without affecting the oxidative stability of the products.  相似文献   

15.
A series of microencapsulated blends of waterborne polyurethane (WBPU) as a matrix polymer and phase change material octadecane as a domain material were prepared in the presence of emulsifier. Nylon fabrics were coated with the coating materials formulated from microencapsulated blends, thickener, and hardener. The morphology and thermal behaviors of microencapsulated octadecane and WBPU/octadecane‐coated nylon fabrics were investigated using SEM, DSC, and KES‐F7. The size of octadecane microspheres increased with increasing octadecane contents. However, the size of microcsphere (1–6 μm) decreased with increasing emulsifier contents. ΔHfusion, ΔHcrystallization, and their filling efficiencies of octadecane in film samples were found to increase with increasing microencapsulated blends, thickener, and hardener contents. Especially, thickener and hardener could function in trapping microencapsulated octadecane. Thermal characteristic Qmax (J/cm2 s) values of WBPU/octadecane‐coated nylon fabrics are much higher than those of the control nylon fabric and WBPU‐coated nylon fabrics, indicating that the nylon fabrics coated with WBPU/octadecane blends have cooler touch sensation compared with nylon fabrics and WBPU‐coated nylon fabrics. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1596–1604, 2005  相似文献   

16.
The aim of the present study was to highlight the main differences between seed oils produced from conventionally cultivated crops and organically cultivated ones and processed using mild extraction procedures. The composition and the nutritional and health aspects of both types of sunflower seed oils were compared and were analytically tested to determine the macroscopic differences in proximate composition, the main differences in the minor components, the main quality parameters, the in vitro antioxidant activity, and the presence of trans-ethylene steroisomers in FA. No significant trends were found in the oil samples for TAG and FA composition, but remarkable differences were found in the composition of minor components and in the main chemical and analytical quality properties. The organically grown samples had a higher total antioxidant activity compared with the conventional samples. Trans FA were found only in the conventional oils.  相似文献   

17.
This study investigated the supercritical fluid extraction (SFE) of geranium essential oil from geranium (Pelargonium graveolens) using supercritical carbon dioxide solvent. The extraction yield was measured as a function of pressure, temperature and carbon dioxide flow rate. At low pressure (10 MPa) and high temperature (343 K), waxes were co‐extracted with the essential oil, resulting in artificially elevated essential oil extraction yields as no method was available with the SFE apparatus used to separate co‐extracted waxes and oil. At high pressure (30 MPa) and low temperature (313 K), the amount of wax co‐extracted decreased. Under these ‘optimum’ conditions, the extraction yield increased with decrease in flow rate giving a maximum extraction yield of 2.53%. All samples were analyzed by gas chromatography–mass spectrometry and the effect of pressure and extraction time on oil composition was studied. The percentage compositions of terpene hydrocarbons, terpenols, geraniol and geranyl esters were significantly affected by pressure and extraction time. The oil samples obtained by SFE were also compared with commercially obtained steam distilled samples. All major components of the commercially obtained oils were present in the SFE‐obtained oils; however, the percentage composition of the major components differed greatly between steam distilled and SFE oils. Copyright © 2005 Society of Chemical Industry  相似文献   

18.
The present study was aimed to assess the anti‐bacterial activity and dyeing property of the pigments obtained from five fungal species. Cotton fabric and leather samples were dyed with the purified pigments and their anti‐bacterial activity was assayed under in‐vitro conditions. Post‐mordant cotton fabric and leather samples exhibited maximum bacterial reduction when compared with the pre‐mordant and dyed samples. Pigment exhaustion, colour coordinates and fastness properties of the dyed cotton fabric and leather samples were also assessed. The toxicity of the pigments was evaluated by seed germination assay.  相似文献   

19.
Highly unsaturated fatty acids derived from fish or algal oils, particularly EPA and DHA, are in high demand as healthy food ingredients in fortified foods. Due to their oxidative instability most food products incorporate stabilized microencapsulated EPA and DHA oils to avoid negative sensory impact associated with oxidation of these fatty acids. Complex coacervation has been particularly successful in stabilizing fish oil and providing an ingredient with a sensory shelf‐life consistent with that of the food product. Overcoming the technical challenges associated with the instability of these oils will help drive growth of the omega‐3 fortified healthy food ingredient market.  相似文献   

20.
Camellia japonica and Vernicia fordii seed oils were employed as a feedstock for production of biodiesel by transesterification with methanol on alkali catalysts. The composition and physicochemical properties were investigated in the raw seed oils and the biodiesel products. The fatty acid methyl ester (FAME) contents in the biodiesel produced from the seed oils were above 96% on KOH catalyst in the reaction. It was acceptable for the limit of European biodiesel qualities for BD100. Other qualities such as cetane number, acid value, density, and kinematic viscosity, of the produced biodiesels also matched the biodiesel qualities.  相似文献   

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