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1.
天然植物油脂在化妆品中的应用   总被引:4,自引:0,他引:4  
叙述了油脂在化妆品中的功效性评价及天然植物油脂的市场现状,介绍了植物油脂的重要活性物ω-3和ω-6脂肪酸)的皮肤功效及天然植物油脂的重要来源。指出,以植物油脂为原料的天然化妆品将越来越受到消费者喜爱。  相似文献   

2.
Panel evaluations have been made of room odors developed by edible oils and cooking fats heated to frying temperatures. Vegetable and mixed fat shortenings, as well as oils of different iodine value and from special processing, were investigated with and without added stabilizers. When silicones were added to frying fats, room odor scores improved markedly. Certain added autoxidative cleavage products had little effect on odor scores at levels where they were detected easily in taste tests. To be discernible in room odors, these additives had to be present at levels ca. 100-fold greater than their taste thresholds. Panel results show that the undesirable frying odors contributed by unhydrogenated soybean oil in mixtures with other oils could be detected readily at 25% levels. As the level of soybean oil was lowered further, the room odor scores of oil mixtures improved perceptibly. One of 13 papers presented in the symposium “Flavor Research in Fats and Fat Bearing Foods,” AOCS Meeting, Atlantic City, October 1971. N. Market. Nutr. Res. Div., ARS, USDA.  相似文献   

3.
Rapid qualitative and quantitative methods for determining the free fatty acid (FFA) contents in common oils and fats are reported. Qualitative method is based on the type of color developed in the presence of BDH indicators (Universal and “678”) when a known excess of alkali is added to an alcoholic solution of oil or fat. By this method, low (0.0–0.25), medium (0.26–0.99) and high (1.0 and above) FFA levels in fatty oils may be distinguished. Quantitative method is a simplified modification of the usual procedure of determining the FFA contents of oils and fats by titration against standard alkali solution in the presence of BDH Universal or “678” indicator. The results of the rapid methods agree well with those of the standard AOCS method.  相似文献   

4.
Historically, glycerol, a valuable by product of the fatty acid insutry, is priced higher in the market-place than any of the common fatty acids. Glycerol “credit” from fat-splitting, frequently in time of economic stress, makes the difference between a profitable stearic acid operation and an economically unsound one. Theoretical yields of glycerol for the common fats and oils range from 9–13.5%; practical plant yields, corrected for FFA and upgrading yield losses, are 9–12.8% on 100% glycerol basis, or 10.3–14.8% on an 88% glycerol basis. Glycerol “credit” per pound of fatty acid ranges from 1 to 3 cents/pound. Upgrading “sweetwaters” from splitting operations in the fatty acid industry requires removal of dissolved salts, elimination of color, and fat and oil impurities, concentration (evaporation of water) and/or distillation. For Twitchellized sweetwaters this generally involves (a.) lime treatment. (b.) filtration, (c.) evaporation to half-crude, (d.) precipitation of excess lime, (e.) filtration, (f.) evaporation to a concentration of 88–90%, and probably, (g.) distillation. For autoclave or continuous process sweetwaters the upgrading includes (a.) light lime treatment, (b.) filtration, (c.) evaporation concentration to 88–90%, and probably, (d.) distillation. Glycerol may also be upgraded by ion-exchange processing followed by evaporation concentration in which distillation may be eliminated. Ion-exclusion (Dow process) is also feasible. Many special triglyceride products are required of different fatty acid homolog distribution than those of the parent or hydrogenated fats and oils. These are prepared by splitting the fats or hydrogenated oils, fractionating the fatty acids, upgrading the glycerol, and recombining the desired fractionated acids with glycerol by reesterification. One example is high lauric triglyceride from coconut oil suited for use as a coco butter substitute.  相似文献   

5.
The dietary and nutritional role of fats and oils is quite complex, as evident in the new biological findings about some of their components that are essential to man. Fats and oils must be considered for both their quantitative and qualitative aspects, their fatty acid compositions and relationships with average diets in different countries should be emphasized. Because of some adverse physiological effects ascribed to saturated fatty acids, a tendency to increase the intake of polyunsaturated vegetable oils has occurred to provide a good source of essential fatty acids, mainly linoleic acid. However, saturated fats still are an important part of the diet in developed countries, especially “invisible” fats. Research must continue that is related to modifications fats and oils undergo during industrial processes which affect their nutritional value. Compositions of many fats and oils are provided.  相似文献   

6.
Basic oleochemicals are produced by splitting and further reactions of oils and fats: fatty acids, glycerine, fatty acid methyl esters, fatty alcohols and amines. The last two are included in the list of oleochemical raw materials, primarily because of their importance in the preparations of further derivatives. The wide range of derivatives of oleochemical raw materials such as fatty alcohol ethoxylates, fatty alcohol sulfates, fatty alcohol ether sulfates, quaternary ammonium compounds and soaps are summarized. Oleochemicals such as fatty alcohols and glycerine from oils and fats have equivalents on the basis of petrochemicals. Using the customary terminology, petrochemical products are referred to as “synthetics.” The are included in the present discussion because in the application of oleochemical raw materials the origin of the material is often less important than the structure. Oleochemistry can be regarded as a mature branch of chemistry, with many applications for its products, but with few completely new fields. The challenge and the opportunities for oleochemistry today lie in the changing economic and ecological conditions. Availability and price development of oils and fats are discussed with particular reference to European conditions, for these are the prerequisites if oleochemicals are to be competitive and are to improve their chances in the marketplace. The importance and development of the oleochemical raw material fatty acids, fatty acid methyl esters, glycerine, fatty alcohols and amines are considered on the basis of historical data. In considering future developments of oleochemicals, the capacity, demand and the possible influence of petrochemistry or crude oil is discussed. The highly developed oleochemical raw materials industry is a flexible supplier of medium-to long-chain fatty alkyl groups. These facts, together with the well organized supply lines for raw materials and the considerable potential of these renewable raw materials, could provide the necessary conditions for the oleochemical raw materials industry to fulfil its future tasks on a larger scale. This could arise, for example, due to the partial substitution of petrochemical surfactants, if this should become necessary as a result of developments in the price and availability of crude oil, or on grounds of ecological factors.  相似文献   

7.
Some “official methods” for preparing methyl esters of the fatty acids from oils or fats may be referred to by users as the boron trifluoride (BF3) method and invariably have two stages. The first stage, brief treatment with alkali [commonly NaOH in methanol (MeOH), sometimes NaOCH3] and heat has been popularly described as a saponification step for over 30 yr. In fact, the disappearance of visible fat or oil is mostly transesterification, which can be accomplished in a few minutes under mild conditions. Free fatty acids (FFA) originally present, or produced by saponification, are not converted to methyl esters at this stage. The second stage, heating in BF3-MeOH, has in practice been as short as 2 min. It can convert all FFA to methyl esters, but this step requires at least 30 min. Examples from the recent literature illustrate the necessity of extending the time for BF3-MeOH transesterification of lipids or oils and methylation of FFA. No alkali transesterification is needed. Presented in part at the 88th Annual Meeting of the American Oil Chemists’ Society, Seattle, WA, May 1997.  相似文献   

8.
The depletion of natural resources, the increasing use of valuable land surface for human activities, and the generation of waste are detrimental to the planet. Sustainable alternatives to guarantee a sufficient supply of food, feed, and biomaterials are needed. Insects may hold an interesting position in a circular economy to tackle contemporary societal challenges. Using insects for food, feed, biomaterial production, and to valorize side-streams, have gained increased interest. Mealworms are amenable to large-scale farming. Herein, the potential of mealworm oil for implementation in a cosmetic hand cream is evaluated. It is shown that mealworms are rich in oil (≈30% of the dry weight), and the oil can be extracted using hexane or ethyl acetate as a solvent. The euthanization step of mealworms has profound effect on the free fatty acid content. The fatty acid profile indicates a large proportion of unsaturated fatty acids, which is promising for use in cosmetic applications. In a proof of concept, the mealworm oil is implemented in a hand cream and compared to hand cream containing macadamia nut oil. No differences in odor and aspect/stability are observed, but mealworm creams are slightly less white color. Mealworm oil is suitable for cosmetics applications. Practical applications: Several insect species can be sustainably reared on low-value organic side-streams, requiring only small amounts of land-surface, less water, and producing less greenhouse gases. In addition, they have short life cycles and can be reared continuously and locally. This implies that insects are an interesting source of biological materials including proteins and oils. Insect oils, including oil of mealworms, have interesting fatty acid profiles that make them amenable to replace oils of vegetable origin for applications within cosmetics. The results indicate that mealworm oil can be a novel, sustainable ingredient for use in the cosmetics industry.  相似文献   

9.
Crude edible fats and oils contain variable amounts of nonglyceride impurities, such as free fatty acids, non-fatty materials generally classified as “gums”, and color pigments. Most of these impurities are detrimental to end product fresh and aged quality characteristics, hence must be eliminated by a purification process before the finished fats and oils are suitable for human consumption. The object of this process is to remove these objectionable impurities with the least possible loss of neutral oil and tocopherals. Key theoretical and practical factors for degumming and refining crude edible oils are discussed with particular reference to processes, flow charts, control systems and analytical testing requirements. In addition to typical large volume oils, such as soya and cotton, techniques are also reviewed for smaller volume oils, including palm, lauric and corm.  相似文献   

10.
Production of fatty alcohols from fatty acids   总被引:3,自引:0,他引:3  
Detergent-range alcohols from natural feedstock can be produced by high pressure hydrogenation of either methyl esters or fatty acids. The increasing quantities of fats and oils on the world market secure a reliable and economically priced material. Although fatty acid is an abundant worldwide commodity, most alcohol producers hydrogenate methyl esters, because direct hydrogenation of fatty acids is difficult as the catalyst is sensitive to acid attack. The process described here makes it possible to hydrogenate fatty acids directly to alcohols of high quality without prior esterification. The reaction takes place in the liquid phase over a fine-grained copper chromite slurry in a single reactor vessel. A special reactor design with an optimum arragement of the feeding nozzles causing an appropriate circulation of the reacting components inside the reactor facilitates the rapid “in situ” esterification reaction. This minimizes the free fatty acid concentration in the reactor to nearly zero. This results in a low consumption of catalyst. The most important advantages of the process are: direct feed of fatty acids of various origins, use of reasonably priced raw materials such as soapstock fatty acids and lower grade tallow acids, no process steps with methanol, and excellent economics. The process is industrially proven.  相似文献   

11.
The effects of fat crystallization induced by thermal treatment on the rheological properties of creams and physical phenomena at the oil droplet surfaces were investigated. Creams A or B were prepared from commercial proprietary fats A or B (vegetable oils with different triaclyglycerol composition) and aqueous solution containing proteins. Thermal treatment of the creams at the “critical temperatures” (temperatures inducing a small percentage of solid fats in the oil droplets) caused a rapid increase of solid fat contents in the following cooling process. The thermal treatment of cream B at the “critical temperature” caused an increase of viscosity of the cream and an increase of protein surface coverage during the subsequent cooling process. These results suggest that the oil droplet aggregation induced by the thermal treatment at the “critical temperature” and the subsequent cooling occurred via further adsorption of proteins. Electron spin resonance measurement demonstrated the dramatic reduction of fluidity of triacylglycerol molecules at the oil droplet surface in cream B during the cooling process after thermal treatment at temperatures below “critical”. Based on these results, we speculated on the mechanism for the destabilization of thermally treated creams during the cooling process.  相似文献   

12.
Soybean oil was continuously hydrogenated in a slurry system to investigate the effects of linolenate content and additives on cooking oil performance. Room odor evaluations carried out on oils heated to 190 C after frying bread cubes showed that the oils hydrogenated with Cu catalyst to 2.4% linolenate (Cu-2.4) and with Ni catalyst to 4.6 linolenate (Ni-4.6) had a significantly lower odor intensity score than the unhydrogenated soybean oil (SBO). Other hydrogenated oils (Cu-0.5 and Ni-2.7) were not significantly better than SBO. Oil hydrogenated with Ni (Ni-0.4) scored poorly because of its strong “hydrogenated-paraffin” odor. The performance of all partially hydrogenated oils (2.4, 2.7 and 4.6% linolenate) was improved by adding methyl silicone (MS), but the most hydrogenated oils (0.5 and 0.4% linolenate) were not improved. Although with tertiary butyl hydroquinone (TBHQ) no improvement was obtained, with the combination of TBHQ + MS all odor scores were lower, indicating a synergistic effect. Evaluations of bread cubes after intermittent heating and frying showed that the breads fried in most hydrogenated oils (Ni-0.4, Cu-2.4 and Ni-2.7) were rated significantly better in flavor quality than breads fried in SBO. The bread cubes fried in MS-treated oils had significantly higher flavor quality scores than breads fried in SBO or SBO containing TBHQ. Dimer analyses by gel permeation chromatography and color development after heat treatments also did not correlate with sensory analyses.  相似文献   

13.
The triacylglycerol fraction of three samples of margarine, namely “Flora” (Holland), “Kaliakra” (Bulgaria), and “Corona” (Holland), were studied by13C nuclear magnetic resonance spectroscopy. By examining the various carbon chemical shifts of the saturated and unsaturated carbon nuclei, “Flora” margarine was shown to contain a mixture of hydrogenated and unhydrogenated vegetable oils. This technique allowed all major acyl groups (saturated, oleate, linoleate, and linolenate) and minor acyl components [different positional isomers of long-chain (E)- and (Z)-monoenoic moieties, arising as by-products during catalytic hydrogenation] to be identified. The amount of each fatty acid present in the margarine was also estimated from the relative intensities of the corresponding signals. “Kaliakra” margarine consisted of a blend of unhydrogenated natural fats and oils that contained saturated fatty acids, oleate, and linoleate. There were no signs in the spectrum of “Kaliakra” of any (E)-isomers, nor signals associated with positional unsaturated acyl groups (other than oleate and linoleate). The sample of “Corona” margarine consisted of a mixture of hydrogenated and unhydrogenated vegetable oils and butter (1.3%). The presence of butter in this sample was identified by the characteristic carbon shifts of the C-1 to C-4 carbon atoms of butyrate. The distribution of the fatty acids on the glycerol “backbone” also was estimated by this technique.  相似文献   

14.
Catalytic transfer hydrogenation of soybean oil   总被引:4,自引:0,他引:4  
The catalytic transfer hydrogenation of soybean oil by various hydrogen donors and solvents with palladium-oncarbon catalyst was investigated in batch and continuous modes. The choice of reaction conditions, donor and catalyst allowed the manufacture of partially hydrogenated oils or semi-solid fats with controlled fatty acid contents, iodine value, melting point and solid content index. The level of “iso” forms of fatty acids was similar to, and average initial selectivity was higher than that obtained with gaseous hydrogenation under pressure with a catalyst of the same type. The best results were obtained in aqueous solution with sodium formate as hydrogen donor at 60°C.  相似文献   

15.
The Kreis test is one of the procedures for early detection of oxidative products of fats and oils. The reaction is complicated, sensitive and continuous. The kinetics of the Kreis test have been studied as a function of reagent, phloroglucinol, oil quantity and incubation period for three oils with different fatty acid profiles, storage life and presence of compounds other than triglycerides. A central composite rotatable design with each factor at five levels required 20 experiments for each oil. The results of experiments carried out in duplicate have been examined by analysis of variance, and polynomials of appropriate degree were fitted to the data. The polyhedron search method was used to compute optimum conditions for carrying out the test for each oil. Three-dimensional graphs were generated to bring out the differences in the oils and the kinetics for each oil. Though “compromised” optimized conditions have been reported, the results indicate the necessity of more detailed investigation into the reaction.  相似文献   

16.
Food technological aspects on the use of rape-seed oil and otherCruciferae seed oils as salad oils, in margarine, shortenings and some other foods are briefly reviewed. It is concluded that these oils in hydrogenated or nonhydrogenated form may compete favorably with other vegetable oils and animal fats. One of nine papers published from the Symposium, “Cruciferous Oilseeds,” ISF-AOCS World Congress, Chicago, September 1970.  相似文献   

17.
Dichlorocarbene was generated in the presence of lard, olive, safflower, tung and menhaden oil. When solutions of fats or oils in ethyl trichloroacetate were mixed with sodium methoxide inn-heptane at 2C, unsaturated components were transformed in high conversion to dichlorocyclopropane derivatives; fats were converted to methyl-and-ethyl esters (90%) or appeared as glycerides (10%). The proportion of dichlorocyclopropane rings was the same in the glycerides as in the ester products. The reactivity of safflower oil required metered addition of reactants at 25–55C. Properties were measured on dichlorocyclo-propanoid fatty esters freed from glycerides but containing saturated esters. Chlorine content ranged from 12–33%. Compatibility with silicone oils was substantially improved. Viscosities and densities increased with chlorine content. Viscosity indices were 135,150,49,67 and 79 for products from lard, olive, safflower, tung and menhaden oil. Dichlorocarbene could be generated without alcoholysis of glycerides by decomposition of sodium trichloroacetate. This gave dichlorocyclopropanes from safflower oil unsaturates in 50% conversion, but failed with lard. Analyses were performed by TLC, argentation and GLC. Presented at the AOCS Meeting, Minneapolis, 1963. A laboratory of the E. Utiliz. Res. & Dev. Div., ARS, USDA.  相似文献   

18.
The first naturally occurring phytyl esters from a marine alga were isolated from a dinoflagellate,Peridinium foliaceum (Stein) Biecheler, cultured photosynthetically and harvested at stationary phase of growth. At this stage, phytyl esters were the major wax esters present, constituting 5% of the total lipid, and may be present largely in the “eyespot” structure. The fatty acids esterified to the phytol were predominantly polyunsaturated: 16∶3 n−3 (15%), 18∶5 n−3 (6%), 20∶5 n−3 (36%), and 22∶6 n−3 (17%).  相似文献   

19.
Animal fats and partially hydrogenated vegetable oils (PHVO) have preferentially been used for deep‐frying of food because of their relatively high oxidative stability compared to natural vegetable oils. However, animal fats and PHVO are abundant sources of saturated fatty acids and trans fatty acids, respectively, both of which are detrimental to human health. Canola (Brassica napus) is the primary oilseed crop currently grown in Australia. Canola quality Indian mustard (Brassica juncea) is also being developed for cultivation in hot and low‐rainfall areas of the country where canola does not perform well. A major impediment to using these oils for deep‐frying is their relatively high susceptibility to oxidation, and so any processing interventions that would improve the oxidative stability would increase their prospects of use in commercial deep‐frying. The oxidative stability of both B. napus and B. juncea crude oils can be improved dramatically by roasting the seeds (165 °C, 5 min) prior to oil extraction. Roasting did not alter the fatty acid composition or the tocopherol content of the oils. The enhanced oxidative stability of the oil, solvent‐extracted from roasted seeds, is probably due to 2,6‐dimethoxy‐4‐vinylphenol produced by thermal decarboxylation of the sinapic acid naturally occurring in the canola seed.  相似文献   

20.
A versatile and large group of fatty acid esters are prepared from monohydroxy alcohols (C1 to C22 members), glycols (ethylene and propylene glycols and others), etherglycols (many polyoxyethylene glycols), triols (glycerol and others), tetraols (pentaerythritol and others), polyglycerols, carbohydrate materials (sorbitol, sorbitan, sucrose and others). The two most important direct esterifications of fatty acids are those done with monohydroxy alcohols (methanol, butanol, etc.) and glycerol itself. Esterifications of these materials are carried out with or without the use of catalysts. For edible ester products, the choice of catalyst is determined by (a) rate of reaction promotion permitted by the use of the catalyst; (b) color of product obtained; (c) ease of removal of catalyst; (d) toxicity of catalyst, and perhaps; (e) other factors including promotion of acrolein formation from glycerol, loss by volatilization at high temperatures, inactivation above certain threshold temperatures, and catalyst corrosivity on the materials of construction of the esterifier. In certain instances the last factor may indeed be the paramount one in a particular catalyst choice for a direct esterification. Industrial production of methyl esters is principally by a process of interesterification called methanolysis. Polyols require conditions for complete esterification that are vigorous and severe. The two most important interesterification methods used in the fatty acid industry are the methanolysis of fats and oils for the production of methyl esters and the glycerolysis of fats and oils for the production of three kinds of so-called “monoglycerides”, namely the 40%, 60% and 90% monoglycerides.  相似文献   

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