中国油脂化学工业的进展与预测

叙述了中国油脂化学工业近20年来的发展，肥皂工业经过1989年消费高峰，肥皂产量迅速下降，目前正处在产品结构调整阶段，开始有了较好的效果，油化学品一脂肪酸，脂肪醇和脂肪胺都有较大的发展，但都存在产品供大于求的困难。对此，作了分析和预测，考虑到中国植物油资源基本是以C18脂肪酸为主，对发展油脂化学工业带来了局限性，应充分利用国内外两种油脂资源。     

Vegetable oil raw materials

Vegetable oils that are important to the chemical industry include both edible and industrial oils, which contribute 24% and 13.5%, respectively, compared to 55% for tallow, to the preparation of surfactants, coatings, plasticizers, and other products based on fats and oils. Not only the oils themselves but also the fatty acids recovered from soapstock represent a several billion pound resource. Coconut oil is imported to the extent of 700-1,000 million pounds per year. Its uses are divided about equally between edible and industrial applications. Safflower oil has a relatively small production, but 15–25% of the oil goes into industrial products. Soybean oil, the major edible oil of the world, is produced in the United States at the rate of 11,000 million pounds per year with more than 500 million pounds going into industrial uses, representing 5% of the total production. Castor oil is imported to the extent of about 100 million pounds per year. Linseed oil production has declined drastically over the last 25 years but still amounts to about 100 million pounds per year. Oiticica and tung oils are imported in lesser amounts than castor and linseed oils. New crops that have industrial potential, as well as the traditional vegetable oil crops, include seed oils from crambe,Limnanthes, Lesquerella, Dimorphotheca, Vernonia, andCuphea plants. Crambe oil contains up to 65% erucic acid. Oil fromLimnanthes contains more than 95% of fatty acids above C₁₈.Lesquerella oil contains hydroxy unsaturated acids resembling ricinoleic acid from castor oil.Dimorphotheca oil contains a conjugated dienol system.Vernonia oils contain as much as 80% epoxy acids. TheCuphea oils contain a number of short chain fatty acids. Of these, crambe,Limnanthes, andVernonia are probably the most developed agronomically. Competition between vegetable oils and petrochemicals for the traditional fats and oil markets has been marked over the past 25 years, but prices for petrochemicals have accelerated at a greater rate than those for vegetable oils; and, it is now appropriate to reexamine the old as well as the new markets for fatty acids.     

Animal fat feedstocks for oleochemicals

Inedible tallow is a major raw material source in the manufacture of fatty acids and hence in the production of oleochemicals. The U.S. generates about 55% of the world’s total tallow production of six million metric tons, but supplies about 80% of the tallow imported by other countries. U.S. inedible tallow and grease usually is a blend whose principal component is rendered beef fat. It consistently has been and still is the least expensive of the various fats and oils and is traded in various grades depending on physical characteristics.     

Dietary polyunsaturated fat in relation to mammary carcinogenesis in rats

High fat diets promote the development of mammary tumors induced in rats by 7,12-dimethylbenz(a)anthracene (DMBA), and polyunsaturated fats are more effective than saturated fats. This difference is related to the linoleic acid content of polyunsaturated vegetable oils, but the amount of linolealte required for maximum tumor promotion appears to be higher than indicated by earlier experiments. Comparison of the effects of a polyunsaturated vegetable oil (corn oil) containing linoleate with a fish oilo (menhaden oil) containing polyunsaturated fatty acids derived from linolenic acid showed that higher dietary mammary tumors, while corresponding levels of menhaden oil had an inhibitory effect. This is further evidence that promotion of mammary tumorigenesis by polyunsaturated vegetable oils may be mediated by prostaglandins or other biologically active eicosanoids derived from n−6 fatty acids.     

Growth potential for soybean oil products as industrial materials

Crude soybean oil, as a major source of edible oil for the world, is available on such a scale that it serves additionally as the origin for many industrial applications and for such materials as phospholipids (lecithins, cephalins), tocopherols (for vitamin E), sterols (for pharmaceuticals) and recovered fatty acids from acidulated soapstocks. The latter always have offered the oleochemicals manufacturer a low cost source of valuable fatty acids, and soybean oil itself, after hydrogenation, serves as the most readily available, lowest cost source of 90% stearic acid from among all fats and oils. As an alternative to alkali refining and the soapstock produced, physical refining of the degummed soybean oil is a potential source for fatty acids and for recovery of larger amounts of valuable sterols and tocopherols, but this process severely degrades the oxidation stability of the fatty acids. The largest potentials for growth in industrial applications are for soybean oil itself in pesticide dispersion and grain dust control; triglycerides and fatty acids split therefrom for 90% stearate oleochemicals and selected food additivies; fatty acids from soapstocks up-graded medium-grade oleochemicals, medium-grade soaps for industrial cleaning operations, and in animal feeds and pet foods; phospholipid gums in fractionated and modified lecithins and cephalins; soy deodorizer distillates containing α-to copherol (vitamin E) and sterol-derived sex hormones. Inclusion of food additives, feed and pet food additives with the more usual industrial markets results in the conclusion that industrial utilization of soybean oil could reach 12% of total consumption in the U.S. within five years.     

应对月桂油的短缺

随着油脂化工生产的扩张，价格和基本原材料的获得是其成功的关键。月桂油（棕榈仁油和椰子油）对于油脂化学品的需求而言，在价格方面是最敏感的油品。目前月桂油主要用于食品方面，因此，油脂化工需求的增加必然导致月桂油的供应面临困难。月桂油的供应取决于椰子油和棕榈仁油的产量。油棕的产油率比椰棕高。很明显，将来月桂油供应主要取决于棕榈仁油生产的增加，这是棕榈油产量提高的结果。因此，为了提供充足的月桂油以满足油脂化学工业的需要，其用于食用方面的量将不得不减少。     

Challenges to a mature industry: Marketing and economics of oleochemicals in Western Europe

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.     

Quality of fried foods with palm oil

The amount of imported palm oil in Japan during the past few years has been 140,000–150,000 tons per year, or about 9% of the total consumption of vegetable oils in Japan. In 1975, part of the palm oil was imported as refined type from Malaysia. At the present time, almost all of the palm oil from Malaysia is refined. At the starting point quality of the refined palm oil was not so good, but today it is fairly improved by efforts of Malaysian processers. Palm oil has excellent properties against oxidation, and it has been generally accepted by consumers as a vegetable oil for health foods. There also is a big potential for increasing consumption of palm oil in fried foods. Severe regulation of food additives restricts the use of artificial antioxidants and therefore strict quality control is required to get stable frying oils. Consumer knowledge of foods is increasing, and our responsibility for making good quality frying fats is very important.     

Low linolenic soybeans and beyond

Low linolenic soybean oil is the first in a series of modified oilseed products to be introduced to meet food company and consumer needs. Consumer packaged goods and foodservice companies are currently using this oil to successfully replace partially hydrogenated soybean oil, resulting in the reduction of trans fatty acids from the food supply. In addition to meeting consumer demand for healthier foods, many food processors have chosen low linolenic soybean oil based on taste, performance and cost benefits. Seed companies continue to utilize traditional breeding, marker assisted breeding and biotechnology approaches to modify oilseeds that produce oils with health and nutrition benefits. Additional modified oilseeds are at various stages of development. Soybeans with increased levels of stearic acid are being developed as an alternative to partially hydrogenated fats and high saturate fats required to provide solids and structure to food. High stability fry oils with increased levels of oleic acid, reduced levels of linolenic acid as well as a version with lower saturated fat are being developed. Soybeans are also being modified to offer more sustainable sources of omega‐3s including stearidonic acid and eicosapentaenoic acid/docosahexaenoic acid which will result in more efficacious sources of omega‐3s compared to alpha‐linolenic acid‐containing vegetable oil and improved functionality/stability compared to fish and algal oils.     

Cottonseed oil and meal utilization

For five consecutive years world-wide production of cottonseed has set new highs, and cottonseed is more valuable as a source of food, feed, and fiber than ever before. However this paper is primarily concerned with the utilization of cottonseed oil and meal in the United States. During the three-year period, 1963–65, U.S. farmers received about $300 million annually for 6.18 million tons of cottonseed. Annual U.S. crushings were 5.79 million tons, having produced 1.94 billion pounds of crude oil valued at $222 million, 2.72 million tons of meal valued at $174 million, and 1,609,700 running bales of linters valued at $41.2 million. Retail value of cottonseed products is estimated to have been $1.1 billion annually. Changes in the U.S. cottonseed industry include shifts westward, to fewer and larger extraction plants and to the use of new and improved extraction techniques which involve solvents and high-speed expellers. The cottonseed extraction industry has a payroll of $38.2 million and consists of 188 oil mills in about 14 states, employing 8,400 people. Cottonseed oil accounted for 11.5% of total 1965 U.S. factory consumption of 12.7 billion pounds of fats and oils. Some 62% was used in salad or cooking oil, 27% in baking or frying fats, and 8% in margarine. During the 1960–65 period, usage increased in salad or cooking oils, in baking or frying fats, and in inedible products but decreased in margarine, mellorine, and other edible products. Increases exceeded decreases, and total consumption of cottonseed oil in edible and inedible products increased from 1.28 billion lb. to 1.47 billion lb. Practically all of the 2.76 million tons of cottonseed meal produced in the three-year period beginning October 1963 was used for feed. Relatively insignificant amounts were used as fertilizer on farms of cotton growers. Cattle, sheep, horse, and mule rations consumed 1.88 million tons, poultry rations 440 thousand tons, and swine rations 350 thousand tons. Cottonseed meal in cattle rations has had a downward trend since the early 1950’s although usage in poultry and swine rations has increased. It is estimated that 1.52 million tons were used by feed manufacturers in the preparation of mixed feeds during the 1964–65 season, representing a steady increase over the past two decades and a 54% increase over 1962–63. Domestic use of cottonseed flour has not changed appreciably during the past few years.     

Manufacture of fatty alcohols based on natural fats and oils

The present worldwide capacity of fatty alcohols is ca. 1.0 million metric tons per year. About 60% of this capacity is based on petrochemical feedstocks, 40% on natural fats and oils. Three basic dominating commercial-scale processes are used to manufacture fatty alcohols: the Ziegler process and the Oxo synthesis starting from petrochemical feedstocks, and the high-pressure hydrogenation of natural fatty acids and esters. Basically, the high-pressure hydrogenation can be used with triglycerides, fatty acids or fatty acid esters as feedstock. The direct hydrogenation of fats and oils has not been developed to a commercial-scale process, mainly because it was not possible to prevent decomposition of the valuable byproduct glycerol. Conversion of fatty acids into fatty alcohols by catalytic hydrogenation without preesterification requires corrosion-resistant materials of construction and acid-resistant catalysts. Required reaction temperatures are higher, resulting in a higher hydrocarbon content. The majority of fatty alcohol plants based on natural fats and oils use methyl esters as feedstock. These can be made either by esterification of fatty acids or by-transesterification of triglycerides. For catalytic high-pressure hydrogenation of methyl esters to fatty alcohols, several process options have been developed. The bawic distinguishing feature is the catalyst application either in a fixed bed arrangement or suspended in the methyl ester feed.     

Seed roasting improves the oxidative stability of canola (B. napus) and mustard (B. juncea) seed oils

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.     

Manoeuvring the physicochemical and nutritional properties of vegetable oils through blending

Modification of vegetable oils is carried out to make them suitable according to their specific end use as most of the vegetable oils in original forms do not meet the recommended dietary allowance of saturated (SFA), monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids. Vegetable oils are modified using a variety of techniques including hydrogenation, interesterification, fractionation, and blending. However, blending is the most widely accepted method for improving the physicochemical properties, nutritive value and oxidative stability of vegetable oils because it is simple, cost-effective, non-destructive, and does not involve chemical treatments. Blending vegetable oils with contrasting fatty acid compositions or blending omega 3 fatty acids and antioxidants rich minor oils with major oils are two common strategies to formulate blends. Blended oil with balanced fatty acids could play substantial role in improving the consumers' health. However, while designing vegetable oil blends, it is important to keep in mind the intended application of the formulated blend, consumer's demands and also food laws. This review paper covers the literature related to blending of vegetable oils with a focus on effect of vegetable oils blending on their physicochemical and nutritional properties, health benefits and utility in food industries.     

Spurennachweis von mehrfach verzweigten Fettsäuren in Fetten

Detection of Traces of Polybranched Fatty Acids in Fats A method for the detection and quantitative determination of saturated polybranched fatty acids in animal and vegetable fats is described. The method is based on gas-chromatographic determination of polybranched fatty acid methyl esters in the methyl esters which do not form urea adducts. The following amounts of polybranched fatty acids were determined in animal fats: whale oil 15 000 ppm., fish oil 6000 ppm., butter fat 4000 ppm., beef tallow 2000 ppm. and lard 110 ppm. In different vegetable oils and fats upto 200 ppm. of polybranched fatty acids were found. Not only the difference in total content of polybranched fatty acids but also differences in their percentage composition and retention volumes in gas-chromatograms were found. This method therefore offers the possibility of identification of some of the animal fats.     

Current advances in sunflower oil and its applications

The fatty acid and triacylglycerol composition of a vegetable oil determine its physical, chemical and nutritional properties. The applications of a specific oil depend mainly on its fatty acid composition and the way in which fatty acids are arranged in the glycerol backbone. Minor components, e. g. tocopherols, also modify oil properties such as thermo‐oxidative resistance. Sunflower seed commodity oils predominantly contain linoleic and oleic fatty acids with lower content of palmitic and stearic acids. High‐oleic sunflower oil, which can be considered as a commodity oil, has oleic acid up to around 90%. Additionally, new sunflower varieties with different fatty acids and tocopherols compositions have been selected. Due to these modifications sunflower oils possess new properties and are better adapted for direct home consumption, for the food industry, and for non‐food applications such as biolubricants and biodiesel production.     

Antioxidants for vegetable oils

Several chemical compounds having antioxidant efficacy in food fats and oils and cleared for food use by governmental regulatory agencies are available for such use by vegetable oil processors in many nations of the world. These antioxidants are reviewed with particular attention to major benefits and possible shortcomings they may afford when added to vegetable oils. Some guidelines in selecting antioxidants to achieve optimum results are offered. Also, precautions to be observed in adding antioxidants to fats and oils are discussed.     

Thermochemical applications for fats and oils

Fats and oils are well established in food, surfactant and coatings applications. Historically, fats and oils were employed to provide lighting and warmth. Increasing production of fats and oils and increasing uncertainties regarding the reliability of petroleum resources make it desirable to reconsider thermochemical applications of fats and oils. Difficulties associated with the use of fats and oils for vehicular applications are discussed, and use in stationary diesel engines is suggested. Conventional kerosene space heaters are designed to make use of the vaporization behavior of this fuel. Changes in heater design are required to take into account the pyrolytic degradation of the fuel when fats and oils are used, and a traveling grate burner was designed for this purpose. Pyrolysis of fatty acids at temperatures exceeding 500 C yields a mixture of gaseous and liquid products. The gaseous products include ethylene, but little propylene. The liquid product is primarily a mixture of substituted styrenes. Further development is needed for these thermochemical applications of fats and oils. Fuel and olefin markets present valuable cushions to keep the price of fats and oils from fluctuating as during the early 1980’s, when soybean oil has varied from $0.15 per pound to $0.40 per pound. The triglycerides can provide a future source of feedstocks for petrochemicals, if petroleum prices and availabilities change dramatically. Most of the development work needed consists of down-to-earth large-scale experiments in semi-commercial or commercial equipment to determine the best methods of fuel storage, feeding and conditions for combustion and steam cracking.     

Structure of the human milk fat globule

Milk is a sophisticated oil‐in‐water emulsion in which triacylglycerols, the single largest component of the infant's energy supply, are enclosed by an unusual trimolecular layer of polar lipids, proteins and cholesterol. Recently, interest has turned to the possibility that not just the membrane components and triacylglycerol fatty acids, but also their unusual structures may be particular features that enable delivery of intact bioactive molecules to the intestine, while facilitating efficient absorption and processing of milk fats, without metabolic stress. These features mean that the functional properties of milk fats are not replicated by mixtures of vegetable oils and emulsifiers and may be lost by processing. However, they offer opportunities for use of milk fat globule membranes and triacylglycerols structured to resemble milk fats.     

Fat in today’s food supply—Level of use and sources

Nutrient fat—food fats and oils, as well as fat from meat, milk, and other fat containing foods—in the U.S. food supply has increased ca. one-fourth over the past 60 years or so on a per person/day basis. Ca. two-fifths of the fat currently comes from fats and oils, including butter; over a third comes from meat (including fat pork cuts), poultry, and fish; and ca. one-eight comes from dairy products. This large increase in nutrient fat is due mainly to the use of more vegetable fats—margarine, shortening, and salad and cooking oils. The per capita amount provided by animal fats actually has decreased, because the large decreases in consumption of butter and lard are only partly offset by increases in fat associated with greater consumption of meats. Despite the decrease in consumption of animal fats, they continue to provide ca. one-fourth of the total calories. Although the proportion of calories from vegetable fats has increased, animal products still account for the largest share of the calories provided by fat. Shifts in sources of fat and the increased amount of fat have changed the fatty acid content of the food supply. One of five papers presented at the symposium, “Status of Fat in Food and Nutrition,” AOCS Fall Meeting, Chicago, September 1973. ARS, USDA.     

Aspekte bei der Hydrierung von Fetten und Fettsäuren

Aspects of Hydrogenation of Fats and Fatty Acids Hydrogenation of fat products is of great significance, both for human and animal nutrition as well as for technical purposes. In the area of nutrition, adequate food for the increasing world population is unthinkable without utilization of all fat resources, that can be made available as food fats only after catalytic hydrogenation. In the area of technical use, a similar development is observed owing to shortage of mineral oils. Thus, fatty alcohols derived from vegetable oils and waxes can already compete in price with fully synthetic fatty alcohols derived from mineral oils. In the past 70 years of hydrogenation of fats till the present time, catalysts based on nickel have been most commonly used. In addition, small proportions of catalysts based on copper and noble metals have also been used. Homogenous catalysts have been used very recently. The present communication deals primarily with the hydrogenation of neutral fats and fatty acids using nickel catalysts. The aspects of selectivity and isomerization in the partial hydrogenation of neutral fats are discussed. In the hydrogenation of fatty acids and their derivatives, emphasis is laid on other factors, such as activity, poisoning and acid resistance of the catalyst. These factors are discussed.