Über den Einfluß der Begleitstoffe der Fettsäuren auf die Kinetik ihrer Hydrierung

Ta Influence of Concomitant Substances of Fatty Acids on the Kinetics of their Hydrogenation In the present paper the influence of concomitant substances of animal fats and their degradations components on the kinetics of the hydrogenation of free fatty acids of these fats was investigated. Our attention was directed to the balance of organic sulphur, phosphor and nitrogen compounds during high pressure splitting of fats, distillation of fatty acids and following hydrogenation. During the splitting process 70% of nitrogen and sulphur containing substances were degradated or removed, the content of phosphor containing substances didn't change basically. Another decrease of concomitant substances and their splitting products occurs during distillation of fatty acids. In the subsequent hydrogenation the content of phosphor containing compounds decreased significantly. Residual contents of amino acids and sulphur compounds were absorbed by the Ni-catalyst and contributed to the decrease of its activity. The effect of the confirmed substances on the decrease of its activity. The effect of the concomitant substances on the decrease of the hydrogenation velocity was confirmed by their addition to the fatty acids of sunflower oil after chromatographic isolation. This addition (concentration from 1 to 3%) lowered the reaction velocity up to 50%.     

Interchangeability of fats and Oils

The requirement for interchangeability of fats and oils is a result of such factors as availability and cost of raw materials, and the effects of legislation or market preference on product composition. Such changes should not affect the product’s quality or performance. Interchangeability is practiced today in the production of products for human food, animal feed and technical uses, and is frequently controlled by computer. It is necessary fully to identify a product and its essential features whether simply by melting point or a full triglyceride structure. Modern analytical techniques such as NMR, GC, HPLC and DSC have enabled this identification to become a more exact science. The interchange may consist of a simple substitution of one oil or fat for another, or it may be more complex, involving a number of oils and fats and processes. Finally, the nature of the product may be such that it has to be “tailor-made” using sophisticated processes to produce the required triglyceride composition. The unit processes which are employed are blending, hydrogenation, fractionation and interesterification. In the last process the recently published use of enzymes is of particular interest. Problems encountered are mainly concerned with the polymorphism of fats and oils which frequently sets limits on the proportion of a particular fat which can be used. Limits are also imposed by plant processing capacity. Palm and lauric acid oils are particularly important in the context of interchangeability for both edible and technical purposes because of their fatty acid and triglyceride compositions. They provide good examples of usefulness, problems resulting from polymorphism and the difficulties of substitution.     

Comparison of radiolytic compounds from saturated and unsaturated triglycerides and fatty acids

Formation of certain radiolysis products from palmitic acid, oleic acid, tripalmitin and triolein has provided a means for comparing the radiolytic effects in saturated and unsaturated triglycerides and fatty acids. These substances were chosen to represent the major constituents of fat found in beef. Fractionation and concentration of radiolytic compounds from the irradiated samples was accomplished by the means of size exclusion chromatography. Quantitative and qualitative analyses were performed using a combined GC/MS computer system. In addition to the primary radiolytic compounds, recombination products of relatively high molecular weight and various propanediol diesters from the corresponding glyceryl moities were identified. Quantitative analyses indicated a greater yield of various radiolytic compounds from free fatty acids than from the corresponding triglycerides. Similarly, radiolytic compounds were produced in greater quantities from the saturated fats than the unsaturated fats. Most of the radiolytic compounds identified in this study have not been previously reported.     

Farbe von Ölen

Colour of Oils For many products, particularly edible oils and fats, color is an essential indicator for quality. Today instruments are used to measure the color in oils, fats, fatty acids or other substances. The Tintometer is a subtractive colorimeter, which used red, blue and yellow glass standards. Almost everywhere in the world, the Lovibond color scale is nowadays considered as an accepted means of assigning precise color values to edible oils and fats. But there are also, of course, alternative ways and techniques of determining or measuring color. In recent years, the development of microprocessor-controlled colorimeters has made it possible to automatically measure and compare Lovibond color scale and correlating international standard values pursuant to the CIE System.     

Physikalisch-chemische Trennverfahren in der Biotechnologie

Physicochemical separation processes in biotechnology. A number of special features of the work-up of products of biotechnological processes play a decisive role in selection of a separation process. Thus the products generally have to be isolated from dilute aqueous solutions. Moreover, the substances to be isolated are generally sensitive to external influences such as temperature or pH value and have to be isolated from mixtures with chemically similar compounds. Demands for greater selectivity of separation are met by processes based on differences in molecular structure of the substances to be separated. These include separation methods which have practically no significance in chemical engineering, e. g. chromatographic, membrane, and electrophoretic processes. The development of industrially utilizable processes to exploit the high separation efficiency of the physicochemical techniques requires close collaboration between process engineers and chemists.     

Chemical constituents and protein food processing of rapeseed

In rapeseed, as in other oilseeds, there are some substances that adversely affect nutritional value. By application of appropriate technological processes, the antinutritive factors are removed and the final protein products appear to have high nutritive value. Compared with the soybean, rapeseed presents some unique problems. When processing rapeseed into protein foods, it is necessary to take into account high losses of nitrogen substances (nonprotein nitrogen), and higher costs of removing glucosinolates and their derivates, as well as phenolic compounds. Technically and economically feasible methods of reducing cellulose and phytate contents should be developed. In view of the presence of many constituents which lower the nutritional value of rapeseed protein products, it would appear that rapeseed is presently not a suitable raw material for production of food grade protein flour and grits. On the contrary, rapeseed protein concentrates and their texturates have satisfactory nutritional quality and feature good functional properties. Rapeseed isolates, except for poorer spinning properties, have similar characteristics to those of soybean isolates, but, as a result of low protein yields, their production is uneconomical. Recent progress in the breeding of glucosinolate-free and low fiber rapeseed varieties offers a new approach for development of processing methods for useful protein products based on this raw material.     

Bleaching of edible fats and oils

Almost all fats and oils are subjected to so‐called bleaching during processing. Originally bleaching was only used to reduce the colour. Today, however, the bleaching step is used mainly to remove or convert undesired by‐products to harmless ones from fats and oils. This will guarantee that such compounds do not interfere with the processing and that the requirements for human food are being met.     

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.     

Hydrogenation of palm and lauric oils

The technology and equipment for hydrogenating fats and oils is described. Advantages and disadvantages of various batch and continuous processes are discussed. Continuous hydrogenation is suggested for plants that process essentially only one type of oil. When several different feedstocks are to be processed in the same equipment, batch autoclaves may be advantageous. Hydrogenated palm kernel and coconut oils or fractions have many uses in food products, especially in products where specific melting points and good oxidative stabilities are important. Trends in hydrogenation indicate that more and more energy-saving and automation devices will be used to reduce energy and labor costs and to make more uniform products, especially in batch processes.     

Die Flotation — ein geeignetes Verfahren zur Aufbereitung öl- und fetthaltiger Abwässer

Flotation — a Useful Procedure for Treatment of Oil and Fat Containing Waste Water Waste water of the oil and fat manufacturing industry is characterized by a high content of by petrolether extractable compounds (fats and oils), protein and similar compounds. A considerable part of the contained oil is submitted in emulsified form and cannot be removed by mechanical treatment (gravity separator). Therefore an extensive precleaning is necessary before emission into an outfall ditch, passing in circuit of single streams or introducing into a biological cleaning stage. For this purpose physical/chemical processes are used, whereat in connection with a flocculation chamber the sedimentation — but preferred the flotation — comes into question. Different technical designs and constructive measures which are to con sider for optimal cleaning efficiency are described. Proposals for the design of plants are given too.     

Fettchemische und petrochemische Rohstoffe - Gegensatz oder Ergänzung?

Fatchemical and Petrochemical Raw Materials - Contrast or Complementation? Fatchemical products are used in all branches of industry and crafts for a variety of purposes. The areas of application are determined by the types of fatty acids which are available as raw materials. It is shown that the C₁₈ chain length is dominant. The most commonly occurring fatty acids are oleic- and linoleic acids. Lauric acids, which is so important for the major areas of application, only represents a small fraction of the world supply of fats. The use of raw material alternatives instead of fats is explained by the relative uniformity of the fatty acid spectrum found amongst the natural fatty acids. In addition, the special place occupied by coconut oil is economically attractive. A survey of the various possibilities and processes for fatchemical products which are derived from fats and petrochemical derivatives is presented. It may be expected that further positive developments of agricultural oil. and fat-production will occur by better yields as well as by successful breeding, resulting in changes in the fat composition. In the long term it may be assumed that the range of natural fats will not only expand, but that it will also be widened by new fatty acid compositions. Petrochemical processes can also have good prospects for the future. Fatchemical and petrochemical raw materials can complement each other in a positive fashion thus enriching the spectrum of fatchemical products.     

Fats and other Lipids from Single Cell Cultures,Plants, and Animals

Through the ages, a major portion of fats and oils produced by man has been used as human food and animal feed. For little more than a century, most of the inedible fats, together with substantial proportions of edible fats and oils, have served as raw material for the production of bulk commodities such as soaps and detergents, paints and varnishes, as well as lubricants and plastics. These products are beneficial on account of their physical and chemical properties. The biological properties of some naturally occurring lipids are being recognized and appreciated since the 1930ies. As a result of intensive research efforts, the structures of these substances, notably of the fat-soluble vitamins, hormones, essential fatty acids and oxylipids derived therefrom, pheromones, platelet activating factor and other ether lipids, are now known. Both naturally occurring lipids and semisynthetic or synthetic analogues are being applied in agriculture, bio-medical research and clinical therapy. A ‘fat tree’ devised in 1958 by the late H. P. Kaufmann illustrates the wide applicability of fats and oils at that time. The present article includes a figure showing further ramifications of Kaufmann's tree. The structures, properties, and uses of the substances added recently are outlined in a series of publications that appeared in a special issue of the journal Fat Science Technology.     

Palm oil fatty acids in soap and detergent formulations

Palm oil fatty acids can be used in increasing quantities in combination with selected minor oils from Indian in making lower cost laundry or toilet soaps and derivatives suitable for use as surface-active compounds in many formulations. Experimental soap formulations using palm oil products and indigenous fats are provided.     

A review of conventional and renewable biodiesel production

The need for sustainable fuels has resulted in the production of renewables from a wide range of sources, in particular organic fats and oils. The use of biofuel is becoming more widespread as a result of environmental and economic considerations. Several efforts have been made to substitute fossil fuels with green fuels. Ester molecules extracted from processed animal fats and organic plant materials are considered alternatives for the use in modern engine technologies. Two different methods have been adopted for converting esters in vegetable oils/animal fats into compounds consistent with petroleum products, namely the transesterification and the hydro-processing of ester bonds for the production of biodiesel. This review paper primarily focuses on conventional and renewable biodiesel feedstocks, the catalyst used and reaction kinetics of the production process.     

High voltage electrical discharge reactions of fats and related compounds

Studies are reported on the modification of fats and related compounds by electrical discharge reactions. Several types of fatty compounds were subjected to silent electrical discharge of the ozonizer type of 15,000 volts AC and analyzed by gas-liquid and thin-layer chromatography, infrared spectral and elemental analyses. Evidence was obtained for a free radical reaction in accordance with the general theory of discharge reactions. The major products of the reaction were polymers of varying degrees of complexity. Shortchain hydrocarbons were also detected. Hydrogenations via the formation of hydrogen radicals was demonstrated; branching via long-chain radical interreactions was also indicated. The incorporation of nitrogen and oxygen into polymeric products was demonstrated when the reaction was carried out in the presence of these gases. Reaction mechanisms are proposed to explain the products formed under various conditions.     

The Biotechnology of Fats – a Challenge and an Opportunity

Oleochemical products and biotechnological methods are making equally important contributions to a chemistry of the future which - energy-saving and kind to the environment - has its foundations in regenerative raw materials. In the past, research results of biochemistry have only indirectly affected oleochemistry - for example through crop improvements in oil plants. Although biotechnological processes for the modification or production of fats (for example by fermentation) have been investigated, they have only been adopted in a few specialized fields. However, with the general advance of the bioreactor and genetic engineering, many new and interesting ideas for the biotechnology of fats have been developed in recent years, including for example the commercial application of lipases for splitting fats and the use of bioemulsifiers for secondary and tertiary oil recovery. Further innovations are likely and are being discussed.     

Crystallization and polymorphic behaviors of cocoa butter alternatives: A review

Although cocoa butter (CB) has remarkable physical properties, its high price, growing difficulties, and increased consumption have been the main incentive to explore alternatives to replace or improve it. The potential of fats systems obtained from tropical butters, mixtures of them with vegetable oils, or marine fats as cocoa butter equivalent (CBE), extender (CBEx), substitute (CBS), replacer (CBR), or improver (CBI) have been deeply investigated and their physical chemical properties have been compared to those of CB. The TAGs composition of fats systems is a key factor that determines fats crystallization and polymorphic behaviors, and the suitability for an application. Fats with high concentrations of the TAGs StOSt, StOA, or StOB and low concentrations of POP compared to CB show some incompatibility with CB as analyzed by iso-solid diagrams and a more complex polymorphic behavior. The presence of low melting TAGs such as POO, StOO, and AOO also leads to significant differences in physical behavior compared to CB. In those fats systems, co-crystallization and polymorphic transitions of co-existing solid solutions were reported. A few of the studied fat systems may behave as CBE. However, most of them have potential as CBS, CBR, CBEx or CBI in confectionery products. Studies reported the relevance of fractionation and interesterification processes to modify TAGs composition and the need of finding the right processing conditions and additives to extend fats applications.     

Changing practices and changing residues in animal fats and plant oils 1890–1980

Summary Following World War II and the movement of people from the rural to the urban environment, producers of food have become increasingly dependent on organic chemical substances to control pests affecting the production of food. Because of scientific evidence and public concern, constant changes have occurred in the types of pesticides being used over the last three decades. The persistent organochlorines which accumulated in fats and oils were removed in the early 1970s. Since that time, residues in animal fats and plant oils have declined markedly and almost disappeared in most cases. No early evidence was found in Ontario that these compounds accumulated in plant oils and so no indepth study was undertaken. With the threat of biological resistance ever looming larger, Integrated Pest Management programs have been investigated and are being implemented to reduce the dependence on chemical pesticides. Current pesticides rarely appear in oil and fats and those that do are controlled below the MRL by following the days to slaughter for livestock and the days to harvest for crops. In general, pesticide residues in fats and oils produced in the Province of Ontario have declined during the last decade and are continuing to decline. Monitoring for all pesticide residues will continue to ensure that this state of affairs is maintained. Presented at the AOCS meeting, Toronto, May 1982.     

A nutritive evaluation of over-heated fats

According to the tests used, harmful substances do not occur in fried foods or in fats used in preparing foods. It is possible to obtain biologically undesirable materials by excessively heating and/or oxidizing fats in the laboratory, but the conditions required for the production of such materials differ greatly from those used in practical cooking or processing of foods. There appears to be no reason to believe that fats are nutritionally damaged when handled by normally-accepted good practice in present-day food preparation.