Die weitere Entwicklung der Codex Alimentarius Standards für Öle und Fette

Further Development of Codex Alimentarius Standards for Oils and Fats The present status of Codex Alimentarius Standards for oils and fats is reviewed. Further development of these standards is reported, based on discussions at the 8th meeting of the codex committee for oils and fats in London. The discussions concerned standards for low-erucic rapeseed oil, low-fat spreads, coconut-, palm-, palm kernel-, babassu-, grape seed- and marine oils as well as issues involving the range of application, fatty acid composition of individual oils and fats and use of solvents in the recovery and processing of fats.     

Die Weiterentwicklung der Codex Alimentarius Standards für Öle und Fette

Further Development of Codex Alimentarius Standards for Oils and Fats Further development of Codex Alimentarius standards for oils and fats, which was discussed at the 7th meeting of the Codex Committee in London, is reported. Limits of fatty acid composition of individual oils and fats, problems of solvent residues as well as the development of new standards for lowerucic rapeseed oil, low calorie spreads, coconut oil, palm oil and palm kernel oil were discussed at the above meeting. It has already been realized that the Recommended Standards have a significant impact both on harmonization work within the European Community and international development of food legislation.     

Die Weiterentwicklung der Codex Alimentarius Standards für Öle und Fette

Further Development of Codex Alimentarius Standards for Oils and Fats A report is given on the further development of Codex Alimentarius Standards for oils and fats, which was discussed in the 9th meeting of the Codex Committee on Fats and Oils from 28th November to 2nd December 1977 in London. Topics discussed were a collaborative report by FAO and WHO on the role of fats in human nutrition, the general standard for oils and fats, and standards for reduced fat margarine, low erucic acid rapeseed oil, coconut oil, palm oil, palm kernel oil, babassu oil, grape seed oil as well as marine oils. Furthermore, the limits of fatty acid composition as criteria for identification of specific oils and fats were discussed.     

Relative nutritional value of various dietary fats and oils

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.     

Detection of interesterified fat in hydrogenated fat by lipase hydrolysis and by cooling curve analysis

Porcine pancreatic lipase hydrolysis and Jensen’s cooling curve methods can be adopted for detecting interesterified fat products in a mixture with hydrogenated fats. Lipolysis of interesterified fats shows a relatively greater amount of saturated fatty acids in the 2-monoglycerides in comparison with hydrogenated fats. A similar trend of the distribution pattern of fatty acids also can be noted in a mixture. Interesterified fats do not show any rise in temperature in Jensen’s cooling curve experiment, whereas hydrogenated fats show a distinct rise in temperature. A gradual increase in temperature is obtained for an interesterified fat when it is mixed with increasing content of a hydrogenated fat. On the other hand, hydrogenated fat shows a lowering in the rise of temperature when it is mixed with an interesterified fat. Simultaneous determination of the fatty acid profiles of the 2-monoglycerides and Jensen’s cooling curve characteritics can be utilized in detecting the occurrence of one modified fat in another.     

Component fatty acids of some cruciferae oils

Summary The oils from yellow mustard seed (Brassica alba), black mustard seed (Brassica nigra) of Indian origin, and rapeseed (Brassica Compestris) of unknown origin have been analyzed for their fatty acid composition without preliminary resolution of fatty acids by lead-salt-alcohol or fractional crystallization methods. The results compare very favorably with those determined by other recently developed methods. It may be concluded therefore that this method can be favorably employed for the determination of fatty acid composition of fats containing higher unsaturated acids. Confirmatory evidence has been obtained for the presence of eicosenoic acid in rapeseed oil. The nature and amount of fatty acids of yellow mustard seed oil of Indian origin do not differ in any significant manner from those of other cruciferous seed oils. The present analysis of black mustard seed oil reveals a higher amount of linolenic acid, and the presence of a C₂₀ monoethenoid acid, not heretofore reported. Contribution No. 708 from the Department of Chemistry, University of Pittsburgh. Presented in part at the Spring meeting of the American Oil Chemists’ Society, held in New Orleans, La., May, 1948. Baliga and Hilditch’s paper. “The Component Acids of Rapeseed Oil” (J. Soc. Chem. Ind.67, 258–262 (1948).     

Rapid and direct lodine value and saponification number determination of fats and oils by attenuated total reflectance/fourier transform infrared spectroscopy

A simple, rapid and reproducible method of determining the iodine value (IV) and saponification number (SN) for fats and oils was developed with an attenuated total reflectance/Fourier transform infrared spectrometer and commercially available triglycerides as calibration standards. Partial least squares was used to determine the spectral regions correlating with the known chemical IV and SN values, and the calibration set was augmented with additional standards generated by spectral co-adding techniques. The calibration model obtained was used to analyze commercially available fats and oils with a wide range of IV and SN values, and the results were compared to the values obtained by American Oil Chemists’ Society methods. With the spectrometer calibrated and programmed, IV and SN results could be obtained within 2–3 min per sample, a major improvement over conventional wet chemical methods.     

Composition and control of potato chip frying oils in continuing commercial use

Summary The oils in use on a continuing commercial basis in the production of potato chips on a nation-wide scale are found to be free of thermal polymers. This conclusion is supported by the similarity in physical properties and in chemical composition between the fresh and heated oil in any one operation. In a) degree of unsaturation of oils, b) melting point, c) setting point, d) fatty acid composition, e) free fatty acid content, f) concentration of fatty acid isomers, g)solids content index, and h) in the crystallizing properties of the oils, there are no differences between fresh and heated oil of such magnitude to warrant criticisms of the wholesomeness of the oil being absorbed by the chip. The constancy in composition between heated and fresh oil, particularly with respect to the essential fatty acid content, which is largely responsible for the noncaloric functions of fats in the diet (19), permits the same conclusions to be made in regard to the nutritive value of the heated oils,i.e., of the triglycerides contained therein, as have been drawn from studies conducted on the corresponding fresh oils. Based upon statistical quality control considerations, the oils employed in the survey of the potato chip industry have been characterized by having a free fatty acid value of no greater than 0.60% and a decrease in iodine value of no greater than 3.0% in 95% of the operations. These control limits characterize the oils, which, on test, have led to the generalization about the absence of thermal polymers in commercial potato chip frying oils. Much of the material in this paper and in one recently published (1) was presented at the 48th Annual Meeting of the American Oil Chemists' Society in the Symposium on “Fats in Nutrition and Health,” New Orlens, La., April 30, 1957.     

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.     

Seasonal variation in the fatty acid composition and quality of sardine oil from sardinops sagax caeruleus of the gulf of California

One of the few sources of long-chain n-3 polyun-saturated fatty acids is fish oil’ but considerable variation may exist according to species and season. In this study’ the fatty acid profiles of sardine oils from Sardinops sagax caeruleus of the Gulf of California’ Mexico’ were evaluated in three seasonal catch periods. Oil quality was also evaluated by peroxide and free acid values. The most abundant fatty acids found in the oils were palmitic acid (19.3%)’ oleic acid (14.3%)’ eicosapentaenoic acid (EPA’ 20.4%)’ and docosahexaenoic acid (DHA’ 12.2%). There was no significant difference in the composition and quality among the six reduction plants where the samples were obtained. However’ a significant difference in the proportion of EPA and DHA in one of the catch seasons analyzed was observed.     

Die Codex Alimentarius Standards für Fette und Öle I

Codex Alimentarius Standards for Fats and Oils I A short introduction on the principles of Codex Alimentarius is given, which is being developed jointly by Food and Agricultural Organization (FAO) and World Health Organization (WHO) under participation of 75 member states. In the meanwhile Recommended Standards for fats and oils have been laid down. They will be forwarded to governments for acceptance or rejection. Development of these standards is reported here and the most significant regulations are discussed. Some important Recommended Standards are presented in appendix in their English version.     

Fractional distillation

While practically all the fatty acids produced in the fatty acid industry are distilled products, these materials are all, at least to some degree, fractionated fatty acids. Rarely indeed are today’s fatty acids suited for any of the many applications to which they are put without the quality and homolog distribution improvements which only fractional distillation can guarantee. Thus, this separation is of vital importance within the fatty acid and derivative industries. Fractional distillation is industrially a practical separative method for: (a) 16:0 and 18:0 fatty acids, such as those derived from hydrogenated fats and oils like tallow, soybean, cottonseed soapstocks, palm oil and others; (b) 18:0, 20:0, 22:0, and 24:0 fatty acids from hydrogenated fish oils or high erucic rapeseed oil; and (c) 8:0, 10:0, 12:0, and 14:0 fatty acids from the hydrogenated fatty acids from the lauric oils group (coconut, palm kernel, babassu, etc.). While theoretically possible under idealized conditions in the laboratory, it is not practical to separate palmitic, oleic, heptadecanoic, and stearic acids by means of fractional distillation     

Chemical interesterification with regioselectivity for edible oils

Chemical interesterification reaction conditions that provide regioselectivity regarding fatty acid positions in triacylglycerol have been investigated. Sodium methoxide-catalyzed ester interchange between soybean oil and methyl stearate was performed in hexane at low reaction temperature,i.e., 30 to 60°C. The results showed regioselectivity was obtained at 30°C. The ester interchange at 1,3-carbons progressed 1.7 times faster than at 2-carbon of the glycerol moiety of triacylglycerol at 24 h. Preheating of the mixture of reactant and catalyst at 60°C for 15 min promoted catalyst activation to accelerate the interesterification while maintaining regioselectivity. This method is believed to be feasible for modification of edible fats and oils. Presented at the American Oil Chemists’ Society’s Annual Meeting, May 10–14, 1992, Toronto, Canada.     

Chemical analysis of polymerization products in abused fats and oils

For more than a decade, numerous analytical methods have been proposed for the detection and measurement of polymers in vegetable fats and oils. Many of the methods have been little more than laboratory curiosities, either because they were concerned with only very specific compounds or were too cumbersome and time consuming to become very popular. More recently, a number of methods in common use for analysis of fats and oils has been shown to be useful for indirectly measuring polymeric materials in heat abused oils. The present report shows, by the use of gel filtration chromatography, the validity of two of the indirect methods of estimating polymeric products of abused fats and oils. These methods are: the estimation of polymers through changes in the iodine value and the measurement of retention materials on a gas liquid chromatographic column. A new simplified internal standard gas liquid chromatographic procedure utilizing triglyceride standards also is presented. This latter method permits estimating the degree of degradation of vegetable fats and oils by any laboratory capable of determining the fatty acid composition of a sample by gas liquid chromatography. Presented at the AOCS Meeting, Ottawa, Canada, September 1972.     

The importance of glycerol in the fatty acid industry

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.     

Rapid quantitative determination of free fatty acids in fats and oils by fourier transform infrared spectroscopy

Rapid direct and indirect Fourier transform infrared (FTIR) spectroscopic methods were developed for the determination of free fatty acids (FFA) in fats and oils based on both transmission and attenuated total reflectance approaches, covering an analytical range of 0.2–8% FFA. Calibration curves were prepared by adding oleic acid to the oil chosen for analysis and measuring the C=O band @ 1711 cm^–1 after ratioing the sample spectrum against that of the same oil free of fatty acids. For fats and oils that may have undergone significant thermal stress or extensive oxidation, an indirect method was developed in which 1% KOH/methanol is used to extract the FFAs and convert them to their potassium salts. The carboxylate anion absorbs @ 1570 cm^–1, well away from interfering absorptions of carbonyl-containing oxidation end products that are commonly present in oxidized oils. Both approaches gave results comparable in precision and accuracy to that of the American Oil Chemists’ Society reference titration method. Through macroprogramming, the FFA analysis procedure was completely automated, making it suitable for routine quality control applications. As such, the method requires no knowledge of FTIR spectroscopy on the part of the operator, and an analysis takes less than 2 min.     

Rapid methods for determination of free fatty acids contents in fatty oils

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.     

Lipids from Wastewater-Activated Sludge Cultivated on Acetic Acid as Potential Alternatives to High-Value Oils and Fats

This study focuses on new interpretations of the published literature by statistically evaluating the potential of microbial lipids from activated sludge (AS) as alternatives to high-value oils and fats. There are two data analysis stages involved in this study after compilation and organization of fatty acid profiles from the literature databases: (1) comparison of fatty acid profiles of the cultivated AS lipids with that of oils and fats found in the literature databases, and (2) hierarchical cluster analysis of the fatty acids of the combined dataset of literature oils and fats, and the AS lipids. Results show that fatty acid profiles of lipids from cultivated AS were similar to the fatty acid profiles of some oils and fats of plant, animal, single-microbial cultures, and algal origins; hence, lipids from AS could be potential alternatives to specialty oils and fats. The cultivation conditions of AS during lipid content enhancement may influence lipid application.     

Exhaust Emissions from an Engine Fueled with Biodiesel from High-Oleic Soybeans

Biodiesel is a fuel comprising mono-alkyl esters of medium to long-chain fatty acids derived from vegetable oils or animal fats. Typically, engines operated on soybean-based biodiesel exhibit higher emissions of oxides of nitrogen (NOx) compared with petroleum diesel. The increase in NOx emissions might be an inherent characteristic of soybean oil’s polyunsaturation, because the level of saturation is known to affect the biodiesel’s cetane number, which can affect NOx. A feedstock that is mostly monounsaturated (i.e. oleate) helps to balance the tradeoff between cold flow and oxidative stability. Genetic modification has produced a soybean event, designated 335-13, with a fatty acid profile high in oleic acid (>85%) and with reduced palmitic acid (<4%). This high-oleic soybean oil was converted to biodiesel and run in a John Deere 4045T 4.5-L four-stroke, four-cylinder, turbocharged direct-injection diesel engine. The exhaust emissions were compared with those from conventional soybean oil biodiesel and commercial No. 2 diesel fuel. There was a significant reduction in NOx emissions (α = 0.05) using the high-oleic soybean biodiesel compared with regular soybean oil biodiesel. No significant differences were found between the regular and high-oleic biodiesel for unburned hydrocarbon and smoke emissions.     

Determination of monoglyceride in fats and oils by oxidation with periodic acid

Summary A method based upon oxidation of monoglyceride by periodic acid has been developed for the determination of monoglyceride in fats and oils. The reaction and conditions that influence the determination have been described and discussed. This paper was presented at the Chicago meeting of the American Oil Chemists’ Society, October 25–27, 1944.