Fette und Geschmack

Fats and Taste Fats and oils have a strong effect on the taste of food-stuffs, although in a refined state the former have hardly any taste of their own. In this communication the storage stability and the physical behaviour, especially the meeting of fats, are dealt with. Precautionary measures, that should be adopted in order to maintain acceptable taste, and the types of fats required to achieve special effects are discussed.     

Polycyclic aromatic hydrocarbons in crude and deodorized vegetable oils

The efficiency of the refining process in removing polycyclic aromatic hydrocarbons (PAH) from crude vegetable oils was studied. Samples of the crude oils (coconut, soybean and rapeseed oils) and the corresponding refined, deodorized oil were taken on-line in three Swedish oil refineries and margarine manufacturing plants and analyzed for 20 different PAHs. Of the crude oils, coconut oil had by far the highest PAH levels. However, the PAH levels in the refined coconut oils were very low. This shows that the activated charcoal treatment used for removing PAHs from coconut oil achieves the desired effect. The crude soybean and rapeseed oils contained relatively low, but varying, amounts of PAH. At present these oils are not purified by activated charcoal. Nevertheless, the PAH levels in the refined oils were considerably lower than those in the corresponding crude oils. This probably is due to evaporation of PAH in the deodorization process, where steam is passed through the hot oil under high vacuum. However, deodorization has only a marginal effect on the high molecular PAHs, of which several are classified as carcinogens.     

Zur Bestimmung,zum Vorkommen und zur Zusammensetzung von polycyclischen aromatischen Kohlenwasserstoffen in Ölen und Fetten

On the Occurrence, Determination and Composition of Polycyclic Aromatic Hydrocarbons in Crude Oils and Fats Various methods have been published regarding analytical determination of polycyclic aromatic hydrocarbons (PAH). In principle, all methods are composed of following steps: Enrichment, clean-up and quantitation. The authors prefer the caffein-complexation technique. They have been using this since many years for the routine PAH-analysis of fats and oils. This report contains the results of PAH determination in the most common crude oils used in Europe as well as the statistical trend of their contamination with “light” and “heavy” PAH's. Moreover, the PAH contamination of different oils according to their geographical origin is shown and possible sources of contamination are discussed. The role of Benzo[a]pyrene as the “reference PAH” and its correlation with “heavy” PAH is subjected to a critical evaluation.     

Analysis of traces of anionic detergents in oils and fats

A method to analyze oils and fats for anionic detergents, mainly sodium lauryl sulphate (NaLS), has been developed. After extracting the detergent from the oil, a chloroform-soluble complex with methylene blue is formed, and the concentration of this complex is determined spectrophotometrically. The method was found suitable for oils and fats containing 0.05 to 5.0 mg NaLS per kg. The analysis can only be used to assess fully refined oils and fats because partly refined and commercially available products may contain minor components and emulsifiers also solubilizing methylene blue into chloroform.     

Zur lebensmittelrechtlichen Beurteilung hervorhebender Hinweise bei Fetten und fetthaltigen Zubereitungen

Legal Food Estimation of Remarks Concerning the Quality of Fats and Fat Containing Preparations For legal food estimation of commercial fats and oils as well as of preparations, industrially produced of fats and oils, the general regulations of the food and requisite law of 15. 8. 1974 in context with definitions e. g. in the rules of the German foodbook or in guiding principles of the food management are to notice concerning accentuating quality hints as “fine”, “first class”, “good”, “pure”, “natural” or similar. The relations are explained on butter or pure butter fat and butter pastry, on lard, lard pastry, on native and refined sunflower oils as on hardened marine animal oil and preparations produced of these ingredients.     

50 Jahre Technologie pflanzlicher Öle und Fette - ein Erfahrungsbericht

50 Years Technology of Vegetable Oils and Fats - a Report of Experiences In a survey about the development of the technology of vegetable oils and fats between 1932 and 1982 above all those areas are dealt, in which the author could contribute to the optimization of technological process steps and to the quality improvement of final products. It is described in detail: influence of solvent composition on benzine losts and on hydrocarbon retention in the oil seed extraction, improvement of the lecithin removal process, the entire desliming of extracted oils and its influence on raffinate quality, methods for determination of refining lost and for estimation of quality of raw and refined oils, comparison between various alkali-neutralization methods, relations between bleaching earth activity and oxidation stability of the oils, recovery of oil from used bleaching earth, distillative neutralization and determination of optimal deodorising conditions. The report is finished with hints on the importance of special fats for the fat processing industry obtained by hydrogenation, interesterification or fractionation.     

Refining,bleaching and hydrogenating meat fats

Meat fats are most often steam refined. This has been the accepted practice for at least 35 years. Meat fats are caustic refined for a few specialized products. The caustic refining conditions differ from those used for vegetable oils primarily in the amount of mixing used after the addition of caustic. Bleaching of meat fats is accomplished easily. Most meat fats are light in color and require clarification more than bleaching. The green color of tallows containing large amounts of chlorophyll is easily removed with activated earth. Meat fats are hydrogenated to develop the SFI curves needed for various products and also are hydrogenated to saturation for use as plasticizing agents. The hydrogenation of lard and tallow is not as complicated as that of most vegetable oils, because the original fat is more saturated and the reaction has fewer possible routes to follow.     

Die polarographische Bestimmung von Tocopherolen und Tocopherylchinonen in Ölen und Fetten

Polarographic Determination of Tocopherols and Tocopherylquinones in Oils and Fats A method for the polarographic determination of α-, γ-, and δ-tocopherols and the corresponding tocopherylquinones in oils and fats was worked out. After saponification of the samples and extraction of unsaponifiable matter with ether, the tocopherylquinones originally present in oils and fats are directly determined polarographically. Tocopherols present in the sample are oxidized quantitatively with cerium(IV) sulfate to the corresponding tocopherylquinones and latter are then likewise polarographed. The presence of substances accompanying tocopherols in the unsaponifiable matter does not interfere with the determination of tocopherols or tocopherylquinones. The tocopherol contents of different oils and fats are given.     

Interference of polar lipids with the alkalimetric determination of free fatty acid in fish lipids

An examination of the suitability of an alkalimetric method for the determination of free fatty acid (FFA) contents in fats, oils, and lipid extracts was conducted by comparing AOCS method Ca 5a-40 with a method based on a Chromarod-latroscan thin-layer chromatography-flame-ionization detector (TLC-FID) system. The FFA contents determined by the alkalimetric method were consistently higher than the genuine FFA contents obtained by the latroscan TLC-FID method. Phospholipids were found to be the major components that contributed to the alkali-titratable, nongenuine FFA in the total FFA determined alkalimetrically. Contributions from other polar lipid components were smaller, but they dominated as the proportion of phospholipids fell. The other alkali-titratable polar components may include oxidized lipids and their by-products bound to protein fragments. The accurate determination of FFA contents by alkalimetric methods may only be applicable to those commercially refined fats and oils that contain negligible amounts of phospholipids. Corrections for the alkalimetrically determined FFA contents should be made for those fats and oils with relatively high phospholipid contents by correlating the nongenuine FFA contents and the phospholipid contents.     

Rapid determination of heavy polycyclic aromatic hydrocarbons in edible fats and oils

A new rapid method has been developed to determine polycyclic aromatic hydrocarbons (PAHs) in edible fats and oils. Samples are dissolved in isohexane/butylmethylether and PAHs are adsorbed onto a polystyrene solid‐phase extraction cartridge. Triglycerides and non‐aromatic components are eluted stepwise with different mixtures of isohexane and butylmethyether. PAHs finally are eluted with tetrahydrofurane. After evaporation of solvent, PAHs are redissolved in acetonitrile and analysed by RP‐HPLC with fluorimetric detection. Recoveries of 5‐ and 6‐nuclear PAHs are 85—95%, recoveries of 4‐nuclear PAHs are about 60—75%, for 2‐ and 3‐nuclear PAHs the solid‐phase extraction method is not suitable.     

Der Futterwert von Fetten und Ölen aus Verarbeitungsprozessen bei Geflügel

Feeding Value of Fats and Oils from Finishing Processes for Poultry Altogether two trials with 22 different fats/oils have been carried out. In the first trial the interesterification and the digestibility of the fatty acids of seven fats and oils from the finishing processes with different contents of polymeres have been determined with broilers, aged 2–3 and 5–6 weeks as well as adult cocks. The age of the animals and the shares of the fatty acids were of high influence on the feeding value. In the second trial the fattening performance of broilers that had got ratios of 13 different frying oils, bleaching earth oils or distillation residues, was determined. The results with frying oils were successful, those with bleaching earth oils were moderate and with distillation residues extremely bad. A dependence between the content of polymeres and the feeding value of fat and oils could not be found out.     

Fatty acid esters of glycidol in refined fats and oils

Discrepancies in the analysis of 3‐chloropropane‐1,2‐diol (3‐MCPD) esters can be explained by the hypothesis that in some refined oils significant amounts of fatty acid esters of glycidol (glycidyl esters) are present in addition to 3‐MCPD esters. Glycidyl esters were separated from triacylglycerols by gel permeation chromatography (GPC) and detected by gas chromatography‐mass spectrometry (GC‐MS). Six samples of palm oil and palm oil‐based fats were analyzed by GPC and GC‐MS. In chromatograms of all samples, significant peaks, retention time and mass spectra in conformity with self‐synthesized glycidyl palmitate and glycidyl oleate were detectable. Quantification of individual glycidyl esters was not possible because of a lack of pure standards. Concentration of ester‐bound glycidol in different samples of fats and oils was estimated using an indirect difference method. Glycidyl esters could be detected only in refined, but not in crude or native, fats and oils. The highest concentrations were detected in palm oil and palm oil‐based fats. In a palm oil sample, glycidyl ester concentration varied according to different deodorization parameters, temperature, and time, while 3‐MCPD ester concentration was relatively constant, indicating that mitigation of glycidyl esters possibly may be achieved by optimizing refining parameters.     

Quality control in storage and transport of edible oils

Care for quality of edible fats and oils during transportation and storage is especially important for partially or fully refined products. This paper describes some examples of deterioration caused by a brass sampler, by improper reheating during voyage, by contamination in a pipeline, and by absorption of oxygen during various processing steps. Trade associations have published recommended procedures to minimize some of these problems. From these recommendations and many personal experiences, PORIM has drafted a “Code of Practice” bringing together elements of good design of physical facilities and of good operating practices. A copy of this code appears as an appendix to this paper.     

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.     

Tocopherole — Antioxidative Wirkung bei Fetten und Ölen

Tocopherols — Antioxidative Effect on Oils and Fats The main reason for the deterioration of fats and oils is a chemical reaction between the oxygen and the double bonds which are contained in the unsaturated fatty acids. In the course of the autoxidation intermediate peroxides affect the vitamines sensitive to oxidation. They lower the content of physiologically valuable essential fatty acids. The oxidation stability of oils and fats depends on the natural content of tocopherols as well as on the composition of the fatty acid. The effect of the added tocopherols depends on the natural content of tocopherols. Lipids with lower contents can be stabilized very well with antioxidants consisting of tocopherols. Here animal fats as well as synthetical lipids are considered which in particular are used in cosmetic industry and in the field of pharmacy but also in food industry. Vegetable oils contain, due to their nature, high contents of tocopherols which are partly removed or oxidised during raffination and storage. Therefore adding antioxidants containing tocopherols is adviseable. Also an addition of reducing substances as for instance ascorbylpalmitate is recommended. Moreover antioxidant systems should consist of heavy metal chelating substances.     

Acetin fats. I. Products made from mixed acetin fats

Summary The most striking effect of the introduction of the acetyl group into the glyceride molecule is the reduction in melting point. This effect permits the preparation of low melting fats and oils, or acetin fats, of a high degree of saturation and of a significantly increased oxidative keeping quality. Mixed acetin fats containing monoacetyl (monoacetins), diacetyl (diacetins), and normal triglycerides were made by random interesterification of normal fats or oils with triacetin, followed by removal of the residual triacetin. In general, mixed acetin fats may replace normal triglycerides in any edible fat use. Edible fat products including shortenings, margarines, or spreads, salad oils, and frying oils were made from acetin fats and oils. Suggested inedible use applications of the acetin fats and oils include plasticizers, tinning oils, and hydraulic oils.     

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.     

油脂市场走势分析

对世界油脂市场状况及中国油脂市场的现状进行了阐述,对中国的棕榈油市场及大豆油市场进行了分析。中国油脂消费量已经达到一定水平,中国已成为食用油消费、进口主要国,中国油脂市场的发展对世界油脂市场具有很大的影响力。2008年-2009年中国植物油产量提高较快,直接进口保持稳定。中国将努力扩大大豆和油菜籽等主要油料作物生产,大力发展芝麻和胡麻等油料作物的生产。论述了中国政策调控对国内油脂市场的影响。     

<Emphasis Type="Italic">cis</Emphasis>-, <Emphasis Type="Italic">trans</Emphasis>- and Saturated Fatty Acids in Selected Hydrogenated and Refined Vegetable Oils in the Indian Market

The fatty acid composition of 27 samples of commercial hydrogenated vegetable oils and 23 samples of refined oils such as sunflower oil, rice bran oil, soybean oil and RBD palmolein marketed in India were analyzed. Total cis, trans unsaturated fatty acids (TFA) and saturated fatty acids (SFA) were determined. Out of the 27 hydrogenated fats, 11 % had TFA about 1 % where as 11 % had more than 5 % TFA with an average value of about 13.1 %. The 18:1 trans isomers, elaidic acid was the major trans contributor found to have an average value of about 10.8 % among the fats. The unsaturated fatty acids like cis-oleic acid, linoleic acid and α-linolenic acid were in the range of 21.8–40.2, 1.9–12.2, 0.0–0.7 % respectively. Out of the samples, eight fats had fatty acid profiles of low TFA (less than 10 %) and high polyunsaturated fatty acids (PUFA) such as linoleic and α-linolenic acid. They had a maximum TFA content of 7.3 % and PUFA of 11.7 %. Among the samples of refined oils, rice bran oil (5.8 %) and sunflower oil (4.4 %) had the maximum TFA content. RBD palmolein and rice bran oils had maximum saturated fatty acids content of 45.1 and 24.4 % respectively. RBD palmolein had a high monounsaturated fatty acids (MUFA) content of about 43.4 %, sunflower oil had a high linoleic acid content of about 56.1 % and soybean oil had a high α-linolenic acid content of about 5.3 %.     

Über den Einfluß von Licht verschiedener Intensität und Wellenlängenbereiche auf den oxydativen Verderb von Speiseölen II: Versuchsergebnisse und Diskussion

Influence of Light of Varying Intensity and Wavelength on the Oxydative Deterioration of Edible Oils II: Experimental Results and Discussion Since the action of light is a major cause for the deterioration of oils and fats, light-catalyzed oxidation of refined soybean oil was carried out under defined conditions of intensity and wavelength and the quantum yields were calculated. Not only was the intensity of light varied at a constant wavelength but also, in contrast to hitherto known work, the quantum density was held constant at various wavelengths. The photochemical action was dependent on the wavelength and the former increased with decreasing wavelength to a much greater extent than as might have been expected from the energy content of the light quantum.