Palmöle und Palmöl-Fraktionen und ihre analytische Differenzierung

Palm Oils and Palm Oil Fractions and their Analytical Differentiation Due to the increasing production of palm oils and the correlating production of palm oil fractions there is a need to differentiate analytically between palm oils and palm oil fractions. The analytical differentiation of these products on the one hand and the detection of unwanted additions and mixtures on the other hand is intended to be achieved. Palm oils of different origin and palm oil fractions, fractionated by different procedures, were examined in this context. The composition of total fatty acids, fatty acids in 2-position of the triglycerides, slip point, iodine value, composition of triglycerides by gaschromatography as well as saturated triglycerides were determined. The slip point, which can easily be determined, and the palmitic acid content in 2-position of t he triglycerides proved to be most suitable for the analytical practice.     

Triglyceride analysis by combined argentation/nonaqueous reversed phase high performance liquid chromatography

Full analysis of triglycerides of natural fats and oils has been investigated by the combination of argentation high performance liquid chromatography (HPLC) with nonaqueous reversed phase (NARP) HPLC. An infrared detector was used in argentation HPLC, because it indicated molar responsibility to all triglycerides. After peak trapping with argentation HPLC, each triglyceride fraction was analyzed with NARP chromatography using the glyceride-selective post-column reactor detector. The results of the analyses of triglycerides of palm oil and cocoa butter by the proposed method agreed well with those reported earlier.     

Determination of glyceride composition of several solid and liquid fats

Cocoabutter, Sumatra palm oil, lard, groundnut oil, soybean oil and cottonseed oil have been analyzed by separating the triglycerides according to their degree of unsaturation by means of thin-layer chromatography on silica impregnated with silver nitrate. Of each triglyceride fraction obtained in this way, the fatty acid composition—overall and at the 2-position—has been determined. Moreover, the triglyceride composition of the fractions of cocoabutter, Sumatra palm oil and lard has been determined by means of gasliquid chromatography. The results confirm the correctness of Vander Wal’s theory on the distribution of fatty acids in the triglycerides of vegetable natural fats.     

Separation of crude palm oil components by semipreparative supercritical fluid chromatography

Successful separation of triglycerides, diglycerides, free fatty acids, carotenes, tocopherol, and tocotrienols from crude palm oil has been achieved by supercritical fluid chromatography (SFC) with a combination of a C18 and a silica gel column. The separation was carried out by the programmed extraction elution method. Free fatty acids were separated into five components by gas-liquid chromatography; tocopherol and tocotrienols were also separated into four components by SFC analysis, and the pure fractionated carotenes were obtained by preparative SFC. Thus, by using supercritical fluid chromatography, crude palm oil components can be separated and fractionated, based on differences in their functional groups.     

Gradient Elution HPLC of Fats and Oils with Laser Light Scattering Detection

Gradient elution HPLC of oils and fats using reversed-phase HPLC separation systems with laser light-scattering detection are described. Potential advantages and shortcomings are discussed. Flexible solvent gradient programming permits an adaptation of the system to several types of applications. Using systems of this type the usual solubility problem with long-chain saturated triglycerides can easily be overcome. A useful test-mixture consisting of a series of saturated triglycerides two carbon numbers apart can be obtained by interesterification of hydrogenated palm kernel oil and hydrogenated palm oil. HPLC systems of this type will also permit the simultaneous investigation of diglycerides and triglycerides in oils.     

Glyceride analysis of palm oil after solvent fractionation

A procedure is described for determing the triglyceride composition of palm oil and its fractions by the use of silver nitrate thin layer chromatography (TLC) and gas liquid chromatography (GLC). The triglycerides separated by silver nitrate TLC according to the number of double bonds are quantified using infrared spectroscopy before further analysis by GLC according to carbon number. The results from the two techniques enable the composition of the oil and fractions to be computed on a molecular basis in relation to fatty acid types. The potential application of this procedure is to analyze fractions obtained from the fractionation of oils and fats to which the 1,3-Random-2-Random distribution theory is not applicable.     

Die quantitative DC-Analyse von Triglyceriden

Quantitative Thin-Layer Chromatographic Analysis of Triglycerides Natural and synthetic mixtures of triglycerides can be separated to a considerable extent by the combination of argentation and reversed phase chromatography. Various methods are available for the quantitative determination of the triglycerides that are pre-fractionated on silver nitrate plates. However, for the subsequent reversed phase chromatography, no satisfactory method was available so far for the quantitative determination of the separated triglyceride fractions. For such fractions a modified chromotropic acid procedure has been developed which enables the determination of triglycerides in the presence of a large excess of paraffin. The aforesaid method in combination with a new technique for staining offers a wide scope for qualitative and quantitative determination of complex mixtures of triglycerides that could not be separated so far. An application of these methods is demonstrated on an example of the triglycerides of palm kernel oil.     

HPLC of triglycerides

Triglyceride separation was investigated on a reverse phase high performance liquid chromatography (HPLC) column using two different solvent systems. Complete separation of model compounds differing by two methylene groups was achieved. Partial or complete separation was also observed in critical pairs; for example, the different types of triglycerides consisting of palmitic and oleic acids. This observation was confirmed on natural oils (coconut oil, palm kernel oil).     

Influence of the position of unsaturated fatty acid esterified glycerol on the oxidation rate of triglyceride

The influence of the position of unsaturated fatty acid esterified glycerol on the oxidation rate of triglyceride was investigated at 50 C. Randomized triglycerides used were prepared by random interesterification between saturated and unsaturated monoacid triglycerides using sodium methoxide as catalyst. The monoacid triglycerides used were tripalmitin, tristearin, triolein and trilinolein. The molecular species of the randomized triglycerides were analyzed by high performance liquid chromatography (HPLC) in combination with gas liquid chromatography (GLC) and enzymatic hydrolysis. From the results of oxygen absorption measurement by GLC, the randomized triglycerides were more stable towards oxidation than the triglyceride mixtures which were prepared by mixing the equivalent quantities of the same monoacid triglycerides as used in the random interesterification. This may be due to the decrease in the contents of most unstable unsaturated monoacid triglycerides by random interesterification with saturated monoacid triglycerides. Furthermore, from the results obtained with the detailed analysis of the randomized triglycerides at different stages of oxidation, it became clear that the triglycerides having unsaturated fatty acids linked at the 2-position of glycerol are more stable towards oxidation than those linked at the 1(or 3)-position. The carbon chain length of saturated fatty acids has essentially no influence on the oxidation rates of unsaturated fatty acids esterified in the same glycerol.     

Fractionation of palm oil

Because of its fatty acid composition, which includes 50% saturated and 50% unsaturated fatty acids, palm oil can readily be fractionated, i.e. partially crystallized and separated into a high melting fraction or stearin and a low melting fraction or olein. Three main commercial processes for fractionating palm oil are in use: the fast dry process, the slow dry process and the detergent process. All these processes lead to specific products of different quality with different yield and operating costs. The physical and chemical characteristics as well as the triglyceride compositions by high performance liquid chromatography (HPLC) of palm oil fractions from these industrial fractionation processes are given. Other varieties of products produced by specific fractionation are presented with analytical data: the superoleins, palm-mid-fractions and cocoa butter substitutes.     

A Practical Method for Analysis of Triacylglycerol Isomers Using Supercritical Fluid Chromatography

Triacylglycerol (TAG) isomers have been reported to have differing physical and nutritional properties. The analysis of TAG isomers is therefore important for understanding the physical properties of lipids as well as their digestion and absorption. However, methods for the quantitative analysis of TAG regioisomers and enantiomers in vegetable oils and biological samples are still under development. Recently, methods using recycle high-performance liquid chromatography (HPLC) and silver ion column-HPLC have been reported. However the recycle HPLC method requires more than 1 hour, in general, for each sample that is analyzed. Furthermore, existing methods are unable to quantify regioisomers and enantiomers simultaneously. Thus, we aimed to develop a practical method to simultaneously quantify regioisomers and enantiomers of TAG. Three isomers of sn-POO, OPO, and OOP were separated by supercritical fluid chromatography coupled with triple quadrupole mass spectrometer (SFC/MS/MS) using a CHIRALPAK^® IG-U column with acetonitrile and methanol as mobile phase. The separation was completed in 40 min, which is a shorter run time than the conventional techniques published to date. Linear calibration curves with standards were obtained and used to quantify sn-OPO, sn-POO, and sn-OOP in extra virgin olive oil, refined olive oil, palm oil, palm olein, and interesterified palm olein.     

The triglyceride composition of linseed oil

The triglyceride composition of linseed oils obtained under different ecological conditions and having different fatty acid compositions was determined by a combination of several chromatographic techniques. The triglyceride mixture was first separated in 8 fractions of different polarity by reversed-phase paper chromatography. Each glyceride fraction was then separated in a partition chromatographic system as the triglyceride coordination complexes with silver ions into individual compounds. The fatty acid compositions of the original oil, single glyceride fractions, and individual triglycerides were determined by gas-liquid chromatography. The molar ratio between the two neighboring glyceride fractions was determined by relating the fatty acid composition of each fraction to the fatty acid composition of their sum. The triglyceride composition of the total oil was then calculated from these results. The presence of 18–19 triglycerides was ascertained in the samples studied, and the molar concentration of each glyceride was estimated. Linseed oil contains only triunsaturated and monosaturated-diunsaturated triglycerides. Within each of these types the fatty acid distribution is close to random. At the same time, the content of some triglycerides departed regularly from a random pattern. A method for calculation of linseed oil triglyceride composition from the fatty acid composition is given. The same general pattern of glyceride formation in linseed is followed regardless of ecological conditions; therefore, the qualitative and quantitative triglyceride composition reflects the differences in fatty acid composition of linseed oil.     

Gas-liquid chromatography of triglycerides from erucic acid oils and fish oils

By critically selecting optimum operating conditions, quantitative gas-liquid chromatography of triglycerides has been extended to molecules containing substantial amounts of C₂₀, C₂₂, and C₂₄ fatty acids. The triglycerides of four erucic acid oils (water cress, rapessed, nasturtium, andLunaria annua) and two fully hydrogenated fish oils (menhaden and tuna) have been quantitatively analyzed by this technique. The average fatty acid chain length calculated from the triglyceride composition of each oil agreed closely with that determined by GLC of its respective methyl esters. Several conclusions about the triglyceride composition of the fats analyzed are discussed. Winner, AOCS Bond Award. Presented at the AOCS Meeting in Cincinnati, October 1965.     

Near infrared spectral patterns of fatty acid analysis from fats and oils

A near infrared (NIR) spectral pattern of oil contains information about fatty acid composition, because NIR absorption bands around 1600–1800 nm and 2100–2200 nm are due to the straight carbon chain andcis double bonds, respectively. This study was undertaken to build a foundation for the rapid determination of the fatty acid composition in oil by an NIR method. First, NIR spectra of pure triglycerides were measured and characterized. Fatty acid compositions could be estimated roughly by comparing the spectra of fats and oils (butter fat, pig milk fat, soybean oil and palm oil) with those of pure triglycerides. Secondly, the NIR spectra of these fats and oils were reconstructed by summation of the triglyceride spectra, which are multiplied by factors corresponding to the fatty acid composition of the sample determined by gas chromatography. The calculated spectra agree with the originals, especially for that of soybean oil. However, in order to reconstruct spectra precisely, it may be necessary to reevaluate the loading weight of each triglyceride, which was equal in this study. Part of this study was presented at the 3rd International Conference on Near Infrared Spectroscopy on June 28, 1990, Brussels, Belgium.     

Using SPME-GC/MS to Evaluate Acrolein Production in Cassava and Pork Sausage Fried in Different Vegetable Oils

This work presents the quantification of acrolein in cassava and pork sausage fried (temperature of 170 °C) in five different vegetables oils: canola, palm, sunflower, soybean and corn using a method of solid-phase microextraction (SPME) combined with gas chromatography and mass spectrometry. The results showed that the highest concentration of acrolein was found in samples fried in sunflower oil and canola oil. The concentration of acrolein in pork sausage (3.7 and 2.0 ng/g/g) was lower than in cassava (10.2 and 3.8 ng) when fried in sunflower and soybean oils, respectively. In contrast, when the denser oils (canola and palm) were used for frying, the concentration of acrolein in pork sausage (6.3 and 3.8 ng/g) was higher than in cassava (3.7 and 2.8 ng/g). Using corn oil, the concentrations of acrolein in both cassava and sausage were similar (approximately 5 ng/g). The viscosity of the oil, the fatty acid composition, especially the level of saturated and unsaturated fatty acids from the food, and oil uptake are factors that influence the acrolein concentration found in fried food.     

Unusual lipids II: Head oil of the north Atlantic pilot whale,Globicephala melaena melaena

Pilot whale head oil (blackfish head oil, raw) was analyzed by means of IR spectroscopy, NMR, thin layer chromatography, and gas liquid chromatography-mass spectrometry. The oil consisted of hydrocarbons (mainly pristane) (3%); waxes and cholesterol esters (9%); triglycerides (87%) (i.e. non-11%, mono-19% and di-57% isovalero triglycerides) and cholesterol and diglycerides (1%). By mass spectrometry, the diisovalero triglycerides were shown to be mainly symmetrical. Fatty acids were isobranched or normal (only traces of anteiso acids were found), saturated, or monounsaturated. Isovaleric acid predominated (54 mole % fatty acids), the rest having 10–18 carbon atoms. A 5-carbon fatty acid was the only acid found in the waxes. The alcohol composition qualitatively resembled that of the fatty acids, but major quantitative differences were present. This rules out direct interconversion of all fatty acids and alcohols. The possible role of these lipids in ultrasound transmission is discussed.     

Processing for industrial fatty acids - II

Fatty acids are produced industrially from tallow, palm oil, palm stearin, palm kernel oil and coconut oil. The current and future supply situations of these raw materials and market economics favor palm stearin and palm kernel oil as major raw materials for fatty acids. The Malaysian oleochemical industry has adopted high-temperature and high-pressure “splitting” of triglycerides. Variations in product yields occurring in the processing of tallow and palm stearin and of coconut oil and palm kernel oil are indicated. Developments on the enzymic hydrolysis of triglycerides to fatty acids have been made, particularly in Japan. Enzymic hydrolysis at low temperature has the advantage of energy conservation compared to the high-temperature and pressure-splitting process. But enzymic hydrolysis is only applicable to triglycerides of low titre, such as palm kernel oil.     

Effect of medium-chain triglycerides on calbindin-D9k expression in the intestine

These studies determined the effect of the saturated fat source in infant formula on the expression of calbindin-D9k (CaBP-9k). Piglets were fed from birth to 8 d with milk or formula containing saturated fatty acids as medium-chain triglycerides (MCT), coconut oil, palm oil (Palm 1), or synthesized triglycerides with 16∶0 directed to thesn-2 position (Palm 2). Levels of intestinal CaBP-9k mRNA were significantly (P<0.01) higher in piglets fed formula with MCT than in piglets fed the other formula or milk; and higher in piglets fed the Palm-1 than in piglets fed Palm-2 formula. This is the first evidence that MCT alter piglet intestinal CaBP-9k mRNA.     

Formation of Polar Compounds During Deep‐frying—Determination by 1H NMR and ESR

The present study aims to elucidate the factors influencing the generation of polar compounds in oils during deep‐frying. Oils with different fatty acid compositions, including palm oil (PO), refined palm kernel oil (RPKO), and refined coconut oil (RCO), are applied in successive frying processes. ¹H NMR spectra reveal that heated PO has a higher percentage of allyl acyl group and is more prone to formation of non‐polar dimeric triglycerides as compared to other types of oils. In addition, electron spin resonance (ESR) spectra indicate that alkyl radicals are more predominant than alkoxy radicals in heated PO. In contrast, RPKO and RCO are inclined to generation of alkoxy radicals during the thermal treatment. The results reveal that oils with high unsaturated fatty acid content are more prone to generation and oxidation of non‐polar dimeric triglycerides. Practical Applications: The change in free radical profile and concentration is one of the indicators of lipid oxidation and polymerization. Alterations in the levels of alkyl and alkoxyl radicals, revealed by ESR, can be used to illustrate the formation of polar compounds in deep‐fried oils with different fatty acid compositions. The percentage of allyl acyl group, revealed by ¹H NMR, can be used to predict the generation of polar compounds. Therefore, this study provides useful information for the development of different methods to reduce polar compound formation in oils during thermal processing depending on the fatty acid composition of different deep‐fried oils.     

Determination of the glyceride structure of fats: Distribution of individual saturated and unsaturated acids1

A method has been devised which gives the distribution of saturated and unsaturated fatty acids. It involves fractionation of the triglycerides into groups on the basis of total unsaturation by employing chromatography on a silicic acid-silver nitrate column. The glyceride composition of each fraction is then determined by gas-liquid chromatography (GLC) of the oxidized glycerides. Using this method, the glyceride composition of lard and cocoa butter was determined to give quantitative amt of 24 and 18 glycerides, respectively. Duplicate analyses agreed to within ±0.5%. The fatty acid composition calculated from the glyceride composition agreed to within ±1.5% with that of the original fat. This approach provides a new basis for the evaluation of the glyceride tyes in natural fats and for the first time permits the quantitative determination of all the chemically different glycerides of myristic, palmitic, stearic, oleic, linoleic and linolenic acids in a fat. Presented at AOCS Meeting in Minneapolis, 1963. Issued at NRC 7947. National Research Council Postdoctorate Fellow. Prairie Regional Laboratory, Saskatoon, Sask.