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A new catalyst, ruthenium-tin-alumina is found to selectively hydrogenate oleic acid to 9-octadecen-l-ol (ohyl + elaidyl alcohol) at low pressure with high yield. Catalyst preparation methods, catalyst raw materials and activation conditions have a significant effect on the activity of the catalyst. The optimum atomic ratio of ruthenium to tin is about 1:2. Catalyst prepared by an improved sol, el method shows higher activity and selectivity than catalysts prepared by impregnation and coprecipitation methods. Chloride is found to have a negative effect on catalytic activity. The best catalyst is prepared from chloride-free ruthenium and tin raw materials. Under the optimum reaction conditions of 250°C and 5.6 MPa, the selectivities for 9~Y~adecen-l-ol and total alcohol (9~ctadecen-l~l + stearyl alcohol) formation are 80.9% and 97%, respectively, at a conversion of 81.3%. KEY WORDS: 9-Octadecen-l-al, oleie acid, ruthenium-tin-alumina catalyst, selective hydrogenation, sol-gel method.

In direct screw pressing, kernels must undergo seed preparation steps of size reduction, flaking and steam conditioning prior to mechanical extraction. Mechanical wear and tear, maintenance expenses and electricity are the major costs. The direct solvent extraction process is used in larger plants. Production cost depends mainly on solvent loss and energy used in solvent recovery and pelletizing. However, oil recovery is more complete than in screw pressing. A third processing method uses pre‐pressing followed by solvent extraction. The choice of process or machinery depends on capital investment, production cost, oil recovery and its value. Whether the higher investment and production cost incurred in solvent extraction is offset by the higher oil extraction rate needs to be determined. Strict quality control right from fruit processing to kernel extraction is necessary to ensure production of good quality oil and by‐products. Malaysian palm kernel oil has proven to be of consistent quality, with narrow ranges in chemical characteristics. The palm kernel cake and pellets are important ingredients for animal feed.

Seven samples of domestic and imported Malaysian tub margarines were analyzed for their fatty acid and triglyceride (carbon number) composition, solid fat content, dropping and softening points, crystallization temperature, polymorphic form, color, and textural attributes. Domestic margarines were formulated from palm oil or palm olein and palm kernel oil with a liquid oil but no hydrogenated oils. Two imported products contained hydrogenated palm oil product, which resulted in a high level of lY crystals, whereas the domestic nonhydrogenated products contained more 13 than 13' crystals. Crystal habit was related to the fatty acid and triglyceride composition of the high-melting glycerides. Domestic products were firmer in texture, probably because they were formulated to be sold in a tropical climate. JAOCS 73, 995-1001 (1996).

A rapid Fourier transform infrared (FTIR) spectroscopic technique coupled with fixed NaCl cell (1 mm pathlength) was developed to measure peroxide value (PV) in crude palm oil (CPO) and crude palm kernel oil (CPKO). Calibration standards were prepared by oxidizing CPO in a fermentor at 60C over a period of 24 h. A partial least squares (PLS) calibration model for predicting PV was developed based on the 3710–3210 cm‐1spectral region with reference to a single‐point baseline at 3710 cm‐1. The optimization of calibration factors was guided by the predicted residual error sum of squares (PRESS) test. The standard deviation (SD) of the calibration obtained was 0.46 PV over the range of 0.51–17.82 PV and the correlation coefficient (R2) was 0.998. The model was validated with an independent set of samples consisting of both laboratory and field samples. The overall SD for the validation set was sligthly higher (SD = 1.46 PV) with R2 of 0.989. Thus, it was demonstrated that PV measured by FTIR techniques was comparable to that obtained by the chemical method. The FTIR method has the

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A simple and reliable high-performance liquid chromatography method for the analysis of diesel oil in contaminated edible oils is described. Analysis is performed using a diol column with a mobile phase of heptane and isopropanol (94:6, vol/vol). Although baseline separation between diesel and other background fluorescent components was not achieved, quantitation was still possible using baseline integration. The method is linear over the range of 5-1000 µg/g with a correlation coefficient (r 2 ) of 0.9984. Average recoveries from spiked edible oils were 94.4-101.3%, with a limit of quantitation (LOQ) of 5 µg/g for sunflower oil, palm olein, and groundnut oil. Corn oil has a higher content of ester components, thus, LOQ was slightly worse (40 µg/g). The applicability of the method was confirmed by gas chromatography-mass spectroscopic detection to show the presence of diesel hydrocarbons in the suspected contaminated crude palm oil. This procedure provides a simple and sensitive method for determining diesel oil concentration in contaminated edible oils without prior sample cleanup or extraction.Paper no. J9730 in JAOCS 78, 519-525 (May 2001).

A method using high-performance liquid chromatography and fluorescence detection is optimized and validated for the determination of Dowtherm A TM in spiked oleochemicals and edible oils. The samples are directly injected into a reversed-phase C18 column, and Dowtherm A is detected using a fluorescence detector set at 247 nm excitation and 310 nm emission wavelengths. The simple isocratic mobile phase used is a mixture of methanol and water (90:10, vol/vol) at a flow rate of 1 mL/min. The limits of quantitation are from 0.1 to 0.2 µg/g. Mean recoveries ranged from 93.0 to 116% with reproducibilities of 1.29-3.84%. The procedure provides a simple, reliable and sensitive method for determining Dowtherm A residue in oleochemicals and edible oils without prior sample cleanup or extraction. KEY WORDS: Biphenyl and diphenyl oxide, Dowtherm A, thermal heating fluid.Deodorization, which is the final stage of the refining of an edible oil, requires temperatures up to 270°C. This is achieved by indirectly heating the oil in heat exchangers with a suitable heating medium whose temperature may reach 300°C. High-pressure steam is preferred nowadays, though thermal heating fluids (THF) are still used in many older plants. A commonly used THF is a eutectic mixture of biphenyl and diphenyl oxide, trademarked as Dowtherm A and Therminol VP-1. However, concern arises if contamination results from pinhole leaks or faulty joints of the coils (1,2). Although there were attempts to ban the use of THF in edible oil processing plants (3), the Codex Committee on Fats and Oils (CCFO) had resolved to allow the use of THF other than high-pressure steam on the basis of safety and risk evaluation and inspection procedures (4).Gas chromatographic (GC) methods have been reported for the determination of Dowtherm A in fats and oils (5-7). They require pretreatment of the samples prior to analysis via either a thin-layer chromatographic clean-up or a distillation step, whereas the American Oil Chemists' Society procedure (8) uses a solvent extraction technique. Although these GC techniques are sensitive, with detection limits of 0.2 µg/g, the procedures are time-consuming and tedious.A new high-performance liquid chromatographic (HPLC) method with fluorescence detection was developed by Moh and Tang (9) for the determination of Dowtherm A in spiked edible oils and oleochemicals. The limit of quantitation was found to be 0.1 µg/mL for all types of samples analyzed. This method is superior to those GC methods previously reported in that it requires no pretreatment. In order to ascertain the validity of the method developed, an interlaboratory study was undertaken to establish reproducibility data. MATERIALS AND METHODSAll solvents were of HPLC grade.Reference standards. Biphenyl and diphenyl oxide, 98% purity, were purchased from Fluka Chemika AG (Buchs, Switzerland). Dowtherm A was supplied by Dow Chemical Company (Midland, MI).Working standards. A 100-µg/mL stock solution was prepared by dissolving 10 mg Dowtherm A with methanol to the mark in a ...