Investigation of 1-decyne formation in cottonseed oil fried foods

1-Decyne identified in oxidized cottonseed oil was previously thought to originate from oleic acid. However, we have demonstrated that 1-decyne is a degradative product from the photo-oxidation of cyclopropenoid fatty acids (CPFA) naturally present in cottonseed oil. Products containing photooxidized cottonseed oil have the distinct off-flavor of 1-decyne. Experiments were conducted to identify the factors involved in 1-decyne formation. Reactions were done under the following conditions: (a) in the dark or under light, (b) with or without removal of CPFA from cotton-seed oil, (c) in the presence or absence of singlet oxygen quenchers, (d) in the presence or absencc of a hydroperoxide-reducing agent (triphenylphosphine), and (e) with or without photosensitizers. Methyl sterculate was used as a substrate for studying 1-decyne formation under photosensitized oxidation conditions in a model system. We have concluded that 1-decyne is formed by the photo-oxidation of CPFA utilizing chlorophyll as a photosensitizer. A reaction mechanism for 1-decyne formation is proposed. Presented at the 73rd AOCS annual meeting, Toronto, 1982.     

Quality of nigerian palm oil after bleaching with local treated clays

Laboratory investigations into the possibility of using local Nigerian clays in refining the Nigerian crude palm oil revealed that the Okija clay may possess some potential as an adsorptive cleanser in the refining process. Activated bentonite was used as the standard clay of comparison, and the performance of two local natural clays, leached with various concentrations of sulfuric acid, was evaluated for their use as alternative adsorptive cleansers in refining Nigerian crude palm oil. Measurements of peroxide values, para-anisidine values, carotene content and stabilities of the oils using the active oxygen method were used in assessing the relative performance of the clays. The clays exhibited similar trend of effects on identical batches of alkali-neutralized palm oil. In one set of experiments poor results were obtained when the degummed and alkali-neutralized palm oil was treated with clays leached with sulfuric acid at concentrations of 1M and 4M. Better results were obtained at acid concentrations of 2M and 3M. Bentonite proved better than Okija clay when the leaching was performed with 2M H₂SO₄, but both clays had comparable effectiveness when 3M H₂SO₄ was used for leaching. The Nsu clay gave the least encouraging results. In another series of experiments the results showed that for various dosages of clay, up to 3% by weight of the oil to be refined, the oxidative stability of the processed oil was reasonably good for an oil which was neither deodorized nor treated with antioxidants.     

Polymorphism of palm oil and palm oil products

Palm oil, palm stearin, hydrogenated palm oil (IV 27.5) and hydrogenated palm olein (IV 28) were crystallized at 5°C, temperature cycled between 5 and 20°C, and kept isothermally at 5°C for 36 days. The polymorphic state of the fats was monitored by X-ray diffraction analysis. Soft laser scanning of X-ray films was used to establish the increase inβ crystal content. Palm stearin was least stable in theβ′ form, followed by palm oil. The hydrogenated oils were very stable in theβ′ form. Differential scanning calorimeter (DSC) analysis was used to complement the X-ray data.     

Stability of tapioca chips fried in RBD palm olein treated with antioxidants

The effectiveness of tertiarybutylhydroquinone (TBHQ), butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in stabilizing tapioca chips was assessed by determining the peroxide andp-anisidine values, absorbances at 232 nm and 268 nm and the 18:2/16:0 ratios of oil extracted from tapioca chips. The order of effectiveness of the antioxidants in stabilizing the chips was found to be TBHQ > BHT > BHA. The order of effectiveness of antioxidants, TBHQ > BHT > BHA, was maintained for chips from corresponding 1st, 4th and 7th fryings. The loss of antioxidants during storage could not be directly related to oxidation parameters.     

Frying performance of a sunflower/palm oil blend in comparison with pure palm oil

The aim of this study was to test the performance of a vegetable oil blend formulated as alternative to pure palm oil as frying medium. For this purpose, the evolution of many analytical parameters (free acidity, spectrophotometric indices, total polar components, fatty acid composition, short‐chain fatty acids, tocopherol and tocotrienol content and composition, color, flavor evaluated by means of an electronic nose) of the selected blend (sunflower/palm oil 65 : 35 vol/vol) has been monitored during a prolonged frying process (8 h discontinuous frying without oil replenishment) in comparison to pure palm oil. Sensory attributes of the fried food were also evaluated. The blend proved to keep qualitative parameters comparable to those shown by palm oil during the prolonged frying process. Even if some oxidation indices, such as spectrophotometric indices, short‐chain fatty acids and total polar components, increased faster in the blend, it showed a higher tocopherol content and a lower increment in free fatty acids as compared to pure palm oil. Chips fried in the two oils did not show significantly different sensory profiles.     

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.     

Influence of processing and palm oil on the carbonyls and fatty acids in Nigerian cassava foods

Monocarbonyls, free fatty acids and total fatty acids were determined for traditionally and mechanically processed gari, lafun, and crude palm oil. n-Alkanals and 2-alkanones were most abundant in the cassava foods, and unsaturated aldehydes contributed by palm oil to yellow gari were observed to a limited extent. 2-Alkanones were not found in the palm oil, which indicated that they arise through the fermentation processes. Mechanically processed gari exhibited a total fatty acid profile generally similar to traditionally processed gari. On leave from the Department of Food Science and Technology, University of Ife, Ile-Ife, Nigeria.     

Comparative evaluation of palm oil color measurement using a prototype palm oil colorimeter

The color of refined palm oil and palm oil products is conventionally measured using the manually operated Lovibond^® Tintometer. In the present study, one manual/visual and three automatic colorimeters for the measurement of vegetable oil color were used for color measurements of refined palm oil. All colorimeters used were commercially available instruments except for an automatic palm oil colorimeter developed specifically for the measurement of palm oil color. The color values obtained from all four instruments were compared using the visually obtained readings as reference values. Results showed that all three automatic instruments gave correlation coefficients of greater than 0.9300 for red color measurements. In addition, the Student t-test showed no difference between the analysis of red color using the visual method and the palm oil colorimeter. This investigation concludes that, although it is extremely difficult to reduce the lack of precision in color measurement of palm oil, a properly designed and calibrated automatic instrument may still be the better choice because reproducibility and repeatability are required in all standard test methods. The palm oil colorimeter offers a ready and relatively inexpensive solution to the problem of color matches based on visual observations.     

The palm oil situation

In broad perspective, total world demand for oils is growing rapidly, and palm oil will be seen in future years as a welcome addition to total world supply. It also seems clear that palm oil utilization is broadening at a faster rate than production is increasing. It appears this utilization is growing fastest in the “new markets” of Asia, the Mid-East and Latin America, rather than in the “old markets” of Europe and the United States.     

Reaction of carotenes in palm oil with acid

Carotenes in palm oil reacted with strong acid under nonaqueous conditions to produce blue-green cations that initially absorbed with a broad maximum at approximately 900 nm. These cations were postulated to be formed from the protonation of the α- and β-carotene at the seventh carbon atom, with the charge delocalized between the 8 and 9 conjugated double bonds. They were unstable at room temperature and may, by isomerization and oxidization, form carotenoid compounds with shorter conjugation. The resulting carotenoids can be protonated further to form cations, which absorbed between 500–900 nm, with γ_max of approximately 800 nm. The transient blue-green color observed in partially bleached palm oil is likely due to the presence of these cations.     

Ouricury palm kernel oil

A small sample of ouricury palm fruits from Florida, as well as the oil expressed from the kernels imported from Brazil have been investigated. The fruits consisted of 47.5 per cent of pulp and 52.5 per cent of palm nut, of which the kernel amounted to 23.8 per cent. On the basis of the whole fruit, the oil in the pulp only amounted to 0.9 per cent. The kernels from Brazil contained 69.7 per cent of oil, some of the characteristics of which were as follows: Saponification value, 256.9, iodine number (Hanus), 14.69, thiocyanogen value, 12.78, Reichert-Meissl value, 5.93, Polenske number, 18.38, and unsaponifiable matter, 0.27 per cent. The percentages of fatty acids found in the oil were as follows: Caproic 1.66, caprylic 9.10, capric 7.64, lauric 42.7, myristic 8.43, palmitic 7.15, stearic 2.15, arachidic 0.96, oleic 12.18, and linoleic acid 2.04 per cent. Attention has been called to the importance of not assuming the presence in distilled ester fractions of the lower homologues of oleic acid from deductions made only from calculations using the iodine number and saponification value of the fraction without confirmation by other evidence. The present investigation has shown the danger of such assumptions. Carbohydrate Research Division, Bureau of Chemistry and Soils, U. S. Department of Agriculture     

Dehulling of palm kernel of oil palm (Elaeis guineensis) to obtain superior-grade palm kernel flour and oil

A novel method has been developed for the removal of the thin, dark-brown skin, called testa, from the palm kernel of the oil palm (Elaeis guineensis) by chemical treatment. Studies carried out for this purpose included physical or mechanical means, dry or wet heat, solvents and other chemicals. Of the procedures tried, treatment with hydrochloric acid (HCl) resulted in complete removal of the testa, producing a pearl-white palm kernel. All other treatments were found to be ineffective. Based on our laboratory studies, semi-large-scale trials were made with 4N HCl for continuous dehulling of palm kernel in an abrasive peeling machine for the preparation of superiorgrade kernel flour and oil.     

Characterization of palm acid oil

Palm acid oil (PAO) is a by-product obtained from the alka-line refining of palm oil. It is used for making laundry soaps and for producing calcium soaps for animal feed formulations. The properties and composition of PAO may differ according to variations in the palm oil feedstock and the alkaline refining process. Because information on the characteristics of PAO is limited, this investigation aims to establish the properties of this product. Quality and oxidative parameters of 27 samples of PAO were determined. The six parameters analyzed were moisture and free fatty acid content, peroxide value, iodine value, saponification value and unsaponifiable matter. Headspace-gas-chromatographic (HSGC) analysis and gas-chromatographic analysis of the extract from Likens-Nickerson steam distillation of the samples were also carried out. Mean moisture content was 0.98%, free fatty acids 62.6% (palmitic acid), peroxide value 4.1 meq/kg, iodine value 50.2, saponification value 186 and unsaponifiable matter 0.53 HSGC profiles of a few samples showed the presence of one to three peaks, while the steam distillation extract showed the presence of aldehydes, ketones, furans and acids.     

棕榈油市场分析

分析了2008年度的棕榈油市场发展状况,对2009年度的棕榈油市场进行了展望和预测。同时,对全球棕榈油库存及库存使用比以及在全球贸易中所占比例进行了分析。     

Steam deacidification of palm oil

This work presents the application of response surface methodology (RSM) to the study of the effects of three factors (temperature, percent stripping steam and the stearin/olein ratio) on the losses/transfer of fatty compounds during the steam deacidification of blends of palm oil fractions (stearin and olein) as model systems. The responses of interest were the final oil acidity and the loss of neutral oil (NOL). These experiments were unprecedented in terms of the monitoring and controlling of the process variables during the heating and stripping periods in a laboratory scale batch deodorizer. The results revealed that the oil composition was an important and statistically significant factor in the selection of more suitable processing variables, besides temperature and steam.     

Torrefaction of oil palm wastes

This paper describes the effect of torrefaction on the basic characteristics of agricultural biomass wastes in Malaysia, such as empty fruit bunches (EFB), mesocarp fiber and kernel shell as a potential source of solid fuel. Mesocarp fiber and kernel shell exhibited excellent energy yield values higher than 95%. EFB, on the other hand, exhibited a rather poor yield of 56%.