Search

The bromthymol blue (BTB) method is currently used for the assessment of color in olive and seed oils by visual comparison with standard solutions. Two BTB scales were prepared with 2 yr difference and compared, and the recent one was used to analyze 502 virgin olive oil samples, obtained by the Abencor® technique reproducing the industrial procedure. The temporal chromatic degradation of the BTB samples after 2 yr [3.93 Commission Internationale de l’Eclairage (CIE) 1976-(L*a*b*) (CIELAB) units, on the average], as well as the small percentage of virgin olive oils matching the colors of the samples provided by the BTB scales (13.1% with a suprathreshold color tolerance of 1.52 CIELAB units), indicates the limitations of the BTB method. Linear regression models are proposed in order to compute with acceptable accuracy the BTB indices from chromaticparameters. The use of CIELAB for the specification and future studies on color in virgin olive oils is recommended.

Crude corn oil that contained 380 ppm of phosphorus and 5% of free fatty acids was degummed, bleached, and winterized for physical refining. The pretreatment and the steam-refining conditions were studied in pilot plant scale (2 kg/batch). The efficiency of wet degumming and of the total degumming processes, at different temperatures, was evaluated. TriSyl silica was tested as an auxiliary agent in the reduction of the phosphorus content before bleaching. The experimental conditions of the physical refining were: temperature at 240 or 250°C; 8 to 18 mbar vacuum, and distillation time varying from 1 to 3 h. Degumming at 10 or 30°C resulted in the removal of more phosphorus than at 70°C. Water degumming was more efficient than the processes of total degumming or acid degumming. Corn oil, degummed at 10 or 30°C, after bleaching passed the cold test, irrespective of the degumming agent used. Degumming and winterization took place simultaneously at these temperatures. The pretreatment was able to reduce the phosphorus content to less than 5 ppm. The amount of bleaching earth was reduced by carrying out dry degumming or by using silica before bleaching. Corn oil acidity, after physical refining, varied from 0.49 to 1.87%, depending on the residence time. Contrary to alkali refining, physical refining did not promote color removal due to the fixation of pigments present in the crude corn oil.

Two rapid turbidimetric methods have been applied to determine the content of wax in refined and refined-bleached sunflowerseed oils in the range of 0 to 120 ppm. Synthetic wax-oil mixtures were prepared to construct calibration plots. Turbidimetric results were compared with visual evaluation of these mixtures as well as of the industrial oils by an expert panel, during 2 wk, under cold-test (0°C) and tempering (15°C) conditions. Based on the standard AOCS cold-test, the visual turbidity threshold of these Argentine oils was under 40 ppm, a value significantly lower than that found in European cultivars. Also, while both types of industrial oils passed the cold-test, the refined oil developed cloudiness after tempering for 14 d, whereas the refined-bleached oil remained transparent. Because the calibration plots showed that the turbidity difference values, given by these fast methods, corresponded to wax contents that caused visible turbidity but fell into the nonsensitive region of the instrument, a simple standard addition technique was used to extend their sensitivity to these low wax contents. With this improvement, oils that contained more than 40 ppm of wax by fast turbidimetry, which can be expected to develop cloudiness on storage in the winter season, can be promptly identified, thus allowing any desired corrective action.

Color as a fundamental quality of edible oils has been determined primarily by visual comparison methods for many decades. The automatic colorimeters introduced recently made it possible to replace the manually operated visual color instrument, which requires experience to master and is often sub- ject to operator variabilities. A previous study with an automatic colorimeter, Colourscan, to measure the colors of refined and re- fined bleached cottonseed oils showed good agreement (r 2 = 0.99) with visual color measurements by means of the Lovibond- AOCS Color Scale. The current work is to establish a broad-scale correlation between the automated colorimeter and visual color measurements. In this international effort, factory-processed re- fined and refined, bleached, deodorized (RBD) canola, corn, cot- tonseed, peanut, sunflower and soybean oils, as well as refined palm olein, RBD palm oil, and washed, dried, filtered and de- odorized tallow were used. A total of 14 laboratories from the United States and Canada, and 16 laboratories from 12 countries outside of North America, participated in this collaborative study. The results of this study, with statistical analyses, are reported. JAOCS 74, 731-738 (1997).

Two sets of alkyd resins of variable oil lengths with the required properties for offset printing ink formulations, modified by sunflower and rapeseed oil, were synthetized according to the “monoglyceride” process. The influence of the acyl composition of the modifying vegetable oil and of the oil content on alkyds’ properties was determined by detailed chemical and rheological characterization. Molecular structure, size, and molecule size distribution appeared to be linked to these two factors. A comparative study with two usual linseed oil-modified alkyds led to determination of the more appropriate alkyds for applications in offset varnishes.

The economics of pilot- to large-scale processing of the new oilssed cropsCrambe abyssinica, Euphorbia lagascae, andDimorphotheca pluvialis into oil, fatty acids, or esters were estimated. It was found that the processing costs forCrambe seed to oil is in the same range as that for rapeseed (≈0.5 U.S. $/kg). Production of fatty acid esters from vernolic and dimorphecolic acids requires some special downstream processing operations that result in processing costs of about 1 U.S. $/kg ester. Good-qualityDimorphotheca oil is much more difficult to obtain and requires supercritical carbon dioxide extraction. Processing costs can be as high as 4 U.S. $/kg oil.

This research explores the feasibility of extracting cocoa butter and xanthines (theobromine and caffeine) from cocoa beans with supercritical CO2. It is difficult to carry out the extraction with CO2 alone in the temperature range 40–90°C at pressures between 80 to 300 bar. However, the addition of a polar cosolvent, such as ethanol, greatly enhances solubilities, especially that of cocoa butter. Based on experimental investigations and theoretical inference, the design of a potential industrial process for extracting cocoa butter and xanthines is proposed, in which ethanol is used as cosolvent, and distillation is used to separate and regenerate ethanol. The pressure required is much less than that for CO2 alone as specified in the patent literature.

An evaluation of the exhaust emissions from a compression ignition engine for fuels composed of 100 and 30% methyl esters of soy oil (SME) is described. These fuels were compared with a low-sulfur, petroleum #2 diesel fuel in a Caterpillar 3304, prechamber, 75 kW diesel engine, operated over heavy- and light-duty transient test cycles developed by the United States Bureau of Mines. More than 60 h of testing was performed on each fuel. The objective was to determine the influence of the fuels upon diesel particulate matter (DPM) and gaseous emissions. The effect of a modern diesel oxidation catalyst (DOC) also was determined in an effort to minimize emissions. Neat SME produced a higher volatile fraction of the DPM, but much less carbon soot fraction, leading to overall DPM reductions of 23 to 30% for the light- and heavy-duty transients. The DOC further reduced the volatile fraction and the total DPM. The SME fuel reduced gaseous emissions of CO by 23% and hydrocarbons by over 30% without increasing NOx. The DOC further reduced CO and hydrocarbon levels. Mutagenicity of the SME exhaust was low. Results indicate that SME fuel, used with a proper DOC, may be a feasible emission reduction technology for underground mines.

Crude palm oil was processed by continuous supercritical carbon dioxide. The process reduces the contents of free fatty acids, monoglycerides and diglycerides, certain triglycerides, and some carotenes. The refined palm oil from the process has less than 0.1% free fatty acids, higher carotene content, and low diglycerides. Solubility of palm oil in supercritical carbon dioxide increased with pressure. A co-solvent improves the refining process of palm oil.

In our study, we characterized the antioxidant activity and oxidative stability of cold-pressed macadamia, avocado, sesame, safflower, pumpkin, rose hip, Linola, flaxseed, walnut, hempseed, poppy, and milk thistle oils. The radical scavenging activity of the non-fractionated fresh oil, as well as the lipophilic and hydrophilic fractions of the oil was determined using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The fatty acid composition of the fresh and stored oils was analyzed by gas chromatography. The acid value, peroxide value, p-anisidine value and conjugated diene and triene contents in the fresh oils, as well as in those stored throughout the whole period of their shelf life, were measured by CEN ISO methods. The antioxidant activity of the oils expressed as Trolox equivalent antioxidant capacity (TEAC), ranged from 0.17 to 2.32 mM. The lipophilic fractions of the oils were characterized by much higher antioxidant activity than the hydrophilic ones. There were no significant changes in fatty acid composition and only slight changes in the oxidative stability parameters of the oils during their shelf life. Through the assessment of the relationship between antiradical activity and the oxidative stability of oils, it is proposed that a DPPH assay predicts the formation of oxidation products in cold-pressed oils—however, the correlations differ in fractionated and nonfractionated oils.

A novel continuous subcritical n-butane extraction technique for Camellia seed oil was explored. The fatty acid composition, physicochemical properties, and benzo[a]pyrene content of Camellia seed oil extracted using this subcritical technique were analyzed. Orthogonal experiment design (L9(34)) was adopted to optimize extraction conditions. At a temperature of 45 °C, a pressure of 0.5 MPa, a time of 50 min and a bulk density of 0.7 kg/L, an extraction yield of 99.12 ± 0.20 % was obtained. The major components of Camellia seed oil are oleic acid (73.12 ± 0.40 %), palmitic acid (10.38 ± 0.05 %), and linoleic acid (9.15 ± 0.03 %). Unsaturated fatty acids represent 83.78 ± 0.03 % of the total fatty acids present. Eight physicochemical indexes were assayed, namely, iodine value (83.00 ± 0.21 g I/100 g), saponification value (154.81 ± 2.00 mg KOH/g), freezing-point (−8.00 ± 0.10 °C), unsaponifiable matter (5.00 ± 0.40 g/kg), smoke point (215.00 ± 1.00 °C), acid value (1.24 ± 0.03 mg KOH/g), refrigeration test (transparent, at 0 °C for 5.5 h), and refractive index (1.46 ± 0.06, at 25 °C). Benzo[a]pyrene was not detected in Camellia seed oil extracted by continuous subcritical n-butane extraction. In comparison, the benzo[a]pyrene levels of crude Camellia seed oil extracted by hot press extraction and refined Camellia seed oil were measured at 26.55 ± 0.70 and 5.69 ± 0.04 μg/kg respectively.

Using advanced electron paramagnetic resonance techniques (EPR), oxidation of crude vegetable oils and their components (fatty acids and triglycerides) by radicals generated from hydrogen peroxide was investigated. The correlation rotational times were determined allowing us to characterize radicals formed during edible oils oxidation. Additionally 1H- and 14N-hyperfine coupling constants differentiate the fatty acids dependently on their unsaturation. The acids with a higher number of unsaturated bonds exhibit higher AN values of PBN/·lipid adduct. The waste oil with high free fatty acids content underwent the oxidation reaction more efficiently, however due to saturation and the high content of the fatty acids the carbon-centered radicals formed (upon hydrogen peroxide radicals) and their PBN (N-tert-butyl-α-phenylnitrone) adducts were less stable. The antioxidant effect was dependent on the amount of α-tocopherol added. In small amounts of up to 0.35 mg/1 g of fatty acid or triglyceride, it inhibited the creation of PBN/·lipid adducts while with higher amounts it intensified adduct formation. The α-tocopherol (AT) addition influence was also studied as spin scavenging dependence and indicated that any addition of the antioxidant in the investigated samples led to free radical scavenging and the effect increased with the increase in AT content.

Fuel properties of beef tallow, soybean oil, their esters, and blends with No. 2 diesel fuel and ethanol were determined. Fuel properties tested were viscosity, specific gravity, API gravity, distillation ranges, calculated cetane index, energy content, flash point, water content, sulfur content, carbon residue, particulate matter, acid value, copper-strip corrosion test, ash content, melting point, cloud point, and pour point. Gas-chromatographic analyses of tallow, soybean oil, and their esters were performed to determine their major constituents. Viscosities of soybean oil and tallow were significantly reduced by esterification. Other fuel properties of the esters and their blends with No. 2 diesel fuel and ethanol were similar to the properties of No. 2 diesel fuel.

Physical refining of edible oils offers several advantages over alkali refining. The method described for physical refining of rapeseed oil involves several novel factors, including the availability of cold-pressed rapeseed oil low in phosphatide content and deacidification/deodorization in a film molecular evaporator. Parameters are presented from a pilot plant unit with an output of 500 metric tons per year. Further applications of the technology are proposed, including the processing of oils to pharmaceutical-grade products.

Dynamometer engine tests at steady-state conditions and a wear characteristics study were carried out on an indirect-injection diesel engine with palm oil diesel (POD) and its emulsions. The POD fuel was obtained in commercial form, and its emulsions were created by mixing POD fuel to contain 5 and 10% of water by volume. Variations in the engine’s performance characteristics were determined from the results of steady-state tests carried out at fifteen selected torque-speed matrix points of the engine’s performance map. The wear characteristics tests were performed by running the engine at half throttle setting for twenty hours for each fuel system. Then a desk-top comparison study was performed between the base-line fuel system of ordinary diesel (OD), POD, and its emulsions. Promising results have been obtained. Neither the lower cetane number of POD fuel nor its emulsification with water presented obstacles to the operation of the diesel engine during a series of steady-state engine tests and the twenty-hour endurance tests. Engine performance and fuel consumption for POD and its emulsions are comparable with those of OD fuel. Accumulations of wear metal debris in crank-case oil samples were lower with POD and its emulsions than with baseline OD fuel.

Rice hull silica and a rice hull carbon ash were evaluated as adsorbents for the soy oil bleaching process under commercial temperature and pressure conditions. Their performance in adsorbing pigment, phospholipid, free fatty acids, and peroxides was compared with that of a commercial bleaching clay and silica hydrogel. With the exception of phospholipid binding, rice hull-derived adsorbents were ineffective. Rice hull silica showed potential as a phospholipid adsorbent but was not as effective as the synthetic silica hydrogel on an adsorbent weight basis. However, it was a superior adsorbent when the data were expressed as adsorbate bound per unit surface area. The low surface area of the rice hull silica limits its commercial viability. It may have value in areas of the world where rice hulls are plentiful and an inexpensive phospholipid adsorbent is required for oil processing. Research is in progress to increase the surface area of rice hull silica for commercial oil processing.

Authentication of olive oils is of great importance, not only because they command a high price but also because of the health implications of adulteration with seed oils. A method for predicting the level of adulteration in a set of virgin and extra-virgin olive oils adulterated with corn oil, sunflower oil, and raw olive residue oil by near-infrared spectroscopy is presented. The best result was a correct prediction for 98% of the samples. Principal component analysis was used to predict the type of adulterant. The best result was a 75% prediction rate. From these results, it is concluded that it is possible to design a quality control system, which uses near-infrared technology to measure the level of adulteration. In the case where the only test is whether the sample is adulterated or not, a simple calibration for adulteration can be used. The results suggest that principal component analysis may offer a means of identifying the adulterant, although more work is required to give an acceptable level of accuracy.

Extraction of oilseeds with supercritical carbon dioxide (SC−CO2) is a promising technique to obtain vegetable oils. However, instability of such oils has been associated in the past with SC−CO2 extraction. The reasons underlying such instability were unclear. Results presented here suggest that oil instability may be related to the oxygen content of CO2. In fact, oil stability decreases sharply when refined oil (additive-free) is re-extracted with SC−CO2 and can be related to the oxygen content in the CO2. Never-theless, oil stability could be improved to the level of conventionally extracted oil by adding trace amounts of ascorbic acid.

The recent development of combustion-type nitrogen analyzers capable of handling relatively large samples with semi automatic operation offers a potential replacement for the Kjeldahl method for direct determination of nitrogen. Nitrogen analyses for canola seed, flaxseed, sunflower seed, mustard seed and soybeans on a LECO (St. Joseph, MI) FP-428 Nitrogen Analyzer were evaluated against results from the Grain Research Laboratory's (GRL) Kjeldahl system. The nitrogen analyzer gave significantly higher values than the Kjeldahl method, resulting in a correction of low values in the GRL Kjeldahl, caused by the inability to use mercury as catalyst. The standard error for results from the analyzer was comparable to that for the Kjeldahl method. The nitrogen analyzer also was faster than the Kjeldahl method and had less environmental impact. The combustion method has replaced the Kjeldahl method for routine nitrogen determinations in oilseed surveys conducted by the GRL.

Traditionally, hydrocarbons have been used for biosurfactant production. However, urban waste, peat pressate and agroindustrial by-products, such as olive oil mill effluent and acid whey, are possible substitutes for microbial growth and biosurfactant production. The state of the art has been reviewed, augmented by some new information onPseudomonas fermentation of olive oil mill effluent. More research is needed to improve yields and production economics.

Simulation of commercial processing of Cuphea seed to obtain needed quantities of oil and meal was accomplished with pilot facilities. Cuphea seed was conditioned in a single-deck cooker. Cooked seed was pressed with a mechanical screw with two-speed shaft, variable-speed drives and a four-section cage with cored sleeves. A feed rate of 22 kg seed/h and a feed screw-to-main shaft ratio of 2:1 gave good press cake with 8.1% residual oil. Press cake was extracted in a batch-type modular extraction pilot plant. Miscella stages were sequentially pumped through the beds, followed by hexane rinses. Spent cake was desolventized and toasted, and full miscellas were stripped to recover the crude oil. The finished Cuphea meal had only 0.30–0.55% residual oil. Thus, conditioned Cuphea seed was easily pressed without prior flaking to acceptable cakes, and conditions simulating commercial solvent extraction efficiently removed residual cake oil.

Results of performance, emission and tribological evaluations of palm oil methyl ester and its blends with conventional diesel in an automobile diesel engine test bed are presented. Polymerization and carbon deposits on the fuel injector were monitored. CO, CO2, O2, combustion efficiency and temperature of exhaust gases were also measured. Palm oil methyl ester and its blends have great potential as alternative diesel fuel. Performance and exhaust gas emission for palm oil methyl ester and its blends with conventional diesel are comparable with those of conventional diesel fuel. Palm oil methyl ester does not pose a severe environmental problem and will not deteriorate engine and bearing components.

The so-called press effect is widely credited with enhancing the overall efficiency of bleaching clays in commercial operations. Laboratory bleaches are generally done with one use of bleaching clay, while plant operations often include a process in which spent clay in a filter press acts as a fixed bed to remove additional impurities from slurry-treated oil. In this study, the press effect is simulated in the laboratory by measuring the influence of a progres-sively-built filter cake on concentrations of carotenes and chlorophyll in successive batches of slurry-contacted oils. The oil used was canola; the clay tested was a commercially available acid-activated clay classified to two different average particle sizes. Conditions were chosen to simulate those used in commercial operations. Better total bleaching was seen from the first batch to the last as filter cake was built up. In addition, a significant particle size effect was seen.

The investigation focussed on the use of carbohydrase enzymes to enhance oil extraction during pressing in a laboratory expeller. Enzyme-treated seeds at 6% moisture were pressed in the expeller set at full-press conditions. Control seeds were pressed at wider choke openings but at the same barrel pressures as enzyme-treated samples. Time of pressing and temperature and pressure inside the expeller barrel were used to calculate throughput and energy requirements per unit weight of processed material. Treatment with enzymes improved throughput of the expeller, increased oil flow rate and oil recovery. Material throughput was increased by 30–50%, depending on canola variety. The recovery of the oil was increased from 72% of the seed oil for control samples, to 90–93% for enzyme-treated samples. The average residual oil content in presscakes from enzyme-treated seeds was 7.4%. The oil quality was inferior to cold-pressed control but was much better than has been reported for solvent-extracted oil.

Life-cycle inventories were compiled to characterize natural resource requirements and environmental emissions associated with the sourcing and production of selected, detergent-grade surfactants and surfactant feedstocks. Petrochemical surfactant types examined were linear alkylbenzene sulfonate, alcohol sulfate (AS), alcohol ethoxylate (AE) and alcohol ethoxylate sulfate (AES). Oleochemical surfactants derived from palm oil, palm kernel oil and inedible tallow were AS, AE, AES and (for palm oil and tallow) methyl ester sulfonate. It was determined that natural resource requirements were primarily related to the source of feedstock and secondarily to surfactant type. Likewise, the composition and mass of atmospheric, aqueous and solid emissions were principally determined by feedstock source. Energy requirements varied as a function of both feedstock and surfactant type. The inventories do not support fundamental shifts in surfactant usage or feedstock sourcing on the basis of environmental concerns, as no single surfactant or feedstock was identified as superior across all resource and emissions criteria examined. The data provide baselines for evaluating opportunities for resource optimization, pollution prevention and waste minimization within each production technology surveyed.

An LC–MS method using a single quadrupole mass spectrometer was developed for direct analysis of glycidyl esters of fatty acids in vegetable oils. Without any sample clean-up, this method provided acceptable recovery of seven glycidyl esters, comparable results to a previously-published method utilizing two solid-phase extraction steps, and consistent detection parameters after greater than 200 injections without any cleaning operations performed. This method could readily be implemented as a screening assay for glycidyl esters in most oil laboratories.

The biorefining process under optimum conditions de-acidified the high-acid mohua oil by nearly 85% with considerable improvement of color. The process, in combination with alkali-refining, bleaching and deodorization, yielded excellent oil with respect to color, unsaponifiable matter content and triglyceride content. The combination of biorefining and physical refining significantly reduced the loss of oil, and the color, unsaponifiable matter and diglyceride content increased while triglyceride content decreased. The physical refining process alone, on the other hand, produced oil with considerably darker color, increased unsaponifiable matter and diglycerides, and decreased triglyceride. Biorefining followed by alkali-refining, bleaching and deodorizing steps or by physical refining can be regarded as a much better alternative refining process than the physical refining process alone for oils of high acidity.

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.

Deodorization and steam-refining parameters have significant impact on the quality of finished oil. Hence, optimization of parameters is critical for the production of acceptable oil. Temperature, time, throughput rate, sparging steam rate and pressure must be optimized to produce edible oil with desirable characteristics. Process optimization modeling in the laboratory, pilot plant and refinery is utilized to obtain predictive equations correlating product characteristics with deodorization parameters and feedstock properties. This optimization technique is demonstrated on model feedstocks and typical commercial oil. Finished corn and soybean oil quality are expressed by tocopherols and free fatty acid levels and sensory attributes during accelerated storage.

Lampante olive oil has been treated in a supercritical CO2 extraction plant operating in a continuous countercurrent mode. We report the results of a systematic investigation to define the optimal operative parameters. We also have examined the compositional variation of lampante olive oil samples with different characteristics and of different geographic origins before and after refining at optimal conditions. Although practical feasibility of the proposed procedure can be questioned, the results demonstrate the possibility of fractionating components contained in the starting oil even if present at trace levels.

Canarium schweinfurthii Engl. (Burseraceae) is a wild tree found mostly in Africa, which produces fruit similar to olives and which is barely used. On a dry matter basis, the fruit pulp from Cote d’Ivoire (the Ivory Coast) was found to contain 5.6% protein, 30–50% fat, 8.2% starch, 11.8% cellulose and 8.3% ash (the highest mineral elements being potassium, 1.2% and calcium, 0.4%). The melting and solidification points of the extracted fat (44.5°C and 35.2°C, respectively) are higher than those of all the commercial and otherCanarium-species oils. This oil shows low iodine, peroxide and carotene values (36, 17 meq-g and 2 mg, respectively). The fatty acid composition of the oil revealed a high content of oleic (89.4%) or stearic (67.7–84.0%) acids in the liquid, semi-solid and solid forms of the oil. Consequently, the content of these two acids is much higher inCanarium schweinfurthii oil than in any other vegetable oil. The three forms (liquid, semi-liquid and solid) of the oil depend on the maturity of the fruit and these stages will be investigated further in future work.

The application of epoxidized rapeseed oil as a biodegradable lubricant is described. The epoxidation treatment has no adverse effect on the biodegradability of the base stock. Epoxidized rapeseed oil has superior oxidative stability compared to rapeseed oil based on the results of both oven tests and rotary oxygen bomb tests. Moreover, the oxidative stability can be dramatically promoted by the addition of a package of antioxidants. The epoxidized rapeseed oil has better friction-reducing and extreme pressure abilities according to tribological investigations. Formation of a tribopolymerization film is proposed as explanation of the tribological performance of epoxidized rapeseed oil.

The disposal and re-use of spent bleaching clay from the vegetable oil processing industry is a problem of growing importance.

This preliminary analysis was undertaken to determine if the operations being developed for the aqueous ethanol extraction of cottonseed oil are economical and whether further research of this process should be pursued. Results of the conversion of hypothetical hexane extraction plants to ethanol extraction, in the plant capacity range of 300-600 tons of cottonseed flakes/day and operating 150-350 days annually, show that two unconventional operations, namely, chill-separation of miscella exiting the extractor and reduction of oil in recycled ethanol by reverse osmosis, require less energy and are less expensive than conventional alternatives. However, additional work is needed to determine the overall efficiency of an alcohol process as compared to a conventional hexane process.

Artificial cakes of bleaching clay/vegetable oil have been studied for their pyrophoric character using both Differential Scanning Calorimetry and a constant-temperature, fixed-interval, spontaneous heating (CaTFISH) test developed in this laboratory. It was determined that this is a two-step process involving a first-stage low-temperature spontaneous heating reaaction followed by a second-stage high-temperature spontaneous heating reaction. The latter is characterized by charring and, in some cases, flaming combustion. A study of relevant variables has established that clay type, filter cake age, oil retention, moisture, and the presence of antioxidant significantly affect the spontaneous heating characteristics of clay/oil masses. Oil type was not found to be a significant variable in these studies.

Lacquered metal cans, green glass bottles, amber glass bottles, clear glass bottles and clear plastic bottles filled with freshly produced Nigerian crude palm oil were stored in direct sunlight (40±1°C) and in the dark (27±1°C). Assessment of the stability of the oils towards hydrolytic and oxidative deterioration was made periodically by measuring the free fatty acid, peroxide and anisidine values over a period of 98 days. The study showed that crude palm oil packaged in plastic bottles and clear glass bottles recorded higher total oxidation values than oils packaged in either lacquered metal cans or amber and green glass bottles. Lacquered metal cans gave the greatest protection against oxidation. Oxidation proceeded faster in cases where the packaging materials were stored in direct sunlight.

Ultrasonic energy has been applied to continuous degumming for the efficient removal of phospholipids from crude soybean oil. The crude oil and water (2.0% by weight) were pumped through an ultrasonic processing cell, oil and hydrated gums were separated by centrifugation, and the recovered oil was vacuum bleached. The degummed and bleached oil had a residual phosphorus content of less than 10 ppm and was subsequently deacidified-deodorized in all-glass laboratory deodorization equipment. Odor and flavor evaluation indicated that the salad oil produced by the process of ultrasonic degumming/deodorization-deacidification was equivalent in quality and stability to a conventionally processed salad oil.

Jojoba oil has good lubricity and it can be utilized as a component in lubricating oil formulations. The physicochemical properties of the oil when compared with those of mineral oil base stocks showed that the pour point, acid value and oxidative stability were the limiting factors in its use as a base stock. Studies were carried out to improve these properties. The results indicated that these properties can be modified by physical and chemical methods and also by additive viscosity of jojoba oil by partial sulfurization, resulting in widening the scope of its utilization in developing lubricant formulations.

Edible oils may contain traces of metals. In oil refining procedures these metals have to be removed to guarantee oxidatively stable products. In this study we present a hollow fiber membrane extraction system for the removal of metals from an oil. Several extraction liquids were tested, of which an ammonia solution gives the best distribution coefficient (m=11.7). From mass transfer calculation it follows that the resistance to mass transfer in the extraction phase in the fiber wall can be neglected compared to the resistances in the oil phase inside the fibers and the extraction phase outside the fibers. A cost evaluation shows that such a membrane extraction can be profitable in conventional refining if more than 1.5% bleaching earth has to be added in surplus to remove metals.

Vernonia galamensis seed containing 40–42% oil and 30–34% epoxy acid, (cis-12,13-epoxy-cis-9-octadecenoic) was processed to oil and meal. Seed conditioning, pressing and solvent extraction research were conducted in pilot facilities at the French Oil Mill Machinery Co. (Piqua, OH). The robust lipase system was successfully inactivated by treating 200 lb. batches ofV. galamensis seed in a cooker/conditioner at 195–200°F and >10% moisture. Conditioned seed was mechanically pressed and the press discharge cone setting was varied during operation from 1/32″ to 3/32″ to demonstrate the feasibility of both full pressing and prepressing. Prepressing successfully reduced oil level in the press cake to ca. 20%. Press cake was extracted with hexane in a 1.5-ft3 batch-type, four-stage percolation unit with a 6″ square extraction cross section. Solvent extraction reduced oil level in the defatted meal to 1–2%. The defatted meal was desolventized and toasted. Excessive foaming of the vernonia oil extract made complete solvent stripping in the oil stripping unit difficult.

Most of the cottonseed oil mills in the United States have already converted to expander solvent extraction and miscella refining. This practice permits mills to produce and market a consistently light-colored, prime bleachable summer yellow cottonseed oil at reduced cost and refining loss. A laboratory-scale miscella refining test was developed to asses the oil quality in terms of its color. The test involves the addition of 3 parts oleic acid per 100 parts of crude oil in the miscella followed by refining with 2.5 parts NaOH when crude oil contains less than 4.5% free fatty acid (FFA). When crude oil contains FFA between 4.5 and 7.5%, no oleic acid is added prior to refining with 2.5 parts NaOH. When crude oil contains FFA higher than 7.5%, no oleic acid is added and the caustic addition table in American Oil Chemists' Society Method Ca 9a-52 is followed. The test was conducted at room temperature and gave reproducible colors comparable to commercially refined oils.

Energy crisis and growing fuel shortage is a global concern. This phenomenon is more conspicuous in the populous, developing countries. In order to look for alternatives and extenders to the conventional fuels, studies were performed on the seed oil of some relatively unknownPutranjiva roxburghii, a plant that is abundantly available in the Indian tropical subcontinent. In a prototype experiment, the physicochemical properties of theP. roxburghii seed oil were found to be suitable for blending with diesel up to 50% without any sacrifice in performance of an internal combustion engine. Another industrially useful material, factice (vulcanized oil), was also prepared from the same oil. It was found to be suitable for blending with rubber, improving its strength, hardness, viscosity, and scorch time, and also increased its degradation temperature. This oil is not commercially traded in the market and has not yet been recommended as edible; hence industrial exploitation will not affect consumer market directly. A few more preliminary experiments indicated that the by-product oilcake is a good plant nutrient and the oil exerts profound antifungal activity. These properties need to be investigated more extensively. This plant and its oilseed deserve further attention and investigation, particularly in the tropical, coastal developing countries.

Preparation and characterization of factice by vulcanization of oil extracted fromPutranjiva roxburghii, a fairly abundant plant of the tropical Indian subcontinent, is presented. This information serves as a processing aid for substituting commercially available factices. Mechanical and thermal studies of this new type of factice, blended with rubber, showed higher thermal stability and improved processing characteristics during extrusion and calendering operations compared to rubber without factice.

Dear Sir, In the November issue of JAOCS, you published an article [1] on the use of an artificial neural network for process optimization. I started reading this article with great interest and out of curiosity about this process investigation technique, which, as far as I am aware, has not been the subject of any article in this journal before. However, I soon realized that the authors lacked insight into the chemistry of the degumming process, as a result of which the model the authors propose has little to offer and is even misleading. The combined degumming and bleaching process of palm oil studied by the authors is commonly referred to as the ‘‘dry degumming process’’ [2, 3]. It involves a decomposition of the non-hydratable phosphatides (NHP) present in the oil by phosphoric acid, followed by a bleaching earth treatment. It is very suitable for oils and fats with low NHPcontent (palm oil, lauric oils and animal fats) and has the advantage that it reduces the number of refining steps to only two: dry degumming and physical refining. When summarizing their process, the authors mention that the amount of phosphoric acid used in Malaysian industrial palm oil refineries varies between 0.5 to 1.0 wt% of crude palm oil, and that the amount of bleaching earth varies between 1.0 to 2.0 wt%. In this respect, they disagree with a presentation at a recent short course [4], where 0.1 and 0.07 wt%, respectively, were reported. The authors provide a flow diagram of the combined process (Fig. 1).This flow diagram shows that the phosphoric acid is mixed with an unspecified fraction of the crude palm oil, and that the bleaching earth is mixed with the remainder. Subsequently, the oil stream containing the phosphoric acid and the oil stream containing the bleaching earth are both fed into a degumming and bleaching vessel. The temperature in this vessel is 100 C, the pressure 7 kPa, and the contact time in the batch process is 30 min. The strength of the phosphoric acid and the type of mixer used to disperse the phosphoric acid in the oil are not mentioned. Adding phosphoric acid to only part of the oil completely negates its role in degumming: the decomposition of NHP. For the phosphoric acid to react with as large a fraction of the NHP present as possible, a number of conditions must be met

A procedure for micro stereospecific analysis of triacyl-sn-glycerols (TGs) by high-performance liquid chromatography (HPLC) on a chiral column is presented. TGs were partially hydrolyzed with ethyl magnesium bromide, and total products were immediately converted to 3,5-dinitro-phenylurethane derivatives. Each of the 1- and 2-monoacylglycerol (MG) derivatives was isolated by HPLC on a silica column. The 1-MGs were resolved intosn-1 andsn-3 MG fractions by HPLC on a Sumichiral OA-4100 column (Sumitomo Chemical, Osaka, Japan). Fatty acid methyl esters obtained from thesn-1,sn-2 andsn-3 MG fractions were analyzed by gas-liquid chromatography on a capillary column. Analyses of standard TGs showed that, even with 1 mg of sample, accuracy was comparable to that obtained with 100-mg samples. Applying this procedure to the stereospecific analysis of 5 mg of jujube pulp, TGs revealed the positional distribution of the (n-5) series of monounsaturated fatty acids they contained.

High-quality brown factice is produced from meadowfoam and rapeseed oils, while a poorer-quality factice is produced from soybean oil, a less expensive oil. A one-to-one mixture of soybean and meadowfoam or rapeseed oil produces a factice that has similar physical characteristics as factice produced from 100% meadowfoam or rapeseed oils. In addition, meadowfoam oil and rapeseed oil act as accelerators when mixed with castor or jojoba oils. White factice productions from soybean oil can also be improved when mixed with meadowfoam or rapeseed oils. The difference in cost, obtained by using as much as 50% soybean oil instead of the higher-costing oil, will translate into significant savings for the factice and rubber industries.

Storage of oil palm fruits resulted in crude oil that was difficult to bleach, especially from bruised fruits. Fruits stored in the shade were less affected than those exposed to sun and rain. Surprisingly, oil from fruits stored at 5°C was highly hydrolyzed and difficult to bleach.

An industrial wet process to obtain oil and meal from jo-joba was set up. The process sequence consists of breaking the seeds, homogenizing with water of suitable pH and temperature, and centrifuging to accomplish separation into oil, process water and wet meal. Oil is obtained with a yield of 70–75% and requires no supplementary refining treatment for the industrial purposes for which it is destined. The meal obtained is devoid of the toxic components simmondsin and simmondsin-2′ ferulate, and the protein content may be considered unchanged. The procedure contemplates a drying treatment for the meal with a view to using it as animal feed. This system is simple, economical and flexible in use.