Showing papers in "Journal of the American Oil Chemists' Society in 1983"

Lipase-catalyzed interesterification of oils and fats

Abstract: Extracellular microbial lipases can be used as catalysts for the interesterification of oils and fats. Use of specific lipases gives products which are unobtainable by chemical interesterification methods. Some of these products have properties of value to the oils and fats industry. The catalysts for enzymatic interesterification are prepared by coating inorganic support materials with the lipases. For batch interesterification reactions, the catalyst particles are activated by addition of a small amount of water and then stirred with a reactant mixture dissolved in petroleum ether. At the end of the reaction period, the catalyst particles are removed by filtration, and the interesterified triglycerides isolated by conventional fat fractionation techniques. The catalyst can be used in subsequent batch reactions. As an alternative to the batch reaction system, continuous enzymatic interesterification processes can be operated by pumping water containg feedstock through a packed bed of activated catalyst.

Comparison of alternative solvents for oils extraction

Abstract: A comprehensive review of the literature about use of solvents for extraction of oilseeds is presented. Mention has been found of over 70 solvents. Currently, hexane is the major solvent in use, but recent price increases and safety, environmental and health concerns, have generated interest in alternatives. Solvents vary considerably in chemical and physical properties which affect their performance in oil extraction. The choice of solvent depends upon the primary end product desired (oil or meal). Recent research on alternative solvents has focused on ethanol, isopropanol, methylene chloride, aqueous acetone, and hexane/acetone/water mixtures.

Conversion of used frying oil to diesel fuel by transesterification: preliminary tests

Abstract: Used frying oil was transesterified by reaction with excess alcohol under both acidic and basic conditions. The alcohols used were: methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-ethoxyethanol. Yields of the fuels determined by gas chromatography and their viscosities are reported. The best result was obtained using methanol with catalysis by potassium hydroxide. The methyl ethyl and 1-butyl esters all ran very well in short-term engine tests with a laboratory high-speed diesel engine.

Applications of phytic acid

Abstract: Phytic acid (myo-inositol hexaphosphate) constitutes 1-3% of most plant seeds. Its tremendous chelating potential and its effects on the absorption of polycationic nutrilites such as Ca2+, Zn2+ and Fe3+ have been the subject of intense investigation for several decades. Yet in the American literature there is virtually no information available on other chemical properties of phytic acid or on its beneficial utilization. This review summarizes the present medical, dental, nutritional and industrial applications of phytic acid and suggests additional novel uses for this inexpensive and easily obtained chemical.

Vegetable oils as diesel fuels: Overview

Abstract: Rapport succinct de synthese des communications consacrees a la preparation et l'utilisation d'huiles vegetales comme carburant Diesel presentees a un Symposium tenu a Toronto en mai 1982

Fatty acid composition of the fat in selected food items with emphasis on trans components1

Abstract: The fat in 220 samples from 35 food types has been analyzed for component fatty acids by gas liquid chromatography on a 15-m capillary column coated with SP-2340. The methodology permitted the determination of trans-octadecenoic fatty acids in the food samples. For food types in which the majority of samples containedtrans fatty acids, the range (weight percent of methyl esters) of this class of acids arranged by fat content of the food types was: high fat levels (>70% fat) — animal and dairy fats, 0.3–6.6%, stick margarines, 15.9–31.0%, tub margarines, 6.8–17.6%, and vegetable shortenings, 8.7–35.4%; moderately high fat levels (40–70% fat) —diet margarines, 11.3–13.3%; moderate fat levels (10–40% fat) — breading mixes and fried crusts, 8.1–32.7%, cakes, candies and frostings, 3.2–33.2%, cream substitutes, 0.4–11.5%, cookies, 2.5–34.2%, crackers, 1.9–29.0%, pastries and pastry crusts, 0.6–31.2%, corn and mixed grain snack chips, 0.4–30.4%; low fat levels (<10% fat) - breads and rolls, 0.2–23.6%, pretzels, 10.8–29.2%, and puddings, 28.4-35.1%. The majority of samples in the following food types did not containtrans fatty acids, except in cases where the label indicated partial hydrogenation of the oil: mayonnaises and salad dressings, salad and cooking oils and potato chips. For samples in these three food types which containedtrans fatty acids, the range was 0.2-23.2%. None of the peanut butters or pizza crusts analyzed containedtrans fatty acids.

Determination of tocopherols and sterols by capillary gas chromatography

Abstract: A method is described for simultaneously determining tocopherols and sterols in fats and oils by quantitative capillary gas chromatography. Samples containing ca. 100 mg of lipid were saponified in capped tubes with aqueous KOH by heating for 8 min at 80 C; the unsaponifiable fraction was extracted with cyclohexane, freed of solvent, derivatized to form the trimethylsilyl ethers of both tocopherols and sterols, and chromatographed on a 50 m×0.25 mm glass capillary column coated with Dexsil 400. Most of the individual tocopherols and common sterols were well separated, although interfering peaks were seen in some samples, which for better specificity should be subjected to an initial purification. For most samples, however, the simplified sample preparation, without preliminary purification, was adequate when combined with capillary gas chromatography. Recovery, method and gas liquid chromatographic precision, and applications are discussed.

Calcium phytate: Effect of ph and molar ratio on in vitro solubility

Abstract: Calcium and phytate phosphorus were highly soluble below pH 4 at all molar ratios of calcium (Ca) to phytic acid (PA) studied (0.512.67). As pH is increased above 4, there is a drop in solubility, the magnitude of which depends on the Ca:PA molar ratio. Above pH 6, the greatest calcium precipitation occurred at molar ratios between 4 and 6.5; both lower and higher Ca:PA molar ratios showed higher calcium solubility. In contrast, phytate phosphorus solubility decreased in proportion to the Ca:PA molar ratio, showing essentially complete precipitation above the Ca:PA ratio of 5. The pentacalcium phytate salt probably predominates when calcium is not limiting. Under calcium-limiting conditions, the complexes resolubilize as the pH is increased above 7.

Winter rape oil fuel for diesel engines: Recovery and utilization

Abstract: Although vegetable oil cannot yet be recommended as a fuel for general use, considerable progress in recovery and use of rapeseed oil (Brassica napus L.) for diesel operation has been made. Operation of a small-scale screwpress plant (40 kg/hr) was demonstrated. Maintenance of screw and end rings was a major problem. The plant has operated with a recovery efficiency of 77% and has processed 10,100 kg of seed in 230 hr. High viscosity of the rapeseed oil and its tendency to polymerize within the cylinder were major chemical and physical problems encountered. Attempts to reduce the viscosity of the vegetable oil by preheating the fuel were not successful in sufficiently increasing the temperature of the fuel at the injector to be of value. Short-term engine performance with vegetable oils as a fuel in any proportion show power output and fuel consumption to be equivalent to the diesel-fueled engines. Severe engine damage occurred in a very short time period in tests of maximum power with varying engine rpm. Additional torque tests with all blends need to be conducted. A blend of 70/30 winter rape and No. 1 diesel has been used successfully to power a small single-cylinder diesel engine for 850 hr. No adverse wear, effect on lubricating oil or effect on power output were noted.

Phospholipid content of foods

Abstract: The content of total lipids and total and component phospholipids in ca. 140 foods was compiled in response to frequent requests for data by researchers in nutrition and medicine, and to fill the appar-ent need for a reliable up-to-date tabulation of recent data. Eggs, organ meats, lean meats, fish, shellfish, cereal grains and oilseeds are good sources of phospholipids, especially the choline phosphatides: phosphatidylcholine, sphingomyelin and lysophosphatidylcholine. Leafy vegetables, fruiting parts, roots and tubers are, with few ex-ceptions, relatively poor dietary sources of total lipids and phospho-lipids. Foods or tissues in which the phospholipids perform similar functions also have similar relative phospholipid distributions. The data were tabulated by food group in separate tables with appropri-ate discussion. The use of conversion factors for calculating the total and individual phospholipids, sources of error, and research needs are discussed.

Palm Kernel and coconut oils: Analytical characteristics, process technology and uses

Abstract: Palm kernel and coconut oils are the most used of the lauric acid group of oils. The characteristic of this group is their high content of saturated acids, lauric and myristic, and it is from this feature that their principal uses are derived. Due to their triglyceride composition, both oils have steep melting curves and melt below body temperature. Their low degree of unsaturation gives them high oxidative stability. As a result of these properties they are found widely used as hard butters and in vegetable fat ice-creams, coffee whiteners and similar products. Their use in margarine gives that product an attractive coolness in the mouth. Coconut oil is also used extensively as a raw material for soaps and detergents and as a body oil. The oils are susceptible to hydrolytic splitting and to trace metal catalyzed oxidation. They are particularly affected by contamination with other oils which produce either reduced oxidative stability or, when the contaminant is high melting, an unacceptable palate cling. Refining is normally done with caustic soda solutions and refining conditions are chosen to minimize neutral oil losses due to saponification. Physical refining is also practised and is particularly useful for treating palm kernel oils with high free fatty acid content. To improve their quality and applicability for several uses, both oils are hydrogenated, fractionated and interesterified in various combinations. Fractionation is done either by dry “pressing” or with the assistance of detergents or solvents, the highest quality products being obtained using solvents. The relatively high solubility of the fatty acids can result in effluent problems.

Detection of adulteration

Abstract: A program of work is in progress to establish the levels and ranges of fatty acids and other components present in the major edible vegetable oils Authentic samples from the major producing areas for such oil have been obtained and analyzed In the case of palm oil, ranges of the fatty acid composition and of the acids at the triglyceride 2-position, have been obtained for about 40 samples These data were used to calculate enrichment factors, and triglyceride carbon number compositions, using a small computer program Comparison with experimentally determined carbon number compositions were then made Good correlations were found for whole unadulterated oils, but not for oil fractions Unfortunately, these differences were insufficient to detect contamination of palm oil by 10 or 20% levels of other oils, or of palm fractions Compositional ranges of sterols and tocopherols have also been determined on a selection from the original set of palm samples Work on sunflower seed and groundnut oils has followed the same lines, particular attention having been paid to linolenic acid and, in the case of groundnut oil, also erucic acid, levels Some groundnut kernels were found to have an oil with a component which cochromatographed with methyl erucate during fatty acid determination This unknown constituent was studied by gas chromatography-mass spectrometry, and is thought to comprise a mixture of epoxy fatty acids Analysis of the triglyceride fraction isolated from groundnut oil by thin layer chromatography removes this unknown constituent, and simplifies interpretation of the fatty acid composition of groundnut oil

Investigation of soybean oil as a diesel fuel extender: Endurance tests

Abstract: Engine performance and crankcase lubricant viscosity were followed with 1∶2 and 1∶1 fuel mixtures of degummed soybean oil in No. 2 diesel fuel in tests with a John Deere 6-cylinder, 404 cubic in. displacement, direct-injection, turbocharged engine for a total of 600 running hours. A crankcase oil contamination problem resulting in an unacceptable thickening and a potential for gelling did exist with a 50/50 blend or a greater concentration of soybean oil, but it did not occur with the 1∶2 blend. The data accumulated during the initial 600 hr running time indicates that a fuel blend of one-third degummed soybean oil and two-thirds No. 2 diesel (1∶2 blend) may be a suitable fuel for agricultural equipment during periods of diesel fuel shortages or allocations. Additional data are being accumulated and will be analyzed in the future.

Phenolic acids in rapeseed and mustard

Abstract: The compositions of free phenolic acids in rapeseed flours of diverse origin and white mustard were highly variable but represented less than 10% of the total phenolic acids. Phenolic acids released from hydrolysis of soluble esters constituted the major fraction, with Polish varieties having higher levels than a Canadian variety or white mustard. Yellow Sarson contained low levels of phenolic acids. Sinapic acid isomers constituted over 94% of the 13 phenolic acids found in the rapeseed varieties. Only traces of several phenolic acids appeared to be structurally bound to rapeseed and mustard proteins and carbohydrates.

Interpenetrating polymer networks from triglyceride oils containing special functional groups: A brief review1

Abstract: Although most triglyceride oils contain only double bond functionality, a few oils such as castor oil, vernonia oil, lesquerella oil, etc., contain other functional groups. These functional groups include hydroxy and epoxy groups, permitting the easy formation of polyesters and/or polyurethanes. In addition to the natural formation of epoxy-bearing oils, the double bond functionality in ordinary triglyceride oils can be epoxidized. When these oils are polymerized to form polyesters or polyurethanes in the presence of polystyrene to synthesize interpenetrating polymer networks (IPN), a new class of tough plastics is formed.

Polymorphism and transformation energetics of saturated monoacid triglycerides from differential scanning calorimetry and theoretical modeling

Abstract: Differential scanning calorimetry studies on saturated monoacid triglycerides were extended to include most odd and even chain lengths from tricaprylin (C8) through tritriacontanoin (C30). Two β’-forms were common with triglycerides C15 through C24: shorter odd chain length triglycerides (C9-C13) exhibited only one β’-form; short even chain length triglycerides (C8-C14) exhibited three. Odd chain length C21 and C23 triglycerides showed two β-forms. Triglycerides of even chain lengths greater than C21 produced two α-forms. Apparent energies of phase excitation for α-form transformations (determined from scans at different heating rates) showed odd-even alternation for short chain lengths, but increased linearly with chain length above C14, evidencing the importance of extended chain conformation and interactions as determinants of polymorph properties. Changes in melting point patterns, particularly for β’ and β-forms, at C14 correlated with the change in apparent phase excitation energy. Comparisons of X-ray data with dimensions from space-filling models and agreement between observed entropies of fusion and values calculated for probabilistic models also emphasize the importance of extended chain conformation and suggest configurational differences, and possibly different polymorph conversion pathways for odd versus even chain length triglycerides.

Effects of processing and chemical characteristics of plant oils on performance of an indirect-injection diesel engine

Abstract: Engine performance curves were obtained for crude, degummed, and degummed-dewaxed sunflower oils and for crude, degummed, and alkali refined cottonseed oils using a single-cylinder, precombustion chamber design diesel engine Crude oils gave very poor performance and are considered unsuitable for use as alternative diesel fuels Performance curves for processed sunflower and cotton-seed oils were slightly better than for diesel fuel, but increased carbon deposits and lubricating oil fouling were noted Although processed oils may be acceptable fuels for short-term use, they are not recommended as alternative diesel fuels at this time

New sources of γ‐linolenic acid

Abstract: γ-Linolenic acid (18:3Δ6,9,12) occurs in significant amounts in various species of plants surveyed. Of the species analyzed in this study, Nonnea macrospernia, with 5.1% 7-linolenic acid in the seed, is the richest source of this fatty acid. Other species in the same family (Boraginaceae) are also good sources: Adelocaryum coelestinum, Alkanna froedinii, Alkanna orientalis and Brunnera orientalis. Scrophularia marilandica (family Scrophulariaceae) seeds contain 37.9% oil, of which 9.6% is γ-linolenic acid. All species mentioned above are better sources, when the total amount of γ-linolenic acid in the seed is considered, than that used traditionally, Evening Primrose (Oenothera biennis, family Onagraceae). None of the other Onagraceae nor any of the Ribes (family Saxifragaceae) species analyzed are as rich in γ-linolenic acid as Evening Primrose. Octadecatetraenoic acid (18:4Δ,6,9,12,15) was found in significant amounts in most of the Boraginaceae and Ribes surveyed. The Onagraceae and Scrophulariaceae lack detectable amounts of this fatty acid.

Laboratory endurance test of a sunflower oil blend in a diesel engine

Abstract: The effects of using a 25/75 blend (v/v) of alkali refined sunflower oil and diesel fuel in a direct-injection diesel engine were compared to a baseline test with diesel fuel. There were no significant problems with engine operation during the baseline test. However, problems were experienced while using the blended fuel. The major problems were (a) abnormal buildup on the injection nozzle-tips, (b) injector needle sticking, (c) secondary injection, (d) carbon buildup in the intake ports, (e) carbon deposits on the exhaust valve stems, (f) carbon filling of the compression ring grooves, and (g) abnormal lacquer and varnish buildup on the third piston land. The 25.75 blend cannot be recommended for long-term use in a direct-injection engine.

Participation of sesamol in stability of sesame oil

Abstract: Sesame oil is known to be the most resistant to oxidative rancidity. Constituents of sesame oil such as sesamolin, sesamol and sesamol dimer (a possible intermediate of oxidative degradation of sesamol) were determined by high performance liquid chromatography using a reverse-phase column. Sesamol was specifically determined in an alternative way by use of hydrogen peroxide/horseradish peroxidase. Sesamolin was relatively stable but sesamol and sesamol dimer were unstable when irradiated in benzene, and the final degradation products were identical. Whereas sesamolin was inactive, sesamol and sesamol dimer showed significant antioxidant activity in several kinds of fat and oils. Stability of Japan Pharmacopoeia sesame oil free from sesamol was relatively low; antioxidant activity of sesamol incorporated in the oil was unexpectedly low and was rapidly lost in the oil activated by oxygen. Edible sesame oil with intrinsic sesamol was highly stable. Activation of the edible oil gradually increased the sesamol content with concomitant decrease of sesamolin. High stability of edible sesame oil could not be ascribed to sesamol, but it could be explained by another powerful antioxidant(s) which might stabilize both the oil and unstable sesamol.

Canola and high erucic rapeseed oil as substitutes for diesel fuel: Preliminary tests

Abstract: A cooperative project using the facilities of the POS Pilot Plant Corporation, the Saskatchewan Research Council and the Agricultural Engineering Department, University of Saskatchewan, and funded by Agriculture Canada, was initiated in 1980 to investigate the feasibility of using canola and high erucic rapeseed oil as a replacement/extender to diesel fuel in direct-injection diesel engines. Work carried out included the documented production and refining of canola and R500 (high erucic) vegetable oils, preparation of methyl ester and of blends of all these fuels with methanol and ethanol. These fuels were evaluated by ASTM and improvised tests to determine their usefulness as diesel fuel. Engine tests involved a 2-cylinder Petter diesel and a 6-cylinder John Deere turbocharged diesel. Results were similar for both engines in short-term performance tests, and indicated that: (a) maximal power was essentially the same when burning canola oil as when burning diesel fuel; (b) specific fuel consumption was ca. 6% higher when burning canola oil, but because canola oil has a heating value 14% less than diesel fuel, the thermal efficiency is somewhat higher when operating on canola oil; (c) there were no starting problems down to 10 C; (d) there were fewer particulates in the exhaust when burning canola oil; and (e) there was generally less combustion noise when burning canola oil. The high viscosity of canola oil (ca. 35 times that of disel fuel at 20 C) poses a major problem in using the oil at low temperature. Blending with diesel fuel and the creation of a methyl ester from the canola oil both proved effective in reducing viscosity, but neither lowered the pour point apprecibly. Efforts on reduction of pour points and further work on blends and on heating the fuel are described.

Lipid from yeast fermentation: Effects of cultural conditions on lipid production and its characteristics of rhodotorula glutinis

Abstract: To produce lipids from microbial origins, Rhodotorula glutinis (syn Rhodotorula gracilis) NRRL Y-1091 was cultured in batch and continuous systems under nitrogen- and carbon-limited conditions The lipid production patterns are shown to be different from each other depending on growing conditions In continuous cultures under nitrogen-limited conditions, the maximum lipid accumulation was observed at the lowest dilution rate examined, giving the efficiency of substrate conversion of 164 g lipid per 100 g glucose consumed As the dilution rate increased, cell biomass, lipid content, lipid productivity and lipid yield decreased In carbon-limited continuous cultures, cell biomass decreased with increasing dilution rate, but lipid content remained almost constant Neutral lipid portions in nitrogen-limited cultured yeast cells decreased as the dilution rate increased, and glyco- and phospholipid portions showed the reverse trend Major components in the neutral lipid portions in yeast cells are triglyceride, free fatty acid, steryl ester and sterol Phosphatidylserine was the predominant phospholipid in yeast cells The dilution rate also affected the fatty acid composition of all lipid portions; polyunsaturated fatty acids increased and saturated and monounsaturated fatty acids decreased with increasing dilution rates The degrees of unsaturation of each lipid class and total lipids were also increased by increasing the dilution rate

Varietal variations in content, characteristics and composition of mango seeds and fat

Abstract: Wide variations were found in the content, characteristics and composition of seed and fat of 43 varieties of mango (Mangifera indica) fruit. The seed in fruit amounted to 3–25% and kernel in seed 54–85% on an as-is basis. The contents of fat, protein and ash in kernel ranged 3.7–12.6, 4.0–8.1 and 1.0–3.7 (% on dry basis), respectively. Acid value of fat varied from 2.1 to 8.8 and unsaponifiables from 1.0 to 5.3%. The ranges for fatty acids, as determined by gas chromatography, were: 16:0, 3–18; 17:0, traces-2.0; 18:0, 24–57; 18:1, 34–56; 18:2, 1–13 and 20:0, traces-4 (area %).

Efficacy of the antioxidants BHA and BHT in palm olein during heating and frying

Abstract: The effectiveness of butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in retarding the deterioration of RBD palm olein during static heating (180 C) and frying operations was assessed by determining the peroxide, anisidine, acid and iodine values; absorbances at 232 and 268 nm; and the fatty acid composition of the oil. During static heating of the oil, BHA was found to be a more effective antioxidant than BHT whereas, during intermittent frying of potato chips, both the antioxidants were relatively ineffective in retarding the deterioration of the oil. The loss of BHT from the oil during static heating exceeded that of BHA. On the other hand, when potato chips were fried in the oil periodically, a higher loss of BHA was observed.

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

Abstract: 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.

Lecithin production and utilization

Abstract: Commercial lecithin is the most important byproduct of the edible oil processing industry because of its functionality and wide application in food systems and industrial utility. The recovery of lecithin from oil is a relatively simple process. Hydration of the phosphatides by water or steam followed by recovery by centrifuge and drying is all that is required. But in order to maximize lecithin’s utility and functionality, processing conditions all the way back to the bean or seed must be carefully controlled. Bean storage and handling, crude oil storage, refining pretreats, drying processes, bleaching, chemical modification, and storage all can affect lecithin quality and performance. The effects of processing on lecithin quality and performance is one of the major focal points in this presentation. Utilization of lecithins has expanded beyond the traditional application in paints, chocolate, and margarine. Food technologists have used lecithin as a functional ingredient in many modern systems. Its multifunctional properties and its “natural” status make commercial lecithin an ideal food ingredient. The major functional properties include: emulsification, instantizing and particle wetting, release, viscosity modification and nutrition. The nutritional impact of lecithin is currently being assessed in the medical field as an important factor in improving neurochemical disorders. Other medical and health related activity areas include positive changes in cholesterol, blood chemistry and circulatory factors. Lecithin is also used in numerous industrial and nonfood applications such as pigment dispersing, mold release, and animal feeds. The major source of commercial lecithin is from the processing of soybean oil. Evaluation of lecithins from other seed crops such as cotton, corn, and rapeseed is being pursued. The growth of these sources will be a function of demand.

Development of a pilot-plant process for the extraction of soy flakes with aqueous isopropyl alcohol

Abstract: Soy flakes were extracted with aqueous isopropyl alcohol (IPA) at 77 C in a Kennedy countercurrent continuous extractor at a retention time of 71 min. IPA concentration was varied from 85.0 to 90.5% w/w and included the 87.7% IPA-water azeotrope. Solvent to meal ratios were varied from 1.5 to 3.0. The oil-IPA miscella leaving the extractor was chilled and coalesced to yield an oil phase and an IPA phase. The IPA phase was recycled to the extractor without being distilled. Excess IPA was expressed from the defatted flakes, and this also was recycled to the extractor. IPA recovered by distillation in the evaporator-stripper and desolventizer-toaster accounted for less than 10% of the total. Refined deodorized oils from the IPA extraction process compared favorably with their hexane counterpart in color, peroxide value and phosphorous and free fatty acid contents. Desolventized meals from the IPA process compared favorably with their hexane-extracted counterpart in protein, ash and fiber content.

Physical and chemical properties of randomly interesterified blends of soybean oil and tallow for use as margarine oils

Abstract: Refined, unhydrogenated soybean oil and edible beef tallow were interesterified with sodium methoxide. This was done as an alterna-tive to hydrogenation for the production of plastic fats for use as margarine oils. Using 0.5% sodium methoxide at 80 C, interesterifi-cation was complete in 30 min as determined by lipase hydrolysis. A blend of 60% soybean oil and 40% edible beef tallow was found to have physical characteristics (melting point, solid fat index) similar to those of commercial tub margarine oils. The level of poly-unsaturated fatty acids was slightly lower and the level of saturated fatty acids slightly higher than the commercial margarine oils. Iodine value andtrans fatty acid determinations indicated no dis-cernible effect on the degree of unsaturation or the level of isomeric fatty acids by the interesterification process. The interesterified blend did contain 3.0%trans fatty acids which were originally present in the tallow. Oxidative stability of the interesterified oils was estimated by peroxide value determinations over several days on samples stored at 60 C. Experimental blends treated with 0.1% citric acid had poorer stability than the partially hydrogenated margarine oils; however, 0.01% BHA significantly delayed oxidation of the experimental samples.

Consistency of fats: A review

Abstract: The consistency of fats can be measured with the cone penetrometer (AOCS Method Cc 16-60). Several suggestions have been made to convert readings of penetration depth into parameters such as yield value, hardness or hardness index. This may extend the usefulness of the method. Motor-driven penetrating devices yield results in terms of force/area or stress. More basic information about the rheological properties of fats can be obtained with creep measurements. This includes the viscous flow component as well as instantaneous and retarded elastic components. Such methods are more suitable for research purposes than for quality control. Characteristics and application of various methods will be reviewed.