Metals in soybean oil

Certain metals often produce deleterious effects when present in soybean oil. Trace quantities of copper, iron and manganese dramatically reduce the oxidative stability of edible oils. The presence of calcium and magnesium in crude oils reduces the efficiency of degumming and refining operations. Sodium soaps reduce bleaching efficiency by inactivating adsorption sites on bleaching earth. Phosphatides or phosphorous containing lipids exert a poisoning effect on hydrogenation catalysts. Nickel, an artifact of hydrogenation, must be removed from the oil for health, stability and safety considerations. This paper provides an overview of the various effects of metals on processing and stability, describes how to inhibit or diminish their activity, and discusses various analytical techniques for identification and quantitation of the metals present in soybean oil.     

Flavor reversion in soybean oil

Summary It is evident that the oxidation rate of soybean oil may be varied over a considerable range without influencing the organoleptic evaluation of the degree of reversion. Even when the rate of oxidation is greatly reduced by the use of inert atmospheres, there is no diminution in the tendency to revert. On the contrary, with low oxygen concentrations, a type of reversion is produced that is more persistent in taste than that resulting in air or oxygen. The generous finacial assistance of the National Association of Margarine Manufacturers is gratefully acknowledged. Contribution No. 612 from the Department of Chemistry, University of Pittsburgh.     

Taking prophets in soybean oil

Conclusion It's a tough year on farmers as well as on industries that use farm products. It is no simple matter for the analyst either. “Prophettering” can be dangerous to your health, as Jonah and others before and since this time have learned. What was the final chapter in the experience of Jonah? He finally got to Nineveh and made his prophecy about the coming destruction of the city if the citizens did not repent. They did change their ways and the city was saved. Consequently Jonah felt that the was a failure since the city was not destroyed. Well, it can happen to all of us. (David M. Batholomew is a regular contributor to JAOCS, In thhis article, originally presented Oct. 18, 1983, to a meeting of the North Central Section of the American Oil Chemists' Society, he describes how supply-demand balances for the current crop year tend to increase the value of soybean oil in a bushel of soybeans relative to the value of the meal content.)     

Flavor reversion in soybean oil

Summary A simulated soybean oil has been synthesized from purified fatty acids. The flavor characteristics of the oil after heat and light treatment are described and compared to those of soybean and cottonseed oils. The generous financial assistance of the National Association of Margarine Manufactures is gratefully acknowledged. Contribution No. 613 from the Department of Chemistry, University of Pittsburgh.     

Flavor reversion in soybean oil

Summary The ultraviolet spectral changes produced in soybean oil by treatment with heat and visible and ultraviolet light have been determined. Heat treatment appears to cause more deep-seated changes than does exposure to visible or ultraviolet irradiation. Distinct flavor changes occur in soybean oil under these different conditions; that produced by visible light of strong intensity being the easiest to recognize. A preliminary study is reported on the methods used to concentrate and isolate the substances responsible for the off-flavor of heat-treated soybean oil. The generous financial assistance of the National Association of Margarine Manufacturers is gratefully acknowledged. Contribution No. 592 from the Department of Chemistry, University of Pittsburgh.     

Effect of soybean pretreatment on the color quality of soybean oil

Color reversion in soybean oil can be prevented by reducting the enzyme activity of soybeans before cracking and flaking. Soybean oil extracted from steamed, intact soybeans (18% moisture) had lower Rm (max. red) values in RBD oil, higher amounts of γ-tocopherol, plus its isomers, in both crude and RBD oil, and also higher amounts of hydratable phosphatides in crude oil than those in the oils from the same beans without steam treatment. For soybean pretreatments, a toasting process is less effective than the steaming process for the inhibition of color reversion of soybean oil. To prevent the occurrence of color reversion in RBD soybean oil, the amount of γ-tocopherol and γ-TED (5-[tocopheryloxy]-γ-tocopherol) should be above 550 ppm in crude oil.     

Photosensitive acrylates containing bio-based epoxy-acrylate soybean oil for 3D printing application

Stereolithography is a 3D-printing process that is rapidly shifting from being an expensive and limited technology to an affordable, precise, and fast method of mass production. However, most of the current resins are petroleum-based, which makes them toxic, non-degradable and with poor biocompatibility. In this study, a standard petroleum-based resin containing urethane acrylate and acrylic monomers was combined with epoxy-acrylate soybean oil (EASO), aiming to reduce its impact on the environment. Ratios varying from 10 to 50 wt% of EASO were incorporated into the commercial resin while maintaining the viscosity low, between 0.27 and 1.06 Pa s. The printed samples showed good quality and complete integration between the layers. The addition of 50 wt% of EASO increased the samples elongation at break by 108% (from 2.3% to 4.8%) and decreased the contact angle by 26.4% (from 72 to 53°). Moreover, the mixture showed good thermal and swelling stability and tensile strength in the range of other commercial cured systems. The addition of EASO may significantly contribute to the exploitation of greener materials, which well matches today's circular economy concept.     

Ternary phase diagram of soybean phosphatidylcholine-water-soybean oil and its application to the water degumming process

Crude soybean oil contains phospholipids (2.5 wt%) that must be removed from oil during processing. A common method is the water-degumming process. A ternary phase diagram of soybean oil-water-soybean PC, a major component of phospholipids, was established. From this diagram, phase transitions and compositions of phases can be determined. A theoretical model describing the relationship between aggregation curvature and the amount of water added is presented to explain the phase transitions. The amount of water absorption by the lamellar phase should be larger than the critical value of 34 wt% based on the total weight of water and PC. Below this critical amount, phospholipids tend to form liposomes. Above the critical point and below the saturation point, larger aggregates of particles form and can be easily separated. When more water is added to reach the water adsorption limit, about 40 wt% based on the total weight of water and PC, a phase transition boundary is observed, beyond which a third phase, water, appears and the particle size falls dramatically. In between the critical line predicted by the model and the water adsorption saturation line observed experimentally, there is an operation window on the ternary phase diagram for the water-degumming process.     

Hydrogenation of oxidized soybean oil

Anderson Clayton Foods, Richardson, TX 75080 Portions of refined and bleached soybean oil were stored at various temperatures for various lengths of time, then hydrogenated to 70 iodine value (IV) to find the effect of peroxides on the rate of hydrogenation and on characteristics of hydrogenated product. Samples were treated up to 3 wk at up to 65°C and provided samples with peroxide values (PV) of up to 358. All samples were analyzed, hydrogenated, and reanalyzed. Peroxides affected the fatty acid composition as determined by gas chromatography, the calculated iodine value based on fatty acid composition, and rate of hydrogenation. Peroxides also affected the selectivity of hydrogenation and slope of the solids curve in hydrogenated products.     

The combined application of extrusion and enzymatic technology for extraction of soybean oil

This paper describes a new technological process for soybean oil extraction. The process deals with the combined effect of thermoplastic extrusion of beans and the subsequent action of hydrolytic and proteolytic enzymes in aqueous medium to recover the oil, thus, avoiding solvent application. The thermoplastic extrusion is fundamental for the process, because it facilitates the action of enzymes in oil containing cells, reduces the non-hydratable phosphatides and promotes protein denaturation by reducing the emulsion stability and thus enhancing the oil extraction. The main parameters affecting the oil yield are: the temperature and diameter of the die in the extrusion process, the dilution, the concentration of enzymes and the incubation time of the enzymatic treatment. The highest yield was obtained under the following conditions: extrusion of beans at 90°C and exit die of 6 mm, enzymatic incubation time of 6 h, extruded soy/water dilution ratio 1:10 and concentration of enzyme 6%. With these conditions 88% of the oil were obtained after centrifugation. Moreover, the aqueous enzymatic extraction is easier than solvent extraction, and leads to high value products: a solvent-free meal more suitable for human consumption, a protein hydrolysate that can be used as ingredient for liquid foods and an oil of better quality. The non-hydrolyzed meal contains ca 25% of original soybean protein and the residual oil. The protein hydrolysate in the liquid phase contains ca 75% of the total protein in the original grain with a molecular weight below 20 kDa.     

The hydrogenation of soybean oil

Journal of the American Oil Chemists' Society - 1     

Ethanol extraction of soybean oil

Extraction of soybean flakes with 90, 95, 98 and 100% ethanol resulted in more rapid lipid and less rapid non-lipid removal with the increasing ethanol concentrations. There was little difference in the quality of the oil produced by the different solvents. Protein content of the residual meal averaged 52.1%.