Improving soy bean oil color

Summary 1. Increased heat developed in the Expeller barrel as the capacity and efficiency have been increased in the modern types of Expellers has resulted in increasing the color of crude soya bean oil to a point where it is objectionable for some uses. 2. Reducing and controlling the barrel temperature by spraying cool oil over it resulted in materially reducing the color of crude soya bean oil.     

Adsorption of soy oil phospholipids on silica

An experimental method for adsorption of phospholipids from soybean oil was developed based on chromatographic properties of the oil components. The traditional method for removing phospholipids involves hydrating the gums. However, when crude oil in hexane is applied to thin layers or columns of silica, the phospholipids irreversibly adsorb. The triglycerides can be eluted with non-polar solvents and phospholipids with a polar solvent system. Hence, there is a basis for a selective adsorption of phospholipids on silica. The system involved stirring one hundred milliliters of oil in solvent (i.e., miscella) with one gram of silica for 15 min. The phosphorus content, before and after the reaction, was analyzed by wet ashing and Fiske-Subbarow colorimetric reaction. Addition of isopropanol (at least 1%) to the hexane miscella caused an increase in phosphorus adsorption, most likely due to liberating triglyceride from adsorption sites. Increased adsorption was achieved by deactivating the silica. Oil concentration did not appear to affect the adsorption. The amount of phosphorus adsorbed depended on the concentration of the phospholipid. When phospholipid adsorbed per gram of silica is plotted vs the residual phospholipid, the plot resembles a Freundlich isotherm for reversible adsorption. Yet the adsorption is irreversible. Possible explanations for this type of adsorptive behavior are explored.     

Processing and utilization of by-products from soy oil processing

Crude soybean oil contains a number of materials which must be removed to produce a neutral, bland-flavored and light-colored refined oil. While at times these materials may have been considered waste constituting a disposal problem, they are, in fact, valuable byproducts when efficiently recovered and processed. Methods of recovery and processing lecithin, soapstock and deodorizer distillate at the refinery level are reviewed. Process and analytical control are discussed. Some of the important end uses are listed.     

Biocomposites synthesized from chemically modified soy oil and biofibers

Composites with good mechanical properties were prepared from chemically modified soy oils and biofibers without additional petroleum‐based polymers. These composites were prepared from maleic anhydride and epoxide functionalized soybean oils that were cured in the presence of various biofibers (e.g., kenaf, kayocell, protein grits, and solka‐floc) by a flexible amine catalyst. Rigid thermosets characterized by a high‐crosslink‐density network and a high gel fraction were obtained. Fourier transform infrared was used to follow the cure reaction via the disappearance of the characteristic anhydride adsorptions. Composites with high tensile strength and low elongation were obtained when kenaf fibers were treated with (2‐aminoethyl)‐3‐aminopropyl‐trimethoxysilane and then added to the epoxidized/maleated soy matrix and cured with hexamethylenediamine. These biobased composites could provide inexpensive epoxy resin alternatives for a wide variety of industrial applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 69–75, 2006     

Techniques for flavor and odor evaluation of soy oil

Means of evaluating soybean oil for flavor on a “now” basis and on a “predictive” basis are presented. Emphasis is placed on more recent objective methodology for measuring oil volatiles and using their correlation with flavor. Applications of a modified volatile technique for use with soy isolates or soy proteins is shown. The importance of sensory analysis and a summary of methodology currently being used are discussed.     

Analysis of processed soy oil by gas chromatography

Two basic gas chromatographic approaches are currently used for the analysis and characterization of processed soy oil and other lipid materials. One approach separates the intact glycerides after silylation whereas the complementary approach determines the fatty acid composition of the glycerides by the formation and subsequent separation of the corresponding fatty acid methyl esters. A brief history of the development of these gas chromatographic procedures and a more detailed discussion of current packed and capillary column technology used for the separation of both intact glycerides and fatty acid methyl esters is presented. Emphasis is placed on the advantages of the newly emerging capillary techniques over the more conventional packed column separations. High resolution chromatograms are shown for the separation of mixed glyceride isomers and also for the separation of unsaturated methyl esters with respect to the number, geometry and position of the double bonds. The separation of the methyl esters can provide information equivalent to classicalcis,cis-lipoxygenase, iodine monochloride titration and infraredrans analyses. Finally, the use of short capillary columns to achieve rapid low cost separations (with resolution equivalent to packed column separations), ideal for quality control, also are discussed.     

Iron and phosphorus contents of soybean oil from normal and damaged beans

Analyses of commercial crude soybean oils showed a highly significant correlation of 0.74 between free fatty acid and iron content. Poor flavor characteristics exhibited by finished oils extracted from damaged beans may be caused in part by a higher free fatty acid and related higher iron content in crude oils. Source of the increased iron appears to be both damaged beams and steel processing equipment. Crude oil from damaged beans is 2–10 times higher in iron than crude oil extracted from sound beans. Iron appears loosely bound in soybeans, since autoclaving, spontaneous heating in storage, or treating with alcohol increased the level of iron in laboratory extracted crude oil from 0.2 to more than 1 ppm. Present data do not indicate that iron and phosphorus contents are associated statistically in extracted oils.     

Degumming soybean oil from fresh and damaged beans with surface-active compounds

Oils from both properly stored and damaged soybeans were degummed with a series of 4 nonionic, 2 cationic and 5 anionic surfactants and with lecithins as amphoteric emulsifiers. Efficiency of phosphatide removal in the presence or absence of citric acid was determined by colorimetric analysis of phosphorus in the degummed oils. For normal oils, efficiency of citric acid degumming was improved by the addition of fatty alkyl oxazoline, polymeric sulfonate, alkyl sulfate and crude or purified lecithin. Success in degumming of oils from partially damaged soybeans was limited; however, the average phosphorus content was lowest for those solutions degummed with alkyl sulfate. Aqueous citric acid degumming of oils from severely damaged soybeans indicated high levels of nonhydratable phosphatides (NHP). When added to the oil from severely damaged beans, several nonionic and anionic surfactants showed statistically significant improvements in degumming efficiency. However, the nonhydratable phosphorus contents of the degummed oils were still too high, indicating the need for special processing of damaged oils. Crude lecithin was effective in removing NHP from oil of fresh soybeans, but was ineffective on oils of stored and severely damaged beans. Biometrician, North Central Region, ARS, USDA, stationed at the Northern Regional Research Center, Peoria, Illinois 61604.     

Soy hull as an adsorbent source in processing soy oil

Soy hull, a co-product of the soybean industry, was evaluated as an adsorbent source for processing soy oil. Ground soy hull (<100 mesh), boiled soy hull, and soy hull carbon were each added to crude soy oil at various levels in the laboratory under commercial bleaching conditions. The free fatty acid (FFA), peroxide value (PV), pigments, and total phospholipid contents (PL) of treated samples were measured. The microstructure (scanning electron microscopy, SEM), X-ray diffraction patterns (XRD), and Fourier transform infrared (FTIR) spectra of the soy hull adsorbents were also examined. The soy hull carbon was more efficient as an adsorbent relative to the ground or boiled soy hulls. The differences between ground and boiled soy hulls in the reduction of FFA were not significant. The effectiveness of adsorbents to reduce PV was: soy hull carbon > boiled soy hull = untreated soy hull; and for PL adsorption: soy hull carbon = ground soy hull > boiled soy hull. Boiling resulted in an open, porous structure, as evident from the SEM data, but carbonization did not affect the particle size. The XRD patterns of ground and boiled soy hulls were similar to those of powdered amorphous cellulose, but the carbon was more amorphous and had a random structure, as well as a more polar surface, as revealed by the FTIR spectra.     

American safflower seed oil

Summary The chemical and physical characteristics of a sample of hot pressed oil from saflower seed grown in Montana have been determined. This oil was found to contain 87.72 per cent of unsaturated acids, and 5.92 per cent of saturated acids. The composition of the oil has been determined with the following results, and, for comparison, results for sunflower seed and soy bean oils previously obtained, are also given. It will be observed that safflower oil contains a considerably larger proportion of linolic acid and less oleic acid than either of the other two oils, and this fact would account for its superior drying power.     

Synthesis of polyether polyols with epoxidized soy bean oil

Epoxidized soy bean oil (ESBO) polyether polyols have been prepared and evaluated as potential bio-renewable replacements for bisphenol A based epoxy coatings. Zinc triflate was found to be more efficient in catalyzing the ESBO hydroxyl reaction than methanesulfonic acid or boron trifluoride etherate. With an excess of n-butanol, ESBO epoxide groups ring open to give the expected polyether polyol, but as the n-butanol concentration is reduced, dimers, trimers, and higher molecular weight analogs of the triglycerides appear. Weight average molecular weight can be increased in a controlled fashion to over 10,000 Da by using trimethylolpropane (TMP) in place of n-butanol. The addition of solvent reduces molecular weight of the polyether polyol, at an equivalent TMP level while still allowing good reaction control. These polyether polyols can be cured with phenolic resins, but solvent and blush resistance, adhesion, and wedge bend flexibility are inferior to a commercial bisphenol A epoxy control.