RESEARCH • Use of ordinary solvents and equipment • Speed—as little as two hours. • Small sample size—50 to 100 micrograms total cholesterol compounds. e N o need for preliminary purification of lipids from certain tissues. Other paper chromatographic techniques that offer good possibilities, she says, include one- and two-dimensional systems for separating certain cholesterol esters of fatty acids of varying chain length. A two-step chromatographic system separates free from ester cholesterol. Apparendy, Quaife notes, the system subdivides cholesterol esters into saturated fatty acid esters and into esters of unsaturated fatty acids. This, she concludes, could serve as a step in the isolation (for measurement) of cholesterol esters of essential fatty acids.
proteins. The ultimate result of these effects is the formation of insoluble complexes of varying composition. In the course of previous research, notes Rackis, the solubility of phosphorus in water extracts as a function of p H closely parallels, over an entire pH range, the solubility of nitrogen compounds found in defatted meal. Coupling the fact that 9 2 % of the nitrogen is due to protein, together with the amount of phosphorus accounted for by phytin, the solubility results can b e considered as representative of phytic acid and protein solubility. Therefore, claims Rackis, phytin elimination becomes a necessity in the isolation of soybean meal protein. • Phytin Removal. When isolating
protein from defatted soybean oil meal by* water extraction and acid precipitation, there i s little or no reaction in the initial water extract at p H 6.6. But, says Rackis, the reaction increases as the acidity i s increased for protein precipitation. According to results obtained at the Peoria laboratories, 8 0 % of the protein in a water extract is precipitated at p H 4.2. This precipitate, Rackis says, contains 4 to 5 % phytin. T h e resulting supernatant—soybean whey solution—is unstable because of a continuous deposition of a protein-phytin complex. Phytin c a n b e removed from the water extract of the meal by dialysis, and followed by treatment with Dowex1-X10 (acetate) at p H 7.0. The isolated protein becomes completely sol-
Fightin' Phytin USDA see greater industrial and nutritional uses for soybean meal if phytin is removed ^KfefT^P^^^^^ ^ e commerS K f t S S ^ ^ r ^ S cial value of soy^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ B bean meal for in-
dustrial
extractabihty of its protein. Phytin—the acid hexaphosphoric ester of inositol—hinders extraction by forming insoluble complexes with the meal protein. Phytin can now be eliminated by a combination of dialysis and anion exchange resin treatment. According to J. J. Rackis and A. K. Smith of Northern Utilization Research Branch, Department of Agriculture, greater industrial utilization of soybean protein may come about if the phytin is removed. Even though soybean protein is available for industrial utilization and nutritional research, Raclds told the Division of Biological Chemistry, studying its properties is hampered considerably b y the presence of impurities. Of these impurities, phosphorus compounds are the main culprits. And phytin, says Rackis, accounts for about 7 0 % of the total phosphorus in defatted soybean meal. During water extraction of defatted soybean oil meal, Rackis continues, phytin exerts a pronounced effect upon the solubility characteristics of the meal OCT.
!,
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protein groups react with phytic acid's phosphate groups. T h e reaction rate increase with decreasing p H is due to the formation of positively charged amino groups. Presence of salt, according to Rackis, appears to decrease the formation of the protein-phytin complex.
• Important Possibilities. T h e phytin removal studies, according to the USDA scientist, suggest some interesting possibilities in soybean protein chemistry—theoretical as well as practical. Some of the reasons which cause the difficulty encountered in purification and in obtaining proteins with reproducible characteristics may b e revealed b y the data. Phytin as an impurity7 can also adversely affect other properties of the protein. In addition, nutritionists may find the phytin-free material a help in their evaluation of the biological value of soybean protein.
A test cell used in studies of organosilicon syntheses and radiation effects is discussed b y Simon W. Kantor, Maurice Prober, and John F . Brown, Jr., (left to right), a l l of General Electric Research Laboratory
Better Hooks for Silicones
WERSAT1LM i •
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I Products
rrom
I orn I I I I
M E T H Y L G L U C O S I O E — the cyclic poiyo! used to obtain improved drying oils, resin modifications, resinous coatings, plastidzers and surface-active agents. POLYOSES— characterized by high clarity and stability, these synthetic polysaccharides are excellent cold-water-dispersible adhesives. Z E I N — a high quality protein valued in such applications as coatings, printing inks and cork binders because of its excellent film-forming and binding properties.
Chemical Division
C O R N PRODUCTS REFINING
COMPANY
17 Battery Place, New York 4, N. Y.
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Vinyl silicons, plus active hydrogen compounds give carbon functional silicones
Polymer chemistry thrives on presence of reactive groups as convenient hooks for stringing long chains together. Silicone polymer chemistry i s no exception, b u t today's silicones merely have simple hydrocarbon groups, such as methyl or phenyl, attached to the siloxane backbone. These, needless to say, are not nearly as reactive as groups available to hydrocarbon polymer chemists. It is no wonder, then, that much of today's silicone polymer effort is directed toward building n e w carbonfunctional compounds. O n e n e w route to silicone polymers with functional groups come from Maurice Prober at General Electric, w h o told the Division of Organic Chemistry that active hydrogen compounds a d d to vinyl silicon compounds. Products: ^-substituted carbon functional silicones. Typical of Prober's reactions is: CoH 5 OH + C H 2 =
CHSi(OC2H5)s~»
Prober has also tried 4772
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n-butyl mer-
