Identification of the chemical forms of selenium in soy protein

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6318269

Rodibaugh, R

Soybeans (Glycine max. L. Merr., Century) were grown hydroponically and intrinsically radiolabeled with {sup 75}Se, an isotope of selenium (Se). The isotope was provided as {sup 75}Se-Na{sub 2}SeO{sub 3} during the reproductive stage of growth until onset of senescence. Harvested seeds were processed into defatted soy meal. Soluble proteins were extracted in 20mM Tris-HCl buffer and fractionated into 11S, 7S, and 2S protein fractions by isoelectric precipitation. The 11S and 7S globulins, containing the glycinin and conglycinin storage proteins respectively, constitute the majority of extractable soy proteins. These storage proteins are the predominant proteins in soy protein isolate frequently used in food for human consumption. Approximately 24% of the defatted meal was soluble protein and accounted for 65% of the radioactivity associated with the soybean meal. The 11S fraction contained approximately 31% of the extracted protein and 27% of the extracted radioactivity. The 7S fraction contained approximately 32% and 35% of the extractable protein and radioactivity, respectively. The 2S fraction, containing the sulfur (S)-rich trypsin inhibitors, accounted for 17% of the protein and 27% of the radioactivity extracted from the defatted soy meal. Purification of the storage proteins by gel filtration and affinity chromatography showed higher levels of radioactivity associated with glycinin than conglycinin. Purified 11S proteins contained 1.09 ng Se per mg protein while 7S proteins contained 0.36 ng Se per mg protein.

• Research Organization: Purdue Univ., Lafayette, IN (USA)
• OSTI ID: 6318269
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
560300* -- Chemicals Metabolism & Toxicology
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BETA DECAY RADIOISOTOPES
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
FOOD
FRACTIONATION
GROWTH
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
METABOLISM
NUCLEI
ORGANIC COMPOUNDS
PLANT GROWTH
PLANTS
PROTEINS
RADIOISOTOPES
SELENIUM
SELENIUM 75
SELENIUM ISOTOPES
SEMIMETALS
SEPARATION PROCESSES
SOYBEANS
TRACER TECHNIQUES
VEGETABLES