Aqueous ethanol extraction of dietary soy protein isolate improves sup 59 Fe absorption by the rat from a casein-based test meal

Journal Article · Wed Nov 01 00:00:00 EST 1989 · Journal of Nutrition; (USA)

OSTI ID:7168155

Thompson, D B ^[1]

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1. Penn State Univ., University Park (USA)

A commercial soy protein isolate (SPI) was further processed in an attempt to understand how a diet based on SPI can cause decreased iron retention by the rat from a separately administered casein-based test meal. Groups of eight rats were fed either a casein-based diet or a diet based on SPI. The acid-precipitated SPI was incorporated into diets as such, after neutralization, after 60% (v/v) ethanol extraction and neutralization, or after 60% ethanol exposure and neutralization. All dietary SPI was heat-treated by exposure to steam at 108 degrees C for 30 min. Rats were fed their respective diets, each containing 25 mg Fe/kg, for 13 d, and then all rats were fed a {sup 59}Fe-radiolabeled 2.5-g casein test meal containing 64 micrograms of iron. Ingested radioactivity was determined following the meal, and retained radioactivity over the subsequent 10-d period. Absorption was not distinguishable for groups fed the casein-based (78.3 {plus minus} 3.6%) and the ethanol-extracted, SPI-based diet (80.2 {plus minus} 5.4%). Absorption was lower (P less than 0.01) for groups fed each of the other SPI-based diets: SPI as such (68.3 {plus minus} 8.9%), neutralized SPI (69.8 {plus minus} 5.0%) and ethanol-exposed SPI (67.6 {plus minus} 4.8%). An ethanol-extractable component of SPI may be responsible for decreased iron absorption by animals fed SPI prior to a radiolabeled test meal.

• OSTI ID: 7168155
• Journal Information: Journal of Nutrition; (USA), Vol. 119:11; ISSN 0022-3166
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
IRON
INTESTINAL ABSORPTION
PROTEINS
BIOCHEMICAL REACTION KINETICS
CASEIN
DIET
HEMOGLOBIN
IRON 59
METABOLISM
RATS
SOLVENT EXTRACTION
TRACER TECHNIQUES
WEIGHT
ABSORPTION
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
DAYS LIVING RADIOISOTOPES
ELEMENTS
EVEN-ODD NUCLEI
EXTRACTION
GLOBINS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INTERMEDIATE MASS NUCLEI
IRON ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
METALS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PIGMENTS
PORPHYRINS
RADIOISOTOPES
REACTION KINETICS
RODENTS
SEPARATION PROCESSES
TRANSITION ELEMENTS
UPTAKE
VERTEBRATES
550501* - Metabolism- Tracer Techniques