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The effect of food processing on the bioavailability of selenium in tuna and wheat : human and rat studies

Bioavailability of selenium (Se) in processed tuna and
wheat products was studied in humans and rats. The protein
source of the rat diets was torula yeast with Se supplied by
either raw, precooked or canned tuna, or whole wheat flour,
bread or bran. Sodium selenite was used as a control. Each
Se source was fed at three levels; 0.05, 0.10 and 0.15 ppm.
Using increase in glutathione peroxidase (GSH-Px) activity
in various tissues of rats as an indicator of bioavailabiiity,
no difference was seen among the three tuna products or
among the three wheat products tested. However, significantly
lower GSH-Px activity was found in the combined tuna
groups as co»pared to the combined wheat groups, suggesting
that the Se an wheat was more available than that in tuna.
Se concentration m four rat tissues (Liver, Kidney, Whole
blood and muscle) was also measured. A significant increase
in the liver Se content of rats fed canned tuna over those
fed raw or precooked tuna was observed. Since this did not
correspond with an increase in GSH-Px activity it was concluded
that it did not represent increased bioavaiiability
of canned tuna.
In the human experiment, eight young men ate controlled
diets where the Se was supplied by either whole wheat bread
or canned tuna for two week periods. The Se content of the
tuna diet was 331.5 ug/day and the bread diet was 354 ug/
day. No difference was observed in whole blood GSH-Px or Se
due to the tuna or bread diets but this may be due to the
short time period. No significant difference in excretion
of Se was observed in the balance study. On the tuna diet,
the subjects excreted 72.7% of the Se consumed and on the
bread diet they excreted 70.4%. / Graduation date: 1982

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/27277
Date22 January 1982
CreatorsAlexander, Anne Rose
ContributorsMiller, Lorraine T., Whanger, Philip D.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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