Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1976-7-6
pubmed:abstractText
The mechanisms of the low availability of endogenous folates in orange juice and the inhibitory effects on the availability of pteroylheptaglutamate (PteGlu7) caused by orange juice supplements were investigated in man by the use of simulated orange juice (containing the principal components: citric acid, malic acid, etc.) with several different pHs. The endogenous folates in orange juice were identified as mainly 5-methyl reduced derivatives of pteroylpolyglutamates (40-45% pentaglutamate, 10-15% tetraglutamate, 30-40% monoglutamate, and the rest were tri-and diglutamates). The availability of PteGlu7 is decreased to 54% by supplementation with 600 g concentrated orange juice (pH 3.7) and to 39% and 66% by the supplement of 24 g and 12 g citric acid (pH 3.7), respectively. Neutralization of 12 g citric acid to pH 6.4 largely reverses the inhibitory effect. On the other hand, the availability of pteroylmonoglutamate (PteGlu) is not influenced by a supplement of orange juice or citric acid. The results suggest that the low availability of PteGlu7 is due to the inhibition of intestinal conjugase caused by the low pH. These observations suggest that pH of foodstuffs may be an important factor in the absorption of polyglutamate forms of folate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0007-1048
pubmed:author
pubmed:issnType
Print
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
123-33
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
The availability of folates in man: effect of orange juice supplement on intestinal conjugase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.