Improvement of zinc intestinal absorption and reduction of zinc/iron interaction using metal bound to the caseinophosphopeptide 1-25 of beta-casein.
Binding zinc (Zn) to soluble caseinophosphopeptides (CN), produced by the hydrolysis of caseins, improves its absorption and could prevent inhibition by other nutrients such as iron (Fe). The absorption of Zn (100 mumol/L) bound to the 1-25 CN (beta-CN(1-25)) of beta-casein, or as ZnSO4 was studied using the isolated, perfused rat intestinal loop system. Fe (Fe-CN or Fe gluconate (Fe Gluc)) was added at Zn/Fe ratios of 2:1, 1:5 and 1:10. Disappearance from the lumen (Q1) and net absorption (ZnAbs) of Zn-CN were statistically greater than for ZnSO4; Zn retention by the mucosa (Q2) did not significantly differ. Fe Gluc reduced Q1, Q2 and ZnAbs for ZnSO4 at ratios of 1:5 and 1:10 and for Zn-CN at a ratio of 1:10. Fe-CN reduced Q1 and ZnAbs of both forms of Zn at a ratio of 1:10; Q2 remained unchanged. Binding Zn to beta-CN(1-25) improved Zn absorption and prevented Fe from inhibiting its absorption.
Pérès
J M
JM
Laboratoire de physiologie digestive et nutritionnelle, CHU de Caen, France.
Bouhallab
S
S
Petit
C
C
Bureau
F
F
Maubois
J L
JL
Arhan
P
P
Bouglé
D
D
D000704:Analysis of Variance; D000818:Animals; D002364:Caseins / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D007408:Intestinal Absorption; D007501:Iron / Q000378:metabolism*; D007583:Jejunum / Q000378:metabolism; D010748:Phosphopeptides / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015032:Zinc / Q000378:metabolism*; D019287:Zinc Sulfate / Q000378:metabolism
D002364:Caseins; D010748:Phosphopeptides; D019287:Zinc Sulfate; D007501:Iron; D015032:Zinc