title: [Effects of intake of heated mixtures of glucose-lysine and glucose-methionine on bone calcium].
abstract: During food thermal treatment Maillard's reaction may occur, which implicates mainly the carbonyl groups of reductory sugars and amino protein groups. Maillard's reaction products (MRP) may interfere with mineral bioavailability because of modifications of their physical-chemical moiety in the food or the lumen, disrupting the absorption process or its normal metabolism. In this study, we sought to investigate MRP influence on issues related to Ca bioavailability in vitro and in vivo. Equimolar mixtures of glucose-lysine (GL) and glucose-methionine (GM) (40% moisture) were heated at 150 degrees C for 90 minutes (samples GL90 and GM90, respectively). In vitro solubility was measured by additioning each samples to a 3.75 mM Ca solution at intestinal pH and ionic strength; after shaking and centrifugation, soluble and insoluble calcium was determined. Three percent of GL90 and GM90 were individually added to the AIN93-G diet to obtain D-GL90 and D-GM90 diets. Three Wistar rats groups were fed for 21 days with both diets and with AIN93-G as control, carrying out calcium balance during last week and extirpating various organs after sacrifice. GM90 did not affect calcium solubility; GL90 reduced it slightly, remaining in both cases more than 94% soluble. D-GL90 and D-GM90 did not modify calcium bioavailability, with as effective usage as with the control diet (57.6 +/- 1.3%, 57.8 +/- 2.3% and 63.9 +/- 2.6% in control diet, D-GL90 and D-GM90, respectively). MRP intake produced, however, metabolic changes that decreased bone calcium, accumulating compensatorily in other organs.
authors.affiliation: Unidad de Nutrición, Estación Experimental del Zaidín, CSIC, Granada. cdelgado@eez.csic.es
authors.forename: C
authors.initials: C
authors.lastname: Delgado-Andrade
authors.forename: I
authors.initials: I
authors.lastname: Seiquer
authors.forename: Maria P
authors.initials: MP
authors.lastname: Navarro
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000187:drug effects* / Q000378:metabolism; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology*; D006361:Heating; D006801:Humans; D008239:Lysine / Q000494:pharmacology*; D015416:Maillard Reaction; D008715:Methionine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D008715:Methionine; D005947:Glucose; D008239:Lysine; D002118:Calcium