Occurrence of free D-amino acids (DAA) was quantified in raw milk from animals normally bred for food production and characterized by different digestive physiology. Free DAA were extracted from cow, sheep, goat, mare and sow milk in ethanol and proteins were precipitated by addiction of picric acid. After centrifugation the supernatant was passed through a column packed with a Dowex 50 WX8 cation exchanger resin and the amino acids were eluted with aqueous ammonia. N-trifluoroacetyl-O-isopropyl esters of amino acids were prepared and analised by capillary gas chromatography using a chiral stationary phase. The results suggest that contribution of gut bacteria and microbial protein to the occurrence of DAA in milk could be less important in monogastric animals than in ruminants.
|Titolo:||Occurrence of free D-amino acids in milk from food-producing animals|
VALFRE', FRANCO (Ultimo)
|Parole Chiave:||D-amino acids ; milk ; N-trifluoroacetyl-O-isopropyl esters|
|Settore Scientifico Disciplinare:||Settore AGR/19 - Zootecnica Speciale|
|Data di pubblicazione:||1996|
|Appare nelle tipologie:||01 - Articolo su periodico|