Identification of spinacine as the principal reaction product of gamma-casein with formaldehyde in cheese.
Formaldehyde is added to milk in the production of grana cheese as an antimicrobial agent. In order to study the fate of the formaldehyde, a grana cheese preparation was made using 14C-labelled formaldehyde. The 14C-activity in the cheese was found to be mainly associated with the caseins, but it was not uniformly distributed among the different fractions (alpha s, beta- and gamma-caseins). gamma-Casein, separated by electrophoresis, was the most reactive component showing the highest specific activity. In the gamma-casein fractions, 99% of 14C-activity was associated with the basic amino acids. The only radioactive reaction product present in the gamma-casein fraction was identified by HPTLC and by an amino acid analyser to be spinacine, a condensation product of formaldehyde and histidine. Using the same method, other unknown radioactive products, of much less relevance, were detected in the total casein hydrolysate.
Restani
P
P
Institute of Pharmacological Sciences, University of Milan, Italy.
Campagner
P
P
Fiecchi
A
A
Resmini
P
P
Galli
C L
CL
D002364:Caseins / Q000378:metabolism*; D002611:Cheese; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D002855:Chromatography, Thin Layer; D005557:Formaldehyde / Q000378:metabolism*; D007093:Imidazoles / Q000032:analysis*; D011725:Pyridines / Q000032:analysis*
D002364:Caseins; D007093:Imidazoles; D011725:Pyridines; D005557:Formaldehyde; C055336:spinacine