Effects of thermal industrial processing on acid-soluble nucleotides of milk

Abstract

SUMMARY: Commercial bulk milk contained, in its acid-soluble nucleotide fraction, small quantities of CMP and AMP as well as a high proportion of orotate (503±16 μg/g of total solids). These components were altered by thermal treatment during processing. Standard sterilization and spray drying of milk lowered significantly the CMP, AMP, and orotate concentrations. HTST pasteurization caused a slight decrease in CMP and AMP concentrations, but the orotate content remained unchanged. The UHT sterilization seemed to be the thermal treatment in which the acid-soluble nucleotides of milk underwent least change. It is therefore concluded that the decrease in concentration of the nucleotides of milk is more directly related to the time for which the milk remains at the processing temperature than to the temperature itself.