PRESERVATION OF RAW-MILK BY ACTIVATION OF THE NATURAL LACTOPEROXIDASESYSTEMS

The preservation of raw ovine, bovine and caprine milks by activation of their natural lactoperoxidase (LP) systems was investigated. Milk s amples with different concentrations of thiocyanate ions (SCN-) rangin g from 15 to 150 mg/l and hydrogen peroxide (H2O2) ranging from 10 to 100 mg/l were stored at 4 degrees, 22 degrees and 30 degrees C. Change s in titratable acidity, fetal colony counts and coliform counts of th e milk samples were followed during storage. No significant difference s were observed between samples with different concentrations of the a dded reagents, and this indicated that concentrations of 15 mg/l (SCN- ) and 10 mg/l (H2O2) would be adequate for preserving milks of differe nt mammals - at least at 4 degrees C. At higher temperatures, the effe ctiveness of the LP systems was, as monitored by the increases in acid ity of much shorter duration. Copyright (C) 1996 Elsevier Science Ltd.