Use of Microwave Ovens to Pasteurize Milk

High-temperature short-time (HTST) and low-temperature long-time (LTLT) pasteurization were simulated using uninoculated and inoculated milks that were heated in microwave ovens. Heating milk (76 ml) for 59 s at 700 W achieved a temperature of 71.7°C, but heating for 60-65 s and holding for 15 s failed to inactivate all added cells of Salmonella typhimurium , Escherichia coli or Pseudomonas fluorescens . Milk, 453.6 g (ca. one-half quart) or 604.8 g (ca. two-thirds quart), was heated to >62.8°C, but <71.7°C, in 4.5 to 5 min, depending on power (550 or 700 W) that was used, and refrigerated overnight. Such treatments failed to reduce the population of Streptococcus faecalis in the milks by the degree that occurred when inoculated milk was heated in a water bath at 62.8°C for 30 min.