Milk pasteurization at low temperature under N2O pressure

Non-thermal inactivation techniques in food industry are a major research issue, driven by an increased consumer demand for fresh and nutritious food products that are microbiologically safe, with a long shelf-life. Here we demonstrate for the first time the potential of pressurized N2O as a non-thermal inactivation processing aid for bacterial reduction in the pasteurization of raw fresh milk at mild operating conditions. Treatments were performed in a multi-batch apparatus at 12 MPa and at different temperature conditions (40–50 °C). Chemical parameters (pH, titratable acidity (TA)) of the untreated and treated samples were monitored and compared. Four independent experiments have been carried out at each operative condition (temperature, time, pressure). The study clearly demonstrates the great potentiality of the emerging technology: further development of the N2O process may open the doors to a new low temperature method for milk pasteurization, to be exploited on an industrial scale.