Combination of microfiltration and heat treatment for ESL milk production: Impact on shelf life

Thermized defatted cow milk was submitted to different heat treatments (between 73 and 130 °C, 2 and 15 s) and combined with a microfiltration step (1.4 μm cut-off ceramic membrane) to study the influence of these treatments on milk shelf life. Thirty thousand colony forming units/mL was selected as the limit parameter for extended shelf life. The logarithmic reduction in bacteria was estimated for each treatment and the total bacteria count was measured during the storage of milk at 4-6 °C and at room temperature. Microorganism growth kinetic data during storage were also estimated. A maximum extended shelf life of 74 days was found for milk after the combination of microfiltration and direct heat treatment at 125-130 °C and storage at room temperature. An extended shelf life of 33 days was obtained after microfiltration followed by pasteurization at 90 °C and storage at 4-6 °C.