Production of extended-shelf life milk by processing pasteurized milk with pulsed electric fields

Abstract

Thermally pasteurized milk bulk-shipped to distant places is usually pasteurized for a second time after arrival at the point of consumption. Such double thermal treatment has the potential to reduce the sensory and nutritional quality of milk; hence the use of a nonthermal preservation method was investigated. High-temperature short-time (HTST) pasteurized milk was treated with five pulsed electric fields (PEF) having peak electric field of 35 kV/cm and 2.3 μs of pulse width, at a temperature of 65 °C for less than 10 s. PEF treatments were applied either immediately after thermal pasteurization to produce an extended-shelf life product, or eight days after thermal pasteurization to simulate processing after bulk-shipping. Application of PEF immediately after HTST pasteurization extended the milk’s shelf life to 60 d, while PEF-processing after eight days caused a shelf life extension of 78 d, both proving to be successful strategies to extend the shelf life of milk.