From Stone Tools to (very) High Pressure: Pressure-Based Evolution in Food Processing

Stone tools were the oldest pressure-related food processing tools (approx. 3.3 million years ago) until the use of fire for thermal processing (approx. 0.5–0.3 million years ago) became the prime food processing aid. During the last 40 years, gentle, resource-efficient pressure-related technologies for partial replacement of thermal processes were developed and gained rapid dissemination and acceptance. This paper provides an overview of food processes where pressure is the key mode of action ranging from negative pressures (below 0.00001 MPa) to very high pressure (1400 MPa). Working principles, applications, advantages/limitations as well as needs and opportunities for these processes using dynamic or static pressures are presented. Based on the high number of existing and developing pressure-related unit operations, we propose a new pressure-based food processes classifications system organized in pressure ranges (max. 0.1, 1.0, 10, 100, 1000, > 1000 MPa) embracing the temperature range used in food processing.