Individual Presentation: High-Pressure Thermal Processing (HPTP): Overcoming Technical Barriers to Industrial Application

Developing low-acid food products with high water activity (aw >0.97) that remain stable at room temperature or under refrigeration requires strict control of proteolytic and nonproteolytic Clostridium botulinum spores. These spores can produce the potent botulinum neurotoxin under favorable conditions, posing a major food safety risk. Traditional thermal preservation methods achieve this control by applying time-temperature combinations equivalent to P90 = 10 min (90°C) and F0 = 3 min (121°C), providing the necessary spore inactivation for product safety. The main drawback of these methods is extended exposure to high temperatures, which degrades sensory attributes, reduces nutritional quality, and promotes the formation of chemical contaminants such as furan.High-pressure thermal processing (HPTP) leverages adiabatic heat generated during compression of water and other compressible molecules within food. Under high pressure (typically 600 MPa), temperature rises rapidly and uniformly due to the isostatic nature of the process, reaching 90-121°C much faster than conventional heating. Pressure and temperature may act synergistically in spore inactivation, enabling equivalent lethality at lower temperatures compared to traditional methods.Industrial implementation has faced challenges, particularly maintaining temperature stability during pressure holding time. Recent engineering advances allow HPTP on conventional High-Pressure Processing equipment using insulated canisters filled with preheated water and product. These canisters minimize temperature gradients when pressurized and enable throughputs of up to 1,500 kg/h, comparable to or exceeding conventional retort systems for similar batch sizes, while offering improved uniformity.Benefits of HPTP include achieving equivalent lethality (F0) in significantly shorter times, preserving flavor, texture, and nutrients, and reducing contaminant formation because reactions responsible for these compounds do not occur under high pressure, in accordance with the Le Châtelier principle. By overcoming technical barriers, HPTP opens opportunities for new categories of shelf-stable or refrigerated-stable products such as baby food, ready-to-eat meals, ready-to-heat dishes, and premium pet foods.