Food Industry Employs High-Pressure Processes for Various Applications

High-pressure processing (HPP) is a groundbreaking food pasteurization method that uses elevated pressures to alter food attributes and inactivate harmful and spoilage microorganisms. This innovative technique, often compared to the traditional thermal treatment, offers several advantages over conventional methods.

The core of HPP lies in pressurizing food packaged in a flexible container, transmitting pressure through the package into the food, and holding the food under pressure for a specific time before depressurizing. This process, originally matured from high-pressure equipment design in the chemical processing industry, provides an alternative means of killing bacteria without causing thermally induced off-flavors and retaining quality attributes, especially in heat-sensitive products.

Commercial-scale equipment for HPP is available with vessel volumes ranging from 35 to 525 liters. Notable manufacturers include Quintus Technologies, Hiperbaric, Avure Technologies, and ThyssenKrupp. For processing large volumes of beverages, bulk High-Pressure Processing equipment is an option.

After processing, the liquid is discharged through a discharge valve and collected in an aseptic storage tank. Liquid food for bulk HPP is packaged into large, pre-sanitized polymer bags (up to 500 liters).

One of the key benefits of HPP is its limited effect on low-molecular-weight compounds such as flavor compounds, vitamins, and pigments. This results in food quality similar to fresh food products. On the other hand, high-pressure treatment modifies the cellular morphology of microorganisms and damages cell membranes, ribosomes, and enzymes, including those involved in DNA replication and transcriptions.

HPP products need to be refrigerated during their distribution due to the fact that pressure treatment at ambient temperatures does not inactivate bacterial spores. However, the extended shelf life of food products is a significant advantage, with HPP treatment capable of extending shelf life up to 120 days depending on the choice of process parameters and product formulation.

Ultrashear technology (UST), a next-generation, continuous high-pressure processing method for treating liquid foods, is another promising development in the field. UST-treated liquids are reported to have desirable quality changes such as particle size reduction, and changes in rheological, emulsification, and homogenization characteristics.

Research facilities throughout the United States and Europe, such as The Ohio State University Center for Clean Food Process Technology Development, offer opportunities for food processors to evaluate HPP technology.

The cost for HPP pasteurization is estimated to be 10.7 cents/L for a processing capacity of 3,000 L/h (792.5 gal/h), while the cost for comparable thermal treatment is 1.5 cents/L. This cost-effectiveness, coupled with the preservation of food quality and extended shelf life, makes HPP an attractive option for the food industry.

While the search results do not directly list companies specializing in industrial high-pressure processing systems, firms involved in high-pressure equipment often include specialized industrial manufacturers or suppliers. Additional research from industry sources or databases would be necessary to identify such companies precisely.