High Pressure Processing

Introduction

The technology has its roots in the material and process-engineering industry where it has been commercially used in sheet metal forming and isostatic pressing of advanced materials such as turbine components and ceramics.

High Pressure Processing is a food processing method wherein the food is subjected to high pressures (up to 87,000 pounds per square inch) at ambient or chilled temperatures to kill bacteria present in the food. The technology can also be used to enhance desired food attributes. High pressure processing can ensure food safety by destroying the bacteria that cause food borne illness and spoilage, and parasites that cause diseases.  In a typical process, a pre-packaged raw product is loaded inside a pressure chamber and subjected to high pressures for specific time. This whole process may take 10 minutes or less. Pressures used in the food processing are almost ten times greater than in the deepest oceans on earth.

High-pressure pasteurization generally causes limited or no change in the ‘fresh’ characteristics of foods. Small molecules that are responsible for flavor and nutrition are typically not changed by pressure. Pressure processed foods are also reported to have better texture, nutrient retention, and color compared to heat processed foods.

In principle, any food material with sufficient moisture content can be subjected to high pressure processing. HPP can be used to process both liquid and solid foods. Food material containing large quantity of air pockets (such as marshmallows) are not suitable candidates for high pressure processing because the high pressure processing removes the air from these foods and thus destroying their appearance.