The food industry has struggled with one question for years, “How do you remove harmful bacteria from food without sacrificing taste and quality?” High pressure pasteurization (or processing; HPP) is becoming a popular choice amongst food manufacturers, due to the fact that it does not expose food to detrimental processing. Heat, which is a popular choice, could potentially change the flavor and nutritional content of a product. This happens when organic matter has been burnt off while neutralizing bacteria and must be supplemented, resulting in obvious changes in composition. New ways to pasteurize with high pressure are likely being developed, but at this time there are only two popular methods of production.
Pasteurization using large tanks is fairly common and simple. Prepackaged food is placed into a tank filled with water. That water is then pressurized, meaning that high pressure is equally distributed throughout the tank, neutralizing the bacteria. The food is unchanged because the pressure is equally distributed throughout the food. The advantage of the tank method is that it can pasteurize large amounts of solid food at one time. One downside is getting the food in and out of the tanks takes time and involves manual labor.
The other form of high pressure pasteurization involves using a high pressure homogenizer to pasteurize liquids or semi-solid products. The product is fed directly into the device and then pushed through a system of tubes and nozzles using the intensified pressure generated by a hydraulic pumping system. The advantage to this form of high pressure pasteurization is that it also allows the product to be emulsified or even broken down while being pasteurized. This removes a step for those products that benefit from the combination of cell rupture and organic matter size reduction. While heat could be a factor during HPP (since it is released when pressure is heightened), heat exchangers and chillers can be used to keep product temperatures low, eliminating any harmful side effects from the processing.
Overall, high pressure pasteurization is a profitable option for the food industry. It neutralizes bacteria while leaving taste behind. The option that any manufacturer chooses is going to be based on their needs. For liquid and semi-solid products, using a high pressure homogenizer is both cost effective and recommended. Product can be both processed and pasteurized simultaneously, meaning that much of the labor used during manufacturing can be applied elsewhere and workflow can be streamlined. For solid products, and those that would not benefit from homogenization or mixing, the tank option is perfect. Large amounts of food can be pasteurized at once, after it has been processed, meaning that quality and taste is retained and any harmful bacteria neutralized. No matter which method is appropriate for a product, you cannot go wrong with high pressure.
