HPP: Power of Water Pressure in Food Preservation

1. Determine Your Goals. There are many reasons to switch to HPP. Understanding and acknowledging your goals and setting benchmarks for what success looks like are keys to settling on the most beneficial transition possible. Some providers utilize HPP to enhance their food safety program, while others are hoping to create a cleaner-label product and reduce sodium levels. Still others use HPP to reduce food waste/shrink or streamline their operations. Depending on the product, HPP may be able to make some or all of those dreams a reality.

Whether it’s expanding market reach through extended product shelf life, increasing your margins, or simply addressing changing consumer demands by converting a product currently distributed frozen to fresh, it’s critical to set an emphasis on what you plan to accomplish from the transition. Doing so helps evaluate success and guides future processing decisions.

2. Know Your Product. It is always important to thoroughly understand your product. HPP is effective on a wide variety of products, but differences among those products or even differences between varying types of the same product can have an effect on process hold time and level of pressure needed with HPP. The following are examples of information you should have about your current product.

• The product pH and water activity—very important with beverages.
• Your target product shelf life compared with your current shelf life.
• Your current packaging—does it provide an air tight/hermetic seal, and is there at least one surface or a combination of surfaces that can accommodate a 15 percent temporary volume change?
• Package barrier properties—does your current package/film have barrier qualities (OTR and MVTR) to maximize the increased shelf life benefit of using HPP?
• Labeling—if there is one, is it waterproof or could it be applied post-HPP?

3. Conduct Research and Obtain Consultation. Once you understand your goals and have defined the characteristics of your existing or new product, you can begin evaluating whether HPP is the right technology for your application. The next step is conducting research—microbiology challenge studies, product shelf life studies under various conditions, and organoleptic/sensory analysis, i.e. taste and flavor, texture, mouth feel, visual appearance, smell, and more.

If you already have an in-house product development team and micro lab, they can research available HPP technical literature on pathogen validation and shelf life studies. If not, there are knowledgeable resources available to you from universities and third-party companies who provide these services. You may simply need to try processing a few samples to know where to start. There are HPP test vessels available at multiple universities and third-party research organizations.

In addition, the two principal HPP equipment manufacturers (Avure Technologies and Hiperbaric) have many of these capabilities in-house or close working relationships with local labs to perform these analyses for your company. The growing network of HPP outsourcers, like Universal Pasteurization, have facilities located across the U.S. and may be able to assist with getting the evaluation process started.

4. Choose Whether to Insource or Outsource Your Processing. Numerous companies have invested in in-house HPP systems as a long-term, go-to-market business strategy. One of the questions you and your team will want to answer is whether you have the space and product volume to justify an HPP equipment purchase. The seven-figure capital expenditure, space and facility requirements, the implementation time, and ongoing staffing to operate and maintain the HPP process are key considerations to keep in mind. The weight of the larger HPP systems typically require special foundations to support the equipment load.

Understand that HPP is a batch-process and doesn’t lend itself well to traditional food processing lines. Manufacturers often create a staging area pre-HPP to provide product queues. Post-HPP, the product package will typically pass through an air knife to remove the moisture remaining from the HPP process. One may need to consider the additional floor space for any pack-off requirements, e.g. ink jetting, kitting, sleeving, overwrapping, boxing, and palletizing.