Editor’s Note: Prepared Foods discusses HPP with Joyce Longfield, vice president of product innovation for Good Foods Group. Longfield also is chair for the Cold Pressure Council (www.coldpressurecouncil.org), an industry association of HPP food and beverage user manufacturers, HPP equipment suppliers, HPP toll processing service providers, and others.
Prepared Foods: What would you say are food scientists’ biggest misgivings or misconceptions about HPP?
Joyce Longfield: The most common misconceptions usually are that the technology does not deliver the level of food safety needed; or the opposite, in that it is a “silver bullet” and will destroy everything. Others think that there is some heat generated because of the extreme pressures. They also think that the pressure will crush their product.
PF: How do you address those issues?
Longfield: Visuals often are the best way to explain technologies and there are many HPP equipment videos now on the internet. Here, one can see that the product going into the machine looks identical to what it does coming out. Sometimes, viewers even can see ice chips on packages as they come out of the machine—and that is because cold water is used in food manufacturing HPP machines. As long as the water is cold, the product remains cold and does not incur an increase in thermal heat.
Meanwhile, the food safety aspect of this is the most critical component within the HPP industry. It’s the No. 1 reason why companies invest in the technology. This also was the driving reason for creating the Cold Pressure Council (CPC). We want to ensure that all companies understand the application possibilities, limitations of the technology and that there’s a validation of HPP treatment that is standardized in the industry.
PF: We expect that HPP’s role to extend shelf life most likely varies by product application. What do you tell food scientists about this topic?
Longfield: On average HPP provides 10x the shelf-life to a non-HPP product. Most HPP treated food would have at least a 30-day shelf-life but average is typically 60-75 days. Depending on the product this could be more than 100 days. The variance depends on if ingredients are “raw” or cooked.
For example, deli meats account for more than 30% of the HPP foods in the market. This is a product that is cooked, packaged and then HPP treated. A typical shelf-life is 120 days, unopened and refrigerated. Elsewhere, a cold-pressed juice contains a blend of fresh pressed fruits and vegetables so the shelf life is probably 45 to 60 days, unopened and refrigerated.
The difference is that “raw” ingredients have a lot of enzymatic activity that will cause a breakdown in the chemistry of the product. This means that a cold-pressed juice treated by HPP might taste bad at the end of its shelf life. The food safety is still there—but the sensory quality has failed. Whereas in the deli meat, the taste after it’s cooked will be retained through the use of HPP because the sensory attributes are quite stable. Even at 120 days, the food safety on an HPP deli meat is also probably still valid.
PF: Tell us about HPP’s growth and how it helps Good Foods Group.
Longfield: HPP experienced exponential growth after 2004, when the USDA put in place a zero tolerance for Listeria monocytogenes. Then we saw another jump in 2012, when cold pressed juices took advantage of the technology’s ability to deliver safe food that does not involve heating. That category’s growth soon opened the minds of product developers in similar categories, such as ready-to-eat foods that are sensitive to damage from heat treatments.
Products that fall within the dips and spreads category are the perfect application for HPP—allowing you to make safe food without heat or preservatives and retain the taste and nutrition. In particular for Good Foods, the launch of our plant-based dips showcases how we can make a traditional dairy dip like queso and make it taste amazing with no cheese at all.