Under pressure: HPP preserves food, texture and taste
The popular technique doesn't alter the food items, but can triple shelf life — all without chemicals
Food manufacturers are always looking for new ways to package products in ways that preserve freshness, extend shelf life, and maintain taste.
These desires come together through high pressure processing — commonly abbreviated as HPP. Its popularity is sweeping the CPG space, using extreme pressure during food processing to paralyze and render harmful pathogens obsolete.
HPP has several different applications. It is very popular in the raw juice category in particular because of its ability to preserve freshness, and is increasingly being used by food companies to innovate the refrigerated space.
Although the non-thermal pasteurization effect of high pressure on foods has been understood since as early as the 19th century, it was not until the mid 1990s that the first HPP products were developed.
“HPP is a wonderful, clean method for extending shelf life on natural and organic products without having to add any additives or preservatives,” Serafina Palandech, CEO and co-founder of organic chicken nuggets manufacturer Hip Chick Farms, told Food Dive. “Consumers are still largely unaware of the benefits and perhaps have only heard about it with juice. With the increase in usage, folks are going to learn quickly about HPP, its benefits for busy families, and for crowded grocery stores.”
Robert Price Sr., project manager at Seiberling Associates and a board member of the Food Processing Suppliers Association, said HPP is continuing to gain ground in the specialty food market sector, where minimally processed products without preservatives have a growing market share.
“By avoiding the traditional methods of using heat for food preservation, processors can subject food to high pressure at ambient temperature to provide extended shelf life of delicate food products whose flavors, nutrients, and texture would otherwise be compromised by a thermal process,” Price told Food Dive in an email. “It’s a growing trend because consumers are looking for foods that have high nutritional value, fresh flavor, and that are high in antioxidants.”
Will Burger, marketing manager for Hope Foods, said HPP is becoming more important than ever.
“It does an excellent job of achieving both superior tasting and quality product, as well as ensuring a safe product for consumers,” he told Food Dive in an email. “More and more people are seeing the benefits of the technology and are responding by finding ways to utilize it in their own manufacturing process.”
Unlike thermal, chemical and other high-heat treatments, HPP runs cold. It doesn’t alter food taste, texture or quality. It doesn't need lots of chemicals for products to stay fresh. Even better, it can extend shelf life up to two or three times longer than traditional preservation methods.
The 411 on HPP
According to the Food and Drug Administration, high pressure processing subjects liquid and solid foods, with or without packaging, to pressures between 100 and 800 MPa — which is more than the amount of pressure that can be felt at the deepest part of the ocean. This level of pressure destroys organisms that could spoil food —including bacteria, yeasts and molds — and enzymes, which can lead to food degradation during storage.
Palandech explains that by exerting a great force of water pressure on a fully cooked chicken sausage, which normally would have a shelf life of five to seven days, it can have a shelf life of up to 90 days. This makes supply chain issues much easier for small producers to deal with, while making things easier for grocery stores and consumers.
“We are very excited to use the technology as a small start-up that is disrupting the meat and poultry space,” Palandech said. “The technology is available for anyone who embraces change and new ways of processing—especially if the brand is seeking clean, natural ways to extend shelf life while maintaining the integrity of the product.”
HPP in action
HPP is being used by a variety of processors for products including cold pressed juices, deli meats, ground beef, and even avocado-based products.
According to Price, there are over 200 commercial sized HPP units in use in the United States today. While most are owned by food companies that utilize them for their own products, an increasing number are operated by toll production facilities that accept packaged food and beverage products in fee-for-service arrangements.
“The entry price of $3 million can prevent smaller companies from owning equipment, but over 60% of the units in operation current co-pack for multiple clients,” Price said.
Züpa Noma, a line of chilled vegetable soups founded by Jon Sebastiani, uses HPP to maintain all of the flavor and nutrients in the company’s fresh produce.
“Research shows that people are simply not getting enough vegetables, in part because they don’t always taste great or aren’t delivered in an accessible way,” Sebastiani told Food Dive. “HPP continues to grow in importance as a way to get consumers all the beneficial vitamins and nutrients that they’re seeking, while still in a convenient format.”
Using HPP for its ready-to-sip soups has enabled the company to develop a roster of six flavors that range from sweet to spicy, packed with produce and powerhouse ingredients like coconut, turmeric and pumpkin seeds.
HPP is an external process—meaning the final product remains untouched. After Züpa Noma soups are blended and bottled, the bottles are placed into a pressure chamber filled with cool water for one to two minutes. They are subjected to elevated pressures (the equivalent of being submerged 20 miles beneath the ocean floor) from all directions to the outside of the bottle, inactivating harmful, pathogenic bacteria without compromising the integrity of the product from a taste or nutritional standpoint.
Recent stories in the media about contaminated food, listeria and salmonella have put consumers on high alert about food safety. High pressure processing can help ease those concerns.
According to Avure HPP Food Processing, high pressure processing has the unique ability to inactivate microorganisms without chemicals or preservatives as HPP machines neutralize listeria, salmonella, E. coli and other deadly bacteria.
Burger noted that other than the obvious safety benefits of the technology, HPP also helps keep the fresh qualities of a product preserved for the consumer without using heat (pasteurization) or chemicals (preservatives.)
“It allows organic products like Hope Hummus to achieve a longer shelf life and reach as many consumers as possible,” he said. “Pressure is able to permeate the cell walls of pathogens while protecting the nutrients in the food.”
However, the expense and the process — which currently requires manual loading and unloading of HPP carriers — can sometimes stop companies from taking advantage of the process.
In the immediate future, Price expects continued growth in market sectors in which non-thermal processing treatment will help preserve the product in a way that consumers will like.
Burger foresees many companies, CPG and co-packers alike, making investments into HPP technology and utilizing it as a part of their process.
“In a day and age that people are rightfully aware and concerned of pathogen outbreaks (especially listeria), HPP provides companies the ability to protect consumers while providing a superior product,” he said.
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