Turn up the pressure

How does Hiperbaric high-pressure processing (HPP) works and what are its benefits over heat pasteurisation?

Joyce Longfield: HPP applies cold water pressure uniformly to products in a flexible package. The water pressure is lethal to microorganisms providing the same food safety as heat pasteurisation. The main difference between heat pasteurisation and HPP is that there is no thermal heat involved with HPP and therefore, nutrients and taste are retained where they would be lost from heat pasteurisation.

Roberto Peregrina: High-pressure processing is a non-thermal pasteurisation technique that uses water and a high level of isostatic pressure to inactive foodborne pathogens, including E. coli, Salmonella and Listeria monocytenes. HPP benefits include food safety, extended shelf life, and preservation of nutritional value and flavour, without the use of preservatives.

How has the trend towards this kind of processing to maintain freshness and nutritional content of products evolved?

JL: As consumer demand for fresh foods made with clean ingredients grows, so does the need for HPP technology, since it allows companies to remove preservatives and retain all of the taste.

RP: The adoption of HPP by the food industry continues to climb at a fast pace. Over the past two decades, among the trends driving HPP is the desire for minimally processed, better-for-you, clean label foods. Among food categories, juices and beverages are the fastest-growing HPP sector over the past two years, taking nearly 35% of HPP equipment sales. Other HPP foods include readyto- eat meals, wet salads such as guacamole and hummus, dairy, baby food and pet food. HPP is ideal for these foods because it eliminates food-borne pathogens but preserves taste and nutrition, without the need for preservatives.

What are HPP’s credentials in eliminating the need for preservatives and other shelf-life-extending additives?

JL: Preservatives are biostatic agents that prevent growth but do not kill pathogens. Because HPP is applied to a finished product in a finished package, there is no risk of recontamination post-HPP and, therefore, it does not require preservatives to reduce the potential for pathogen growth.

RP: HPP is a non-thermal preservation method that maintains the optimal product quality and freshness without negatively impacting vitamins and nutrients, compared with thermal or chemical processes. Because HPP also controls vegetative bacteria and spoilage mechanisms such as yeast and mould, long refrigerated shelf life can be achieved. HPP is an environmentally friendly process.

How has HPP become synonymous with health and wellness?

JL: HPP has always been synonymous with food safety within the food manufacturing industry. It is only now becoming synonymous with health and wellness to the consumer, as this is what interests them. Consumers always assume that all food they purchase is safe, so HPP has become more important as the education surrounding its non-thermal technology, which does not negatively impact nutritional content, increases. The cold-pressed juice category, for example, helped bring HPP into a superstar light as a healthier alternative to traditional pasteurised juices that offered little nutritional value, unless fortified with nutrients.

RP: Consumers are gravitating towards fresh, clean label products without chemical preservatives. Reduced sodium products are also popular for the ageing population and health-conscious consumers. All these innovative products are possible with the help of HPP to address food safety concerns, while at the same time significantly extending shelf life.

Are start-up costs decreasing to make the process more accessible and more affordable for consumers?

JL: From a Good Foods perspective, where all HPP is in-house, this technology provides ongoing return on investment right from the beginning because of the brand protection. To date we have not had any recalls due to risk of harmful bacteria. As food safety concerns grow among retailers, and retailers implement their own auditing and food safety requirements, HPP allows us to have a competitive edge over other companies not using the technology, and that relies on preservatives or pasteurisation, which does not provide the same uniformity as HPP.

Additionally, HPP allows us to be versatile with our product development and package offerings. We are only restricted to the size of the carrier that our packages are placed into. We are not limited to making a specific food or beverage, as is often the case with pasteurisers and even other non-thermal technology such as UV, which is only applicable to liquids.

RP: Because HPP technology is a batch process, producers must consider product volume before investing in the capital equipment and staffing to operate and maintain HPP equipment. Bringing the HPP process in-house may make sense – numerous companies have made successful investments. However, if product volumes don’t justify the capital expenditure, or if there are higher priorities for capital, tapping a growing network of HPP outsourcers may be the smart decision. Hiperbaric has focused its R&D efforts on making our machines the most reliable in the market, and both parts and spare parts last longer thanks to our vertically integrated development for some of the key parts of the machine. This makes HPP process more affordable than it was 10 years ago.

2002
The year the first Hiperbaric high-pressure processing prototype was installed, in a Campofrio meat factory in Spain to process drycured meat products for export.
Hiperbaric

What are the challenges of HPP in order to not negatively impact the nutritional profile of the product?

JL: Because HPP does not transfer thermal heat to the food and drink, there isn’t the traditional denaturing of vitamins and enzymes that occurs with heat pasteurisation. It is known that vitamins and enzymes are susceptible to oxygen and pH, so a company must also consider that the upstream processes they perform could impact these nutrients. Blending, mixing and macerating can incorporate air and alter the pH, which can reduce sensitive nutrients such as vitamin C.

Other nutrients such as macromolecules and minerals are quite stable through both HPP and other upstream mechanical processes, so these are not a concern for change.

RP: Although HPP by itself does not make a product shelf-stable, the process also must overcome such hurdles as pH control, natural inhibitors and refrigeration, when bacterial spores may be of concern.

Can you explain the impetus for the HPC mark, and the work involved to see it through to fruition?

JL: The HPC mark was created with two motives; to provide uniformity to the companies using HPP, so everyone is meeting their regulatory requirements and maintaining them each year, and to educate consumers regarding the benefits of the HPP technology and to seek out foods/beverage treated by HPP. In order to fulfil the first motive, we prepared guidelines based on regulatory requirements, and scientific evidence and advice from industry experts. The documents from a company will be reviewed by a third-party agency, NSF, and reported back to the Cold Pressure Council (CPC) if they meet the guidelines and can receive the mark. This way there is no bias towards a company, nor does the CPC have access to any company documents.

As for the second motive, the CPC and members are committed to growing awareness of the benefits of the HPP technology and why companies that invest in the technology do so in the interest of the consumer. The education of the HPC website is to provide insight into the nutrient retention achieved or the ability for a company to provide a clean label product. All the while the food manufacturer knows that their consumer does not have to doubt the safety of that product, so much so that they can rely on the brand protection the technology provides.

RP: The High Pressure Certified logo was developed by the CPC to promote industry standardisation of HPP. Additionally, the CPC is actively promoting consumer awareness and user education through webinars, speaking engagements, and participation at industry trade shows and events. The council promotes networking among industry professionals and assists in formalising industry best practices. Hiperbaric was one of the founding members of the CPC, and was involved in many of the early discussions and meetings. Having the logo helps educate manufacturers as well as consumers, as manufacturers that carry the seal must comply with strict guidelines established by the CPC to ensure food safety and other industry best practices.

Where do you see HPP advancing in the near future?

JL: As the technology for identifying and tracking food-borne illness and pathogens improves, this will equip inspection agencies better to connect the source of the pathogen causing the illness. With this info available in a shared databank of DNA fingerprinting the pathogens, it increases the fear within food manufacturers that one of these fingerprints could be traced back to a strain found in their facility. Since HPP is an intervention step, FDA and USDA have identified HPP as a technology that can prevent the food from being recalled, if it came from a manufacturer that was found to have a harmful pathogen within the facility. Again, using a preservative is not an intervention step and should a facility be found to have a harmful pathogen within it they will have to recall this product.

The category of freshly prepared, refrigerated foods is the most vulnerable to harmful pathogens, as well as one of the largest categories using preservatives. As this category continues to grow and more companies desire an intervention step that still offers nutrition and a fresh-like taste, HPP will continue to grow.

RP: HPP is used for a variety of food products, and we continue to see the main categories as juices and smoothies and fruit-based waters – for example, watermelon and coconut water. We also see growth in ready-to-drink beverages like cold soups, cold-brew coffees and teas. The functional beverage category, including wellness shots and CBD-infused beverages, is also seeing growth. Hiperbaric also developed HPP Bulk technology to process large beverage productions prior to packaging, allowing any type of packaging material. This is a breakthrough innovation since HPP is a post-packaging process.