Preservatives, heat and various forms of sodium have been the traditional weapons for pathogen control and increased shelf-life in many foods. However, consumers now want fresher, preservative-free and reduced-sodium foods.
High pressure processing (HPP) replaces the need for heat and chemicals in food preservation. Now its traditional cost disadvantage - it is an expensive solution - is being overcome following new developments by organisations including Avure Technologies and Food Science Australia's Innovative Foods Centre.
Avure Technologies' new horizontal HPP system makes advanced food safety technology more affordable for small and mid-range processors. It also enables them to respond to growing consumer preferences for fresher, preservative-free, and reduced-sodium foods.
HPP is the post-packaging lethality treatment that inactivates foodborne pathogens and spoilage organisms in products as diverse as ready-to-eat meats, soups, wet salads, fruit smoothies, and seafood.
According to the company, the new QFP 100-Liter 600 is the next logical step in the evolution of the Avure HPP family, which now processes over US$2 billion of food products around the globe.
The smaller-footprint 100-Liter HPP system is described by the company as a perfect match for small/medium-volume or seasonal processors that want to add this important layer of food safety protection, extend the shelf-life of their products, forego the use of preservatives, or develop new food applications (Fig. 1).
"As food recalls continue to grab the headlines, HPP becomes more and more compelling as a food safety measure," states Pat Adams, Avure's president and ceo. "It also allows processors to plug into the mounting demand for convenient, high-quality, healthful foods that don't contain additives and which have a much lower sodium content. Up until now preservatives and forms of sodium have been the traditional weapons for pathogen control and shelf-life extensiown. HPP is the game-changer. It replaces chemicals while dramatically extending shelf-life. It is not a heat treatment, so there are limited effects on taste, texture, and nutritional properties."
With a sub-US$1 million price tag that parallels its smaller footprint, Avure's new system brings the multiple benefits of HPP technology to a much broader swath of processors.
According to Adams, the lower cost of entry comes with no sacrifice in throughput: "The 100 litre is designed to generate the highest throughput possible at that size." The 12.1in (308mm) -diameter vessel, into which product is loaded, affords maximum efficiency, accommodating various shaped packages, including bottles and cups. Production rates are 28 000 pounds (13 000kg) over a 20-hour workday.
The primary key food sectors for HPP are: ready-to-eat whole muscle and sliced meats; seafood; fresh-cut fruits and juices; deli salads, condiments, and dips; and soups, salsas, and sauces.
In the US, meat accounts for roughly 30 per cent of total HPP usage, but only five percent of all RTE meat undergoes HPP treatment, representing a huge opportunity for growth.
The deli salad segment is another high-growth sector. "Currently, premium salads such as pastas with proteins that are made without preservatives have an average shelf-life of just four to eight days," says Adams. "HPP treatment can extend that to 30 to 50 days, producing a product with a clean label for which consumers are willing to pay a premium price."
Cost of the treatment is very product dependent but averages just pennies per pound. The HPP expense is often partially mitigated by the corresponding reduction in the cost of additives.
In many installations, HPP serves as a process enhancement, for example, tenderising and marinating raw meat or fish products after packaging as part of the safety and shelf-life extension step. It also performs the shucking function on seafood lines, improving yields (100 percent meat separation) and generating significant labour savings.
The HPP-enabled longer shelf-life is expected to create countless new product opportunities. Avure is especially well equipped to work with processors in crafting these new offerings.
"One of our distinctions is the technical assistance we can provide to help clients bring successful HPP products to market," Adams points out. "The food scientists who work in our corporate facility and in conjunction with our network of certified HPP food labs are the go-to guys for creating new applications. We also look for ways to optimise throughput and the fill factor for the most economical processing."
The compact and highly efficient 100-litre is built on a new design platform engineered for reliability, availability, and serviceability, with a high degree of self-diagnostics. The company says it also sets new standards for energy efficiency and water conservation.
A similar innovation in HPP technology developed by Food Science Australia (FSA) to improve the way fruit juices and other food products are pasteurised, is now being used commercially in a Melbourne food processing facility.
The director of FSA's Innovative Foods Centre (IFC), Kees Versteeg, says the technology further developed by the IFC uses pressures of about 6000 times the average air pressure at sea level to pasteurise food products (Fig. 2).
"The unique benefits of HPP are that it kills microbes such as yeasts, moulds and bacteria, and extends the shelf-life of chilled perishable products without adversely affecting the food's freshness, flavour, colour, texture and nutritional value," he said.
"Normally processors would have to use preservatives or heat the product and this inevitably changes the taste and destroys some nutrients. Several years ago we developed prototype juice and other fruit products using HPP and assessed them for quality and shelf-life. We took these out to the industry to see who'd be interested in using the process, Donny Boy Fresh Food Company embraced HPP and we worked with them to develop and commercialise their juice and fruit products."
Donny Boy also uses HPP to preserve other foods and claims to be the first company in the world to supply HPP fruit to the dairy industry.
