High Pressure Processing

Summary

Backgound
High Pressure Processing (HPP) is a technology that delivers hydraulic pressures in excess of 6,000 atmospheres to food products immersed in a liquid medium. The technology was first used in the food industry to prolong shelf life of food products by inactivating food-borne pathogens. It is widely used in the USA to preserve guacamole, by inactivating spoilage organisms such as Listeria monocytogenes, to preserve and shuck oysters and as a non-thermal "pasteurisation" of orange juice. HPP is also used in the USA in meat products to extend shelf life. It has given rise to a range of "sandwich ready" sliced meat products with refrigerated shelf lives of up to 100 days.
There are three main specialist HPP companies in the world (accounting for about 90% of the installed HPP systems in the world) as follows:Avure Technologies from the USAwww.avure.com;NC Hyperbaric from Spainwww.nchyperbaric.com; andUHDE of Germany is an engineering subsidiary of ThyssenKrupp Technologies – with Multivac the Australian agent  http://ca.multivac.com/our-products/hpp-high-pressure-preservation.html
While HPP is a currently available 'off the shelf' technology that can be used to develop shelf stable, new meat based products that have not as yet been available in Australia (although readily available overseas). Hence MLA completed a series of research initiatives that explored the mechanism of HPP upon meat fibres/structure regarding tenderness and shelf life extension for red meat.
Research and related activities
After some early work on HPP (project PRMS.033A in 2003), the Australian red meat industry was reintroduced to High Pressure Processing (HPP) at a workshop, held in November 2009, run by MLA and hosted by CSIRO at Werribee. The workshop was designed to introduce the technology, products and manufacturers to the industry and to demonstrate benefits and value adding opportunities for red meat. These workshops were funded under projects A.MPT.0025 and A.MPT.0039.
A further "Red meat under pressure" workshop was hosted by CSIRO and MLA on 27th November 2014 at CSIRO’s Food Innovation Centre in Werribee, Victoria under project A.RMH.0024.
Project work conducted with funding from MLA under projects A.MPT.0013, A.MPT.0032 and A.MPT.0041 investigated whether tender meat can be achieved from muscles which are normally low value, through the application of high pressure processing (HPP), combined with heat. This work was conducted using the small scale equipment at CFNS-Coopers Plains, using small pieces of meat, and texture assessed by objective measurements (Warner-Bratzler, WB) as well as the large scale (35L) equipment at Werribee. In addition, these trials were co-ordinated to provide rapid progress and results to assist in answering a number of  questions.
Determine if pressure alone can achieve tenderisation in low and high collagen cuts (tri- tip, topside, tenderloin, brisket)Determine if tenderisation can be achieved using low pressures and high temperatures using CSIRO’s Werribee HPP facilityDetermine the impact on tenderness, if any, of pre-freezing samples (-20°C)Determine the impact of brine and HPP on texture of HPP-treated product
Outcomes
From the literature the greatest limitations for the application of HHP technology for meat texture enhancement have been capital equipment cost and need for its application to hot-boned (prerigor) meat for consistent benefit. An additional problem is that current batch sizes are a restriction for operations with high line speeds.  MLA has recommended the formation of an alliance with one or more of the equipment manufacturers to assist them address the needs of the Australian Red Meat Industry.  Additionally MLA is discussing the development of HPP products using business models that encourage a focus on local toll processing to defray the high HPP capital costs.