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P.PSH.0133 Alkaline dehydration process for TSE inactivation and regulatory approvals

Project start date: 04 August 2003
Project end date: 30 June 2006
Publication date: 30 June 2006
Project status: Completed


​MLA and Australian Dehydration Technologies PTY Ltd collaborated on a series of projects relating to  producing meat and bone meal from abattoir wastes, with a specific focus on the ADT process as a method of inactivating Transmittable Spongiform Encephalopathy (TSE).
The initial research conducted with MLA was an evaluation of the ADT process as an alternate method of producing meat and bone meal from abattoir wastes. From this it was determined that the ADT process was an energy efficient, environmentally friendly process that could easily be applied to general rendering to produce high quality protein meals.
The P.PSH.0133 research project was specifically aimed at the ADT process as a method of inactivating TSE. The agent causing TSE is an abnormally shaped prion protein. The biochemical theory to TSE inactivation in this case was that all protein including the prion protein would be broken down or hydrolysed to small poly peptides thus inactivating the causal TSE agent, the prion protein. High alkalinity is known to hydrolyse protein with the degrees of hydrolysis being governed by the concentration of the alkali, the temperature and time of the reaction.
The EU regulators considered that BSE is inactivated if all proteins are hydrolysed to a size of < 10 KDa[1]. The first experimentation of this project was to determine the alkali concentration, reaction temperature and time to achieve complete protein hydrolysis to poly peptides of < 5 KDa in laboratory studies using bovine brain material as the start medium. Once these hydrolysis parameters were determined, they were applied to actual decanter solids from a commercial rendering plant and the degrees of hydrolysis determined. Hydrolysis levels of < 5 KDa were demonstrated.  
The next stage of the research was to apply the same processing parameters to material containing active TSE material. Bioreliance in Scotland who had conducted two similar experiments for ADT previously were contracted to undertake this work. Despite every assistance, they simply could not get the sample preparation correct for analysis. The contract with Bioreliance was terminated and NewLab BioQuality AG in Germany were commissioned to conduct the experimentation. This work then proceeded without any difficulties with the results demonstrating complete hydrolysis of all protein including the prion protein as well as inactivation as determined by immunoblot testing.  
From these research data and findings, the following documentation was prepared.Documentation of all data into an information document.The preparation of a document by Professor Milton Hearn for submission to Australian and International regulatory authorities for the approval of the ADT process as a method of TSE inactivation in general abattoir wastes.A HACCP analysis for the process.
Research outcomes
From the research it was determined that:The ADT process could be operated at a level safely to inactivate any TSE present in the parent material to a safe level.No technical impediments to large scale adoption were found; therefore the process is technically prepared for processing from 1 ton / hour to 20+ tons / hour.Capital and cost parameters for operation were well within commercial acceptance.
With BSE/TSE inactivation now being seem of less importance, to this date (2014) there has been limited or no commercial take up of this technology in Australia or overseas.  Instead, the key benefit of this process is seen as being energy efficiency rather than food safety, and hence a pilot plant is under construction via project P.PSH.0532 to demonstrate this benefit.
ADT and MLA are also jointly co-funding intellectual property protection for the ADT process on a worldwide basis.