Harnessing the Structure Modifying Potential of Pulsed Electric Fields (PEF) – Food Processing Examples in Product Stabilization, Process Acceleration and Compound Extraction

Abstract

Pulsed electric fields (PEF) can electroporate eukaryotic and prokaryotic cells which can be used in food processing for product preservation and extraction of intracellular components. In this paper a number of potential processing applications for PEF will be considered. These will include its incorporation in hurdle preservation strategies, its use in the termination of enzyme hydrolysis of proteins, its application in the waste stream valorization through enhancing compound extraction and also its potential for accelerating processes such as meat tenderization or curing. In terms of product pasteurization, the paired combinations of novel technologies examined certainly inactivated more microorganisms than each technology alone but the effect of the combinations was largely additive or overlapping with few examples of synergy. In addition some combinations introduced high specific energy into products (in some cases higher than conventional UHT). In terms of product sterilization, PEF applied at temperatures of 120°C gave a slight though not significant increase in spore inactivation compared to thermal treatments. The use of PEF for endoprotease inactivation in bioactive compound production also proved to be very promising and could have application in hydrolyses termination especially where the resultant bioactives are heat labile. PEF pre-treatments of potato peel and brewers spent grain increased the extraction of glycoalkaloids and β-glucans respectively which is promising as conventional methods for the extraction of these compounds are expensive and the market value of the target compounds is high. In terms of its application in meat processing, PEF can have a positive impact on meat tenderization, though ageing/conditioning is still necessary. It has also been shown to accelerate the curing of meat when it is applied as a pre-treatment prior to curing. Overall, these applications are all promising though it remains to be seen which of these niche areas are likely to achieve significant commercial uptake.