Submitted to: Journal of Food Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2014
Publication Date: 2/1/2015
Publication URL: http://handle.nal.usda.gov/10113/60663
Citation: Jin, Z.T., Guo, M., Zhang, H.Q. 2015. Upscaling from benchtop processing to industrial scale production: More factors to be considered for pulsed electric field food processing. Journal of Food Engineering. 146:72-80.
Interpretive Summary: Pulsed electric field (PEF) processing has been studied for decades, but currently there is no commercial food production line using the PEF technology. This study was to investigate the various interdependencies of different treatment parameters, product properties and production conditions that need to be considered in commercial juice production. Pomegranate juice was used as a model food, and treated in benchtop and commercial scale PEF systems. The data from this study is useful to overcome some obstacles that block this technology moving from lab scale to full production and promote the commercialization of this technology.
Technical Abstract: Pulsed electric field (PEF) processing has been intensively studied with benchtop scale experiments. However, there is still limited information regarding critical factors to be considered for PEF efficacy in microbial reduction with PEF processing at a pilot or commercial scale production of juice. In the present study, continuous benchtop (3.6-7.6 L/h) and pilot/commercial scale (100 – 1000 L/h) PEF processing systems with co-field treatment chambers and biopolar square waveform pulses were used and simulated production conditions were tested for pomegranate juice. Microbial reductions of Escherichia coli, as affected by PEF process conditions (field strength, pulse width, pulse frequency, total treatment time, input energy), production conditions (flow rate, juice holding time and temperature), and juice properties (pH, conductivity, particulate), were investigated. Flow rate, PEF process parameters, production conditions, type of target microorganism, and properties of juice significantly affected microbial reductions by PEF treatments. E. coli ATCC 35218, a non pathogenic surrogate bacterium, exhibited higher resistance to PEF treatments than E. coli O157:H7 and E. coli K12 in pomegranate juice. Increase of a single PEF parameter (field strength, pulse width, pulse frequency, total treatment time, or energy input) is insufficient to achieve maximum microbial reduction, and optimal PEF treatment conditions for maximum microbial reduction depend on multiple factors including PEF processing parameters, production conditions and product properties. Simply applying PEF process parameters from a benchtop to pilot or production scale system may not achieve the same microbial reduction. This study demonstrates that scale-up and validation studies in a specific PEF system for specific product are very important and necessary before successful commercial application of this novel technology.