Title: Pasteurization of strawberry puree using a pilot plant pulsed electric fields (PEF) system Authors
Submitted to: Annual Meeting of the Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: July 13, 2013
Publication Date: July 16, 2013
Citation: Geveke, D.J., Aubuchon, I., Zhang, H.Q., Boyd, G., Sites, J.E., Bigley Jr, A.B. 2013. Pasteurization of strawberry puree using a pilot plant pulsed electric fields (PEF) system. Annual Meeting of the Institute of Food Technologists. 1:1. Technical Abstract: The processing of strawberry puree by pulsed electric fields (PEF) in a pilot plant system has never been evaluated. In addition, a method does not exist to validate the exact number and shape of the pulses applied during PEF processing. Both buffered peptone water (BPW) and fresh strawberry puree (pH 2.4) were inoculated with Escherichia coli (ATCC 35218) and processed using a pilot plant PEF system at field strengths of 24 – 33.6 kV/cm, outlet temperatures of 45 – 57.5 C and a flow rate of 100 l/hr. An accelerated shelf life study was performed on the strawberry product samples. In addition, a continuous high-speed data acquisition system was developed that records each and every pulse for validation purposes. The populations of E. coli were reduced by 6.5 log in BPW at 28 kV/cm and 57.5 C and 7.3 log in strawberry puree at 24 kV/cm and 52.5 C. The quality of the PEF processed strawberry fared better than that of the thermally processed during the first 4 months of storage. After that, the quality was similar. The novel data acquisition system captured, and showed in real time, the details of every pulse applied at a rate of 500 Hz for 1 hour for a total of 1.8 million pulses. Strawberry puree was successfully processed in a pilot-scale PEF unit. In addition, a data acquisition system was developed that will aid in obtaining FDA approval of the PEF process.