99E-1 |
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Z. T. JIN, M. Kim, S.-Q. Li, and Q. H. Zhang. Dept. of Food Science and Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007 Current regulations require fresh apple cider to be heat-pasteurized. Previous researches showed that processing fresh apple cider by PEF not only extended the shelf life but also maintained the fresh flavor. A new pilot scale fluid handling system with an energy recovery heat exchanger for PEF processing has been built at Ohio State University. The system showed higher energy efficiency and easier operation than previous one, and would be suitable for farms to process apple ciders or other juices if the FDA requirements for microbial reductions were met. Our objective was to evaluate the efficiency of this system in inactivation of natural flora and surrogate to pathogens in apple ciders. The pilot scale fluid handling system with an energy recovery heat exchanger was used for this study. The OSU-5C pilot scale pulse generator provided high voltage pulses. Fresh apple ciders were made by FMC juicer. The cider was incubated at 22o C for 3 days, or inoculated with Lactobacillus planetarium before PEF treatments. The PEF treated ciders were analyzed for microbial counts. Test conditions were: PEF field strength: 32 to 20 kV/cm; total treatment time: 44 µs; holding temperature: dependent on PEF field strength; holding time: 15 s; flow rate: 125 L/h, backpressure: 40 psi. Microbial reductions of both incubated and inoculated ciders were dependent on the PEF filed strengths and holding temperature. The treatment of 32 kV/cm with 70° C holding time obtained 5 log-reduction of aerobic bacteria and 5 log-reduction of mold & yeast in the incubated cider, and 5 logs of L. planetarium were inactivated in the inoculated cider. No recovery was found during one week's storage at 4o C. The fluid handling system provided high efficiency of microbial inactivation in apple ciders. The system combined with OSU-5C pilot scale pulse generator could be used for apple cider pasteurization.
Session 99E, Nonthermal Processing: General II
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |