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Corona discharge plasma jet for inactivation of Escherichia coli O157:H7 and Listeria monocytogenes on inoculated pork and its impact on meat quality attributes

Choi, Soee, Puligundla, Pradeep, Mok, Chulkyoon
Annals of microbiology 2016 v.66 no.2 pp. 685-694
Escherichia coli O157, Listeria monocytogenes, color, electrodes, meat quality, models, nitrogen, peroxide value, pork, sensory properties, thiobarbituric acid
Corona discharge plasma jet (CDPJ) was used for inactivation of Escherichia coli O157:H7 and Listeria monocytogenes inoculated experimentally onto the surfaces of fresh and frozen pork. CDPJ was generated with an output voltage of 20 kV direct current and a frequency of 58 kHz. Optimal inactivation was found with plasma created at a current of 1.5 A, and at a span length of 25 mm between the plasma electrode tip and the sample. Following CDPJ treatment (0–120 s) of pork samples, reductions in E. coli O157:H7 and L. monocytogenes were 1.5 log and >1.0 log units, respectively. The inactivation pattern fitted well to the Singh-Heldman model or pseudo-first-order kinetics. Compared to untreated pork, with the exception of color and appearance, no statistically significant (P > 0.05) changes were observed in volatile basic nitrogen, peroxide value, or 2-thiobarbituric acid reactive substances of CDPJ-treated pork. Furthermore, CDPJ treatment had no significant impact on the sensory characteristics of frozen pork although there was some effect on unfrozen pork.