Microbial inactivation of grains used in saengshik by corona discharge plasma jet

Abstract

Inactivation of microorganisms in grains used for saengshik, a formulated health food, was attempted by corona discharge plasma jet (CDPJ). The initial microbial counts of the grains were in the range of 1.7×103-9.9×105 CFU/g. The CDPJ-inactivation effect was increased with electric current in the range of 1-1.5 A. Regarding span length between the tips of the electrodes and the treatment surface, the highest inactivation effect was observed at 25 mm. The inactivation pattern fitted well to the Singh-Heldman model. Bacteria were more labile to the CDPJ inactivation than yeasts and molds. Among tested grains, white rice showed the highest sterility followed by pressed barley and brown rice. Despite the inactivation by plasma, the thiobarbituric acid content of the grains remained unchanged over 10 min of treatment. Our results indicated the potential of the CDPJ treatment to improve the hygiene of saengshik products with no remarkable changes in lipid quality. ©The Korean Society of Food Science and Technology.