Use of gaseous ozone in soft cheese ripening: Effect on the rind microorganisms and the sensorial quality

The uncontrolled growth of potential spoilage microorganisms in cheese surfaces can deteriorate cheese quality, especially filamentous fungi. This study aimed to evaluate the effect of several gaseous ozone treatments during the ripening of soft cheese on the growth of cheese rind microorganisms at different production scales. On a pilot plant scale, the cheeses were inoculated with potential spoilage microorganisms (Mucor plumbeus, Kluyveromyces marxianus, and Pseudomonas fluorescens), while on an industrial scale, naturally present microorganisms were evaluated. Ozone treatments showed a considerable fungistatic effect on cheese surface molds at both pilot and industrial scale. However, the effect of ozone on yeast growth was only observed at pilot plant scale, while Pseudomonas ssp. was not affected by the ozone concentrations used in this study. The sensory quality of the cheese was also assessed. Cheese typicality was not affected by gaseous ozone. However, the ozonized samples had significantly higher scores than the control samples for rind appearance and color. Hence, ozonation can be considered an alternative approach to control mold growth in soft cheese during ripening and prevent cheese rind discoloration.