Industrial pilot-scale study on the ripening and quality parameters of Toma Piemontese PDO raw milk cheese in ozone-controlled atmosphere.

Abstract

Non-thermal technologies are becoming of high interest in dairy production as sustainable tools to enhance food safety. Raw milk cheeses present microbiological challenges due to spoilage and the absence of real thermal treatments. This study investigates an industrial application of gaseous ozone to control spoilage microflora on Toma Piemontese PDO raw milk cheese rind during ripening to preserve the overall quality. The test was conducted on 'Toma' cheese over 60 days. An automated ozone prototype was installed in a cheese-storing ripening room, and two pilot batch tests were designed: (i) untreated cheese wheels in air ripening room (CTL) and (ii) cheese wheels exposed to low-concentration gaseous ozone atmosphere (O3, 400 ppb, 0.856 mg m-3 in air) for 6 h per night, three times a week, until day 40 of ripening. Thanks to an attempted operational design, treatments were scheduled at night to ensure operator safety. Ozone significantly reduced microbial growth from the first 10 days of ripening, improving microbiological and visual quality. Cheese sensory quality was assessed: the O3 sample showed acceptance scores similar to or higher than the CTL sample, particularly for the rind appearance and color. Both samples exhibited a high perception of milky notes, in line with Protected Designation of Origin (PDO) specifications. No issues related to undesirable compounds linked to lipid peroxidation were observed, as confirmed by stable peroxide values over time. This industrial scalability test suggests that ozone technology can enhance food safety in dairy production and possibly offer advantages in terms of environmental and economic sustainability. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.