Can ozone be used as antimicrobial in the dairy industry? A systematic review

Milk and dairy products are abundantly consumed in all cultures, but unprocessed products can harbor pathogenic microorganisms that can cause serious health risks for its consumers. To avoid this, it is necessary to process the products. Ozonation is a clean technique that has antimicrobial power due to its oxidation potential, reducing the microorganisms and limiting the production of enzymes, but the effectiveness of ozone treatment can be affected by the temperature, pH, additives, humidity, and the amount of organic matter around the cells. The goal of this systematic review was to analyze whether the use of ozone could improve the microbiological quality of dairy products and whether it could be used as an antimicrobial technique. Six databases (PubMed, Scielo, CAPES, Science Direct, Science Core Collection, and PLOS) were used in this research, with 2 independent reviewers selecting articles up to November 21, 2020, with experiments that used ozone as an antimicrobial in dairy products. A total of 731 articles were found, but only 9 were selected. The remainder were excluded according to the following criteria: was not related to the main theme; was a review; did not contain microbiological analysis; did not mention the concentration of gas and time of the ozone treatment; and was not an experiment. Important points were noted in quality criteria, which resulted in the need to standardize the methodology applied in research to improve the quality of the experiments. Studies were carried out with many different samples of milk, but the best results in reducing the microorganism count were obtained from samples containing low levels of fat.