Effect of various forms of non-thermal treatment of the quality and safety in carrots

Fresh carrots were processed using ozone, ultrasonication, alkaline ionized water, and high pressure processing (HPP) as well as quantifying their effects on 28 food quality and safety responses. Out of the four treatments, HPP at 350 and 450 MPa for 5 min achieved the highest reductions by 5.8, 5.7, 6.3, 4.7 and 5.7 log cfu mL(-1) in total mesophilic aerobic bacteria, total mold and yeast, total coliform, Escherichia coli O157:H7, and Salmonella Enteritidis, respectively. No downgrading changes as a function of the treatments were observed in pH, degrees Brix, titratable acidity, conductivity, color values, total antioxidant capacity, organic acids, phenolic compounds, and alpha and beta carotenes. The most pronounced textural changes occurred with HPP. Joint optimization of 25 food quality and safety responses pointed to ozone (8.2 g m(-3)) and HPP (450 MPa) for 5 min as the most effective treatments, respectively.