Microbial inactivation and drying of strawberry slices by supercritical CO2

Abstract

This work explores the feasibility to apply supercritical carbon dioxide (scCO2) to dry and increase the microbial safety of strawberries. Strawberry slices were dried at 10 MPa and 40 °C up to 6 h. The treatment was able to remove the 98% of the initial moisture content, corresponding to a weight loss of 90%. The method showed a limited inactivation power towards total mesophilic bacteria, while yeasts and moulds were under the detection limit of the technique (<10 log CFU/g). The process is efficient against different strains of pathogens (E. coli O157:H7, Salmonella spp. and L. monocytogenes), which were inoculated on the sample surface. Results highlight the potential of scCO2 drying as innovative food drying technology for the simultaneous drying and stabilization of the product without the use of high temperatures.