High-pressure spraying (HPP) is a non-thermal technology with emerging applications in the canned food industry.

In a recent study conducted by a group of Spanish researchers (Torrents-Masoliver et al., 2024), the effects of the HPP process (300 MPa for 2 minutes) were evaluated on banana and apple puree samples, depending on the analytical methodology used to measure the counts of Listeria monocytogenes, Salmonella spp., and Escherichia coli. Furthermore, the performance of the HPP treatment was also evaluated considering the impact of acid exposure (24 hours before the process) and sampling time. Counts were performed immediately and 24 hours after the HPP treatment.

It was observed that selective counting on agar overestimates microbial inactivation compared to counts performed on nutrient-rich media. Furthermore, such inactivation is highly dependent on acid exposure and sampling time. Finally, the experimentation allowed the identification of the microbial strains most resistant and those most sensitive to HPP treatment.

In conclusion, the authors argue that all the factors assessed during the experimentation should be taken into account when designing HPP treatments, through the execution of product-specific validation studies and the definition of appropriate verification procedures.

References: B. Torrents-Masoliver et al., Foos, 13, 2024, 1-14