A quasi-energetically costless novel food preservation methodology: Moderate pressure pasteurisation followed by hyperbaric storage, both at room temperature

Abstract

Firstly, fish soup preservation by hyperbaric storage (HS; 25-100 MPa) at room temperature (RT; 20 °C) was compared to refrigeration (RF; 4 °C) as a way to restrain microbial growth. Additionally, to greater microbial growth restrain, HS at higher pressures (above 75 MPa) revealed also considerable levels of microbial inactivation, leading to study a possible new food pasteurisation methodology, moderate pressure pasteurisation (MPP; 150-250 MPa) at RT, followed by HS at 75 MPa (post-MPP/75 MPa).MPP (150-250 MPa; 12-24 h) at RT caused a significant reduction of microbial counts, either spoilage or pathogenic microorganisms, of at least 4.0 log CFU/g for total aerobic mesophiles (MPP; 24 h) and Salmonella Senftenberg (MPP; 6 h), while Listeria innocua reduction under MPP (24 h) was 6.9 log CFU/g. Additionally, post-MPP/RF showed microbial development (to above 8.5 log CFU/g), mainly after 21 days, contrarily to post-MPP/75 MPa, where microbial inactivation continued along storage, reaching the detection limit (< 1.0 log CFU/g). Accordingly, for MPP (200 MPa; 12-24 h), the pH, total soluble solids and colour of fish soup was equal or even better under post-MPP/75 MPa than post-MPP/RF.Overall, the present work opens the possibility of using HS/RT (75 MPa) for fish soup preservation and shows for the first time the use of MPP (125-250 MPa) at RT as an interesting methodology for food pasteurisation, followed by preservation storage by HS, resulting in enhanced safety and extended shelf-life compared to RF, as a novel quasi-energetically costless moderate food pasteurisation and storage (MPPS) methodology.