Combined Use of High Pressure Processing (HPP) and Biopreservation to Preserve Meat Products: Screening, HPP-Inactivation and Regrowth of Three Lactic Acid Bacteria

Ensuring the safety and the quality of food products during the entire shelf-life, while minimizing the use of food additives, is an issue that food manufacturers have to address to comply with both regulations and consumer demands. High Pressure Processing (HPP) represents an innovative alternative technology, likely to be used to offset reduction of preservatives. However, the application of such mild preservation techniques may give selective advantage to development of sporeforming bacteria such as Bacillus spp. and Clostridium spp. In the BlacHP project (ANR-14-CE20-0004), the combined use of HPP and biopreservation using lactic acid bacteria (LAB) was challenged to stabilize refrigerated processed meat products. In this presentation, the main steps involved in the selection procedure of the bioprotective LAB strains will be described. They comprise assessment of innocuousness, inhibition against sporeformers, and susceptibility to antibiotics. The three LAB strains selected, were then assessed regarding their resistance to and regrowth following HPP in a model medium (ham). A reparameterized Weibull model was used to determine HPP-induced LAB inactivation from challenge-test experiments. Their regrowth following HPP during chilled storage at 8°C was then modelled using the Rosso model. The strains were ultimately selected on the basis of either their high resistance following HPP or ability to regrow after HPP.