Use of non-thermal treatments to improve the safety, quality, and shelf-life of pork sausages

Nowadays, sustainable approaches to ensure safety, high quality and increased shelf-life of both raw and fermented sausages is a crucial aspect to reduce spoilage phenomena and the risk associated with the presence of pathogenic microorganisms, to eliminate or limit the use of additives and to sell products on the international market. With this purpose, in this PhD thesis, two main strategies have been evaluated. The first concerns the use of High Hydrostatic Pressure (HPP) to increase the shelf-life of raw pork sausages and evaluate its impact on meat colour, texture and microbial growth. Then, a thermal abuse trial was performed on raw pork sausages treated at 600 MPa for 5 min, and a challenge test was conducted to evaluate the survival and growth potential of Salmonella Enteritidis, Staphylococcus aureus, and Listeria innocua (as a surrogate for Listeria monocytogenes). The results demonstrated the effectiveness of HHP to prolong the shelf-life of the raw sausages, reducing also the presence of pathogenic bacteria even if the treatment changed the color and texture of the samples. The second strategy was focused on the use of bioprotective starter cultures to increase the safety and quality of fermented sausages. The inhibiting activity of Lactiplantibacillus paraplantarum BPF2 was tested against the histaminogenic Companilactobacillus alimentarius SE14 through an in vitro test. Then, traditional Spanish fermented sausages were produced in pilot pilot-scale plant to assess the inhibition of contaminant Comp. alimentarius SE14 by Lpl. paraplantarum BPF2 used as starter cultures and the mitigation of histamine accumulation during ripening. The results demonstrated the bacteriocinogenic starters' role in improving fermented sausage safety and quality. Overall, the results highlighted the great potential of HHP and the use of bioprotective starter cultures as effective strategies to extend the shelf-life, improve safety and maintain the sensory and nutritional quality of raw and fermented sausages.