Effect of lyophilized cell-free supernatant dose from Lacticaseibacillus paracasei B1 and Lactiplantibacillus plantarum O24 on selected quality parameters of cooked pork sausages

This study evaluated the impact of freeze-dried cell-free supernatants (CFS) from Lactiplantibacillus plantarum O24 and Lacticaseibacillus paracasei B1 on the physicochemical properties of cooked pork sausages stored at 4 °C for 21 days. Parameters analyzed included water activity (a_w), pH, oxidation-reduction potential (ORP), TBARS, colour (L*, a*, b*, C*, h°), and texture. CFS addition increased a_w values post-production, with effects varying by strain and concentration. During storage, a_w decreased, particularly with L. plantarum O24 CFS. CFS also caused a dose-dependent pH reduction, while control samples showed stable pH until day 14. ORP and TBARS values rose with CFS addition, suggesting enhanced oxidative activity, especially at higher doses. Colour analysis showed initial decreases in lightness (L*) and redness (a*) due to CFS, followed by partial stabilization. The extent of colour change depended on both strain and dose. Texture tests indicated that CFS reduced hardness in a dose-dependent manner, with the greatest softening in sausages treated with 2% L. plantarum O24 CFS. All treated samples also showed reduced springiness, gumminess, and chewiness. In conclusion, freeze-dried CFS notably altered sausage physicochemical characteristics in a strain- and dose-dependent way. High doses, particularly from L. plantarum O24, negatively affected texture and oxidative stability. However, lower or moderate doses, especially from L. paracasei B1, showed potential to enhance uniformity and preserve quality during chilled storage. These findings support the potencial of CFS as a clean-label additive, although further research is needed to optimize sensory quality and shelf-life.