The effect of fermentation and drying temperatures, caliber, and sodium lactate on Listeria monocytogenes inactivation was studied in salami, produced in a pilot scale, inoculated with 10⁷ CFU/g of Listeria innocua ATCC® 33090 as a surrogate microorganism for L. monocytogenes. Fermentation temperature varied between 24 and 30°C, drying temperature between 14 and 20°C, caliber between 5.1 and 13.2 cm, and sodium lactate initial concentrations in salamis were 0 and 2%. L. innocua counts, pH and water activity were determined in salamis over time. Sodium lactate (2%) decreased pH drop and Listeria inactivation during fermentation. Baranyi & Roberts equation was used to fit the experimental data and to estimate, for each test condition, inactivation rate (k), initial (Y₀), and final counts of L. innocua (Y_END). Total inactivation was calculated as Y₀ minus Y_END (Y₀-Y_END). Then, using a Box Benkhen experimental design, a quadratic model for k and a two-factor interaction model (2FI) for Y₀ - Y_END were obtained as functions of fermentation temperature, drying temperature, and caliber size. The models predicted that maximum k and Y₀ -Y_END, -2.62 ± 0.14 log₁₀ CFU/g/day and 4.5 ± 0.1 log₁₀ CFU/g, respectively, would be obtained fermenting at 30°C and drying at 20°C regardless of caliber. Drying at 14°C allowed Listeria growth until a water activity (a_w) of 0.92 was reached. Therefore, if initial Listeria contamination is high (3 log₁₀ CFU/g), drying at low temperatures will compromise product safety.

The diet of dairy cows influences the fatty acid (FA) profiles of their milk and cheese, but how these are affected by different conditions during confinement in a mixed system (MS:grazing + total mixed ration:TMR) is not known. The aim of this study was to compare the FAs of the milk and cheese from MS in a compost-bedded pack barns (CB-GRZ) versus an outdoor soil-bedded pen (OD-GRZ) during confinement, and with a confinement system (100%TMR) in a compost-bedded pack barns (CB-TMR). Individual milk samples (n = 12 cows/group), cheese, and pooled milk (MilkP) samples were collected. The saturated FA percentages in the milk and the omega 6/omega 3 ratio in the MilkP and cheese were greater for the CB-TMR (p < 0.0001), while the unsaturated and monounsaturated FA percentages in the milk were lower for the CB-TMR than the MS (p < 0.001). The milk n-3, C18:3, and conjugated linoleic acid percentages were lower for the CB-TMR than the MS (p < 0.001). The milk n-3 and C18:3 were higher for the CB-GRZ than the OD-GRZ (p < 0.01), but no differences were observed between the MS in the MilkP and cheese. In conclusion, CB-GRZ cows during confinement produced better quality milk compared to OD-GRZ cows. However, the FA profiles of the milk, MilkP, and cheese were affected to a greater extent by the feeding management than by the conditions during confinement.