Strain- and matrix-dependent survival of Lactobacillus acidophilus LA-5 and Lacticaseibacillus paracasei 431 in commercial ice cream basesPrijatelj, Kristjan (Avtor) Kozmos, Maša (Avtor) Langerholc, Tomaž (Avtor) ice-creamprobioticsLactobacillus acidophilusLacticaseibacillus paracaseifrozen storageThe survival of Lactobacillus acidophilus LA-5 and Lacticaseibacillus paracasei 431 was evaluated in commercially available ice cream base mixtures differing in dairy and plant-based fat content. The objective was to determine strain-dependent stability during frozen storage and to model viability loss using the Weibull inactivation equation. Following inoculation, samples were frozen and stored at −20 °C for 90 days. Viable counts were monitored periodically, and survival kinetics were described by non-log linear regression. A significant reduction in cell numbers was observed after a single freeze–thaw cycle in both strains. During subsequent storage, gradual inactivation occurred, with distinct strain- and matrix-dependent differences. L. acidophilus LA-5 showed higher stability in formulations with dairy-based fat compared with the plant-based fat, whereas L. paracasei 431 exhibited shorter predicted times to equivalent log-reductions in dairy systems. Survival curves were adequately described by the Weibull model, indicating heterogeneous resistance within bacterial populations. The results demonstrate marked strain- and formulation specific differences in probiotic stability during frozen storage and provide quantitative parameters for predicting viability loss in ice cream matrices.20262026-09-16 10:17:10Znanstveno delo100390UDK: 579.6COBISS_ID: 285239555DOI: 10.18690/agricsci.23.1.1ISSN pri članku: 2820-610Xsl