Quantitative Comparative Analysis of Pathogenic Microorganism Inactivation Kinetics in Spontaneous versus Directed Fermentation of Raw Milk: Evidence for Differential Efficacy and Food Safety Implications.
Keywords:
Pathogen kinetics, directed fermentation, microbial ecosystem dynamics, biopreservation, food safetyAbstract
Background and Objective Spontaneous fermentation of raw milk, ubiquitous in artisanal dairy production, frequently results in pathogen proliferation and fails modern food safety standards (ISO 22000:2018). Quantitative comparative data on fermentation modalities remain limited.
Material and Methods: Raw bovine milk from Tissemsilt, Algeria (n=20 per group) underwent spontaneous (36 h) or directed fermentation (12 h) with Lactiplantibacillus plantarum and Lactobacillus delbrueckii subsp. bulgaricus (10¹⁰ CFU/mL). Escherichia coli, coliforms, Staphylococcus aureus, and total flora were counted at predefined intervals. Kinetic parameters were modeled via linear regression; ecosystem alterations were assessed by principal component analysis (PCA). Statistical power exceeded 99% with Cohen's d = 23.4.
Results and Conclusion: Natural fermentation displayed pathogen proliferation (+0.0566 Log CFU/mL/h for E. coli), while directed fermentation achieved rapid inactivation (-0.2045 Log CFU/mL/h), creating a net 4.157 Log difference (R² > 0.94). PCA indicated complete separation between modalities (PC1 = 93.4% variance, p < 0.001). Only directed fermentation obtained pH < 4.5 and passed ISO 22000 norms within 12 hours; spontaneous fermentation remained non-compliant after 36 hours. Directed fermentation is categorically distinct, driving opposite kinetic trajectories and providing guaranteed pathogen control. This bioprotective approach should be implemented in dairy operations to ensure consumer safety while retaining traditional product value.
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Copyright (c) 2025 Silarbi Tayeb (Author); Amirouche moesli, Chahbar Mohamed , Hamden Khaled

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