Microbial ecology of salted food products: Preservation, safety, and innovation

This article provides a critical, integrated analysis of the role of salt (NaCl) in the microbial ecology of salted food matrices, including meat, dairy, fish, and vegetable products, with particular emphasis on the emerging technologies capable of reconciling sodium reduction with microbiological safety. Salt acts as a fundamental selective agent, inhibiting sensitive microorganisms through increased osmotic pressure and reduced water activity while favoring beneficial microbial successions in fermentative processes; however, osmotolerant pathogens such as Listeria monocytogenes , Staphylococcus aureus , and Clostridium botulinum not only survive this barrier but may exhibit cross-protection phenomena that increase thermal resistance in the presence of salt, revealing a structural tension between sodium reduction and food safety. The diversity of specialized halophilic and halotolerant communities, including bacteria, fungi, and archaea, is examined in relation to their functional roles in spoilage, fermentation, and sensory quality across different food matrices. The article places central focus on advances in microbial analysis and control as the principal pathway for addressing this tension: metagenomics and next-generation sequencing are shown to overcome a key limitation of culture-based methods, the underdetection of pathogens in the viable but non-culturable (VBNC) state induced by osmotic stress, while biopreservation strategies, protective starter cultures, and CRISPR-Cas-engineered strains offer barriers independent of sodium concentration capable of compensating for reduced salt content. It is concluded that these approaches function as complementary components of a multi-barrier system rather than standalone solutions, and that future research should prioritize the quantitative modeling of how reduced salt, protective cultures, and non-thermal treatments interact, providing a stronger scientific basis for control systems such as HACCP and for the development of safer, lower-sodium salted foods.