Table Olive Fermentation: Microbial Ecology, Metabolite Transformation, and Emerging Non-Thermal and Omics-Based...

Table olive fermentation is a complex microbial process in which lactic acid bacteria and yeasts contribute to the transformation of phenolic compounds, organic acids, and volatile metabolites that influence product quality, safety, and functionality. Fermentation outcomes remain variable because of cultivar characteristics, spontaneous microbial succession, and limited control over microbial and biochemical dynamics. Recent research has therefore shifted toward a more mechanistic understanding of microbial-metabolite interactions and strategies for more reproducible fermentation control. This review critically examines the microbial ecology, phenolic bioconversion, volatile compounds and metabolite formation, and their relationships with table olive quality. Emerging non-thermal technologies, including ultrasound, high hydrostatic pressure, pulsed electric fields, cold plasma, and pulsed light, are evaluated according to their demonstrated and potential roles in microbial modulation, mass transfer, phenolic transformation, and process stability, with particular attention to the strength of table-olive-specific evidence. The review further examines omics and multi-omics approaches for functional microbial characterization and metabolite profiling, together with sensor-based monitoring, artificial intelligence, and machine learning as emerging tools for data-driven fermentation assessment. The evidence indicates that technological maturity varies substantially among emerging approaches and that most omics- and AI-based applications remain more advanced in characterization and classification than in real-time fermentation control. Further development will require integration of strain-resolved microbiology, quantitative metabolite analysis, process monitoring, predictive modelling, and sensory validation under independent pilot- and industrial-scale conditions. Such approaches may support a transition from empirical fermentation toward more reproducible and evidence-based table olive bioprocessing.