Plant-derived antimicrobial compounds are emerging as promising alternatives to synthetic
preservatives in the food industry due to their efficacy against a broad spectrum
of pathogenic and spoilage microorganisms, as well as their consumer acceptance. This
review critically examines the main classes of bioactive phytochemicals, including
essential oils, polyphenols, alkaloids, terpenoids, and saponins, comparing their
relative antimicrobial effectiveness and highlighting representative examples. Notably,
essential oils rich in thymol or carvacrol have shown strong inhibitory activity against
Listeria monocytogenes and Salmonella spp., while polyphenols and alkaloids exhibit
moderate to strong activity depending on concentration and food matrix. Their mechanisms
of action include cell membrane disruption, inhibition of key enzymes, and interference
with DNA or protein synthesis. Applications in food systems (i.e., incorporation into
coatings, emulsions, or controlled-release formulations) demonstrate potential for
extending shelf life and enhancing safety. However, practical implementation is challenged
by matrix-dependent efficacy, compound stability, sensory impact, and regulatory and
toxicological considerations. By synthesizing current knowledge, identifying the most
promising compound classes, and highlighting key limitations, this review provides
a critical framework to guide future research and the development of effective, sustainable
natural preservatives in the food industry.
