Opuntia cladodes fermentation: an insight into antimicrobial activity and volatile profile

Opuntia ficus indica (OFI) cladodes have garnered significant attention due to their rich content of bioactive compounds, which hold promise for diverse applications across various fields. Despite this potential, limited research has examined the effects of fermentation on cladodes. Notably, lactic acid fermentation is known to enhance aromatic profiles and modify bioactive compounds, offering a transformative approach to improving sensory and functional properties. This study delves into the lacto-fermentation of OFI cladodes using various strains and conditions to assess its impact on antimicrobial activity and volatile profiles. Both fermented and unfermented OFI extracts demonstrated relevant antimicrobial activity, particularly against Bacillus coagulans , as well as partial inhibition against Rhodotorula mucilaginosa, Zygosaccharomyces bailii , and Leuconostoc mesenteroides , in some cases extending the Lag phase. Additionally, fermentation induced significant changes in the volatile composition, with certain compounds, such as ethanol (3.86 ± 0.10 μg/mL), 2-furanmethanol (0.93 ± 0.13 μg/mL), p-mentha-1,8-dien-7-ol (0.65 ± 0.11 μg/mL), 2-octenal (1.62 ± 0.08 μg/mL), acetoin (2.36 ± 1.29 μg/mL), and acetic acid ethenyl ester (5.01 ± 0.81 μg/mL) detected exclusively in the fermented matrices. This study underscores the potential of lactic acid fermentation as a strategy to refine the aromatic profile of OFI cladodes while preserving their antimicrobial properties. By generating a unique mixture of volatile compounds, fermentation paves the way for the application of OFI extracts as natural ingredients in industries such as food, feed, or perfumery. • Cladodes extracts showed antimicrobial activity against different bacteria. • Fermented extracts exhibited a distinct blend of volatile compounds. • Fermentation lays the groundwork for creating novel fermented ingredients from cladodes.