Abstract
Background: The increasing demand for plant-based dairy alternatives has stimulated interest in their potential health-promoting properties, particularly when combined with fermentation processes that may enhance the bio-efficacy and bioavailability of bioactive compounds. Methods: The present study investigated the impact of fermentation on the antioxidant, antiplatelet, and anti-inflammatory activities of oat- and soy-based dairy alternatives. Total lipids were extracted and fractionated into lipophilic and amphiphilic lipid fractions, which were subsequently evaluated for antioxidant capacity using 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays, as well as for their inhibitory activity against platelet aggregation induced by platelet-activating factor (PAF) or by ADP. Results: Fermentation significantly enhanced the biological activity of the tested products, with fermented samples exhibiting lower IC(50) values and thus more potent anti-inflammatory and antiplatelet efficacy and improved antioxidant performance compared with the non-fermented plant-based dairy alternative products. The amphiphilic lipid fractions demonstrated the strongest bioactivity, suggesting that fermentation promotes structural modifications in polar lipids that contribute to enhanced functional properties. Overall, fermented soy products exhibited stronger antiplatelet (anti-ADP) and anti-inflammatory (anti-PAF) activities, with lower IC(50) values (indicating higher inhibitory potency), whereas fermented oat products demonstrated particularly enhanced antioxidant capacity, especially in TAC fractions, as evidenced by higher FRAP values and carotenoid content (e.g., oat yogurt TAC: 19.14 ± 9.97 mg CE/g extract). In DPPH assays, TAC fractions of both soy and oat showed comparable radical scavenging activity (TEAC ≈ 0.019 for soy yogurt TAC), while ABTS and FRAP assays highlighted matrix-dependent differences between lipid fractions. Fatty acid analysis further indicated favorable compositional changes associated with fermentation, including favorable alterations in the n-6/n-3 fatty acid ratio of the fatty acid content of the bioactive polar lipid species, while OMICs analysis indicated the specific molecular species of phospho-/glyco-based polar lipids present in these products. Conclusions: These findings suggest that fermentation can substantially improve the biofunctional profile of plant-based dairy alternatives and highlight fermented oat- and soy-based products as promising dietary sources of bioactive polar lipids with potential cardioprotective properties.