Rheological and Physicochemical Properties of Mayonnaise Enriched with Functional Vegetable Oils: A Comparative Screening Study

Sixteen functional vegetable oils were incorporated at a 20% substitution level into a standard mayonnaise formulation to assess the impact of fatty acid composition on physicochemical, textural, rheological, and microstructural properties. Color analysis revealed substantial variation in yellowness (b* = 11.37–30.08) and lightness (L* = 74.39–82.31), while pH remained unaffected across all formulations (3.3–3.6). Texture analysis demonstrated that PUFA-rich oils, particularly linseed, thistle, and corn, produced markedly lower consistency values (17.02–18.68 N·s) compared to MUFA-rich counterparts (up to 69.95 N·s), indicating weaker interfacial network organization. All formulations exhibited non-Newtonian shear-thinning behavior described by the power law model (K = 90.12–130.63 Pa·sn; n = 0.162–0.249). Low-field NMR relaxometry identified three distinct proton populations reflecting differences in proton mobility, while diffusometry revealed mean droplet radii ranging from 2.653 µm (pomegranate oil) to 3.203 µm (linseed oil). Pearson correlation and principal component analysis (PCA) confirmed fatty acid unsaturation as the primary driver of droplet size distribution and textural differentiation among formulations. The study was designed as an exploratory screening of single-batch formulations, and the results are presented descriptively to identify comparative trends among the different oils. Linseed, walnut, and pomegranate oils showed favorable compositional profiles for mayonnaise reformulation, combining favorable PUFA-to-SFA ratios with acceptable emulsion stability and rheological performance.