Innovative functional mayonnaise formulations with watermelon seeds oil: evaluation of quality parameters and storage stability

This study investigates the novel application of watermelon seed oil (WM-SO) as functional oil in both egg-based and eggless mayonnaise, assessing its impact on physicochemical, nutritional, and oxidative stability parameters. WM-SO exhibited high quality, characterized by low free fatty acids (1.21 ± 0.03 %), peroxide value (0.98 ± 0.05 meq O 2 /kg), and rich unsaturated fatty acids, notably linoleic acid (63.70 %) and oleic acid (16.87 %). Incorporating WM-SO significantly enhanced mayonnaise bioactivity: total phenolic content increased by ∼11–14 %, reaching 109.76 ± 2.90 mg GAE/g in egg-based and 97.42 ± 1.65 mg GAE/g in eggless formulations, while total carotenoids rose to 4.63 ± 0.38 mg/g and 4.29 ± 0.41 mg/g, respectively. Radical scavenging activity (%RSA) improved by ∼51 % in egg-based (from 32.59 % to 49.11 %) and ∼39 % in eggless samples (from 45.27 % to 62.88 %). WM-SO also reduced viscosity (e.g., from 1,486 to 1,131 cP in egg-based), decreased water activity (from 0.83 to 0.80 in eggless), and slightly lowered fat content. Particle size analyses showed reduced D90 (from 143.26 to 12.50 µm in egg-based), indicating finer emulsions with better stability. Sensory evaluation confirmed high acceptability (scores ∼8.5–8.6). During 30 days of storage, WM-SO samples exhibited lower peroxide values (1.05 meq O 2 /kg vs. 1.18 in control), reduced free fatty acid increase (∼9 % less in egg-based), and sustained higher RSA. These results position WM-SO as a promising, health-enhancing, and sustainable ingredient for stable, bioactive-enriched mayonnaise formulations.