Nanoemulsion delivery improves the physicochemical stability and sensory acceptability of essential-oil-enriched apple juice compared with homogenized oil dispersion

This study compared two methods for incorporating essential oils (EOs) into apple juice: homogenized oil dispersion (HD), in which the neat essential oil is dispersed into the juice by high-shear homogenization without a nanoemulsification step, and nanoemulsion delivery (NE). Four EOs — cinnamon bark ( Cinnamomum verum ), lemon ( Citrus limon ), grapefruit ( Citrus paradisi ), and ginger ( Zingiber officinale ) — were characterized by GC–MS and incorporated into Gala apple juice at equivalent concentrations. Nanoemulsions were prepared using Tween 80/gum arabic (1:3) via high-shear mixing and ultrasonication, yielding droplet sizes of 125–156 nm, polydispersity index (PDI) < 0.25, and zeta potential values below − 25 mV. NE formulations maintained colloidal stability over 21 days at 4 °C without phase separation, whereas HD samples exhibited creaming (20–35%) within 24 h. Sensory evaluation included triangle tests, quantitative descriptive analysis (QDA), and hedonic testing. Triangle tests confirmed that NE formulations were significantly less distinguishable from the control than HD ( p < 0.05). QDA by a trained panel ( n = 8) showed that NE enhanced fruity aroma (+ 29%), reinforced citrus notes, and reduced astringency (− 25%) compared to HD, which produced excessive spiciness and oily mouthfeel. Principal component analysis explained 95.8% of total variance, clearly separating NE (balanced profiles) from HD (intense, unbalanced). Hedonic evaluation ( n = 30) yielded significantly higher scores for NE (6.5–7.3/9) than HD (4.8–5.4/9). PLS regression identified sweetness and fruity aroma as positive acceptability drivers; astringency and acidity were negative predictors. Overall, grapefruit and lemon nanoemulsions were the most acceptable formulations (hedonic scores 7.3 and 7.2/9, respectively), approaching that of the unenriched control. Under the conditions evaluated here, nanoemulsions therefore provided a more effective delivery system than homogenized oil dispersion for the essential oils, concentrations, and apple-juice matrix studied.