Ultrasound-enhanced deep eutectic solvent extraction and encapsulation of eggplant peel polyphenols for low-fat...

The current study aimed to explore the polyphenols present in eggplant peels, their encapsulation, and application in the low-fat functional mozzarella spread. Eggplant peel extraction was performed with ultrasound-assisted extraction conditions with deep eutectic solvents. The extraction conditions, including ultrasonication time (5-10 min), ultrasonic power (5-10 W), and sample concentration (10-15%), were optimized using a Box Behnken design. W/O/W emulsions were formulated with varying volume fractions of W/O emulsions (10% (E₁), 20% (E₂), and 30% (E₃) (%w/w)) using a fat replacer of aloe vera gel mucilage. W/O and W/O/W emulsions were evaluated in terms of phytochemicals retention capacity, droplet size, creaming, and color stability on 0, 3, 7, and 15 days at 4 °C. Mozzarella spreads were prepared with no emulsion addition (T_o), 10 mL of W/O (T₁), 10 mL of E₁ (T₂), and 10 mL of E₃ (T₃) and assessed for 1, 3, and 7 days at 4 °C based on phytochemicals, antioxidant potential, textural, color, and sensory analysis. Optimized extraction parameters were 7.5 min, 8 W, and 13% to attain 21 mg/g polyphenols, 9 mg/g flavonoids, and 64% DPPH activity. W/O emulsions exhibited a decline in polyphenols, flavonoids, antioxidants, and retention capacity over time. E₁ presented the highest droplet, bioactive retention, and creaming stability with the lowest color change due to higher plant mucilage concentration_, in contrast to E₂ and E₃. T₁ presented higher sensory and functional characteristics in contrast to the control. Overall, the W/O emulsions have the potential for the formulation of mozzarella spread with improved sensorial attributes.