Microencapsulation of lycopene from tomatoes peels by complex coacervation and freeze-drying: Evidences on phytochemical profile, stability and food applications

Lycopene micmparticles were prepared by complex coacervation and freeze-drying using a wall system consisting of whey protein isolate and acacia gum. Tomato peels were used as raw material for ultrasound-assisted extraction, yielding an extract with 72% lycopene. The encapsulation efficiency for lycopene was 83.6 +/- 0.20%. A possible double microencapsulation, mediated by whey proteins, with rounded outer surface coacervates including small particles of sizes ranging from 378.8 nm to 3.56 mu m was highlighted. The powder displayed 27.34 +/- 0.18 mg lycopene/g dry weight (DW), and an antioxidant activity of 2.15 +/- 0.02 mMol Trolox/g DW. A retention of 63% in lycopene was found after storage at 4 degrees C in the dark for 14 days. An inhibitory effect against alpha-amylase of 79.89 +/- 1.74% was identified. The powder was used for functionalization in dressing samples, showing an increased antioxidant activity. The rheological tests indicated that dressing samples showed typical solid-like behavior, with no crossover points between the dynamic moduli.