Sustainable, functional food design: Characterizing and utilizing passion fruit by-product extract in anthocyanin-enriched delivery systems

• 80% ethanol and 500 W ultrasonic power were the optimal extraction conditions • Cyanidin-3-glucoside was the anthocyanin in the purple passion fruit peel extract • The extract alleviated oxidative stress in H 2 O 2 -challenged human erythrocytes • Gummies infused with the extract was sensorially accepted by consumers • Total phenolics in the enriched gummy had a 163% bioaccessibility after in vitro digestion The study evaluated various conditions, including ethanol concentration (60 to 80%) and ultrasonic power (320 to 500 W), to determine the optimal ultrasound-assisted extraction (UAE) parameters for anthocyanins from purple passion fruit ( Passiflora edulis f. edulis ) peel. The results identified that UAE at 500 W for 10 min using 80% ethanol was the most effective condition, yielding 6.47 mg GAE/g of total phenolic content and 0.28 mg CYE/g of total anthocyanins. The extract demonstrated a significant 62% inhibition of reactive oxygen species generation in human red blood cells and exhibited cupric-ion-reducing antioxidant capacity (27.45 mg AAE/g). In a gummy model, adding the optimal extract followed by in vitro digestion simulation increased the bioaccessibility of anthocyanins by 112% and the total phenolic content by 163%. The extract also enhanced the ferric-reducing antioxidant power (FRAP) by 4-fold (bioaccessibility of 128%) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity by 23-fold (bioaccessibility of 84%). However, gummies made with sucrose and artificial red pigment achieved a higher acceptability index (76%) than those with passion fruit peel extract (66%). In conclusion, we identified the optimal extraction conditions for producing a food-grade and sustainable extract rich in anthocyanins. This extract can be utilized as a natural coloring and antioxidant in functional food applications.