Peach Palm Fruit (Bactris gasipaes) Peel: A Source of Provitamin A Carotenoids to Develop Emulsion-Based Delivery Systems

The peach palm fruit (Bactris gasipaes) peel is a byproduct after fruit consumption. The peel flour of two varieties (yellow and red) was separately obtained by hot air drying and was subsequently milled. The proximate analysis showed that the red variety exhibited higher protein, fat, and fiber contents than the yellow one. A higher carotenoid (836.5 +/- 24.5 mu g/g), phenolic compounds (83.17 +/- 1.76 mg GAE/100 g), and provitamin A activity (33.10 +/- 0.83 mu g retinol/g) were found in the cooked red variety. The carotenoid and phenolic compositions were analyzed by HPLC-PDA-MS, finding beta-carotene and gamma-carotene to be major compounds. The effect of thermal treatment increased the amount of these provitamin A carotenoids and lycopene, which were detected only in the red variety. Among phenolic compounds, procyanidin dimer (isomer I), feruloyl quinic acid, and several apigenin C-hexosides were identified as major constituents of peach palm epicarp. A carotenoid-rich emulsion-based delivery system was obtained after the optimization (RSM model) of carotenoid extraction with ultraturrax and sunflower oil and further development of an ultrasound-assisted emulsion. The best conditions for a stable emulsion were 73.75% water, 25% carotenoid-rich oil extract, 1.25% emulsifiers, and 480 W of ultrasonic power for 5 min. The optimized emulsion had a total carotenoid content of 67.61 mu g/g, Provitamin A activity of 3.23 +/- 0.56 mu g RAE/g, droplet size of 502.23 nm, polydispersity index of 0.170, and zeta potential of -32.26 mV. This emulsion was chemically and physically stable for 35 days at 30 +/- 2 degrees C, showing potential as a food additive with biofunctional properties. The strategy here developed is an economical and environmentally friendly process that allows the reuse of the byproduct of B. gasipaes.