Valorization of passion fruit (Passiflora edulis sp.) by-products: Sustainable recovery and biological activities

Large amounts of passion fruit residues are underused by juice industries. Part of the fruit seeds are used for oil production, and the discharged seed cake, the residue from the seed cold pressing, still contains fatty acids and phenolic compounds of interest. This study aimed to apply a sustainable recovery extraction for the valorization of two juice by-products, the passion fruit seed and the seed cake. Different extraction methods were compared in terms of process global yield, and total phenolic content (TPC), antioxidant and antimicrobial activities of the recovered extracts. The methods used were: supercritical fluid extraction (SFE) with CO2 (SC-CO2), conducted at 40 degrees C and 50 degrees C and pressures from 150 to 300 bar, and the low pressure extractions (LPE) cold maceration (MAC) and ultrasonic assisted extraction (UE) with different solvents. The best yields were obtained by SFE at 250 bar/40 degrees C for the seed (27 +/- 1%) and by MAC with EtOH-H2O (1/1, v/v) for the seed cake (6 +/- 1%). Cake extracts obtained by EtOH-H2O presented the best TPC values, antioxidant performance and antibacterial activity against Escherichia coil and Listeria innocua. Therefore, considering the use of green recovery methods to obtain high valuable products from a waste material, the present work presents a sustainable opportunity to aggregate value from passion fruit residues by means of sequential extractions, in order to obtain oil and extract with promising antioxidant and antimicrobial activities. (C) 2016 Elsevier B.V. All rights reserved.