Sequential extraction of bioactive compounds from passion fruit (Passiflora edulis f. flavicarpa) industrial byproducts using pressurized fluids

Abstract

This work aims combining sequential procedures to maximize the extraction of bioactive compounds from passion fruit (Passiflora edulis f. flavicarpa) industrial byproducts. The relevance of this research is based on two common issues on the pulp/juice industry: waste reuse for adding value to it and development of clean techniques for the extraction of bioactive compounds from vegetal matter. The waste, namely, shell and pulp fiber will be acquired from the industry. Then, in the Laboratory of High Pressure in Food Engineering, the shell and pulp fiber will be dried at 50 ºC, milled and analyzed in terms of proximate composition. The particles and extraction bed characteristics will be measured, such as: particle size, real density, apparent density and porosity. The dehydrated raw material will be subjected to three extraction methods: low pressure extraction (Soxhlet), and the processes based on extraction with pressurized fluids, namely, supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE). The high pressure extractions will be performed in two steps: (a) SFE and PLE isolated, (b) SFE and PLE sequentially. As solvents, carbon dioxide (CO2) will be used in SFE and different compositions of ethanol and water in PLE. Both techniques will be studied based on a central composite design for two factors with four replications for the central point. The factors are temperature (35-65 °C) and pressure (15-35 MPa) in the SFE and temperature (30-100 °C) and ethanol percentage in water (0-100 %, v/v) in the PLE. The extracts will be analyzed in terms of global yield, total phenolics, antioxidant activity and characterization of phenolics, carotenoids and fatty acids. Based on the retrieved results from the single extractions, a sequence of procedures will be performed using the same extraction bed, yielding different extracts from the raw material. The extracts of this step will be analyzed in the same way of the previous extractions. Finally, the sequential extraction kinetics will be studied by fitting descriptive models to the experimental data. In order to assess the extraction effects on the material, scanning electronic microscopy can be performed on the particles before and after the extractions. (AU)