Integration of pressurized liquids and ultrasound in the extraction of bioactive compounds from passion fruit rinds: Impact on phenolic yield, extraction kinetics and technical-economic evaluation

Abstract

Passion fruit rind is a by-product rich in bioactive compounds that can be recovered by high pressure extractions and ultrasound using nontoxic solvents in shorter process times. This work investigated Pressurized Liquid Extraction (PLE) and its combination with ultrasound (Ultrasound-Assisted Pressurized Liquid Extraction, UAPLE) to intensify the recovery of phenolic compounds from passion fruit rinds. The influences of process parameters such as temperature, pressure, ultrasonic intensity and solvent mass flow rate on the global yield (X0), total phenolic content (TPC) and antioxidant capacity were evaluated. The major phenolics were determined by UHPLC-QE HRMS. Kinetic extraction curves adjusted by the Spline and two-site models showed that in UAPLE (60 °C, 10 MPa and 360 W/cm2) with solvent flow rate of 10 g/min, 100% of TPC was recovered in 68.54 min of extraction. This condition also provided the greatest economic viability concerning total phenolics, with the lowest estimated manufacturing cost. Industrial relevanceSynthetic compounds in processed food have been increasingly rejected by consumers, who look for natural compounds that promote health benefits and are obtained with sustainable technologies. The bioactive compounds found in passion fruit rinds can meet this industrial demand as potential colorants, additives and natural preservatives in foods or beverages, incorporated in cosmetics, functional food and pharmaceutical supplements. In order to successfully recover bioactive compounds, it is recommended to apply selective extraction techniques in the target compound, thus providing final products with greater added value. In addition, the process optimization is crucial to achieve optimal extraction conditions to maximize the yield of the targent compounds. Given this context, searching for a more sustainable destination of the passion fruit agroindustrial waste and to increase its commercial value, this work proposes the combination of two extraction techniques, Ultrasound and Pressurized Liquid Extraction (UAPLE), to intensify the recovery of bioactive compounds from passion fruit rinds. The findings of this work reveal that UAPLE can enhance the extraction of phenolic compounds from passion fruit rinds even at moderate temperatures, thus encouraging the application of this technique for other agroindustrial by-products. Moreover, the economic evaluation of the UAPLE at the optimal conditions indicates its viability for industrial scale application.