Pressurized liquids extraction as an alternative process to readily obtain bioactive compounds from passion fruit rinds

- Passion fruit rinds showed to be rich sources of phenolic compounds.
- Isoorientin, vicenin, orientin, vitexin, and isovitexin were quantified.
- PLE was more efficient than Soxhlet and maceration to recover phenolics.
- High correlation was found between phenolic content and antioxidant capacity.
- Passion fruit rind extracts can be applied in food, cosmetics and nutraceuticals.

Bioactive compounds from passion fruit industry by-products (rinds) were obtained using ethanolic-water pressurized liquid extraction (PLE), a green and intensified extraction process. The PLE method was compared with Soxhlet and maceration. Ethanol, water, and their mixtures were used as solvents. PLE and maceration conditions were: temperature 30-60 °C, ethanol concentration 70-100% (v/v), pressure 10 MPa (PLE) and atmospheric pressure (maceration). The extraction processes were evaluated in terms of global yield, total phenolic content, phenolic composition, and antioxidant activity. PLE achieved extracts with higher global yield, phenolic content, and antioxidant activity than the conventional methods. Based on these results and the fast extraction time, PLE at 60 °C using 70% ethanol was the best method to recover bioactive compounds from passion fruit rinds. Five phenolic compounds were identified and quantified in the extracts: isoorientin, vicenin, vitexin, orientin, and isovitexin. The antioxidant capacity and phenolic content exhibited high and positive correlation expressed by the Pearson's coefficient. Extraction kinetics were performed and showed that target compounds could be recovered in short extraction times at the best PLE condition. The passion fruit rinds have therefore proved to be a rich source of phenolic compounds and PLE showed high efficiency to recover such compounds.

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