Development of a Pressurized Green Liquid Extraction Procedure to Recover Antioxidant Bioactive Compounds from Strawberry Tree Fruit (Arbutus unedo L.)

Strawberry tree fruits (Arbutus unedo L.) are a natural source of valuable biologically active compounds. Therefore, the aim of this work was to develop a green extraction approach using pressurized liquid extraction (PLE) to provide the highest yield of bioactive compounds. Different extraction solvents (distilled water, 50% and 96% ethanol) and different PLE parameters were investigated: temperature (40, 80, and 120 degrees C), static extraction time (5 and 10 min), and number of cycles (1 and 2). Total phenolic contents (TPC), hydroxycinnamic acids (HCA), flavonols (FL), total flavonoids (TF), condensed tannins (CT), and antioxidant capacity (DPPH and FRAP) were determined in PLE extracts. Solvent type, temperature, static extraction time, and number of cycles had a statistically significant effect on all bioactive compounds and antioxidant capacity (p <= 0.05). All bioactive compounds were positively correlated with temperature, except for TPC and DPPH. For all polyphenols studied, the optimal PLE parameters were a temperature of 120 degrees C, a static extraction time of 10 min and 2 cycles. The best solvent for most bioactive compounds was 96% ethanol, except for TPC, for which 50% ethanol was better. This study suggests that PLE is a promising tool to intensify the extraction of bioactive compounds from strawberry tree fruits.

Automated summary

The aim of this study was to develop a green extraction approach using pressurized liquid extraction (PLE) to obtain high yield of bioactive compounds from strawberry tree fruits. Different extraction solvents, temperatures, static extraction times, and number of cycles were investigated. The results showed that all bioactive compounds and antioxidant capacity were significantly affected by solvent type, temperature, static extraction time, and number of cycles. The optimal PLE parameters were 120 degrees C temperature, 10 min static extraction time, and 2 cycles. Most bioactive compounds were best extracted using 96% ethanol as solvent, except for total phenolic contents, which were better extracted using 50% ethanol.