Effect of extraction temperature on total phenolic content, total flavonoid content and antioxidant activity of pineapple peel extracts

Ananas comosus L. Merr, or pineapple, is recognized for its nutritional and therapeutic benefits, rich in vitamin C and bioactive compounds. However, pineapple waste, including peel, core, and pomace, presents environmental challenges due to inadequate handling practices. This study investigates the influence of drying temperature on the antioxidant properties and phenolic content of pineapple peel. Ultrasonic-assisted extraction with absolute ethanol was employed to extract bioactive compounds. Results indicated that drying pineapple peel at 100°C yielded the highest crude extract (8.74 ± 0.1681%). Additionally, pineapple peel dried at 100°C exhibited the highest total phenolic content (32.23 ± 0.0023 mg GAE/g extract) and total flavonoid content (8.43 ± 0.0004 mg QE/g extract), while the lowest levels were observed at 50 °C (15.90 ± 0.0017 mg GAE/g extract and 5.71 ± 0.0003 mg QE/g extract, respectively). Antioxidant activity evaluated using the DPPH assay showed the lowest IC50 value at 100°C (441.10 μg/mL). In conclusion, drying pineapple peel at 100 °C enhances the extraction of phenolic compounds and antioxidant activity, highlighting its potential as a valuable source of bioactive compounds for various applications.