Microwave-Assisted Extraction of Phenolic Compounds from Broccoli (Brassica oleracea) Stems, Leaves, and Florets: Optimization, Characterization, and Comparison with Maceration Extraction

Microwave-assisted extraction (MAE) to obtain phenolics from vegetable wastes has been of recent interest. Broccoli is one the most globally produced vegetables, and around 43% harvest considered waste. Thus, given significant quantity broccoli waste generated, objective this work was optimize MAE, maximize total phenolic content (TPC) by-products (leaves stems) florets. The Response Surface Analysis used in optimization model evaluate impacts methanol concentration, time, temperature, their interactions on TPC extracts. optimal MAE conditions were found be 74.54% (methanol), 15.9 min, 74.45 °C for stems; 80% 10 73.27 leaves; 18.9 75 Under these conditions, leaves exhibited highest (1940.35 ± 0.794 µg GAE/g DW), followed by florets (657.062 0.771 DW) stems (225.273 0.897 DW). antioxidant activity extracts evaluated under DPPH ABTS assays, same behavior observed both studies, activity, among stems. In addition, vanillic, sinapic, caffeic, chlorogenic, ferulic, gallic, neochlorogenic, p-coumaric acids identified quantified using HPLC. Furthermore, increase yield up 45.70% leaves, 133.57% florets, 65.30% stems, less time compared with maceration extraction. proved an efficient sustainable technique by-products, which can constitute a viable solution valorizing wastes.