Box–Behnken Design Optimization of Green Extraction from Tomato Aerial Parts and Axillary Shoots for Enhanced Recovery of Rutin and Complementary Bioactive Compounds

Tomato aerial parts and axillary shoots represent underutilized agricultural residues with promising phytochemical potential. Despite the recognized antioxidant capacity of rutin, current literature lacks optimized, comparative studies on its extraction from distinct tomato vegetative components. This study aimed to maximize the recovery of rutin and other bioactive compounds from tomato plant biomass using green extraction techniques-microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE)-optimized through Box-Behnken design (BBD) and Response Surface Methodology (RSM). The extraction process was optimized for three key variables: temperature, solvent concentration, and plant-to-solvent ratio. Four main responses were evaluated: total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (DPPH), and rutin concentration. The highest rutin content (8614.23 mg/kg) was obtained in extracts from axillary shoots using MAE. Overall, MAE proved more efficient in recovering both primary and secondary metabolites from axillary shoots, while UAE favored the extraction of certain micronutrients and specific amino acids. Cascade extraction further improved the recovery of key compounds such as vitamin E and quinic acid. The comparative profiling of extracts revealed significant phytochemical differences between tomato aerial parts and axillary shoots, addressing a gap in the literature and underscoring the importance of optimized extraction strategies. These findings highlight tomato plant waste as a valuable source of antioxidant compounds and set the stage for future investigations into their biological activities.