Glucosinolate- and Sulforaphane-Enriched Broccoli Extract as a Potential Dual-Action Antioxidant and Elastase Inhibitor

Broccoli (Brassica oleracea var. italica) is a widely cultivated cruciferous vegetable recognized for its rich content of bioactive phytochemicals with documented health-promoting properties. Fresh broccoli florets represent a rich yet underutilized source of bioactive phytochemicals, particularly glucosinolates, with established health benefits. This study optimized ultrasonic-assisted extraction (UAE) using aqueous ethanol to recover glucosinolates and sulforaphane. Total glucosinolate content (TGC) was quantified spectrophotometrically, while sulforaphane, glucoraphanin and glucobrassicin were determined by ultra-performance liquid chromatography–electrospray ionization–mass spectrometry (UPLC-ESI-MS). Under the optimized UAE conditions (25% ethanol, 41 °C, 32 min), the predicted yield of TGC was 46.6 mg of sinigrin equivalents (SE)/g dry weight (DW), while the actual yield achieved was 36.6 ± 4.4 mg of SE/g DW. Among the compared extraction methods, UAE with 25% ethanol yielded the highest TGC, ferric reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) with values of 35.5 ± 1.26 mg of SE/g DW, 21.2 ± 2.6 µmol of Trolox equivalents (TE)/g DW, and 156 ± 15.2 µmol of TE/g DW, respectively, with TGC and FRAP being significantly higher than all other methods (p < 0.05), while ORAC differences were not statistically significant. In vitro anti-elastase activity was the greatest in the extracts prepared using shaker-assisted extraction (IC50 of 0.51 mg/mL) and UAE-25% ethanol (IC50 of 0.86 mg/mL). Collectively, these findings position UAE with aqueous ethanol as a promising extraction approach for recovering glucosinolates and sulforaphane from broccoli florets for cosmeceutical applications, providing a basis for future scale-up and process optimization studies.