GC-MS Quantification of Bioactive Isothiocyanates in Sinapis alba Essential Oil and Validation of Rapid Bactericidal Kinetics Against Clinically Relevant Pathogens

White mustard (Sinapis alba L.), a member of the Brassicaceae family, is globally recognized for its culinary, agricultural, and medicinal applications. This study comprehensively investigates the chemical profile of S. alba essential oil (EO) using gas chromatography-mass spectrometry (GC-MS) and evaluates its antimicrobial and antioxidant properties. Hydro distilled EO yielded 0.8% (w/w), with GC-MS analysis identifying 32 volatile constituents, predominantly allyl isothiocyanate (72.4%), 4-pentenyl isothiocyanate (12.3%), and β-pinene (4.1%). Antimicrobial assays demonstrated potent activity against Staphylococcus aureus (MIC: 0.25 mg/mL) and Escherichia coli (MIC: 0.5 mg/mL), while antifungal effects against Candida albicans were moderate (MIC: 2 mg/mL). Antioxidant capacity, assessed via DPPH (IC₅₀: 45.2 µg/mL) and FRAP (0.8 mM Fe²⁺/g), indicated moderate free radical scavenging. These findings underscore the potential of S. alba EO as a natural antimicrobial agent and adjuvant in cancer therapy.