Investigating Saussura Costus Extracts' Effects on Sunflower Oil Stability, Including Antioxidants and Antimicrobial Properties

This study evaluated the bioactive compounds and antioxidant, antibacterial, and antifungal properties of Saussurea costus extract (SCE) alongside its efficacy in enhancing the oxidative stability of sunflower oil. The SCE showed a high content of bioactive compounds like naringenin (2952.48 µg/g extract) and chlorogenic acid (2120 µg/g extract). The findings showed that 70% ethanol extract had the maximum content of TPC and TFC, reaching about 139.96 µg GAE/mg and 26.46 µg RUTIN/mg, respectively. This extract was also found to be the most effective in terms of antioxidant activity, as measured by DPPH (89.36%) and FRAP (121.57 µM Trolox eq/mg sample) assays, compared to 80% methanol and aqueous extracts. Antibacterial activities against E. coli and S. aureus were effectively demonstrated with SCE at concentrations of 3 mg/mL, where it was comparably effective as synthetic antibiotics. Moreover, SCE exhibited promising antifungal activities against A. niger, Fusarium spp., and Penicillium spp. Additionally, the induction period (9.84 and 7.77 with SCE and without SCE, respectively) and peroxide values of sunflower oil were significantly improved when supplemented with SCE (9.47 and 15.37 meq. O2/kg oil with SCE and without SCE, respectively), indicating enhanced oxidative stability. These results highlight SCE's potential as a natural additive for improving food safety and stability, suggesting its broad-spectrum utility in food preservation and safety applications.