Extraction of natural antioxidants from Moroccan saffron (Crocus sativus L.) using ultrasound-assisted extraction: An optimization approach with box-behnken design

Abstract

There is increasing evidence of protective health effects of natural antioxidants, such as those contained in saffron ( Crocus sativus L.), but it is challenging to extract polyphenols, which are the purported antioxidants with conventional techniques. This study developed an ultrasound-assisted extraction technique to improve the efficiency of phenolic compound extraction and assess the antioxidant activity of saffron. A response surface methodology, utilizing a Box-Behnken design, was employed to optimize three key extraction parameters: solid-to-liquid ratio, temperature, and extraction time for both saffron stigmas and corms. The total phenolic content and antioxidant activity were analyzed using the Folin-Ciocalteu and the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. The optimal extraction conditions for stigmas were a solid/liquid ratio of 40 mg/30 mL, with an extraction temperature of 50 °C for 15 min, resulting in a total phenolic content yield of 118.55 mg GAE/g DM and an IC 50 value of 0.023 mg/mL. For optimal conditions when extracting from corms, the extraction time was extended to 45 min, resulting in a total phenolic content of 21.18 mg GAE/g DM and a IC 50 value of 1.02 mg/mL. Results were consistent with predicted values provided by the quadratic model, which confirmed the efficacy of the Box-Behnken design in maximizing the extraction of polyphenol content from C. sativus . Although UAE has been refined at the laboratory level, additional research is needed to assess its feasibility and efficiency on an industrial scale. Exploring large-scale UAE systems, evaluating cost-effectiveness, and identifying potential adaptations for commercial production would be highly beneficial.