Chemical, Antioxidant and Microbial Properties of Aqueous and Alcoholic Extracts from Stigma and Petal of Saffron (Crocus Sativus L.)

Saffron is the most expensive spice in the world and the extract of this valuable spice not only has valuable nutritional properties but also has various applications in food formulation. In recent years, there has been a great need for the creation of resources from medicinal plants due to the role of phytochemicals and oxidants in human health. The purpose of this study is to evaluate the chemical properties, antioxidant and antimicrobial properties of stigma and petal extracts.

After extract preparation with perculation method, the total phenol content of the extract was measured by Folin-Ciocalteo and the total flavonoid content was determined by aluminum chloride method. Antioxidant activity was evaluated by DPPH method. The in vitro antimicrobial activity test (zone of inhibition, Minimum inhibitory concentration, Minimum bactericidal concentration) against Staphylococcus aureus,  Salmonella Typhimurium, Bacillus cereus, Listeria monocytogenes and E. coli was carried out by disk diffusion assay.

Comparison of chemical composition between different organs showed that the content and antioxidant activity of these compounds can vary depending on the organ. Regarding total phenolic and flavonoid contents, concerning stigma for Crocus sativus stigma were higher than petals. The antioxidant capacities of stigma were higher than petals assessed by DPPH methods. The highest antioxidant activity may be due to high phenolic contents in the stigma. The results showed that these microorganisms were highly sensitive to methanol and ethanolic extracts of saffron while they were resistant to aqueous extract.

Our findings suggest the potential of Crocus sativus as a natural antioxidant and preservative in the food industry to prevent food oxidation and control of food pathogens.