Polyphenols content, flavonoids and antioxidant activity of petals, stamens, styles and whole flower of Crocus sativus of Taliouine

The main objective of this work is the quantitative estimation of total phenols using colorimetric method as well as an in vitro evaluation of antioxidant activity of methanol in floral parts, following the method of scavenging free radical DPPH (2,2-diphenyl-1-picrylhydrazyl) and reduction powder (FRAP). In case of water extraction, the flower parts with the lowest content of total phenolics are the styles, petals, stamens and whole flowers (flowers without stigmas). The order of content of total phenolic compounds present in extracts of flower parts was as follows: petals › whole flowers › etamines › styles. Petals contain the highest content of flavonoids with 60.64 mg of CE g^-1 of dry plant material and the stamens contain the lowest with 6.41 mg of CE g^-1 of dry plant material in the methanol extracts. The best antioxidants properties were observed in methanolic whole flowers extract with IC₅₀ = 164.76, stamens with IC₅₀ = 235.51, petals with IC₅₀ = 268.02 and styles with IC₅₀ = 342.67. The absorbance values measured at 700 nm in the extracts varied from 0.378 to 0.457 at 200 μg mL^-1 in different polarities of petals extracts, from 0.414 to 0.484 at 200 μg
mL^-1 in the stamens extract, from 0.3 to 0.361 at 200 μg mL^-1 in the styles extracts and from 0.467 to 0.653 at 200 μg mL^-1 in whole flowers extracts. In this study it was found that the whole flower exhibited the strongest reducing power when compared to the extracts from stamens, petals and styles. These results can contribute to the development of the floral parts as additives in food, pharmaceuticals and cosmetics.