The Effect of Various Irrigation Regimes on Phenolic Compounds and Antioxidant Activity of Saffron Stigma Extract

Environmental factors such as plant nutrition and available moisture content of the plant affect the quantity and quality of its compounds, including phenolic compounds including flavonoids, tannins, and anthocyanins. Saffron is one of the indigenous medicinal plants of Iran, whose history of using it is back to the ancient times.The present study was carried out to investigate the quantitative and qualitative properties of phenolic compounds and antioxidant activity of saffron tussock extract under the influence of available moisture content in irrigation (FC), ( 1/2FC) (1/3FC) and (3/2 FC). In this experimental study, saffron bulbs were first cultivated in a completely randomized block and then the phytochemical study of the plant was performed, then the total phenolic and flavonoid compounds were measured by spectrophotometry method. Finally, the antioxidant activity of the extract at different concentrations was measured using 2, 2 diphenyl-1-picriyl-hydrazil (DPPH) radical inhibitory activity. Data were analyzed using SPSS software version 19 and analysis of variance methods. The results of the phytochemical test confirmed the presence of secondary compounds such as tannin, anthocyanin and flavonoids, and the absence of alkaloids in the saffron tussock extract. Also, the flavonoid content of the irrigated sample with 50% FC was higher than the other samples. The sample that irrigated to the extent of FC level and the sample was irrigated to the extent of 1/3FC level showed the highest and lowest amount of phenolic compounds respectively and the sample was irrigated to the extent of FC showed the most antioxidant properties.