Comparison of antioxidant properties of chlorophyll extracted from alfalfa (Medicago sativa L.) using enzymatic and ultrasonic extraction methods

Nowadays, natural pigments are widely used in the food, cosmetics and sanitation industries. In recent years, numerous researches have been done on the methods of extraction and evaluation of the properties of natural pigments. The purpose of this study is comparison of enzymatic and ultrasonic extraction methods for the antioxidant properties of chlorophyll extracted from alfalfa (Medicago sativa L.). Antioxidant activity was performed by three methods including DPPH and ABTS free radicals scavenging and ferric reducing antioxidant power (FRAP). The results show that the concentration of chlorophyll a in alfalfa is higher than that of chlorophyll b and also the enzymatic method demonstrates higher yield in chlorophyll extraction. In addition, higher concentrations of alfalfa extract showed higher antioxidant activity in inhibiting DPPH free radicals and ferric reducing antioxidant power (p <0.05). Also, with increasing the extract concentration, total phenolic compounds and flavonoid compounds increase (p <0.05). Due to the better performance, the enzymatic extracted chlorophyll was used to evaluate the antioxidant properties, inhibition of free radicals DPPH and ATBS and ferric reducing antioxidant power and the result shows the higher chlorophyll concentration, the higher antioxidant properties. Due to the appropriate antioxidant effect of alfalfa chlorophyll extracted by enzymatic method, its application in food, pharmaceutical and health industries can be evaluated and industrial scale extraction systems can be designed using this technique.