Desert legume Prosopis cineraria as a novel source of antioxidant flavonoids / isoflavonoids: Biochemical characterization of edible pods for potential functional food development

Abstract

Flavonoids and isoflavonoids in foods are attracting attention as they are significant antioxidant and phytoestrogenic compounds that are beneficial for human health. In this study, the edible pods of the underutilized desert legume Prosopis cineraria from Rajasthan, India were used to extract flavonoids. The pods from semi-arid zone showed the highest flavonoid content (432 mg Rutin hydrate/gm). UV spectrophotometric analysis was also done to characterize flavonoids. The flavonoids and isoflavonoids were further purified from semi-arid zone plants using column chromatography with Amberlite XAD7HP and Sephadex LH-20. LC-MS analysis revealed the presence of medicinally valuable antioxidant flavonoids and isoflavonoids in the pods, viz. vitexin, puerarin, phloridzin, and daidzein. It was seen that the flavonoids/isoflavonoids are present in the selected legume in different forms i.e. pure aglycone, C-glycoside as well as O-glycoside. This finding makes P. cineraria an attractive source candidate for extraction of these nutraceuticals with a potential for development into functional food.