Variation in phytochemical content, functional properties, antioxidant and hypoglycemic properties of Mirabilis jalapa L. processed tubers: Bioaccessibility evaluation by in vitro simulated digestion

Abstract

Mirabilis jalapa L. is an underutilized tuber crop widely grown as ornamental plant, native to Mexico and South America. Though the occurrence of this plant is abundant and widespread, the investigations made on this plant is countable. Hence, the present study investigated the mineral and proximate composition, functional properties, and in vitro dry matter digestibility of tuber flours processed under different condition. The study also investigated the impact of in vitro simulated digestion (oral, gastric and intestinal phases) on tuber extract's phytochemical composition (total phenolic and total flavonoid content) and in vitro pharmacological properties (hypoglycemic and antioxidant properties). The mineral analysis (macro and micro) revealed the nutritive nature of M. jalapa, as it is a potential source of nitrogen, potassium, phosphorus, calcium, magnesium, iron, zinc, manganese, copper and sulphur. Both the proximate composition and functional properties of tuber flours exhibited its potential nature, which can be employed as an active ingredient in the food industry. The dry matter digestibility of the tuber flour ranged from 18.31 to 39.30%. The phenolic content was varied from 70.32 to 91.21 mg GAE/g, and the flavonoid content was between 16.39 and 44.62 mg QE/g, respectively. Appreciable variation was observed among the IC₅₀ values of digested and undigested extracts obtained in hypoglycemic (α-amylase and α-glucosidase enzyme inhibition) and antioxidant (superoxide and ABTS radical scavenging) assays. The outcome of the study showed that the tubers of M. jalapa are abundant in nutrients and may be able to prevent nutrient deficits and improve human health.