Under-utilized wild fruit Lepisanthes rubiginosa (Roxb.) Leenh: A discovery of novel lycopene and anthocyanin source and bioactive compound profile changes associated with drying conditions

Abstract

Lepisanthes rubiginosa (Roxb.) Leenh (LRL), a wild fruit of Thailand, was characterized for phytochemicals including phenolic acids, flavonoids, carotenoids, anthocyanins, organic acids, and sugars. To process it, three drying methods were investigated, namely, freeze drying (FD), hot-air drying (HD), and sun drying (SD), which affected chemical components and antioxidant activities. The predominant phenolic acids and flavonoids were p-hydroxybenzoic acid, chlorogenic acid, vanillic acid, quercetin, rutin, and myricetin. Remarkably high amounts of lycopene (158 mg/100g db) and cyanidin-3-O-glucoside (2005 mg/100g db) were observed. Flavonoids, carotenoids, and anthocyanin were decreased by all drying methods. Overall, FD was considered to be the most suitable for drying LRL fruit. Fructose conversion to mannitol during drying was explored by FTIR spectroscopy analysis in FD and HD samples. This study has revealed new information about LRL fruits, which could be a potential source of bioactive compounds; an appropriate drying method is suggested for further applications.