The characterization of the bioactive compounds in fermented papaya pulp and leaves: providing new insights on the anti-ageing potential

Abstract

Nowadays, fermented food and beverages derived from plants have become popular choices for consuming functional foods as they provide enormous advantages to human health. Fermented food and beverage might offer more therapeutic benefits than natural nutrition. Papaya contains high antioxidant, antitumor, and immune regulatory effects due to its valuable phytochemical properties. Despite all the advantages, papaya leaves were underutilised as they have an astringent and bitter taste. During this study, papaya pulp and leaves underwent fermentation to enhance their functional properties and improve their taste and flavour. Both papaya pulp and leaves were fermented using mixed cultures of Komagataiebacter sp. bacteria and Dekkera sp. yeast and incubated under a controlled fermentation process. The supernatant extracted from both fermented papaya pulp and leaves was collected and its inhibitory effect towards the elastase, tyrosinase and acetylcholinesterase was analysed. Elastase and tyrosinase were employed for anti-ageing as increasing in dermal enzymatic activities will cause skin disorders. Meanwhile, acetylcholinesterase will affect the cholinergic crisis in the brain. Thus, inhibiting these enzymes is important for preventing hyperpigmentation, skin ageing and improving cognitive function. In comparison to non-fermented papaya pulp and leaves, the fermented papaya extracts demonstrated significant differences (P<0.05) in the inhibition effect against elastase, tyrosinase and acetylcholinesterase with an inhibitory value above 80%. Most of the flavonoids obtained in fermented papaya pulp and leaves were higher than non-fermented pulp and leaves. Protocatechuic acid was the highest compound in fermented papaya pulp (1.22±0.11 µg/mL), while vitexin (113.20±1.18 µg/mL), rutin (10.56±0.52 µg/mL), and ellagic acid (8.76±0.40 µg/mL) highly contained in fermented papaya leaves. The highest organic acids obtained from fermented papaya pulp and leaves acetic acid (13495.42±308.99 µg/mL and 18572.48±78.45 µg/mL), followed by quinic acid (2148.71±63.31 µg/mL and 984.40±2.29 µg/mL) and citric acid (802.57±17.68 µg/ mL and 151.83±6.50 µg/mL), respectively. The findings described the potential of fermented papaya pulp and leaves extracts as potential bio-ingredients to slow down ageing development