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

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