Kecombrang leaf extract (Etlingera elatior) as a natural preservative alternative for tilapia (Oreochromis niloticus)

Abstract

Formaldehyde is commonly used by fishermen to preserve unsold fish, but it is hazardous to health and prohibited as a food additive. Kecombrang leaves serve as a natural preservative alternative due to their bioactive antimicrobial compounds. This study aimed to determine the best solvent and concentration of kecombrang leaf extract applied to tilapia. A nested design was employed with two factors: the type of solvent (ethanol and distilled water) and the extract concentration (2%, 2.5%, and 3% v/w). The research was conducted in two stages: extraction followed by phytochemical and inhibition zone tests, and subsequent application on tilapia to evaluate TPC, Aw, and pH. Phytochemical screening revealed that kecombrang leaf extract contains flavonoids, terpenoids, tannins, and saponins. The highest antibacterial activity was observed in the ethanol extract with an inhibition zone of 13 mm (strong category) against Escherichia coli. The application results on tilapia showed that 3% ethanol extract was the best treatment, yielding a TPC value TPC 2.84 x 105  CFU/g (meeting SNI 2729:2013 standards), an Aw of 0.88, and a pH of 6.23.