Utilization of areca nut (Arecha chatechu L.) extract for tannin based colorimetric indicator in smart packaging

Abstract

Areca nut contains tannin which has a great potential to apply as natural colour agent in food industries. Tannin offers specific colour and alter its colour due to environmental sensitivity. This study aims to fabricate a tannin-based colour indicator from areca nut in smart packaging in the form of a strip type and to characterize the indicator at different storage conditions and at various pH solutions. The indicators were synthesized using filter paper (No.1 and No.42) soaked in a solution with 1, 3, and 5% areca nut ethanolic extract. Then the indicators were stored at room temperature and 4-7°C for 10 days, then their Red Green Blue (RGB) coefficient values were measured. Characterization of the indicators at pH 3-10 were also determined by RGB coefficient. The results showed that the indicator stored at 4-7°C had more stable RGB coefficient than the indicator stored at room temperature indicated the indicator was influenced by the temperature factor. The indicator offered a potential to be used as a sensor on packaging of temperature sensitive foods. The indicator using Whatman paper No.42 with 1% of extract steadily decreased in RGB coefficient and changed its colour to darker in basic pH solution while the indicator with other treatments had unstable alteration RGB coefficient and colour.