pH indicator from kamias (Averrhoa bilimbi L.) flower extract

Abstract

The acidic or basic nature of materials is usually determined using pH meter and commercially-sold or synthetic indicating means. In this study, an eco-friendly pH indicator was prepared from the aqueous and ethanolic extract of kamias (Averrhoa bilimbi L.) flowers containing anthocyanin pigment. The Kamias pH indicator paper was calibrated using buffer solutions pH 0 to 14 to come up with a colored chart. This served as reference in the subsequent effectiveness and acceptability tests conducted of the product. The indicator produced showed a highly acceptable response from the respondents proving that it can be a good alternative to commercially-sold pH indicating means. The shelf-life test also revealed that it could withstand the storage time of 3 months without losing its effectivity. These findings have significant implications to further refine the product and prolong its storage time, and consequently, the production of kamias pH indicator paper.