The pH indicator capability of Basella rubra (alugbati) stem peels aqueous extract

ELISHA L. EUSEBIO, KAIZEN P. NAQUITA, JOHN EARL S. SETIAS, and RAMON ANGELO N. SINCO

Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHSWVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines

Abstract

Synthetic pH indicators pose hazardous effects to humans and the environment. Basella rubra (alugbati) stems contain phytochemicals which are pH-sensitive. Thus, this study aimed to assess the capability of Basella rubra stem peel aqueous extract as a plant-based pH indicator. The extract was obtained through aqueous maceration of Basella rubra stem peels and was tested to solutions with pH levels 3, 5, 7, 9, and 11; then, color and pH changes were observed and analyzed. The trend of color changes observed from acidic to basic pH were red to yellow. Also, the mean pH difference of the solution with pH 9 was relatively higher compared to other pH levels. The mean pH differences were lower in pH 3-7 due to stability of betacyanin in the said range. Hence, the aqueous extract of Basella rubra (alugbati) stem peels is capable as a plant-based pH indicator at pH levels 3 to 7.

Keywords: Basella rubra, indicator, pH, phytochemicals, stem peels

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