International Journal of Advanced Engineering Research and Science (IJAERS) Peer-Reviewed Journal ISSN: 2349-6495(P) | 2456-1908(O) Vol-8, Issue-10; Oct, 2021 Journal Home Page Available: https://ijaers.com/ Article DOI: https://dx.doi.org/10.22161/ijaers.810.35 www.ijaers.com Page | 335 Phyllanthus (Phyllanthus multiflorus Willd.) Fruit as Natural pH Indicator Princess Lydia S Fuentes, Jocelyn S Legaspi, Veronica E Albaladejo Capiz State University, Philippines Received: 09 Sep 2021, Received in revised form: 11 Oct 2021, Accepted: 20 Oct 2021, Available online: 30 Oct 2021 ©2021 The Author(s). Published by AI Publication. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/). Keywords— acid, base, color chart, Phyllanthus, natural indicator Abstract— A substance property as an acid or a base is determined in terms of quantity of pH. It makes use of various tools ranging from simple litmus paper to the sophisticated benchtop pH meter. Natural indicators on the other hand are utilized as an alternative to synthetic acid-base indicators. This paper relates to the preparation of natural indicator from Phyllanthus fruit containing anthocyanin, and the establishment of its effectiveness. The experimental method of this study is composed of the preparation of raw materials, standardization of solutions, calibration, testing for effectiveness, and development of a color chart. The developed pH indicator consists of Phyllanthus fruit, water, and ethanol. The process of producing the pH indicator comprises of the following steps: collecting; washing; weighing; crushing; mixing with water; boiling the mixture; filtering; cooling down; mixing with ethanol; soaking; and drying. The calibration of the indicator involves different solutions with pH 0 to 14 to come up with a color chart. This serves as a reference in the effectiveness test. Treatment 2 of the indicator produced a distinctive color that is comparable to the existing pH measurement tool. This finding indicates that the pH indicator from Phyllanthus fruit consisting of a 1:1 ratio of fruit to water, and a 1:1.5 ratio of the mixture to ethanol can be a cheaper alternative tool in measuring pH that can be used in laboratory testing, as instructional material, and in the household. I. INTRODUCTION In science, a substance property as an acid or a base is one of the main concepts being discussed. The acidity and basicity of solutions are determined in terms of quantity of pH. The “power of hydrogen” is a scale ranging from 0 to 14, with lower numbers than pH 7 representing higher acidity while numbers higher than pH 7 indicate basic solutions [1]. Chemistry titrations, water quality testing, testing of proper composition of biotechnology, food products preservation, and tasting are few of the various activities that need the measurement of acidity and alkalinity of a substance. It makes use of various tools ranging from simple litmus paper to the sophisticated benchtop pH meter. The litmus paper is effective at indicating the acidity or basicity of a substance by changing its color due to chemical reaction when exposed to acid as it turns red, or a base as it turns blue, but cannot report an exact pH value. It works the same with pH test strips but the packages come with a color-coded scale as a reference when paper turns a certain color. A typical pH meter on the other hand can be made of a moving coil or a digital meter, and either one or two probes. It works by dipping the two electrodes into a solution and by ion- exchange it creates a different degree of hydrogen ion activity showing a pH measurement [2]. The sophisticated pH meter from the group of benchtop pH meters, wireless pH transmitters, and portable pH meter offers great accuracy and convenience but is costly.