Utilization of pesticide-free calamansi (Citrus microcarpa) and mango (Mangifera indica) peels for the production of acetic acid with potential industrial application

Abstract

Valorization of calamansi and mango peels by conversion to high-value products can mitigate disposal concerns and lessen operational cost of fruit processing companies. This study explored the potential of producing acetic acid from calamansi and mango peels through fermentation. The high sugar content of calamansi (14.24%) and mango (18.65%) peels as well as the fact that the level of pesticide residues was below the maximum residue limit (MRL) suggested the suitability of the peels for production of acetic acid. Using three setups of liquid extract from the peels with varying sugar concentrations of 15%, 20%, and 25% and the successive addition of Saccharomyces cerevisiae and Acetobacter aceti, the maximum acetic acid produced amounted to 4.79% for calamansi peels (day 25) from 20% sugar solution, and 3.42% (day 13) from 25% sugar solution for mango peels. This acetic acid can eventually be explored further for various industrial applications.