Assessment of biological properties and biostabilization capacity of essential oils of Cymbopogon citratus and Mentha piperita on liquid Gapal

Abstract

Gapal is a traditional food made from pearl millet, produced in Burkina Faso. This product, made from millet combined with yogurt or fresh milk, is very nutritious but deteriorates rapidly without proper refrigeration. Despite its nutritional benefits and socio-economic importance, its preservation remains a challenge. The current study aims to evaluate the antioxidant and antibacterial properties of essential oils from Cymbopogon citratus and Mentha piperita and to test their ability to stabilize pathogenic bacteria in Gapal. Samples were collected at Koudougou township. Gapal biostabilization tests were conducted using two essential oils obtained through hydrodistillation. Extraction yields of the essential oils were 0.90 ± 0.03% for Cymbopogon citratus and 0.76 ± 0.10% for Mentha piperita . Antioxidant capacity was assessed using the DPPH and FRAP assays to evaluate free radical-scavenging potential. The DPPH assay yielded IC 50 values of 21.284 ± 0.381 µL/mL (v/v) for Cymbopogon citratus and 31.085 ± 0.579 µL/mL (v/v) for Mentha piperita, values confirmed by the FRAP assay. Both essential oils demonstrated efficacy against the tested bacterial strains. This study suggested that preserving Gapal with a 12.5% essential oil concentration significantly extended its shelf life at 37 °C. Specifically, the shelf life increased from 6 h to 24 h for Cymbopogon citratus essential oil and from 14 h to 24 h for Mentha piperita essential oil. The essential oils examined provide a natural, safe, and effective method to improve the safety and shelf life of Gapal, supporting its wider consumption and commercialization.