Quality improvement of soaps perfumed with some selected essential oils

Abstract

This work concerned the valorization of shea butter, palm, coconut and kolo oils and, essential oils from Eucalyptus citriodora, Ocimum gratissimum, Cymbopogan citratus and Plectranthus glandulosus by applying a few stages of quality management procedures for soap making. For this purpose, the consumers' needs regarding the soap quality characteristics have been identified. It emerged that the soap smell was of more concern to them. The product was then designed by mixture design of experiment and, 50 g soap samples produced were subject to consumer assessment. Results showed that samples made with coconut (25 g) and kolo (25 g) oils gave the most popular soap according to the rates they received. Among the data of the four quality characteristics, only those from physical measurements of foam height suited the quadratic model. This lead to optimize this characteristic and the values of variables found were coco (17.171 g) and kolo (32.829 g) for a 9 cm maximum and 8 cm minimum foam height. There was no significant discrimination between both the odors of lemongrass and waya essential oils tested. The soaps perfumed with essential oils from Eucalyptus citriodora, Ocimum basilicum and Plectranthus glandulosus exerted an antimicrobial activity against Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus.