Chemical composition and anti-microbial activities of the essential oil of Adansonia digitata stem-bark and leaf on post-harvest control of tomato spoilage

The mirage of bioactive compounds in essential oil (EO) has raised its prospects as an alternative to synthetic chemicals preservatives. The yields of the hydro-distilled EO from the leaf and stem-bark of Adansonia digitata were: 0.302% and 0.403%; while identified compounds were: 23 and 40 respectively. The principal chemical constituents of the EO were: hydrocarbons, alkene alcohol, cyclic ketonic ether, terpenoids, amides, esters. Tetramethyl-2-hexadecen-1-ol (26.31%), 8-dimethyl-2-(1-methylethenyl) (8.20%), Tetracosan (6.54%), Heptacosane (5.81%) and Tetratetracontane (5.59%) were dominant compounds in the leaves EO. While, the major compounds of the stem-bark EO were: Octadecane (9.30%), Cyclopentane (8.81%), 1-Octadecanesulphonyl chloride (8.73%), Heptadecane (8.50%), Eicosane (8.34%), and Tetracosan (7.12%). The antimicrobial activity of the EO against post-harvest decay of tomato fruits stored at room temperature (27±2 °C) indicated significant (P < 0.05) reduction of bacterial and fungal loads at 2000 ppm when compared with control. The lethality assay of leaf and stem-bark EOs showed significant toxicity against brine shrimps, with LC50 values of 1750 μg/ml and 1932 μg/ml respectively. These values were greater than 1000 μg/mL as recommended index for non-toxicity in human. Thus, the study suggested application of the EO as possible antimicrobial agent as possible alternative to synthetic chemicals for the preservation of fresh tomato fruits.