The composition, properties, uses and degradation of the lauric acid o
ils have been discussed. Coconut and palm kernel oil contain approxima
tely 40% medium chain fatty acids (C6:0-C12:0). The medium chain fatty
acids in these oils are readily degraded by filamentous fungi belongi
ng to the following genera, Penicillium, Aspergillus, Cladosporium, Fu
sarium, Trichderma and Monascus to give the methyl ketone one carbon a
tom less. This type of spoilage has been described as ketonic rancidit
y. Ketonic rancidity caused by Penicillium crustosum can be controlled
by the total absence of fungal spores, a temperature less than 4 degr
ees C, water activity less than 0.91; the addition of sorbic acid at 1
000 mg/kg or by the absence of oxygen. Coconut oil is a better substra
te for ketonic rancidity than palm kernel oil due to the higher concen
tration of medium chain fatty acids in the former.