Changes in essential oil during enzyme-assisted ensiling of lemongrass (Cymbopogon citratus Stapf.) and lemon eucalyptus (Eucalyptus citriodora Hook)

Changes in essential oil during ensiling of lemongrass and lemon eucalyptus were studied. Wilted lemongrass and eucalyptus leaves were ensiled in 0.25 -L anaerobic jars. Samples consisted of a control (no additives) and a trea ted sample (0.5% glucose and lactic acid bacteria and 1% cellulase plus 1% hemicellulase plus pectinase). Three jars per treatment were sampled on day s 2, 6, 10, and 36 for analysis of essential oil. Essential oil was obtaine d by extraction and by hydrodistillation. Extraction efficacy of essential oil from the lemongrass was improved by the enzyme treatment, but it was mu ch lower than the amount obtained by distillation. The major components of the essential oil were neral and geranial. In the eucalyptus, total essenti al oils obtained by distillation decreased during ensiling, and the amount was similar to the amount obtained by extraction. Citronellal, which was th e major component of the essential oil in the fresh eucalyptus leaves, decr eased, whereas isopulegol and 3,8-terpinolhydrate increased during ensiling .