Abstract

The preservation of freshly squeezed orange juice with essential oils from the leaves of Cymbopogon citratus and Eucalyptus globulus was investigated. Extraction was carried out using volatile oil distillator at 80°C. The quality assessments of juice were analyzed after 28 days of storage at 4oC. The volatile constituents of test plants were analyzed via GC-MS. Aspergillus flavus, Aspergillus niger, Candida sp, Saccharomyces cerevisiae, Trichoderma sp. were isolated from the freshly squeezed orange juice and branded orthodox juices. Antifungal assay of the oil showed A. flavus exhibiting highest mean zone of inhibition of 10.58 ± 1.10 mm in C. citratus. Quality assessment as days of storage increased indicated an increase in pH values in the control (3.70 to 4.02) while acidity reduced from 3.50 to 3.70 and 3.60 to 3.80 in C. citratus and E. globulus, respectively. Potential browning increased in C. citratus from 1.324 to 1.798 and from 1.215 to 1.764 in E. globulus within the same time of storage. Citronelle (9.5%) and Apha-phellande (8.40%), respectively had highest percentage composition of volatile oils in C. citratus and E. globulus. This study indicated that the volatile oils in the plants have preservative potentials in extending the shelf-life of orange juice.

Key words: Natural preservatives, Volatile oil, Cymbopogon citratus, Eucalyptus globulus, shelf-life