Effects of Processing and Storage Conditions on Oil Constituents of Dried Washington Navel Orange Peel (Citrus Sinensis L) from Egypt

This study focused on the comparison of several ways to store orange peel essential oil, whether to store it in the form of volatile oils or keep it inside the dry orange peel until extracting by hydrodistillation. This experiment includes two parts; the first part includes storing orange peel pieces and orange powder in dry place until the oil is extracted. The second part is storing the distilled oil for orange peel pieces and orange peel powder under cold conditions. The oil and orange peel were stored for one year. The volatile oil of orange peel was analyzed by GC/MS. Orange peel oil was characterized by high amount of monoterpene hydrocarbons MH. The highest percentage of MH recorded 97.35 % in peel powder oil at zero time (control treatment) while the lowest percentage was found with peel oil isolated after one year from stored peel pieces (under room temperature conditions) which recorded 77.21 % against 87.02 % for peel powder under the same conditions. The MH group recorded 92.12 and 86.52 % for peel pieces and peel powder oil under cold conditions. Generally, the results cleared that the main constituent of orange peel oil was D-limonene ranged from 63.5% in stored peel pieces to 90.2 % with stored peel pieces oil under cold conditions.