Benzoic Acid Induced Variations in Essential Oil of Valencia Orange Trees Grown in Reclaimed Land of Egypt

Abstract

Benzoic acid (BA) plays an important role in physiological processes of Valencia orange essential oil. The essential oil of Valencia orange has different medicinal and biological properties. Influences of benzoic acid on essential oil isolated from leaves and peels of these trees were investigated in a new reclaimed region of Egypt. The trees treated with BA at 20 and 40 mg/L compared with an untreated control. Benzoic acid at 20 mg/L resulted in the greatest amounts (0.3 and 0.7%) of essential oil extracted from leaves and peels. The components of sabinene (35.6-37.9%), Δ-3-carene (13.2-14.5%) and limonene (11.1-12.6%) were detected as the major constituents of leaf essential oil; while limonene (70.3-71.5%), myrcene (5.2-7.1%) and γ-terpinene (4.2-5.2%) were detected as main components of peels essential oil. The dose of 20 mg/L BA produced the highest values of all major components. The detected components in essential oil produced from leaves and peels belonged to 4 chemical groups i.e. monoterpene hydrocarbons (MCH), oxygenated monoterpenes (MCHO), sesquiterpene hydrocarbons (SCH) and oxygenated sesquiterpenes (SCHO). The greatest amounts of MCH (79%), SCH (7.5%) and SCHO (1.7%) were recorded with the BA at 20 mg/L, while the highest value of MCHO (18.4%) was recorded with the treatment of 40 mg/L. The results of chemical groups of peels essential oil indicated that control treatments resulted in the highest values of MCHO (10.6%), SCH (3.7%) and SCHO (0.8%) but the greatest value of MCH (88.7%) was recorded with BA at 20 mg/L.