The study of the freezing and drying effects on quantity and quality of Rosmarinus officinalis L. essential oil and caffeic acid

This study to was evaluated the effect of freezing and drying methods on quality and quantity of Rosmarinus officinalis L. essential oil. The leaves of plant in blooming were collected from the medicinal plant garden in Islamic Azad University of Gorgan branch in July 2014. The samples were prepared in four groups: fresh, dried, fresh frozen and dried frozen. Essential oils were obtained by steam distillation (Clevenger apparatus) and were analyzed by GC/MS. The caffeic acid content of samples was measured by HPLC. Results were showed in all oils: iso-bornyl acetate (11.5%-14.3%), camphor (11.34%-12.7%), pulegone (7.8%-10.6%), α-phellandrene (0.3%-9.2%), β-caryophyllene (2.1%-8.87%), α-terpineol (3.34%-9.8%), 1,8-cineol (0.93%-6.7%), linalool (0%-4.45%) and camphen (3.3%-5.7%) were the major common constituents. The greatest amount of caffeic acid was reported in fresh samples of plant (0.016 mg / gram of plant leaves). According to results in both fresh and dried samples the essential oils had the highest quality and quantity ingredients. Although the trans-pinocarveol (5.1%), sabinene (4.8%), trans-ocymen (6.3%), geranyl acetate (15.2%) just were observed in fresh and dried samples. According to another researches, these constituents of plant oil have high antioxidant, anti-pathogen, anti-inflammation and anti-infection activity. Therefore it is recommended to improve the quality of plant processing by using fresh and dried materials.