Comparative Analyses of the Volatile Components of Citrus Aurantium L. Flowers Using Ultrasonic-Assisted Headspace SPME and Hydrodistillation Combined with GC-MS and Evaluation of their Antimicrobial Activities

The volatile components of Citrus aurantium L. flowers were characterized by GC-MS with two different extraction techniques, hydrodistillation (HD) and ultrasonic-assisted headspace solid phase microextraction (UA-HS-SPME). In the SPME method, the volatile components of the samples, irradiated by ultrasonic radiation, were collected on a polydimethyl siloxane (PDMS) commercial fiber as well as some manually prepared nanoporous fibers from the samples headspace. To reach the better results, the extraction conditions were carefully optimized for the PDMS fiber Under the optimized conditions (i.e. somcation time 15 min, extraction time 30 mm and extraction temperature 55 degrees C), 54 compounds were identified by the UA-HS-SPME-GC/MS method. The essential oil components of Citrus aurantium L. flower samples from two different regions of Iran and new and old samples from the same region were compared to one another. The major components identified for the samples with both the SPME and HD methods were lmalool, linalyl acetate, limonene, beta-myrcene, geranyl acetate, and neryl acetate, respectively. However, a substantial vanation m the percentages of the components was identified for different samples and different extraction methods. The antimicrobial activities of the oil were also examined against six standard bactena. There was some activity against Enterococcus fecalis, Escherichia coll, and Bacillus cereus, indicating important biological activities of the oil.