Chemical composition, antibacterial and antioxidant activities of hydrosols from different parts of Areca catechu L. and Cocos nucifera L.

Hydrosols are promising natural anti-microbial and anti-oxidant agents with potential applications in afro-industries. Hydrosols obtained by hydrodistillation in Clevenger-type apparatus from arecanut (Areca catechu L.) and coconut (Cocos nucifera L.) were analyzed by GC-MS and evaluated for the antibacterial and antioxidant activities. GC-MS analysis for hydrosols of areca flower (AFH), areca floral axis (AFAH), areca root (ARH), coconut flower (CFH), coconut floral axis (CFAH) and coconut root (CRH) resulted in the detection of 44, 24, 61, 39, 22, and 29 different volatile components, respectively. All tested bacteria were inhibited by all hydrosol samples using paper disc diffusion and serial dilution methods E. coli O157:H7 ATCC 33150 and S. aureus ATCC 2392 were significantly inhibited by AFH and AFAH, while E. coli ATCC 25922 and C. albicans ATCC 10231 were the most sensitive bacteria against CFH. Hydrosols from the flowers of arecanut and coconut had the highest total phenolic contents, the best scavenging effect on DPPH and ABTS, and the strongest reducing power than those from floral axes and roots.