Caracterização físico-química e atividade antifúngica dos óleos essenciais da cúrcuma

Abstract

PHYSICO-CHEMICAL CARACTERIZATION AND ANTIFUNGICAL ACTIVITY OF ESSENTIAL OILS FROM TURMERIC. The objective of this study was to evaluate the antimicrobial activity of essential oils from Curcuma longa L. obtained by hydrodistillation and by extraction with hexane. The extracts were characterized according to yield, specific weight, refractive index, ester value, curcuminoid pigments by UV-visiblespectrophotometry and volatiles by GC-MS. The antifungal activity against phytopatogenic molds (Alternaria brassicicola, Aspergillus flavipes, Aspergillus niger, Cladosporium sphaerospermum and Fusarium oxysporum) was investigated by the diffusion in agar method using paper disks. A higher yield of essential oils was obtained with hexane,which was simpler and faster compared to hydrodistillation. The essential oil obtained with hexane had significantly higher specific weight, refractive index, ester value and levels of curcuminoid pigments. 26 volatile compounds were detected. 22 were present in thehydrodistilled extract and 16 in the hexane. 8 were identified as terpenes and turmerone (ar and á) was the prevalent. Antifungal activity of both samples was observed against Alternaria brassicicola and Aspergillus flavipes. Higher antimicrobial activity was provided by the hexanic extract compared to hydrodistillation. There was significant effect of thetype of extraction on the antifungal activity.Key words: Curcuma longa L, essential oils, antifungal activity, extration, hexane, hydrodistillation, GC-MS.