Paper Title
Acacia Species as a Sorce of Phenolic Compounds

Abstract
Acacia is an invasive species that occupies extensive areas in Portugal compromising the natural ecosystems of certain regions due to land fragmentation and loss of biodiversity. At this moment the scientific community is focused in obtaining new applications for this species or identifying some compounds of for industry with a biorefinery perspective to promote their harvest and decrease pressure on ecosystems. In this context, flowers and pods of four Acacia species (A. dealbata, A. retinodes and A. pycnantha) were evaluated concerning the extraction of phenol and flavonoid compounds to identify potential industrial uses. The different parts of the Acacia plants were lyophilized and frozen at -80 °C until analysis. The extraction was performed from10 g of lyophilized Acacia samples, with 100 mL of ethanol on an orbital plate shaker for 24 h with constant stirring. After filtration, the extracts were centrifuged (4000x g, 20 min) and concentrated using a rotary evaporation system (40 °C). Phenol and flavonoid profile characterization and quantification were performed by high-performance liquid chromatography-diode array detector and liquid chromatography-electrospray ionizationhigh-resolution tandem mass spectrometry. The lyophilized material was analysed by Vibrational spectroscopy, namely FT-RAMAN and FT-NIR. In FT-RAMAN, the measurement was performed with a spectral resolution of 32 cm-1 and 64 scans in the wavenumber range of 4000 to 200 cm-1in a quartz cell of 5 mm of optic space. In FT-NIR, the samples were measured in the reflectance mode, with a spectral resolution of 16 cm-1 and 32 scans in the wavenumber range of 12000 to 4000 cm-1. A number of flavanols, flavonoids and flavones compoundswere identified in both parts of the acacia species studied, but the concentration and profile are different concerning the raw material (flowers or pods) and species. Principal component analyses were performed using the analytical data for flowers and pods and compared to the spectral information collected byFT-NIR andFT-RAMAN. Both analyses confirm the different profiles of the different species of Acacia. The results demonstrated that the Acacia flowers and pods present potential as a source of flavonoids and phenolic compounds that could be used in different industries, which will be further studied. Vibrational spectro scopy could, also, easily discriminate the differentiation shown by analytical methods. Different parts of Acacia, namely flowers and pods,have distinct compound profiles with severalpotential applications. Keywords - Acacia, Flowers, Pods, Chromatographic analysis, FT-RAMAN, FT-NIR.