Análise exploratória de carotenóides, óleos essenciais e triacilglicerídios do pequi (Caryocar brasiliense Camb.) de municípios brasileiros situados no bioma cerrado

• Autor(a) principal: Geöcze, Katalin Carrara
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/216
• topic: Pequi (Caryocar brasiliense Camb.); Carotenóides; Óleos essenciais; Triacilglicerídios; Análise multivariada; Pequi (Caryocar brasiliense Camb.); Carotenoids; Essential oils; Triacylglycerides; Multivariate analysis; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA

The Caryocar brasiliense Camb. is an arboreal species, typical of the Brasilian cerrado biome. It produces a fruit widely used regionally. Its yellow pulp, with intense flavor, is considered an excellent source of carotenoids and, also, a high content of lipids. It was determined, quantitatively and qualitatively, the composition of carotenoids, essential oils and triacylglycerides, on samples of pequi on different regions of the Cerrado biome, covering the states of Maranhão, Tocantins and Minas Gerais. It is also, through multivariate analysis, Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), the samples were classified according to these chemical characteristics. The determination of provitamin A carotenoids (PVAC), as well as other carotenoids from the pulp of C. brasiliense, was performed by high performance liquid chromatography coupled to a diode array detector (HPLC- DAD). The PVAC found in 18 populations sampled were β-cryptoxanthin and β-carotene. It was observed high variation in concentrations of PVAC, especially given the large difference between the populations of Grajaú-MA (0.63 g g-1) and Januária-MG (255 mg g-1). The multivariate analysis, PCA and HA, organized the 18 pequi samples by the decreasing content of provitamin A carotenoids. Moreover, it showed a group of samples (Januaria, Japonvar, Arinos, Salinas and Montes Claros) with higher levels of carotenoids. In addition to β-cryptoxanthin and β- carotene, other carotenoids identified in the C. brasiliense pulp were neoxantina, violaxantina, lutein and zeaxanthin; the major constituents from this group are: neoxantina and β-carotene. In addition to being a source of PVAC, the pequi may also be indicated as a source of xanthophylls: lutein and zeaxanthin. The analysis of essential oils from the pulp of C. brasiliense was carried out after extraction by hydrodistillation, using gas chromatography coupled with mass spectrometry (CG-MS). The average content of essential oil was around 0.5%, however the Northern Minas Gerais district of Januária stood out from the others, at 1.2%. The lowest values were the districts from Tocantins, which showed an average content of 0.2%. In general, the chemical constituents of pequi essential oils are esters and β-ocimene. The majority of substances are: ethyl hexanoate (MA and MG), isopropyl hexanoate and isopenthyl 2-methylbutanoate (TO). The ethyl esters of short chain confer the fruits from the States of Minas Gerais and Maranhão, a sweet flavor, a floweryfruity, intense aroma enhanced by the monoterpeno β-ocimene. However, the longer chain esters; present in the samples of the State of Tocantins, to which are attributed metallic notes; suggest that they have less fruity flavors. On multivariate analysis (PCA and HCA) it was possible to classify the pequi according to their place of origin, confirming that the composition of essential oils is influenced by geography and/or genetic factors. Additionally, it was made extraction (Soxtec/hexane), derivatization (methyl esters) and chromatographic analysis (GC-MS) for the determination of triacylglycerides (TAG) from the pequi s pulp and almond. The average levels of TAG, from the pulp (53.7%) and almond (49.0%), confirmed the C. brasiliense to be an oilseed species. The majority of fatty acids, about 98%, were palmitic acid and oleic acid. This composition and the absence of free fatty acids adequate these oils for use in food, among other capabilities. In According to ANOVA, the populations from the State of Maranhão stood out on the content of TAG in the pequi s pulp, together with the Januária Districts (Minas Gerais). The chemometric study, by multivariate analysis (ACP and HCA), classified the samples according to the ratio between the content of saturated and unsaturated fatty acids (TAGS/TAGI), as it is not possible to separate them according to geographical location.