Method development for the analysis of volatile compounds in olive oil.

Olive oil consists mainly of triglycerides, in about 97 to 99% by weight. The minor compounds are a complex mixture of polar, apolar and amphiphilic substances, such as tocopherols, phenolic compounds, sterols, chlorophyll, carotenoids, terpene acids, monoglycerides and diglycerides, free fatty acids and volatile compounds. These volatiles are the compounds directly responsible for the aroma of the oil. Extra virgin olive oil has a complex aroma with more than 100 volatile compounds identified, among aldehydes, alcohols, esters, hydrocarbons, ketones and furans. The objective of this study was to develop an analytical method for volatile compounds in olive oils using solid-phase microextraction (SPME), gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). For the SPME, different parameters like flask size (4, 10 and 20 mL), sampling temperatures (40 and 60 °C), headspace conditioning (10 and 60 min) and fiber exposure times (15 and 40 min) were tested. For GC analyses two different internal standards, methyl octanoate and tetradecane, were tested, as well as sub-ambient oven temperatures with liquid nitrogen. A 1 g of sample and a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PMDS) fiber were used in all the tests. Analytical curves from the FID data were constructed for linearity evaluation, whereas internal standard was used for quantification ofcompounds such as 3-hexenol, 2-hexanal and limonene. Identification was performed based on mass spectra, co-injection of standards and retention indices data. The best conditions for SPME analysis were sample temperature of 40 °C, 10 min of headspace conditioning and fiber exposure for 40 min, in a 4 mL flask. For the chromatographic analyzes, tetradecane was chosen as the internal standard. Oven temperature program with cryofocusing led to a much better separation and, therefore, better quantitation and identification of the morevolatile compounds.De 15 a 16 maio 2019. Trabalhos apresentados de forma oral

Analysis of volatile compounds in extra virgin olive oil from Rio Grande do Sul by SPME/GC-MS.

De 15 a 16 maio 2019. Trabalhos apresentados de forma oral

Physicochemical characterization of bunches and oil composition in a backcross progeny (caiaué x oil palm) x oil palm.

Hybrids between caiaué and oil palm (IEH OxG) are explored in genetic improvement with the main objective of associating the high palm oil productivity of oil palm with resistance of caiaué to Bud Rot disease. In addition, caiaué has better oil quality and greater resistance to some pests and diseases than oil palm and these characteristics are transmitted to the hybrid between species. Híbridos interespecíficos de caiaué com dendezeiro (HIE OxG) são explorados no melhoramento genético com objetivo principal de associar a alta produtividade em óleo de palma do dendezeiro com a resistência do caiaué a anomalia Amarelecimento Fatal.Título em português: Caracterização físico-química dos cachos e composição do óleo em progênie do retrocruzamento (caiaué x dendezeiro) x dendezeiro

Bioactive compounds of fractionated palm oil with a higher content of oleic acid.

BRS Manicoré cultivar is an interspecific hybrid between Elaeis oleifera and Elaeis guineensis(ISH OxG). It has shown high yield potential and genetic resistance to phytosanitary problems in cultivation in Brazil. Studies have indicated differences in the composition of ISH OxG and palm oils, as well as the influence of genotype and environment on palm oil characteristics. The aim of this study was to assess the distribution of fatty acids, carotenoids, and tocochromanols in the olein and stearin fractions of the oil produced by the ISH OxG cultivated in municipality of Una, state of Bahia, Brazil by liquid and gas chromatography. There were significant differences for fatty acids, carotenoids and total tocochromanols between olein and stearin (p<0.05). The olein was richer in oleic acid (59% vs 57%), while stearin was higher in saturated fatty acids (31% vs 29%), alpha and beta-carotene (232 vs 213 mg/Kg, and 347 vs 299 mg/Kg, respectively), alpha-tocotrienol (136 vs 90 mg/Kg), and alpha-tocopherol (52 vs 32 mg/Kg). No difference was observed for gamma-tocotrienol (598 ? 450 mg/kg) and delta-tocotrienol; nonetheless, the high content of the former in both fractions was notable. The ISH OxG oil fractions showed distinct patterns, indicating different applications.Título em português: Compostos bioativos de frações de óleo de palma com maior teor de ácido oleico

Expeller pressing of passion fruit seed oil: Pressing efficiency and quality of oil.

The passion fruit juice production generates around 70% of by-products comprising rind, seeds and arils that are commonly discarded. The seeds consist of 4% of fruit weight with the potential to produce around 2,500 ton/year of high added-value oil in Brazil. In this work, passion fruit seeds from different juice manufacturers and the effect of the seed moisture were evaluated towards oil quality and extraction efficiency, using a continuous expeller press of 100 kg/h capacity. The seeds were washed and dried before pressing. The main fatty acids detected were linoleic (67% to 68%), oleic (16% to 17.4%) and palmitic (11%). The oil quality and oil recovery depended on the seed oil content, i.e., the seed moisture before pressing and the different provenances of the seeds. Significant differences were observed for oxidative stability, acidity and conjugated dienes (p < 0.05) for oils from different fruit juice manufacturers. Among them, only one met the requirements of Brazilian regulation regarding oil acidity (less than 2%), thus indicating the need for an effective waste treatment process after juice extraction. Regarding the seed moisture, the highest Oil Stability Index (OSI) (7.4 h) and lowest free fatty acid content (0.63%) were obtained for the oil from the lowest seed moisture content. The oil recovery varied from 78% to 89% and the cake oil content was lower than 8% showing the elements of the feasibility of the process to obtain good quality oil.Prensagem de semente de maracujá: Eficiência da prensagem e qualidade do óleo

Superconductivity in Te-deficient ZrTe2_2

We present structural, electrical, and thermoelectric potential measurements on high-quality single crystals of ZrTe$_{1.8}$ grown from isothermal chemical vapor transport. These measurements show that the Te-deficient ZrTe$_{1.8}$, which forms the same structure as the non-superconducting ZrTe$_2$, is superconducting below 3.2\,K. The temperature dependence of the upper critical field (H$_{c2}$) deviates from the behavior expected in conventional single-band superconductors, being best described by an electron-phonon two-gap superconducting model with strong intraband coupling. For the ZrTe$_{1.8}$ single crystals, the Seebeck potential measurements suggest that the charge carriers are predominantly negative, in agreement with the ab initio calculations. Through first-principles calculations within DFT, we show that the slight reduction of Te occupancy in ZrTe$_2$ unexpectedly gives origin to density of states peaks at the Fermi level due to the formation of localized Zr-$d$ bands, possibly promoting electronic instabilities at the Fermi level and an increase at the critical temperature according to the standard BCS theory. These findings highlight that the Te deficiency promotes the electronic conditions for the stability of the superconducting ground state, suggesting that defects can fine-tune the electronic structure to support superconductivity