Gas chromatographic-olfactometric characterization of aroma compounds in two types of cashew apple nectar

Cashew apple nectar is a secondary product from the production of cashew nuts and possesses an exotic tropical aroma. Aroma volatiles in pasteurized and reconstituted (from concentrate) Brazilian cashew apple nectars were determined using GC-MS and split, time-intensity GC-olfactometry (GC-O/GC-FID. Methional, (2)-1,5-octadien-3-one, (2)-2-nonenal, (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal, beta-damascenone, and delta-decalactone were identified for the first time in cashew apple products. These compounds plus butyric acid, ethyl 3-methylbutyrate, 2-methylbutyric acid, acetic acid, benzaldehyde, homofuraneol, (E)-2-nonenal, gamma-dodecalactone, and an unknown were the most intense aroma volatiles. Thirty-six aroma volatiles were detected in the reconstituted sample and 41 in the pasteurized sample. Thirty-four aroma active components were common to both samples. Ethyl 3-methylbutyrate and 2-methylbutyric acid were character impact compounds of cashew apple (warm, fruity, tropical, sweaty). Using GC-pFPD, 2-methyl-3-furanthiol and bis(2-methyl-3-furyl) disulfide were identified for the first time in cashew apple. Both were aroma active (meaty).

Identification of polycyclic aromatic hydrocarbons in sugar cane soot by gas chromatography mass spectrometry

Fly soot samples collected in the sugar cane fields after the process of burning were extracted in a Soxhlet apparatus (methylene chloride:methanol 4:1). The extracts were fractionated on silica gel Sep-Pak cartridges into three fractions. A gas chromatographic-mass spectrometric study of the fly soot extracts allowed the identification of the PAH with mutagenic and carcinogenic properties. Large amounts of aliphatic hydrocarbons, fatty acid esters and some PAHs were identified by GCMS in full scan mode. GC-MS in the selective ion monitoring mode (SIM) was suitable for the determination of many PAHs, which are often present in the burnt biomass. 31 PAHs and 7 thiophens derivatives were identified. The presence of these compounds should be regarded as a caution to workers and the general population to avoid exposure to the fly soot.

Composition and antifungal activity of essential oils from Piper aduncum, Piper arboreum and Piper tuberculatum

The composition of essential oils from leaves, stems and fruits of Piper aduncum, P arboreum and P. tuberculatum was examined by means of GC-MS and alltifungal assay. There was a predominance of monoterpenes in P aduncum and P tuberculatum and of sesquiterpenes in P arboreum. P aduncum showed the richest essential oil composition, including linalool. The essential oils from fruits of P. aduncum and R tuberculatum showed the highest antifungal activity with the MIC of 10 mu g as determined against Cladosporium cladosponoides and C. sphaerospermum, respectively. This is the first report of the composition of essential oils from P. tuberculatum.

Analysis of camphorquinone in composite resins as a function of shade

Objective. To identify and quantify the camphorquinone (CQ) used in different brands of composite resins as a function of the shade analyzed.Materials and methods. Filtek Z250 A3 (FZA3), Filtek Z-250 Incisal (FZI), Pyramid Enamel A1 (PEA1), Pyramid Enamel Translucent (PET), Filtek Supreme A3E (FSA3) and Filtek Supreme GT (FSGT) were used. Five hundred milligrams of each resin were weighed and then dissolved in 1.0 ml of methanol. The samples were centrifuged to accelerate the sedimentation of the inorganic particles. 0.8 ml of the supernatant solution was collected with a pipette and assessed under gas chromatography coupled to the mass spectrometer (GC-MS). The results were compared to pure CQ solutions, used as a standard. Student's t-test, (p = 0.05) significant at the level of 5%, compared the results of each brand shade.Results. A smaller amount of camphorquinone was found in Filtek Z-250 (FZI) resin incisal shade when compared to (FZA3) A3 shade. on the other hand, Filtek Supreme resin featured a statistically larger camphorquinone amount in the incisal shade. in Pyramid Enamel resin camphorquinone was found only in shade Al, while the photoinitiator used in the Translucent shade was not identified.Significance. Based on the data obtained, it is possible to conclude that a single composite resin brand may feature differences in amount and type of photoinitiator used. (C) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Determination of buprofezin, pyridaben, and tebufenpyrad residues by gas chromatography mass-selective detection in clementine citrus

A gas chromatography-mass-selective (GC-MS) detection method to determine buprofezin, pyridaben, and tebufenpyrad on the pulp, peel, and whole fruit of clementines is described. The extraction/partition procedure was performed in one step and no cleanup was necessary with the GC-MS in the SIM-mode pesticide determination. Recovery ranged from 75 to 124% with coefficients of variance ranging between 1 and 13%. The limit of determination was 0.01 mg/kg for all pesticides. The field trials showed a similar degradative behavior for all active ingredients (AI), with a great residue decrease during the first week and stability in the second. Just after treatment buprofezin and tebufenpyrad showed lower residues than the maximum residue limit (MRL) fixed in Italy, while pyridaben was below the MRL after a week.

Essential oil from leaves of Cryptocarya mandioccana Meisner (Lauraceae): Composition and intraspecific chemical variability

The composition of the essential oil from leaves of Cryptocarya mandioccana has been determined by chromatographic fractionation and GC-FID, GC-MS and C-13 NMR analyses, yielding the identification of 64 compounds with predominance of isomeric sesquiterpenes with molecular weights of 204. The main components of the oil obtained by hydrodistillation were beta-caryophyllene, spathulenol, caryophyllene oxide, delta-cadinene, germacrene D, benzaldehyde and bicyclogermacrene. However, the oil obtained by steam distillation contained higher levels of sesquiterpene hydrocarbons, with predominance of P-caryophyllene (C), germacrene D (G) and bicyclogermacrene (B), and was considered to be more representative of the composition of the oil in its natural state. The intraspecific chemical variability of the essential oil obtained by steam distillation was evaluated within populations of trees growing at three separate locations in the state of São Paulo, Brazil. Three distinct chemical groups could be characterised due to differences in the relative percentages of the three main sesquiterpenes from essential oil: CGB [relative contents of C (14-34%), G (5-28%), B (8-15%)], BCG [B (17-34%), C (9-24%), G (12-25%)] and GCB [G (22-42%), C (4-17%), B (7-15%)]. Individuals from groups CGB and BCG were found to be more frequent at south locations while group GCB is predominant in north location. (c) 2006 Elsevier Ltd. All rights reserved.

Essential Oil Composition of Aloysia gratissima From Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Optimization of the Transesterification Reaction in Biodiesel Production and Determination of Density and Viscosity of Biodiesel/Diesel Blends at Several Temperatures

Waste frying oil has been used to optimize the production of biodiesel. Biodiesel was prepared through sodium ethoxide catalyzed methanolysis from the transesterification of recycled waste frying oil. Optimization of the transesterification reaction for biodiesel production was carried out by means of statistical analyses using ANOVA. The optimum conditions for reaction were the following: a oil methanol mole ratio of 1:9, temperature of 50 degrees C, catalyst mass fraction of 0.9 %, and reaction time of 40 min, which enabled a yield of 98.7 % determined by gas chromatography/mass spectrometry (GC/MS) analysis. The density and viscosity of biodiesel/diesel blends have been determined as a function of composition at several temperatures.

Isolamento e avaliação da atividade biológica dos alcalóides majoritários de Tabernaemontana angulata Mart. ex Müll. Arg., Apocynaceae

"Isolation and evaluation of the biological activity related to the major alkaloids in Tabernaemontana angulata Mart. ex Mull Arg., Apocynaceae." Introducing-new chemotherapeutic agents is a, great demand. in the control of infections diseases.' Brazil is one of the richest countries in biodiversity and the Laboratorio de Extracao at UNIP has been collecting plants from. the Amazon and Atlantic Rain Forests with the aim of screening for new antibacterial and antitumor plant extracts. Previous studies demonstrated that the ethanol fraction obtained from the crude extract of Tabernaemontana angulata stems showed antibacterial activity against Staphylococcus aureus (ATCC 6538 in the microdilution broth assay. Two alkaloids were the major compounds in the active fraction, verified by thin layer chromatography analysis. In the present study, the total alkaloids were obtained from the crude extract and were fractionated by preparative thin layer chromatography for the isolation of the main components. The isolated. compounds were identified by GC/MS and (1)H-NMR as coronaridine,e and voacangine. The alkaloid fractions obtained from the isolation procedure were tested for antibacterial activity, but no activity was detected.

Structural characterization of the cell wall D-glucans isolated from the mycelium of Botryosphaeria rhodina MAMB-05

Three D-glucans were isolated from the mycelium of the fungus Botryosphaeria rhodina MAMB-05 by sequential extraction with hot-water and hot aqueous KOH (2% w/v) followed by ethanol precipitation. Following their purification by gel permeation chrornatography on Sepharose CL-4B, the structural characteristics of the D-glucans were determined by FT-IR and C-13 NMR spectroscopy and, after methylation, by GC-MS. The hot-water extract produced a fraction designated Q(1A) that was a beta-(1 -> 6)-D-glucan with the following structure:[GRAPHICS]The alkaline extract, when subjected to repeated freeze-thawing, yielded two fractions: KIP (insoluble) that comprised a beta-(1 -> 3)-D-glucan with beta-D-glucose branches at C-6 with the structure:[GRAPHICS]and K1SA (soluble) consisting of a backbone chain of alpha-(1 -> 4)-linked D-glucopyranosyl residues substituted at O-6 with alpha-D-glucopyranosyl residues:[GRAPHICS](c) 2008 Elsevier Ltd. All rights reserved.

Fecal Sterols in Estuarine Sediments as Markers of Sewage Contamination in the Cubatao Area, São Paulo, Brazil

Sterol biomarkers serve as an alternative method for detecting sewage pollution. Sterols were extracted from samples of surface sediment collected in Cubato (the Vila dos Pescadores and Vila Esperan double dagger a communities) and quantified using GC-MS after Soxhlet extraction, cleanup, and derivatization. Fecal contamination was evaluated based on the concentration of coprostanol and the ratio of the selected sterols. The most abundant sterol was cholestanol, followed by coprostanol. The concentrations of coprostanol in surface sediments ranged from a minimum of 4.21 mu g g(-1) dry sediment (Vila dos Pescadores station) to a maximum of 8.32 mu g g(-1) dry sediment (Vila Esperan double dagger a station). A coprostanol concentration of about 10 mu g g(-1) was found, indicating areas of high sewage contamination. Coprostanol levels at sewage stations were higher than in other Brazilian coastal areas, which may be attributed to the fraction of the population without sanitation services.

Hepatogenous photosensitization of ruminants by Brachiaria decumbens and Panicum dichotomiflorum in the absence of sporidesmin: Lithogenic saponins may be responsible

As part of a study of plants involved in crystal-associated hepatogenous photosensitization diseases, samples of Brachiaria decumbens and Panicum dichotomiflorum on which cattle and goats had recently been photosensitized were analyzed. The level of saponins associated with these photosensitization outbreaks were determined by GC-MS. Only low levels of Pithomyces chartarum spores were present on the B decumbens, and all isolates obtained failed to produce sporidesmin.

Phytochemical evidence for the plant origin of Brazilian propolis from Sao Paulo state

Propolis and plant secretions from three species, most frequently mentioned as botanical sources of the bee glue in Brazil (Baccharis dracunculifolia, Araucaria angustifolia and Eucalyptus citriodora) have been investigated using GC-MS. Based on chemical evidence, B. dracunculifolia was shown to be the main propolis source in Sao Paulo state. The antibacterial and antifungal activities of all four materials were also tested, the most active being propolis and Baccharis leaf exudate.

Influence of different drying temperatures on the amount of essential oils and citral content in Cymbopogon citratus (DC) Stapf. - Poaceae

Studies were conducted to show the effect of different temperatures in the drying process on the amount and quality of essential oils of Cymbopogon citratus (DC) Stapf. Leaves were harvested in the experimental field of the Agronomical Sciences College, UNESP, Botucatu, SP, Brazil in September, 1996. Blades of the leaves were cut in small parts (about 1-1,5 cm length), dried for several days at 30°, 50°, 70° and 90°C, until establishment of the weights. In the following process a hydrodistillation, during 2.5 hours, by Clevenger apparatus, was subsidized to extract the essential oils. A higher amount of oil could clearly be collected with the lower drying temperatures, except at 30°C, affected by fungus growing. Aspergillus sp., Penicillium sp., Rhyzopus sp., Cladosporium sp., Trichoderma sp. and Alternaria sp. were observed in the leaves. The analysis of the oil by GC-MS showed the variation of citral concentration of the treatments (86,1 to 95,2%). The results proved it is worthwhile to spend more time and effort in the production process using longer times of careful drying.

Drying temperature effects in peppermint essential oil content and composition

Studies were conducted to show the effect of different temperatures in the drying process on the amount and quality of essential oils of peppermint (Mentha piperita L.) The leaves were harvested in the Demeter Farmer, Botucatu, SP, Brazil in december, 1997. The leaves were dried at 40°C, 60°C and 80°C, until establishment of the weights. The essential oil was extracted by destilation in Clevenger apparatus and analysed by GC-MS. Higher drying temperature sharply decreased the essential oil content (% v/w) from 1.0% (40°C) to 0.14% (60°C) and 0.12% (80°C). Higher drying temperatures also affected the composition, decreasing the contents of 1,8 cineol and citronelal until 80°C, and increasing the contents of menthol and neomenthol until 60°C.