Monitoring changes in the volatile fraction of roasted nuts and seeds by using comprehensive two-dimensional gas chromatography and matrix templates.

Static headspace coupled with comprehensive two-dimensional gas chromatography and a flame ionization detector (HS-GC × GC-FID), has been applied to monitor changes in the volatile fraction of commercial edible nuts and seeds (peanuts, almonds, hazelnuts, and sunflower seeds). Effects of the roasting conditions (time, 5-40 min; temperature, 150-170 °C), which were employed under different combinations by using a ventilated oven, on target volatile fraction were examined to identify potential differences in relation to the roasting treatment of raw samples. In addition, reference templates were created, from the HS-GC × GC-FID method, for each of the four food matrices analyzed, and they were applied to characterize the samples according to the presence or absence of volatile compounds. Finally, these templates were successfully employed to make a quick distinction between different roasting conditions.•HS-GC × GC-FID was applied to study the volatile profile of edible nuts and seeds.•Reference templates (GC × GC-FID) were created for each of the four food matrices.•Rapid discrimination between raw and roasted samples was achieved.

A Comparative Study on Chemical Compositions and Biological Activities of Four Amazonian Ecuador Essential Oils: Curcuma longa L. (Zingiberaceae), Cymbopogon citratus (DC.) Stapf, (Poaceae), Ocimum campechianum Mill. (Lamiaceae), and Zingiber officinale Roscoe (Zingiberaceae).

Essential oils (EOs) and their vapour phase of Curcuma longa (Zingiberaceae), Cymbopogon citratus (Poaceae), Ocimum campechianum (Lamiaceae), and Zingiber officinale (Zingiberaceae) of cultivated plants grown in an Amazonian Ecuador area were chemically characterised by Gas Chromatography-Flame Ionization Detector (GC-FID), Gas Chromatography-Mass Spectrometry (GC-MS), and Head Space-Gas Chromatograph-Flame Ionization Detector-Mass Spectrometry (HS-GC-FID-MS).figure The EOs analyses led to the identification of 25 compounds for C. longa (99.46% of the total; ar-turmerone: 23.35%), 18 compounds for C. citratus (99.59% of the total; geraniol: 39.43%), 19 compounds for O. campechianum (96.24% of the total; eugenol: 50.97%), and 28 for Z. officinale (98.04% of the total; α-Zingiberene: 15.45%). The Head Space fractions (HS) revealed C. longa mainly characterised by limonene and 1,8-cineole (37.35%) and α-phellandrene (32.33%); Z. officinale and C. citratus showed camphene (50.39%) and cis-Isocitral (15.27%) as the most abundant compounds, respectively. O. campechianum EO revealed a higher amount of sesquiterpenes (10.08%), mainly characterised by E-caryophyllene (4.95%), but monoterpene fraction remained the most abundant (89.94%). The EOs were tested for antioxidant, antimicrobial, and mutagen-protective properties and compared to the Thymus vulgaris EO as a positive reference. O. campechianum EO was the most effective in all the bioactivities checked. Similar results emerged from assaying the bioactivity of the vapour phase of O. campechianum EO. The antioxidant and antimicrobial activity evaluation of O. campechianum EO were repeated through HP-TLC bioautography assay, pointing out eugenol as the lead compound for bioactivity. The mutagen-protective evaluation checked through Ames's test properly modified evidenced a better capacity of O. campechianum EO compared with the other EOs, reducing the induced mutagenicity at 0.1 mg/plate. However, even with differences in efficacy, the overall results suggest important perspectives for the functional use of the four studied EOs.

Laurel essential oil: biological activities and application for semolina preservation against the red flour beetle Tribolium castaneum (Tenebrionidae).

The phytochemical composition of Laurus nobilis essential oil and their anticholinesterase, antioxidant, and insecticidal potential were studied. Also, the oil volatile fraction was compared in semolina at the beginning and after storage periods. For that, a headspace solid-phase-microextraction analysis (HS-SPME) coupled with gas chromatography and mass spectrometry was undertaken. Significant quantitative and qualitative differences of the oil volatile fraction were detected according to storage periods and occupation space ratios. Additionally, anti-acetylcholinesterase activity of L. nobilis oil against T. castaneum adults was evaluated. Results revealed that insecticide activity varied according to storage duration and occupation space. Besides, the oil acts on acetylcholine hydrolysis by inhibiting the activity of acetylcholinesterase. These results highlighted that L. nobilis essential oil may be recommended as an eco-friendly alternative for preserving semolina during storage.

Elucidation of Analytical-Compositional Fingerprinting of Three Different Species of Chili Pepper by Using Headspace Solid-Phase Microextraction Coupled with Gas Chromatography-Mass Spectrometry Analysis, and Sensory Profile Evaluation.

The aim of the present study was to determine the volatile compounds of three different species of chili peppers, using solid-phase microextraction (SPME) methods in combination with gas chromatography-mass spectrometry (GC-MS). The detection of marker aroma compounds could be used as a parameter to differentiate between species of chili peppers for their detection and traceability in chili pepper food. The sensorial contribution was also investigated to identify the predominant notes in each species and to evaluate how they can influence the overall aroma. Three different pepper species belonging to the Capsicum genus were analyzed: Chinense, Annuum, and Baccatum. A total of 269 volatile compounds were identified in these species of chili peppers. The Capsicum annum species were characterized by a high number of acids and ketones, while the Capsicum chinense and Capsicum baccatum were characterized by esters and aldehydes, respectively. The volatile profile of extra virgin olive oils (EVOOs) flavored with chili peppers was also investigated, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) of the volatile profiles were demonstrated to be a powerful analytical strategy for building a model that highlights the potential of a volatile characterization approach for use in evaluating food traceability and authenticity.

GC-MS qualitative analysis of the volatile, semivolatile and volatilizable fractions of soil evidence for forensic application: A chemical fingerprinting.

This paper proposes a GC-MS analytical method that can be used in forensic investigations, for comparative or provenance studies of soils with the aim to reconnect the evidence to their origin. The volatile, semi-volatile and volatilizable compounds present in soil samples of different sources have been extracted and qualitatively analyzed by GC-MS. The different fractions were extracted by ultrasonic assisted extraction (UAE), and the volatilizable compounds were derivatized by BSTFA-TMCS as silylating agent. Sixty-five soil samples from different locations in northern Italy were collected, analyzed and a GC-MS "fingerprint database" has been created in order to easily access the data for the unknown soil sample provenance obtained with the same procedure and GC apparatus. With this purpose, the origin of blind samples, chosen randomly from those collected, was identified based on a qualitative comparison of the MS chromatographic profiles, which obviates the need for quantitative analyses.

Chemical variability of Rhododendron tomentosum (Ledum palustre) essential oils and their pro-apoptotic effect on lymphocytes and rheumatoid arthritis synoviocytes.

Rhododendron tomentosum (Ledum palustre) is an aromatic plant traditionally used for alleviating rheumatic complaints which makes it a potential candidate for a natural drug in rheumatoid arthritis (RA) treatment. However, the effects of plants' volatiles on apoptosis of synovial fibroblasts and infiltrating leucocytes of RA synovia, have not been reported. Volatile fraction of R. tomentosum is chemically variable and chemotypes of the plants need to be defined if the oil is to be used for therapeutic purposes. In the presented work, cluster analysis of literature data enabled to define 10 chemotypes of the plant. The volatile fractions of known composition were then tested for bioactivity using a RA-specific in vitro models. Essential oils of two wild types (γ-terpineol and palustrol/ledol type) and one in vitro chemotype (ledene oxide type) were obtained by hydrodistillation and their bioactivity was tested in two in vitro models: I - peripheral blood lymphocytes of healthy volunteers and II - synoviocytes and immune cells isolated from synovia of RA patients. The influence of oils on blood lymphocytes' proliferation and apoptosis rates of synovia-derived cells was determined by flow cytometry. Dose-dependent inhibitory effect of the serial dilutions of R. tomentosum oils on proliferation rates of blood lymphocytes was found. At 1:400 dilutions, all the tested oils increased the number of necrotic cells in synovial fibroblasts from RA synovia. Additionally, increased proportions of late apoptotic cells were observed in leucocyte populations subjected to oils at 1:400 dilution.

Evaluation of the volatile composition, toxicological and antioxidant potentials of the essential oils and teas of commercial Chilean boldo samples.

Chilean boldo (Peumus boldus Molina) is the boldo species most consumed around the world. Digestive and hepatobiliary disorders represent the main targets of its action. This work aims to characterize the volatile chemical composition, toxicological, and antioxidant potentials of the essential oils and teas of commercial samples of Chilean boldo packed on sachets [Group 1 (G1): five samples] or in plastic bags [Group 2 (G2): five samples]. Fifty-three compounds have been identified in the essential oils of commercial samples of Chilean boldo from Brazil, while only twelve compounds have been found in the volatile fraction of their infusions. Terpineol, 1,8-cineole, and p-cymene are the major compounds of essential oils. Terpineol is also the major compound of the volatile fraction of teas, followed by limonene dioxide. The presence in all samples of the chemical markers p-cymene, 1,8-cineole, ascaridole, and boldine suggests that they are genuine. The teas offer a better antioxidant capacity than essential oils, thereby indicating that antioxidant activity is concentrated in the non-volatile fraction of these herbs. All LD50 values estimated for the essential oils are below 200 ppm, thus indicating that the oils are highly cytotoxic. G1 and G2 appear to be very similar with respect to all the parameters analyzed. This similarity may indicate a single source for these products.

Antimicrobial activity of endophytic fungi from olive tree leaves.

In this study, the antimicrobial potential of three fungal endophytes from leaves of Olea europaea L. was evaluated and the host plant extract effect in the antimicrobial activity was examined. The volatile compounds produced by endophytes were identified by GC/MS and further correlated with the antimicrobial activity. In potato dextrose agar, both Penicillium commune and Penicillium canescens were the most effective inhibiting Gram-positive and -negative bacteria (up to 2.7-fold compared to 30 µg/mL chloramphenicol), whereas Alternaria alternata was most effective inhibiting yeasts (up to 8.0-fold compared to 25 µg/mL fluconazole). The presence of aqueous leaf extract in culture medium showed to induce or repress the antimicrobial activity, depending on the endophytic species. In the next step, various organic extracts from both A. alternata mycelium and cultured broth were prepared; being ethyl acetate extracts displayed the widest spectrum of anti-microorganisms at a minimum inhibitory concentration ≤0.095 mg/mL. The volatile composition of the fungi that displayed the highest (A. alternata) and the lowest (P. canescens) antimicrobial activity against yeasts revealed the presence of six volatiles, being the most abundant components (3-methyl-1-butanol and phenylethyl alcohol) ascribed with antimicrobial potentialities. Overall the results highlighted for the first time the antimicrobial potential of endophytic fungi from O. europaea and the possibility to be exploited for their antimicrobial agents.

Fractionated dynamic headspace sampling in the analysis of matrices of vegetable origin in the food field.

Recent technological advances in dynamic headspace sampling (D-HS) and the possibility to automate this sampling method have lead to a marked improvement in its the performance, a strong renewal of interest in it, and have extended its fields of application. The introduction of in-parallel and in-series automatic multi-sampling and of new trapping materials, plus the possibility to design an effective sampling process by correctly applying the breakthrough volume theory, have make profiling more representative, and have enhanced selectivity, and flexibility, also offering the possibility of fractionated enrichment in particular for high-volatility compounds. This study deals with fractionated D-HS ability to produce a sample representative of the volatile fraction of solid or liquid matrices. Experiments were carried out on a model equimolar (0.5mM) EtOH/water solution, comprising 16 compounds with different polarities and volatilities, structures ranging from C5 to C15 and vapor pressures from 4.15kPa (2,3-pentandione) to 0.004kPa (t-ß-caryophyllene), and on an Arabica roasted coffee powder. Three trapping materials were considered: Tenax TA™ (TX), Polydimethylsiloxane foam (PDMS), and a three-carbon cartridge Carbopack B/Carbopack C/Carbosieve S-III™ (CBS). The influence of several parameters on the design of successful fractionated D-HS sampling. Including the physical and chemical characteristics of analytes and matrix, trapping material, analyte breakthrough, purge gas volumes, and sampling temperature, were investigated. The results show that, by appropriately choosing sampling conditions, fractionated D-HS sampling, based on component volatility, can produce a fast and representative profile of the matrix volatile fraction, with total recoveries comparable to those obtained by full evaporation D-HS for liquid samples, and very high concentration factors for solid samples.

Phenolic and Volatile Composition of a Dry Spearmint (Mentha spicata L.) Extract.

The present paper reports a complete mass spectrometric characterization of both the phenolic and volatile fractions of a dried spearmint extract. Phenolic compounds were analysed by ultra-high performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MS(n)) and a total of 66 compounds were tentatively identified, being the widest phenolic characterisation of spearmint to date. The analysis suggests that the extract is composed of rosmarinic acid and its derivatives (230.5 ± 13.5 mg/g) with smaller amounts of salvianolic acids, caffeoylquinic acids, hydroxybenzoic acids, hydroxycinnamic acids, flavones, and flavanones. Head space solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) technique, that was applied to characterize the volatile fraction of spearmint, identified molecules belonging to different chemical classes, such as p-cymene, isopiperitone, and piperitone, dihydroedulan II, menthone, p-cymen-8-ol, and ß-linalool. This comprehensive phytochemical analysis can be useful to test the authenticity of this product rich in rosmarinic acid and other phenolics, and when assessing its biological properties. It may also be applied to other plant-derived food extracts and beverages containing a broad range of phytochemical compounds.

Conventional and enantioselective gas chromatography with microfabricated planar columns for analysis of real-world samples of plant volatile fraction.

Within a project exploring the application of lab-on-chip GC to in-field analysis of the plant volatile fraction, this study evaluated the performance of a set of planar columns (also known as microchannels, MEMS columns, or microfabricated columns) of different dimensions installed in a conventional GC unit. Circular double-spiral-shaped-channel planar columns with different square/rectangular sections up to 2m long were applied to the analysis of both essential oils and headspace samples of a group of medicinal and aromatic plants (chamomile, peppermint, sage, rosemary, lavender and bergamot) and of standard mixtures of related compounds; the results were compared to those obtained with reference narrow-bore columns (l:5m, dc:0.1mm, df:0.1 µm). The above essential oils and headspaces were first analyzed quali-and quantitatively with planar columns statically coated with conventional stationary phases (5%-phenyl-polymethylsiloxane and auto-bondable nitroterephthalic-acid-modified polyethylene glycol), and then submitted to chiral recognition of their diagnostic markers, by enantioselective GC with a planar columns coated with a cyclodextrin derivative (30% 6(I-VII)-O-TBDMS-3(I-VII)-O-ethyl-2(I-VII)-O-ethyl-ß-cyclodextrin in PS-086). Column characteristics and analysis conditions were first optimized to obtain suitable retention and efficiency for the samples investigated. The planar columns tested showed performances close to the reference conventional narrow-bore columns, with theoretical plate numbers per meter (N/m) ranging from 6100 to 7200 for those coated with the conventional stationary phases, and above 5600 for those with the chiral selector.

A comparison of volatile fractions obtained from Lonicera macranthoides via different extraction processes: ultrasound, microwave, Soxhlet extraction, hydrodistillation, and cold maceration.

BACKGROUND: Hydrodistillation has been traditionally used to extract volatile fraction in traditional Chinese medicine. However, with the development of Soxhlet extraction (SE), microwave (MW), ultrasound (US), and cold maceration (CM), hydrodistillation (HD) is being replaced to meet some practical requirements. In this study, we investigated the effect of the five methods on the volatile fraction extract of Lonicera macranthoides. METHODS: Volatile fraction from the flower buds of Lonicera macranthoides was obtained by using different extraction methods, HD, SE, MW, US, and CM. The compositions of volatile fraction were analyzed by gas chromatography-mass spectrometric and further compared among extraction methods. RESULTS: Extracts obtained by the five methods reveal the qualitative and quantitative diversity in their compositions, especially for the low-content compositions. According to the results, SE shows the great value in the research where the high molecular-mass compound is of primary interest, and MW offers a way for the isolation of specific compound like octadecadienoic acid and hexadecanoic acid. HD, US, and CM have the advantage over SE and MW for the integrity of the constituents, whereas the phenomenon of compound degradation seems not so serious in solvent extraction methods such as US or CM as HD. Additionally, US and CM show superiority over time or material saving and diversity of the constituent. CONCLUSION: HD is still the best choice for the pure volatile fraction without organic solvent pollution. However, when it comes to some specifically actual demands, it can be replaced by the four methods for the volatile fraction extraction process, especially for production of certain compound groups.

Study of the principal constituents of tropical angico (Anadenanthera sp.) honey from the atlantic forest.

Free proline was significantly (p<0.05) lower compared to that of other honeys from the atlantic forest, caatinga and cerrado biomes. Honeys from the atlantic forest and cerrado had a significantly (p<0.05) lower HMF than angico. Fructose and glucose in angico honeys were significantly (p<0.05) higher than those from caatinga. Mean values for turanose, nigerose, sucrose, isomaltose, maltotriose, panose and raffinose in angico were significantly (p<0.05) different from honeys from the atlantic forest and caatinga. Use of cluster analysis permitted the three kinds of honey to be grouped independently. Angico was closest to caatinga honey, but both were significantly (p<0.05) different from other atlantic forest honey. GC/SNIFFING showed that linalool oxide, 2-ethyl hexanol, phenylethanol, and phenylacetic acid may be important contributors to the flavour of angico honey.

Comparative analysis of anaerobically digested wastes flow properties.

The flow curve of anaerobically digested wastes from different origins was determined through rheological measurements. Regardless of their origin, samples can be divided into two families: simple non-Newtonian liquids well modelled by basic power law below 10%DC and viscoelastic liquids with a yield stress, well modelled by a Herschel-Bulkley model above. In all the cases, the rheological behaviour is driven by both the organic content and the volatile fraction (organic content/solid content), indicating that anaerobic digestion tends to smooth the rheological characteristics of organic wastes, whichever their origins.

A quasi non-destructive approach for amber geological provenance assessment based on head space solid-phase microextraction gas chromatography-mass spectrometry.

Head space (HS) solid-phase micro-extraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to analyze the volatile fraction of ambers of different geological origin. In particular, Romanian (romanite) and Baltic (succinite) amber samples were studied. Both types of amber have nearly similar bulk chemical compositions and could probably reflect only some differences of paleobiological and/or diagenetic origin. The present study shows that amber head space fingerprint, obtained by SPME/GC-MS, can provide a simple and quasi non-destructive method capable of romanite/succinite differentiation. Among the numerous compounds present in the head space, a number of few informative variables could be selected that were able to differentiate the ambers as demonstrated by Principal Component and Cluster Analysis.

Phytochemical and biological studies of Agave attenuata.

The present study was conducted to examine various biological activities of a methanol extract of Agave attenuata leaves. GC-MS analysis of the n-hexane fraction from the extract revealed the presence of 31 compounds, with mono-2-ethylhexyl phthalate (11.37%), 1,2-benzenedicarboxylic acid (6.33%), n-docosane (6.30%) and eicosane (6.02%) as the major components. The leaves contained appreciable levels of total phenolic contents (10.541-39.35 GAE, mg/100 g) and total flavonoid contents (43.35-304.8 CE, mg/100 g). The extract and some of its fractions showed moderate antimicrobial effects. Leaves extract and fractions also exhibited a good antioxidant potential when measured by DPPH radical scavenging activity and inhibition of lipid peroxidation assays. The hemolytic effect of the plant was found to be in a range of 1.01%-2.64%. From the present study it is concluded that this plant could be used as a source of natural antioxidants and functional food nutraceutical applications.

Metabolitos volátiles presentes en Protium heptaphyllum (Aubl.) March. colectado en Tame (Arauca - Colombia) / Volatil metabolites of Protium heptaphyllum (Aubl.) March. from Tame (Arauca-Colombia)

This paper reports the identification of volatile components of the leaves, flowers, resin of the stem, and bark of the branches of the tree Protium heptaphyllum (Aubl.) March. collected from East Plains, Orinoquia, Colombia. The main constituents identified by GC-MS in the volatile fraction of the leaves were guaiol (14,4 percent), alpha-copaene (8,6 percent), 1,10-di-epi-cubenol (8,1 percent), beta-cariophyllene (5,7 percent), and gamma-cadinene (5,4 percent). Germacrene D (13,9 percent), germacrene B (13,4 percent), bicyclogermacrene (11,8 percent), and limonene (8,3 percent) were determined in the flowers, while p-cymene (30,1 percent), alpha-pinene (22,1 percent), and limonene (14,4 percent) were identified in the resin; finally, germacrene D (27,7 percent), 1,10-di-epi-cubenol (7,9 percent), guaiol (7,4 percent), and gamma-cadinene (6,9 percent) were found in the bark. The analysis of the resin showed a high percent of monoterpenes (- 60 percent); while the leaves presented a high content of oxygenated sesquiterpenes (- 60 percent); flowers and bark showed a high composition of sesquiterpenes (40-50 percent).

En este trabajo se reporta la identificación de los componentes volátiles de hojas, flores, resina del tallo y corteza de las ramas del árbol Protium heptaphyllum (Aubl.) March. recolectado en los Llanos Orientales, Orinoquía, Colombia. Los constituyentes mayoritarios identificados por GC-MS en la fracción volátil de las hojas fueron guaiol (14,4 por ciento), alfa-copaeno (8,6 por ciento), 1,10-di-epi-cubenol (8,1 por ciento), trans-beta-cariofileno (5,7 por ciento) gamma -cadineno (5,4 por ciento). Germacreno D (13,9 por ciento), germacreno B (13,4 por ciento), biciclogermacreno (11,8 por ciento) y limoneno (8,3 por ciento) se determinaron en las flores, mientras que, p-cimeno (30,1 por ciento), alfa-pineno (22,1 por ciento) y limoneno (14,4 por ciento) se identificaron en la resina; finalmente, germacreno D (27,7 por ciento), 1,10-di-epi-cubenol (7,9 por ciento), guaiol (7,4 por ciento) gamma -cadineno (6,9 por ciento) se encontraron en la corteza. El análisis de la resina mostró un alto porcentaje de monoterpenos (- 60 por ciento); mientras que, las hojas presentaron una alta proporción de sesquiterpenos oxigenados (- 60 por ciento); las flores y la corteza mostraron una alta composición de sesquiterpenos (40-50 por ciento).

Role of lees in wine production: A review.

The sometimes contradictory role attributed by scientists to lees in wine production is discussed in this review. Studies dealing with the importance of lees in the natural removal of undesirable compounds from wine, the effect of lees-wine contact on the volatile fraction of wines, the key influence of lees on biogenic amine contents in wines, the interactions between lees and phenolic compounds, and the importance of mannoproteins and lipids released by lees have been critically reviewed. Finally, the present exploitation of lees is also outlined.