HS-SPME GC-MS Research Articles

Determination of Volatile Phenol in Cabernet Sauvignon Wines, Made from Smoke-affected Grapes, by using HS-SPME GC-MS

The increased incidence of vegetation fires near vineyards in the Western Cape, South Africa has led to growing concern over the appearance of smoke taint in the affected grapes. This study focused on the effect of smoke exposure on the volatile phenol (VP) composition of wines made from affected grapes over two vintages (2012 and 2013). Cabernet Sauvignon grapes were exposed, 10 days post-veraison, to a single, hour-long treatment with smoke derived from burning a mixture of vegetation (including fynbos) under controlled conditions in enclosures. Enclosures were sealed for 24 h after exposure, and then removed. Grapes were allowed to ripen and wines were then produced. Wines were analysed by headspace gas chromatography mass spectrometry (HS-SPME GC-MS) for selected volatiles. The results of the investigation show that the exposure of grapes to smoke during ripening leads to the accumulation of VPs that were detected in wines. The detected VPs were guaiacol, phenol and the cresols. Smoke exposure of grapes during ripening may have a negative impact on wine quality due to the accumulation of these compounds.

Serum levels of organochlorine pesticides in the general population of Thessaly, Greece, determined by HS-SPME GC–MS method

In this study, exposure levels of organochlorine pesticides (OCs) were determined in general population residing in Larissa, central Greece. Serum samples from 103 volunteers were analyzed by optimized headspace solid-phase microextraction gas chromatography–mass spectrometry, to detect and quantify OC levels. The most frequently detected analytes were p,p′–DDE (frequency 99%, median:1.25ng/ml) and Hexachlorobenzene (HCB) (frequency 69%, median: 0.13ng/ml). Statistical analysis revealed a significant relationship of p,p′–DDE and HCB levels with age.

Volatile compound composition and antioxidant activity of cooked ham slices packed in propolis-based active packaging

Abstract Aiming at studying the possibility of application of propolis as food preservative, active paper sheets obtained by either surface spreading (APP) or by incorporating propolis in paper mass at 0.4% (API) were used to pack slices of cooked ham. A 4 days consumer storage simulating trial, at 4 °C, was performed and cooked ham packed with APP, API and no-propolis (control) papers was analysed for volatile composition by HS-SPME GC–MS, antioxidant properties and samples were submitted to sensory analysis (triangle test). Slices packed in API paper showed antioxidant properties similar to control slices and the gradual migration of terpenoids from packaging into ham slices did not influence the sensory properties. In contrast, in slices packed in APP paper, both DPPH radical scavenging activity and reducing compounds increased with storage, and the changes in aldehydes, ketones, carboxylic acids and alcohols amounts and composition indicated lipid and non-lipid oxidations, which impacted on the sensory characteristics of cooked ham.

Determination and elimination of rotten grape aroma by filter layers with selective adsorbers

The most important mould associated substances like geosmine, 2-methylisoborneol, 1-octen-3-ol in wines of different grape varieties from Austria and also from other foreign countries were analysed by a HS-SPME GC-MS method. These substances were also determined in healthy and rotten grapes. All together, 391 wine-samples and 69 grape samples were examined.The study of rotten and healthy grapes found out a level of geosmin up to 20 ng/L, 1-octene-3-ol concentration up to 700 μg/L and 2-heptanol level up to 9 μg/L. The geosmin concentration of the 391 analyzed wines extended from 1-44 ng/L. The detected level of 1-octene-3-ol ranged from 1 μg/L to 23 μg/L. The determined concentration of 2-heptanol ranged from 1 μg/L up to 38 μg/L. The test with the filter layer Fibrafix TX-R was performed with nine layers a 20 × 20 cm (3.6 m2 ) and a quantity of 625 liters wine. The filtering achieved a significant reduction of the start concentration of 60 ng/L geosmin down to only 6 ng/L (average value of 600l).

Controlled accelerated oxidation of oleic acid using a DBD plasma: Determination of volatile oxidation compounds

Lipid oxidation is one of the main causes of food deterioration, resulting in the loss of nutritional properties and the formation of unwanted aroma properties. Both for scientific and industrial purposes there is a need for accelerated lipid oxidation tests in food research. The conventional thermally-based accelerated lipid oxidation protocols are known to insufficiently correlate to the realistic oxidation mechanisms. Recent studies have investigated the application of an innovative non-thermal plasma technique as a promising alternative approach. The produced reactive oxygen species in non-thermal plasma enabled to accelerate the lipid oxidation process, with a more accurate prediction of antioxidative properties, thus leading to a higher correlation with the product oxidized at room temperature. In order to obtain more profound insights in the plasma-induced chemistry, a profound parameter study was performed by studying the impact of applied voltage, plasma gas composition, distance between nozzle and sample surface, ambient gas composition and treatment time. Using analytical tools (HS–SPME–GC–MS) on one hand, combined with statistical interpretations (PCA/SIMCA/HCA) on the other hand, a selection of the most promising parameter settings was done. For this parameter study, pure oleic acid was used as a model matrix. In the sample oxidized at 25°C, typical oxidation products have been found, such as heptanal, octanal, nonanal, (E)-nonenal, etc.…Comparing the different plasma types (argon, argon/O2 and argon/H2O) in different surrounding gas compositions (air, argon) showed most promising results for Ar/O2 in Ar atmosphere. A correlation of up to 82% was found between the sample oxidized at 25°C and the plasma treated sample.

Screening of the chemical composition and bioactivity of Waldheimia glabra (Decne.) Regel essential oil.

This research aimed at improving knowledge as to the chemical composition and the antibacterial and anti-cancer activities of the essential oil of Waldheimia glabra, a wild plant from the Himalayan Mountains. The results obtained by GC-MS showed that spathulenol, 9-tetradecenol, thujopsene, α-thujone, santolina alcohol and terpinen-4-ol were the main constituents of Waldheimia glabra essential oil. These results were confirmed by HS-SPME GC-MS analysis that also reported high amounts of artemisia alcohol and camphor. Disc diffusion assay suggested a mild antibacterial activity against both Escherichia coli and Staphylococcus aureus. Finally, a dose-response correlation was observed between Waldhemia glabra essential oil concentration and viability of human breast adenocarcinoma cells MDA-MB-231 and MCF-7. Together with the GC-MS method, HS-SPME GC-MS proved to be a reliable technique to characterise the chemical composition of essential oil obtained from aromatic plants. Further studies will focus on W. glabra phytochemicals and their biological activity, in order to support traditional uses of the plant. © 2015 Society of Chemical Industry.

Brewing and volatiles analysis of three tea beers indicate a potential interaction between tea components and lager yeast

Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC–MS analysis. The PCA of GC–MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC–MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested.

Volatile and odoriferous compounds changes during frozen concentrated orange juice processing

Sixty-two volatile compounds were identified in orange juice from frozen concentrated orange juice (FCOJ) processing steps using HSSPME–GC–MS in combination with GC–OSME. Twenty-four compounds were perceived by OSME in the juice from the extraction step, twenty-five from the finishing step, nineteen from the 1st stage of evaporator step, nine from the concentration step and fourteen from the blending step. Ethyl butanoate, d-limonene, nonanal, ethyl octanoate and decanal showed major odoriferous importance for the juice from the extraction step. They were also considered to be of major odoriferous importance in the finishing step, apart from nonanal and ethyl octanoate. d-Limonene showed the highest odoriferous intensity in all the steps and it was the only major compound in the 1st stage of evaporator, concentration and blending steps.The majority of compounds showed a decrease in odour intensity during the processing. Principal component analysis showed that syrup, fruity, green, lavender, citrus and green leaf descriptors were reduced during the processing, from the extraction and finishing steps up to the 1st stage of evaporator step, while stink bug increased. Gas and green leaf descriptors were more important to the aroma of the juice from the 1st stage of evaporator, concentration and blending steps, and eucalyptus and plastic to the juice from the extraction and finishing steps. Ten volatile compounds were quantified by HS-SPME–GC–MS. Ethyl butanoate concentration was higher in the finishing step, being strongly reduced in the 1st stage of evaporator step, and β-pinene, myrcene and longifolene were higher in the extraction step. 1-Octanol, linalool, α-terpineol, β-citronellol, perillaldehyde and decanal were higher in the finishing step. All of them showed a decrease in concentration from the extraction and finishing step up to the end of the FCOJ processing, affecting the final product aroma quality.

Chemical and sensory profiles of rosé wines from Australia

The appeal of rosé wine is attributable to its sensory profiles and underlying chemical composition, which are determined by viticultural and oenological inputs. This study provided the first insight into the sensory attributes and volatile profiles of Australian rosé wines. An HS-SPME–GC–MS method and a recently developed HPLC–MS/MS method were used to quantify 51 volatile compounds, including 4 potent sulfur compounds, in 26 commercial rosé wines. Descriptive analysis on all wines was undertaken and the sensory results were correlated with quantitative chemical data to explore relationships between wine composition and sensory profiles. Based on odour activity values, esters were prominent aroma volatiles, and β-damascenone, 3-methylbutyl acetate, ethyl hexanoate and 3-MHA were deemed to be important, in accord with other studies. Wines were described with terms ranging from developed, spicy and savoury to fresh green, citrus, tropical fruit, floral and confectionery.

Effect of hot air drying on volatile compounds of Flammulina velutipes detected by HS-SPME–GC–MS and electronic nose

Volatile compounds are important factors that affect the flavor quality of Flammulina velutipes, but the changes occurring during hot air drying is still unclear. To clarify the dynamic changes of flavor components during hot air drying, comprehensive flavor characterization and volatile compounds of F. velutipes were evaluated using electronic nose technology and headspace solid phase micro-extraction combined with gas chromatography–mass spectrometry (HS-SPME–GC–MS), respectively. Results showed that volatile components in F. velutipes significantly changed during hot air drying according to the principal component analysis and radar fingerprint chart of electronic nose. Volatile compounds of fresh F. velutipes consisted mainly of ketones, aldehydes and alcohols, and 3-octanone was the dominant compound. Drying process could significantly decrease the relative content of ketones and promoted the generation of alcohols, acids, and esters, which became the main volatile compounds of dried F. velutipes. These may provide a theoretical basis for the formation mechanism of flavor substances in dried F. velutipes.

Simulation and flavor compound analysis of dealcoholized beer via one-step vacuum distillation

The coupled operation of vacuum distillation process to produce alcohol free beer at laboratory scale and Aspen HYSYS simulation software was studied to define the chemical changes during the dealcoholization process in the aroma profiles of 2 different lager beers.At the lab-scale process, 2 different parameters were chosen to dealcoholize beer samples, 102mbar at 50°C and 200mbar at 67°C. Samples taken at different steps of the process were analyzed by HS-SPME–GC–MS focusing on the concentration of 7 flavor compounds, 5 alcohols and 2 esters. For simulation process, the EoS parameters of the Wilson-2 property package were adjusted to the experimental data and one more pressure was tested (60mbar).Simulation methods represent a viable alternative to predict results of the volatile compound composition of a final dealcoholized beer.

Optimization of Biochemical Screening Methods for Volatile and Unstable Sesquiterpenoids Using HS-SPME-GC-MS

HS-SPME-GC-MS has been suggested as a fast and robust analytical platform for the product characterization of sesquiterpene synthases. The choice of fiber and injection temperature can have a significant effect on the observed product profile, due to the chemical rearrangements that can occur on the fiber material. Here we present a systematic study on the effects of fiber choice and injection port temperature on the observed sesquiterpenoid profile of four sesquiterpene synthases expressed in Nicotiana benthamiana. We found that the absorbent material PDMS was much less likely to support acid-induced rearrangement of sesquiterpenoids when compared to the adsorbent materials PDMS/DVB, PDMS/CAR, and PDMS/CAR/DVB. Furthermore, utilizing an injection port temperature at 160 °C almost eliminated the inherent thermal instability of germacrene sesquiterpenoids. Thus, for fast screening of sesquiterpene synthases, the results suggest that PDMS fibers and an injection temperature of 160 °C provide a fast and reproducible HS-SPME GC-MS method when using H2 as carrier gas.

Carotenoids and Norisoprenoids as Carotenoid Degradation Products in Pandan Leaves (Pandanus amaryllifolius Roxb.)

Leaves from Pandanus amaryllifolius Roxb., known as pandan leaves, are used as natural colorants, natural flavor, and herbal medicine in Indonesia. These leaves are sources of natural colorants, which are mostly of carotenoid origin. In addition, carotenoids can act as precursors of several aroma impact compounds such as norisoprenoids. The research objective of this study was to determine carotenoids by reversed phase high performance liquid chromatography photo diode array and to determine norisoprenoids by Head Space Solid Phase Micro Extraction Gas Chromatography Mass Spectrophotometry (HS-SPME GC-MS) with the aim to promote pandan leaves as potential natural flavor and natural colorants. β-carotene and lutein were found as major carotenoids in pandan leaves. Three different norisoprenoids (α-ionone, β-ionone, and β-cyclocitral) were identified in pandan leaves along with their carotenoid precursors (α-carotene and β-carotene).

Changes in the hop-derived volatile profile upon lab scale boiling

Hop terpenes might be oxidized during kettle boiling into more water soluble compounds that could contribute to ‘hoppy’ aroma of kettle hopped lager beers. Our current research proves that the boiling process induces significant changes in the hop oil volatile profile. The discrimination between volatile profiles of unboiled and boiled hop essential oil was evaluated via principal component and cluster analysis (PCA and CA). HS–SPME–GC–MS analysis revealed quantitative changes (e.g. increases in the levels of oxygenated α-humulene and β-caryophyllene derivatives) as well as qualitative changes (i.e. detection of compounds, not found in unboiled hop essential oil) in the hop oil volatile profile upon boiling. Many of these compounds were previously found in lager beer and may therefore contribute to beer flavor. Interestingly, the analytical difference between unboiled and boiled hop essential oil proved to be more pronounced as the initial hop essential oil concentration used for boiling was increased. In addition, lager beers spiked with boiled hop oil were described as ‘hoppy/spicy’ during sensory evaluations. Therefore, the newly formed products and hop oil constituents that are characterized by an increased recovery after boiling, are candidate compounds for ‘hoppy’ aroma in real brewing practice.

Herbs and spices: Characterization and quantitation of biologically-active markers for routine quality control by multiple headspace solid-phase microextraction combined with separative or non-separative analysis

Herbs and spices are used worldwide as food flavoring, thus determination of their identity, origin, and quality is mandatory for safe human consumption. An analysis strategy based on separative (HS-SPME–GC–MS) and non-separative (HS-SPME–MS) approaches is proposed for the volatile fraction of herbs and spices, for quality control and to quantify the aromatic markers with a single analysis directly on the plant material as such. Eight-to-ten lots of each of the following herbs/spices were considered: cloves (Syzygium aromaticum (L.) Merr. & Perry), American peppertree (Schinus molle L.), black pepper and white pepper (Piper nigrum L.), rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.) and thyme (Thymus vulgaris L.). Homogeneity, origin, and chemotypes of the investigated lots of each herb/spice were defined by fingerprinting, through statistical elaboration with principal component analysis (PCA). Characterizing aromatic markers were directly quantified on the solid matrix through multiple headspace extraction-HS-SPME (MHS-SPME). Reliable results were obtained with both separative and non-separative methods (where the latter were applicable); the two were in full agreement, RSD% ranging from 1.8 to 7.7% for eugenol in cloves, 2.2–18.4% for carvacrol+thymol in thyme, and 3.1–16.8% for thujones in sage.

봄철 소나무숲의 NVOC 농도와 숲환경과의 상관관계

This study aimed at a scientific examination of the relationship between NVOCs concentration and the physical environment of red pine forest in spring season. Atmospheric NVOC samples in red pine forest was collected through five trials conducted from March to May 2013, using Tanax-Ta-charged disposable tubes and mini-pumps. At each trial, measurements were taken at three different points in daytime (sunrise, southing and sunset). For maximum accuracy, two tubes were used for each measurement at the same location, and the mean value was used for analysis. Compound analysis on the NVOC samples was done using the HS-SPME method and GC-MS. Analysis of the relationship between NVOC and the physical forest environment found higher concentrations of most substances, including α-pinene and β-pinene, with higher temperature, dew point, and lower concentrations with higher wind velocity. The findings of this study offer scientific evidence which can inform the creation of 'healing forests' and 'recreational forests' as well as forest environment in general, helping to promote public health and recreational activities.

High-quality Italian rice cultivars: Chemical indices of ageing and aroma quality

The volatile fractions of six Italian high-quality rice cultivars were investigated by HS-SPME–GC–MS to define fingerprinting and identify chemical markers and/or indices of ageing and aroma quality. In particular, four non-aromatic (Carnaroli, Carnise, Cerere and Antares) and two aromatic (Apollo and Venere) rices, harvested in 2010 and 2011, were monitored over 12months.Twenty-five aroma components were considered and, despite considerable inter-annual variability, some of them showed similar trends over time, including 2-(E)-octenal as a marker of ageing for all cultivars, and heptanal, octanal and 2-ethyl hexanol as cultivar-specific indicators. The area ratios 2-acetyl-1-pyrroline/1-octen-3-ol, for Venere, and 3-methyl-1-butanol/2-methyl-1-butanol, for Apollo, were also found to act as ageing indices.Additional information on release of key-aroma compounds was also obtained from quantitation and its dependence on grain shape and chemical composition. Heptanal/1-octen-3-ol and heptanal/octanal ratios were also defined as characterising the aroma quality indices of the six Italian rice cultivars investigated.

Bacteria detection based on the evolution of enzyme-generated volatile organic compounds: Determination of Listeria monocytogenes in milk samples

The rapid detection of Listeria monocytogenes contamination in food is essential to prevent food-borne illness in humans. The aim of this study was to differentiate non-contaminated milk from milk contaminated with L. monocytogenes using enzyme substrates coupled with the analysis of volatile organic compounds (VOCs). The method is based on the activity of β-glucosidase and hippuricase enzymes and the detection of a specific VOC i.e. 2-nitrophenol and 3-fluoroaniline, respectively. VOCs were extracted, separated and detected by headspace-solid phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME GC–MS). This approach required the inclusion of the selective agent's cycloheximide, nalidixic acid and acriflavine HCl in the growth medium to inhibit interfering bacteria. The VOCs were liberated by L. monocytogenes provided that samples contained at least 1–1.5×102CFUml−1 of milk prior to overnight incubation. This approach shows potential for future development as a rapid method for the detection of L. monocytogenes contaminated milk.

Method development by GC–ECD and HS-SPME–GC–MS for beer volatile analysis

Two methods for the extraction, identification and quantification of the highest occurrence and lowest perception threshold off-flavours in fifteen different samples of Brazilian Pilsner beers were developed. For this purpose, headspace solid phase microextraction in combination with a gas chromatography coupled to a mass spectrometric detection (HS-SPME–GC–MS) as well as headspace extraction in combination with a gas chromatography coupled to electron capture detection (HS–GC–ECD) were evaluated. The first and the second methods were used for esters and vicinal diketones analysis, respectively. All data were comprehended below the taster‘s threshold detection limit: ethyl acetate 39.48ngmL−1 (RSD mean value 4.2%), isoamyl acetate 3.88ngmL−1 (RSD mean value 3.4%), ethyl hexanoate 0.61ngmL−1 (RSD mean value 3.1%) and 2,3-butanedione 0.10ngmL−1 (RSD mean value 2.9%). The validated method demonstrated to be useful for the analysis of highest incidence beer off-flavours.

Esters in Wines: New Insight through the Establishment of a Database of French Wines

This work aimed to establish a database of wine esters from French wines to update the knowledge of wine aroma composition. Thirty odorant esters were quantified by HS–SPME–GC-MS in 183 commercial French wines from 1 to 29 years old and included red, dry white, sweet white, and rose wines and red wines from carbonic maceration (Beaujolais nouveau; BN). Higher concentrations of ethyl esters of fatty acids (EEFAs) were found in wines made at low temperature (white and rose). However, the relative composition of EEFAs was similar in all types of wines and mainly depended on the length of the carbon chain. Higher alcohol acetate (HAA) levels were favored in wines made under strict anaerobiosis (BN, white), but the relative composition of HAAs depended on the type of wine. Such variability in the relative compositions of HAAs among wines might originate from differences in lipids, oxygen, and nitrogen status of fermented media. Conversely, concentrations of ethyl esters of branched acids (EEBAs) were higher in wines made with grape skin contact (BN, red). The relative concentrations of EEBAs were similar regardless of the type of wine, with ethyl isobutyrate the most abundant. We hypothesized that this specific EEBAs profile in wines might originate from the redox balance regulation of yeast metabolism. Moreover, concentrations of EEBA increased with wine age at similar rates in white and red wines. On the other hand, chemical hydrolysis during wine aging was observed only in the analytical data for higher alcohol acetates in white wines and for ethyl decanoate and dodecanoate in red and white wines. The results help in understanding the aromatic contribution of esters in aged wine.