Composition Of Headspace Volatiles Research Articles

Studies on Sensory and Phytochemical Characteristics of Poppy (Papaver somniferum L.) Varieties for Their Oil Utilisation.

Poppy is a significant pharmaceutical crop, but the seeds and the cold-pressed oil have a big potential as healthy foods. Breeding has mainly focused on agronomical characteristics and alkaloid content. Here, we compared the sensory values, fatty acid and headspace volatile composition of poppy oils and flours produced from different varieties. Two industrial and four culinary varieties were cultivated in our field in 2021-2022. The sensory test differentiated well among varieties. Typical poppy odour and flavour were stronger both in the oils and the flours of the blue-seed varieties compared to the white-seed ones. For most varieties, the harvest year caused no relevant differences. Linoleic, oleic, and palmitic acids were the main components both in oils and flours. Larger differences were detected in the volatiles (e.g., 2 and 3 methyl-butanal and 3 methyl-butanol γ-n-caprolactone, pentofuran), depending on genotype and year. A higher ratio of saturated fatty acids negatively influenced the flavour and odour characteristics. In the headspace volatiles, these features correlated negatively with 2-pentylfuran and hexanal. The oil content of poppy flour has a positive effect on colour, appearance, tactility and poppy flavour. Our results support a goal-oriented use of poppy genotypes for high-quality dietary products.

Glandular trichomes of Coleus amboinicus Lour. and the effect of developmental stage on leaf headspace volatile composition

Coleus amboinicus Lour. is a perennial shrub frequently used in folk medicine for the treatment of cough, sore throat and other respiratory disorders. Although being one of the best chemically documented Lamiaceae species, little is known about the glandular trichomes that secrete essential oils in this species and the effects of leaf development on the volatile composition. We characterized herein the different types of glandular trichomes of C. amboinicus and, using headspace solid phase microextraction coupled to gas chromatography (HS-SPME-GC–MS), we evaluated the chemical composition of leaves in different stages of development. Two main categories of glandular trichomes were observed: short-stalked and long-stalked capitate trichomes, two types of each were described whilst no peltate trichome was observed. The chromatographic analysis showed that carvacrol was the main component of the volatile profile, followed by o-cymene, γ-terpinene, (E)-caryophyllene and α-trans-bergamotene. The proportion of mono- and sesquiterpenes changed as the leaves expanded, every volatile component varied significantly (p < 0.05) such as an increase in carvacrol area percentage and decrease in (E)-caryophyllene and γ-terpinene, suggesting that expanding leaves are chemically distinct to the fully expanded ones. These results provide new insights about C. amboinicus morphoanatomy and phytochemistry, further research is required to establish the effects of leaf developmental stage on volatile composition and glandular trichome distribution in other Lamiaceae species.

Impact of Watermelon bud necrosis virus (WBNV) infected plants on the volatile emission pattern in cowpea plants

Pathogens, including tospoviruses, are known to manipulate the behaviour of vectors after virus acquisition by plants to enhance virus transmission. Furthermore, as recently proven in the maize chlorotic mottle virus pathosystem, the vector's choice for virus-infected plants can change to a preference for noninfected plants after virus uptake by the vector. A similar trend was observed in the cowpea - Watermelon Bud Necrosis Virus (WBNV) - Thrips palmi (Karny) pathosystem. Similarly, in the no-choice bioassay, viruliferous T.palmi (carrying WBNV) settled preferentially more on healthy cowpea plants (56%) compared to virus-infected plants (47.3%), whereas non-viruliferous T.palmi settled preferentially more on WBNV infected (58.67%) cowpea plants compared to healthy plants (44%). The changes in preference of thrips towards host plants before and after virus acquisition may be due to the change of volatile cues. This study looked at the headspace volatile composition of healthy and WBNV-infected cowpea plants that attract thrips. Furthermore, the volatile analysis revealed that 1, 2-Propanediamine (0.62%) and Tuaminoheptane (0.55%) from healthy cowpea plants, as well as Tetradecane (0.35%) from WBNV-infected cowpea plants, both have a higher area percent than other volatiles. The amine (53%) and hydrocarbon (69%) groups of volatile organic compounds make up the majority of host volatiles found in healthy and virus-infected plants. The increased contact rates of viruliferous and non-viruliferous T.palmi towards healthy and WBNV-infected host plants could enhance virus transmission if thrips feed on them and acquire the pathogen prior to dispersal and the recorded host volatiles might be useful in vector management in future.

Olfactory evaluation and untargeted profiling of floral volatiles of fragrant rose cultivars Pusa mahak and its seed parent Century two by HS-SPME-GC × GC-tofms

Pusa Mahak is a recurrent flowering and floriferous rose cultivar bearing attractive dark pink coloured flowers with strong outstanding fragrance. Pusa Mahak, a hybrid tea rose, is ideal for garden display and floral arrangements. It was developed by selection from the open-pollinated seedlings of cv. Century Two, a bold and pink coloured blooming rose used for garden display purpose. This study was undertaken to evaluate intensity and likeability of fragrance of the two cultivars based on olfactory evaluation by an untrained panel and to profile the floral volatiles using headspace solid phase microextraction - 2D gas chromatography time of flight mass spectrometry. The fragrance profiles of cvs. Pusa Mahak and Century Two were found to be distinct in the study. Sensory evaluation indicated that cv. Pusa Mahak had stronger fragrance and greater likeability with sweet woody and mild spicy nuances in comparison to the damask floral and green herb like nuances of Century Two. Biochemical evaluation detected 82 compounds (55% terpenoids) in cv. Pusa Mahak and 66 compounds (37% phenylpropanoids/benzenoids) in Century Two. Major components (≥5%) identified in cv. Pusa Mahak, were β-pinene (20%), β-citronellol (14%), 2- phenyl ethyl acetate (9.5%), 2-phenyl ethanol (8.3%), 3, 5-Dimethoxytoluene (7.23%), geranial (7.23%) and α-myrcene (7%). Major constituents of headspace volatile of Century Two were 3, 5-dimethoxytoluene (67%), 2-phenyl ethanol (19%) and theaspirane (4.5%). Difference in fragrance quality and intensity was attributed to the variation in the composition of headspace volatiles and different aroma impressions of specific compounds.

Chemical Composition and Antibacterial Activity of the Bulgarian Endemic Species Achillea thracica from its Natural Habitat, and in vitro Propagated and ex vitro Established Plants

The present study reports the chemical composition of headspace volatiles (HS) and acetone extracts of the endemic Bulgarian species Achillea thracica Velen. from its natural habitat (N), in vitro propagated (IN) and ex vitro established (EX) plants. Additionally, acetone extracts were tested by a disk diffusion method for antibacterial activity. Irregular monoterpenes were the most abundant HS volatile constituents, while 0,0-dimethyl quercetin was the most abundant flavonoid in the acetone extracts. The secondary metabolites of A. thracica grown in its natural habitat (N), propagated in vitro (IN) and ex vitro established (EX) showed that the qualitative composition is mutually similar, but there are differences in the quantitative composition. Considering antibacterial activity, IN and EX samples showed moderate activity against Pseudomonas aeruginosa and Escherichia coli.

Volatile metabolic diversity of Klebsiella pneumoniae in nutrient-replete conditions.

Microorganisms catabolize carbon-containing compounds in their environment during growth, releasing a subset of metabolic byproducts as volatile compounds. However, the relationship between growth media and the production of volatile compounds has been largely unexplored to-date. To assess the core and media-specific components of the Klebsiella pneumoniae volatile metabolome via growth in four in vitro culture media. Headspace volatiles produced by cultures of K. pneumoniae after growth to stationary phase in four rich media (brain heart infusion broth, lysogeny broth, Mueller-Hinton broth, and tryptic soy broth) were analyzed using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS). Differences in the composition of headspace volatiles as a function of growth media was assessed using hierarchical clustering analysis (HCA) and principal component analysis (PCA). A total of 365 volatile compounds were associated with the growth of K. pneumoniae across all media, of which 36 (10 %) were common to all growth media, and 148 (41 %) were specific to a single medium. In addition, utilizing all K. pneumoniae-associated volatile compounds, strains clustered as a function of growth media, demonstrating the importance of media in determining the metabolic profile of this organism. K. pneumoniae produces a core suite of volatile compounds across all growth media studied, although the volatile metabolic signature of this organism is fundamentally media-dependent.

Real time aroma reconstruction using odour primaries

A methodology was developed to derive odour primaries based on the actual composition of a set of target aromas to be reconstructed. These odour primaries are mixtures of pure aroma components. The methodology was applied to reconstruct the aroma of five Citrus species (lime, lemon, orange, grapefruit and mandarin) in real time using an aroma synthesiser with four nozzles dispersing odour primaries blended using 12 pure odorants that was built for this purpose. The composition of the actual and reconstructed Citrus aromas was analysed using gas chromatography–mass spectrometry (GC–MS). Citrus species could be discriminated based on their headspace volatile composition. The aroma synthesiser was shown to be able to blend aromas in real time. The theoretical and actual correct classification accuracies of the reconstructed aromas were 80% and 73%, respectively. The required number of primaries and also pure odourants to construct these primaries was higher than anticipated, suggesting that further research with respect to the dimensionality of aroma spaces is required.

The Global Volatile Signature of Veal via Solid-phase Microextraction and Gas Chromatography-mass Spectrometry.

The volatile composition of veal has yet to be reported and is one of the important factors determining meat character and quality. To identify the most important aroma compounds in veal from Holstein bull calves fed one of three diets, samples were subjected to solid-phase microextraction (SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-MS). Most of the important odorants were aldehydes and alcohols. For group A (veal calves fed entirely on milk for 90 d before slaughter), the most abundant compound class was the aldehydes (52.231%), while that was alcohols (26.260%) in group C (veal calves fed starter diet for at least 60 d before slaughter). In both classes the absolute percentages of the volatile compounds in veal were different indicating that the veal diet significantly (p<0.05) affected headspace volatile composition in veal as determined by principal component analysis (PCA). Twenty three volatile compounds showed significance by using a partial least-squared discriminate analysis (PLS-DA) (VIP>1). The establishment of the global volatile signature of veal may be a useful tool to define the beef diet that improves the organoleptic characteristics of the meat and consequently impacts both its taste and economic value.

Headspace volatile composition and oxidative storage stability of pressed marama bean (Tylosema esculentum) oil

Marama bean (Tylosema esculentum) is an underutilised legume indigenous to the Kalahari Desert region of southern Africa. The bean has high lipid content and hence is a potential source for production of edible oil. The headspace volatile composition of freshly pressed marama bean oil was explored and the oil was further studied during 7months of storage under different light and temperature conditions. The oxidative stability of the oil was examined by measuring peroxide value, vitamin E content and FT-IR spectra. Additionally, the headspace volatile composition of the oil was investigated during storage by use of dynamic headspace GC–MS. The results showed that marama oil is highly stable and has good natural antioxidant properties; enzymatic lipid oxidation does not take place in marama oil. Light has a greater effect on the lipid oxidation than has temperature, and hence marama oil should preferably be stored in darkness and rather at 25°C than 35°C. Under these conditions, the marama oil has a shelf life of at least 7months.

Sensory analysis of individual strawberry fruit and comparison with instrumental analysis

A new method for measuring fruit-to-fruit variation in strawberries by both sensory and instrumental analyses was developed and applied. The method allowed quantification of fruit-to-fruit variation in sensory attributes and instrumental properties. Two commercial colour gradings (3/4 and 4/4 red) of strawberry commonly used at harvest were investigated. In the main experiment, one-half of a strawberry fruit was assessed for sensory characteristics by a trained panel while the other half was concurrently individually evaluated for soluble solids content (SSC), pH, titratable acidity (TA), firmness, and headspace volatile composition. The sensory evaluation was additionally performed on a bulk purée of fruit from the same harvest and the results were compared with the sensory evaluation on individual fruit. This study suggests that fruit-to-fruit variation is substantial in SSC, TA and fruit firmness and sensory characteristics such as ‘fruity odour’, ‘sweet flavour’ and ‘flavour aftertaste’, whereas other characteristics show similar variation among panellists for both individual fruit and bulk purée analyses. Further, individual fruit flavour characteristics were correlated with fruit biophysical properties. The results obtained are specific to this study and further investigations need to be undertaken to validate this method as a model for fruit-to-fruit variation in small fruit.

Distinction and identification of lignins based on their volatile headspace composition

A new non-degradation methodology is proposed for the distinction and identification of lignins, according to their biological origin and/or isolation methodology, using an electronic aroma sensing system. The system, once trained with representative lignins, could quickly and objectively be used as a simple tool by providing, in real-time, information about the lignin origin, based on their headspace volatile composition. In order to understand which kind of volatile compounds are responsible to the different sensors response present in the headspace, lignins were also analysed by headspace-solid phase microextraction followed by gas chromatography–mass spectrometry detection mode (HS-SPME/GC–MS). Among volatile compounds in the lignin headspace were identified a series of aromatic compounds, C 14 to C 18 fatty acids and an isoprenoid, squalene. It was proposed that a small proportion of volatile degradation products emerged during the lignin partial degradation during the technogenic process (i.e. delignification) play a key role regarding the aroma sensor response.

Changes of hen eggs and their components caused by non-thermal pasteurizing treatments II. Some non-microbiological effects of gamma irradiation or hydrostatic pressure processing on liquid egg white and egg yolk

Experiments were performed to study changes caused by irradiation or high hydrostatic pressure pasteurization of liquid egg white by differential scanning calorimetry, spectrofluorimetry, electronic nose measurements and NIR-spectrometry. The non-thermal pasteurization treatments were also assessed in relation to loss of carotenoid content, and lipid- and cholesterol oxidation of liquid egg yolk. Unlike radiation pasteurization, high pressure processing caused protein denaturation in egg white, which manifested in changes of its DSC-thermogram and intrinsic tryptophan fluorescence. Electronic nose testing showed changes of the head-space volatile composition of egg albumen, particularly as a function of radiation treatment. Both treatments caused changes in the NIR-spectrometric “fingerprint” of the liquid egg white. Various chemometric analyses of the results of the latter instrumental methods, particularly statistical techniques developed by the group of one of the co-authors of this article, demonstrat...

Volatile compounds of original African black and white shea butter from Tchad and Cameroon

Shea butter is used as an edible vegetable fat in many African countries. It can be utilized as a substitute or complete replacement for cocoa butter in various applications and plays an important role in traditional African medicinal practice. Although detection of volatile compounds by solid-phase micro-extraction gas-chromatography mass-spectroscopy (SPME-GC-MS) is a very reliable and reproducible technique, which can be used as an important part of authenticity checking, production monitoring and contamination detection, no published data about volatile compounds of shea butter are available so far. In this investigation, the characteristic volatiles in the headspace of original African shea butter samples were identified by using SPME-capillary-GC coupled to a mass selective detector. Almost 100 different volatile components were identified, e.g. fatty acids, saturated and unsaturated aldehydes and ketones, terpenes, and typical Maillard reaction products such as methylfuranes and pyrazines. Furthermore, the samples have been olfactorily evaluated by a panel of professional flavorists and trained analytical chemists. It can be stated that variations in processing conditions of shea butter result in considerable differences in the composition of headspace volatiles, detected by SPME-GC-MS and human olfaction.

Composition of the concrete, absolute, headspace and essential oil of the flowers of Michelia champaca Linn.

AbstractExtraction of fresh flowers of Michelia champaca L. with pentane afforded the concrete in 1.5 ± 0.05% yield. Precipitating the waxes from the concrete with methanol gave absolute (80%). Distillation of the flowers in a Clevenger‐type apparatus furnished the essential oil in 0.03% yield. The chemical composition of the concrete, absolute and essential oil were determined by GC and GC–MS and compared. The headspace volatile composition of flowers while still attached to the branch of the tree and after plucking was determined by solid phase micro‐extraction on PDMS fibre and these results are also presented. Interestingly, the concrete and absolute contained a much smaller amount of sesquiterpene hydrocarbons, which constitute more than 60% in the headspace. Most of the esters present in the concrete and absolute are not present in the essential oil, which on the other hand contains several monoterpene hydrocarbons not isolated from the pentane extract. The sesquiterpenes detected in the headspace are present in the essential oil. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Sensory Characteristics and Related Volatile Flavor Compound Profiles of Different Types of Whey

To characterize the flavor of liquid whey, 11 samples of whey representing a wide range of types were sourced from cheese and casein-making procedures, either industrial or from pilot-plant facilities. Whey samples were assessed for flavor by descriptive sensory evaluation and analyzed for headspace volatile composition by proton transfer reaction-mass spectrometry (PTR-MS). The sensory data clearly distinguished between the samples in relation to the processes of manufacture; that is, significant differences were apparent between cheese, rennet, and acid wheys. For Mozzarella and Quarg wheys, in which fermentation progressed to low pH values, the starter cultures used for cheese making had a significant influence on flavor. In comparison, Cheddar and Gouda wheys were described by milk-like flavors, and rennet casein wheys were described by “sweet” (oat-like and “sweet”) and thermally induced flavors. The volatile compound data obtained by PTR-MS differentiated the samples as distinctive and reproducible “chemical fingerprints”. On applying partial least squares regression to determine relationships between sensory and volatile composition data, sensory characteristics such as “rancid” and cheese-like odors and “caramelized milk,” yogurt-like, “sweet,” and oat-like flavors were found to be related to the presence and absence of specific volatile compounds.

Analysis of volatiles from black pine ( Pinus nigra): significance of wounding and egg deposition by a herbivorous sawfly

The composition of headspace volatiles of black pine ( Pinus nigra) was analysed by coupled gas chromatography–mass spectrometry (GC–MS). It has been shown in a previous study that egg deposition of the sawfly Diprion pini on P. sylvestris induces a quantitative change of the pine volatile blend . Chrysonotomyia ruforum, an egg parasitoid of D. pini, is known to be attracted by volatiles from egg-carrying P. sylvestris, but not by odour from egg-laden P. nigra. Therefore, the present study focused on the question whether also P. nigra as another host plant of this sawfly responds to egg deposition by change of its volatile blend. The headspace of untreated, egg-carrying, and artificially wounded P. nigra twigs were compared. The artificial damage inflicted to the twigs mimicked the damage by the sawfly female prior to egg deposition. Thirty five mainly terpenoid compounds that were identified in more than 50% of the egg-carrying P. nigra twigs could also be detected in the headspace of untreated and artificially wounded twigs. Quantitative differences of the blends of volatiles from differently treated P. nigra twigs were compared by multivariate data analyses. PLS-DA (projection to latent structures-discriminant analysis) revealed that blends of volatiles from differently treated P. nigra differed significantly. When comparing volatiles from egg-carrying and artificially wounded P. nigra with respective P. sylvestris samples, qualitative and quantitative differences were detected. The differences in volatile composition of P. nigra and P. sylvestris are discussed with special respect to the egg parasitoid’s response to odours of egg-carrying pine twigs.

Dynamic deadspace-gas chromatography-olfactometry analysis of different anatomical parts of lovage (Levisticum officinale Koch.) at eight growing stages.

Volatiles of five different parts of lovage (leaves, stems, flowers, seeds, and roots) were isolated by dynamic headspace (DHS) method and analyzed by GC-FID and GC-olfactometry (GC-O) techniques. In total, 98 compounds were identified in the samples, of which 41 are reported as lovage volatiles for the first time. Qualitative differences in the composition of DHS constituents of various anatomical parts of the plants were not significant, whereas the amounts of a number of identified volatile compounds were different in leaves, stems, flowers, seeds, and roots. Seasonal variations in the composition of headspace volatiles were also determined. Except for roots, beta-phellandrene was found to be the most abundant headspace component in all anatomical parts of lovage constituting from 36.50% to 79.28% of the total GC peak area. The sniffing panel characterized effluents from the GC column, and odor descriptors were attributed to the recognized constituents. alpha-Pinene and alpha-phellandrene/myrcene were the most frequently recognized constituents among 11 GC effluents constituting 12 identified compounds and 1 unknown compound, which were detected by the members of the sniffing panel. None of the detected constituents was recognized as a lovage character impact aroma compound.

Effect of Hopping on the Headspace Volatile Composition of Beer

The effects of hop variety on the beer volatile constituents resulting from kettle hopping were studied. Three specially brewed beers, each hopped with single varieties of hops (Hallertau, Galena, ...

Effect of Hopping on the Headspace Volatile Composition of Beer

Effect of Hopping on the Headspace Volatile Composition of Beer

Studies on tobacco aroma. Changes in the composition of headspace volatiles of flue-cured tobacco by aging.

In order to investigate the headspace volatiles which indicate the againg effect on tobacco, the headspace volatiles of Japanese flue-cured tobacco were collected by active carbon and analyzed by gas chromatography. The data obtained were subjected to principal component analysis (PCA) and stepwise discriminant analysis (SDA). The results of PCA showed that the volatiles indicated the effect of aging on smoking quality. The SDA selected six peaks of the volatiles which classified the samples into four groups according to the aging period. The results described above can show that the relative proportions of the volatiles, such as furfuryl alcohol, benzyl alcohol and solanone, may be used to judge approximately the agint effects on tobacco.