Proportion Of Volatile Compounds Research Articles

Hydrodistillation fractions of coffee (green and roasted) and coffee by-product (silver skin and spent grounds) as a source of bioactive compounds

Coffee silver skin (CSS) and spent coffee grounds (SCG) produced during green coffee roasting (GC) and roasted coffee brewing (RC) are usually disposed of into the environment. In search of alternatives for their use in the form of hydrolates and water residues obtained by hydrodistillation, this work examines their analysis by GC-MS and UPLC-MS2 for bioactive compounds, in addition to GC and RC. The results show that the proportions of volatile compounds in the hydrolates are different, so that each hydrolate has a unique composition, which is crucial for further use. GC and ground GC contained phenols, aldehydes, alcohols, and ketones, while RC and ground RC contained pyrazines, phenols, aldehydes, and furans. Aldehydes (21.45 and 47.56%, respectively) and caffeine (15.13 and 11.65 mg/L, respectively) predominated in the hydrolates from CSS and SCG. Hydrolates from RC had the highest levels of caffeoylquinic acids, followed by CSS and SCG. The GC water residues contained the highest amounts of caffeoylquinic acids, with 5-caffeoylquinic acid (399.02 mg/L) dominating along with 3-p-coumaroylquinic acid, caffeic acid, and p-coumaric acid. Thus, it can be emphasised that the hydrodistillation fractions are a valuable substrate for the isolation of bioactive compounds and should be further investigated for their future potential applications.

Multiple Technologies Combined to Analyze the Changes of Odor and Taste in Daokou Braised Chicken during Processing.

This study analyzed the changes of odor and taste in Daokou braised chicken during processing by GC-MS, GC-IMS, e-nose and e-tongue. The 75 and 55 volatile compounds identified in Daokou braised chicken by GC-MS and GC-IMS, respectively, included hydrocarbons, aldehydes, alcohols, terpenes, ketones, heterocyclics, esters, acids and phenols; among them, aldehydes, alcohols and ketones were the most abundant. The number and proportion of volatile compounds in Daokou braised chicken changed significantly (p < 0.05) in the process. The proportion of volatile compounds with animal fatty odor, such as aldehydes and alcohols, decreased, while that of esters, ketones and terpenes from spices with fruity fragrance increased, especially in the braising stage. An e-nose showed that the odor intensities of sulfur-containing and nitrogen oxide compounds were higher (p < 0.05) after the braising stage, but weakened after 2 h braising. An e-tongue showed that saltiness and richness increased significantly (p < 0.05) after braising. The results of these four techniques showed that braising promoted the release of flavor compounds, and was beneficial to salt penetration and umami release. However, long braising could lead to weakened flavor intensity and the introduction of bitterness and astringency. This study also found that GC-IMS and e-nose were more sensitive to trace compounds such as sulfur-containing and nitrogen oxide compounds, esters, acids and phenolics in Daokou braised chicken than GC-MS. The use of multiple technologies could provide more comprehensive flavor profiles for Daokou braised chicken during processing. This study provides insights into the control of flavor of Daokou braised chicken, and may be of practical relevance for the poultry industry.

Volatile compounds of black cumin (Nigella sativa L.) seeds cultivated in Bangladesh and India

The compositional analysis of volatile compounds of Nigella sativa L. seeds obtained from India and Bangladesh was carried out in this study. Apart from the proportion of volatile compounds, the chemical composition of seeds from both sources were similar. The major volatile compounds in Bangladesh seeds were p-cymene (36.35%), thymoquinone (29.77%), α-thujene (12.40%), carvacrol (2.85%), β-pinene (2.41%), limonene (1.64%), methyl linoleate (1.33%) and sabinene (1.18%), contribution of these is 87.93% of the total volatile oil. On the other hand, the major volatile compounds in Indian seeds were p-cymene (41.80%), α-thujene (13.93%), thymoquinone (10.27%), methyl linoleate (4.02%), carvacrol (3.65%), β-pinene (2.96%), d-limonene (2.11%), 4,5-epoxy-1-isopropyl-4- methyl-1-cyclohexene (1.80%), sabinene (1.50%) and 4-terpineol (1.22%); contribution of these were 83.24% of the total volatile oil. In both seeds, p-cymene, thymoquinone, and α-thujene were the major components. Importantly, N. sativa seeds of Bangladesh contained almost 3-fold thymoquinone compared to Indian seeds. In conclusion, the seeds from Bangladesh contain a higher amount of terpene ketones (29.86%) represented by thymoquinone in comparison to Indian seeds (10.61%); on the other hand, Indian seeds contained a higher amount of terpene hydrocarbons (63.18%) mainly p-cymene, compared to Bangladesh seeds (54.53%). This is the first study to report detailed compositional analysis and comparison of Nigella sativa L. seeds from Bangladesh and India.

Comparative characterization of volatile profiles of French, Italian, Spanish, and Polish red wines using headspace solid-phase microextraction/gas chromatography-mass spectrometry

ABSTRACTThe aim of the study was to investigate whether the wines produced in France, Italy, Spain, and Poland differ in composition of volatile compounds, and whether red wines from Poland can be distinguished from those of other European countries. Thirty-five aroma compounds belonging to several groups – 13 alcohols, 9 acids, 3 aldehydes, 7 esters, 2 ketones, and 1 volatile phenol – were identified in the examined wines. The proportions of volatile compounds in wines from the four selected countries were similar. Statistical analysis revealed significant differences between French, Italian, Spanish, and Polish wines for 3-methylbutan-1-ol, butane-2,3-diol, phenylmethanol, 2-phenylethanol, dodecan-1-ol, propane-1,2,3-triol, diethyl butanedioate, 3-hydroxybutan-2-one, and 4-ethylphenol. In addition, diethyl butanedioate distinguished Polish wines from the other wines. Hierarchical cluster analysis (HCA) showed that the Polish wines were well separated from the other wines.

Volatile profile of Spanish-style green table olives prepared from different cultivars grown at different locations

The volatile profiles of Spanish-style green table olives elaborated with Manzanilla, Gordal and Hojiblanca cultivars grown at different locations in Spain were established by solid phase micro-extraction (SPME) and gas chromatography coupled to mass spectrometry (GC–MS). A total of 102 volatile compounds were identified, belonging to distinct chemical classes, and 20 of them are reported for the first time in table olives. The headspace profile was predominated by alcohols and phenols, followed by acids and esters, whereas the relative amounts of the remaining classes were quite lower (<5% in general). The principal compounds characterizing the headspace for most samples were p-creosol, phenylethyl alcohol, acetic acid, ethanol, benzyl alcohol, ethyl acetate, and (Z)-3-hexen-1-ol. Significant differences in the proportions of volatile compounds between samples from the Gordal cultivar and those from Manzanilla and Hojiblanca cultivars were detected and statistically visualized by principal component analysis (PCA). Among all the identified compounds, only (E)-2-decenal showed significant differences between the three cultivars without being significantly affected by locations where the fruits were grown.

Effect of Star Anise (Illicium verum) on the Volatile Compounds of Stewed Chicken

AbstractElectronic nose and gas chromatography–mass spectrometry (GC–MS) were used to analyze the effect of star anise on the stewed chicken flavor. Both principal component analysis (PCA) and linear discriminant analysis (LDA) of the electronic nose data suggested that star anise had effect on the stewed chicken flavor. The electronic nose was able to detect a clearer difference in volatile profile of stewed chicken using LDA than using PCA. GC–MS analysis showed that the composition and proportions of volatile compounds were greatly changed, and a spicy flavor was imparted to the stewed chicken with the addition of star anise. Compared with the control group, the peak area and percentage composition of aldehydes increased with the addition of star anise, whereas that of volatile compounds derived from Maillard reaction decreased. Fourteen and 16 key odor compounds were assigned by relative odor activity value (ROAV) in the control group and the star anise group, respectively, including aldehydes, alcohols, esters and sulfur‐containing compounds. The result of cluster analysis showed that ROAV was practicable to assign the key odor compounds of stewed chicken.Practical ApplicationsPot‐stewed meat products are well‐accepted because of their unique flavors. Spices have significant contributions to the formation of the flavors. Star anise is one of the most widely used spices in traditional Chinese pot‐stewed meat products. However, the effect of spice on meat flavor has not been widely studied, and the mechanism by which spice affects the flavor development is unclear, which limits the modernization of traditional meat products. This study suggested that the addition of star anise just changed the composition and proportions of volatile compounds and imparted a spicy flavor to the stewed chicken. The key odor compounds of meat products have made significant contributions to the overall flavor and determine the overall flavor. In this study, the key odor compounds of stewed chicken were assigned. These results may be helpful for further study of the mechanism whereby spices affect the flavors of traditional Chinese pot‐stewed meat products.

Generation of volatile flavour compounds as affected by the chemical composition of different dry-cured ham sections

The composition of different dry-cured ham sections has been determined in order to study their contribution to flavour generation. The proteins, free amino acids, free fatty acids and volatile compounds were analysed in different sections of dry-cured hams with 7 and 12 months of processing. The main differences among sections were detected in free amino acids and volatile compounds. To sum up, there was a higher concentration of free amino acids in the centre section than in the butt and shank sections. However, after 12 m of ripening the difference among sections was lower and only the butt was the one with the lowest concentration. Similar results were obtained in the content of volatile compounds, the centre part of the hams contained a higher proportion of volatile compounds after 7 m of ripening than the shank and butt sections. Nevertheless, in 12 months dry-cured hams there are changes in the proportions of volatile compounds being the centre section the one with the highest proportion of volatile compounds due not only to the higher concentration of free amino acids but also to the oxidation of unsaturated fatty acids.

Volatile metabolites of higher plant crops as a photosynthesizing life support system component under temperature stress at different light intensities

The effect of elevated temperatures of 35 and 45°C (at the intensities of photosynthetically active radiation 322, 690 and 1104 μmol·m −2·s −1) on the photosynthesis, respiration, and qualitative and quantitative composition of the volatiles emitted by wheat ( Triticum aestuvi L., cultivar 232) crops was investigated in growth chambers. Identification and quantification of more than 20 volatile compounds (terpenoids-α-pinene, Δ 3 carene, limonene, benzene, α-and trans-caryophyllene, α- and γ-terpinene, their derivatives, aromatic hydrocarbons, etc.) were conducted by gas chromatograph/mass spectrometry. Under light intensity of 1104 μmol·m −2·s −1 heat resistance of photosynthesis and respiration increased at 35°C and decreased at 45°C. The action of elevated temperatures brought about variations in the rate and direction of the synthesis of volatile metabolites. The emission of volatile compounds was the greatest under a reduced irradiation of 322 μmol·m −2·s −1 and the smallest under 1104 μmol·m −2·s −1, at 35°C. During the repair period, the contents and proportions of volatile compounds were different from their initial values, too. The degree of disruption and the following recovery of the functional state depended on the light intensity during the exposure to elevated temperatures. The investigation of the atmosphere of the growth chamber without plants has revaled the substances that were definitely technogenic in origin: tetramethylurea, dimethylsulfide, dibutylsulfide, dibutylphthalate, and a number of components of furan and silane nature.

Volatile compounds in chorizo and their changes during ripening

The volatile compounds extracted from both traditional and industrial chorizo—a dry fermented sausage—were analysed by gas chromatography/mass spectrometry (GC/MS). One hundred and twenty-six peaks were detected relating to volatile extracts of which 115 were identified. The substances identified belonged to several classes of chemical: acids, alkanes, alcohols, aldehydes, sulphur compounds, ketones, esters, ethers, phenolic compounds, aromatic hydrocarbons, lactones, nitrogen compounds, terpenes, chloroform and benzofurane. Among the major compounds isolated were acetic acid, allyl-1-thiol and phenol. Larger quantities of most of the chemical groups were found in industrial compared to traditional chorizo, except for sulphur compounds. Typical breakdown products derived from lipid autooxidation were virtually negligible in chorizo. Of the chemicals isolated, sulphur compounds, phenols, acids, ethyl esters and carbonyls could have particular importance to the overall chorizo flavour. In addition, the changes in the proportions of volatile compounds during the ripening of chorizo were tracked. Most of the volatiles increased during ripening, especially acids, alcohols, esters, phenols, ketones and terpenes. On comparing the distribution of the sulphur compounds observed in chorizo with that of garlic, some noteworthy differences were observed. The reason for these differences is based upon several transformations of the sulphur compounds derived from garlic during the ripening and storage of chorizo.