Headspace Solid-phase Microextraction In Combination Research Articles

Green infant formula analysis: Optimizing headspace solid-phase microextraction of carbonyl compounds associated with lipid peroxidation using GC-MS and pentafluorophenylhydrazine derivatization

The refinement and optimization of a method combining headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS) was successfully performed for the first time to determine seven carbonyl and dicarbonyl compounds, including glyoxal, methylglyoxal, dimethylglyoxal, and malondialdehyde in infant formulae, related to lipid peroxidation. HS-SPME was utilized for simultaneous extraction and derivatization with pentafluorophenylhydrazine (PFPH). Critical parameters such as temperature, pH, extractive phase, and salting-out were meticulously investigated and fine-tuned by an asymmetrical 2232//9 screening design to ensure the method's efficacy and reliability. Optimal conditions included a PFPH concentration of 5 g/L, pH 5.0, head-space extraction at 60 °C within 10 min, utilizing a DVB/CAR/PDMS coating, and a 20% w/w salting-out. The analytical validation of this method, compliant with FDA guidelines, demonstrated exceptional linearity, sensitivity, specificity, precision (RSD ≤13.8%), and accuracy (84.8% ≤ recovery ≤111.5%). The metric approach AGREEprep confirms its eco-friendliness, marking a significant step towards an environmentally conscious approach in infant formula analysis. An occurrence study conducted on 25 infant formula samples revealed widespread carbonyl and dicarbonyl compounds in both powdered and liquid variants. ANOVA results exhibited variations in compound concentrations among different sample groups. Clustering analyses delineated distinct groups based on carbonyl content, indicating the potential of these compounds as markers for lipid peroxidation and food quality assessment. This method serves as a valuable tool for evaluating infant formula quality, stability towards oxidation, and safety.

Relationship between phospholipid molecules species and volatile compounds in grilled lambs during the heating process

The present study used a comprehensive analysis combining headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) to investigate changes in volatile compounds and phospholipid molecules in grilled lambs. The results revealed 19 key volatile compounds (OAV > 1) involved in the grilling process of lambs. Additionally, UPLC-ESI-MS/MS analysis detected 142 phospholipid molecules in grilled lamb, with phosphatidylcholine exhibiting the highest content (36.62 %), followed by phosphatidyl ethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidyl glycerol, and phosphatidic acid. Through partial least squares analysis, 63 key differential phospholipids were identified. Principal component analysis of the key differential phospholipids and volatile compounds indicated that phosphatidylcholine and phosphatidyl ethanolamine phospholipids are the key substrates in forming volatile compounds in grilled lambs. This information is essential for precisely regulating the flavor profile, enhancing the grilling process, and minimizing the production of harmful compounds in grilled meat products.

Volatilomic profile of the tree tomato (Solanum betaceum Cav.) pulp during ripening and senescence using HS–SPME with GC–MS

The volatilomic profile of the tree tomato (Solanum betaceum Cav.) pulp during ripening stages and senescence times was determined by headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry. The HS-SPME-GC-MS analysis allowed the identification of 46 metabolites that produce the metabolic fingerprint of this fruit, the major compounds at all ripening stages and senescence times were ethyl butanoate, methyl butanoate, β-myrcene and eucalyptol. The composition in the different stages was subjected to principal component analysis (PCA), which explained 77.3% of the total variance in the principal components. It allowed to classify the samples by ripening stages and senescence times and it was corroborated with K-means clustering and dendrogram analyses. Through multivariate analyses PCA, partial least squares-discriminant analysis (PLS-DA), and heatmap it was possible to determine volatiles methyl (E)-2-hexenoate, 4-tert-butylcyclohexyl acetate, methyl benzoate, methyl (Z)-3-hexenoate, 3-methylbutyl acetate, β-thujene, cis-3-hexenol, hexanal and trans-2-hexenal as potential markers in the ripening stages, while volatiles propyl butanoate, ethyl octanoate, ethyl acetate, ethyl butanoate, β-myrcene and estragol predominated in the senescence times. HS-SPME-GC-MS analysis of volatiles in combination with the chemometric approach used in this research allowed to make a clear distinction between ripening stages and senescence times in common red variety of tree tomato pulp.

Analysis of Important Volatile Organic Compounds and Genes Produced by Aroma of Pepper Fruit by HS-SPME-GC/MS and RNA Sequencing.

Pepper is an important condiment, and its aroma affects its commercial value. In this study, transcriptome sequencing and combined headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the differentially expressed genes and volatile organic compounds in spicy and non-spicy pepper fruits. Compared with non-spicy fruits, there were 27 up-regulated volatile organic compounds (VOCs) and 3353 up-regulated genes (Up-DEGs) in spicy fruits. The results of KEGG enrichment analysis of the Up-DEGs combined with differential VOCs analysis showed that fatty acid biosynthesis and terpenoid biosynthesis may be the main metabolic pathways for aroma differences between non-spicy and spicy pepper fruits. The expression levels of the fatty acid biosynthesis-related genes FAD, LOX1, LOX5, HPL, and ADH and the key terpene synthesis gene TPS in spicy pepper fruits were significantly higher than those in non-spicy pepper fruits. The differential expression of these genes may be the reason for the different aroma. The results can provide reference for the development and utilization of high-aroma pepper germplasm resources and the breeding of new varieties.

Chemical composition of volatile components in the honey of some species of stingless bees

Using the technique of headspace solid-phase microextraction in combination with gas chromatography and mass spectrometric detection (HS-SPME/GC-MS), the composition of the volatile organic compounds (VOCs) of the honey of four species of stingless bees was studied in comparison with the honey of Apis mellifera bees. Peaks for 284 volatile components were registered on the chromatograms. Only eight components were present in all six studied samples. A high level of specificity in the composition of VOCs is a prerequisite for differentiating honey produced by different types of stingless bees and honey bees. Several specific features have been identified that are characteristic of the composition of VOCs in the honey of each species of stingless bees. These characteristics can be used to distinguish it from the honey of A. mellifera. The data obtained indicate the applicability of the HS-SPME/GC-MS technique for establishing the origin and for quality control of stingless bee honey.

Characterization and Differentiation of Fresh Orange Juice Variety Based on Conventional Physicochemical Parameters, Flavonoids, and Volatile Compounds Using Chemometrics.

The present study focused on the possibility of differentiating fresh-unprocessed orange juice according to botanical origin (variety), based on the use of conventional physico-chemical parameters, flavonoids, and volatile compounds, in combination with chemometrics. For this purpose, oranges from seven different varieties were collected during the harvest years of 2013–2014 and 2014–2015 from central and southern Greece. The physico-chemical parameters that were determined included: electrical conductivity, acidity, pH, and total soluble solids. The flavonoids: hesperidin, neohespseridin, quercetin, naringin, and naringenin were determined using high-performance liquid chromatography (HPLC-DAD). Finally, volatile compounds were determined using headspace solid-phase micro-extraction in combination with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Statistical treatment of data by multivariate techniques showed that orange juice variety had a significant (p < 0.05) impact on the above analytical parameters. The classification rate for the differentiation of orange juice according to orange variety using multivariate analysis of variance (MANOVA) and linear discriminant analysis (LDA) was 89.3%, based on the cross-validation method.

Combining Headspace Solid-Phase Microextraction with Internal Benchmarking to Determine the Elimination Kinetics of Hydrophobic UVCBs

Substances classified as unknown or variable composition, complex reaction products or biological origin (UVCB) present a challenge for environmental hazard and risk assessment. Here, we present a novel approach for whole-substance bioconcentration testing applied to cedarwood oil-an essential oil composed of volatile, hydrophobic organic chemicals. The method yields whole-body elimination rate constants for a mixture of constituents. Our approach combines in vivo dietary fish exposure with internal benchmarking and headspace solid-phase microextraction (HS-SPME) equilibrium sampling followed by suspect-screening analysis. We quantified depuration rate constants of 13 individual cedarwood oil constituents based on relative peak areas using gas chromatography (GC) coupled with Orbitrap-mass spectrometry (MS) and GC triple-quadrupole (QqQ)-MS. For seven constituents with available analytical standards, we compared the rate constants to the results obtained from solvent extraction, clean-up, and targeted GC-MS analysis. The HS-SPME sampling approach allowed for automated sample extraction and analyte enrichment while minimizing evaporative losses of the volatile target analytes and reducing matrix interferences from low-volatility organics. The suspect-screening analysis enabled the quantification of constituents without available analytical standards, while the internal benchmarking significantly reduced variability from differences in delivered dose and analytical variability between the samples.

The Effect of Aromatherapy with Lavender Oil on the Health-Related Quality of Life in Patients with Fibromyalgia

The aim of this study was to evaluate the effect of lavender oil, which has been used in complementary medicine as an aromatherapeutic, on the health-related quality of life in patients diagnosed with fibromyalgia and to determine the main volatile compounds of lavender oil with healing effects. Forty-two patients aged 18 years and over who were diagnosed with fibromyalgia according to the American College of Rheumatology 2010 diagnostic criteria and used lavender oil as an aromatherapeutic by applying it on the wrist or via inhalation for four weeks were included in this study. The Short-Form (SF)-36 Quality of Life Scale was administered to the patients at baseline and after four weeks of lavender oil treatment to determine whether there was any change in their quality of life. The averages and correlation levels between the scores were calculated with the paired-sample t-test taking p &lt; 0.05 as the statistical significance limit. In addition, the chromatographic analysis of lavender oil was performed with the combined headspace solid-phase microextraction and gas chromatography-mass spectrometry methods. When the quality of life scores were evaluated at baseline and after four weeks of lavender oil treatment, improvements were detected in all the subscales of SF-36 at the end of the study. It was found that all the subscale scores, except for general health, were statistically significantly higher compared to the baseline scores ( p &lt; 0.05). The major volatile compounds detected in lavender oil were linalool (29.33%) and linalyl acetate (27.69%). The remaining main compounds were terpinolene, cis-ocimene, eucalyptol, and lavandulol in the order of frequency, which is consistent with the literature. To our knowledge, this is the first study investigating the effect of lavender oil aromatherapy on patients diagnosed with fibromyalgia, and our results support that lavender oil aromatherapy significantly improves the quality of life in these patients. However, further comprehensive studies are needed to confirm our findings.

Discrimination and Identification of Aroma Profiles and Characterized Odorants in Citrus Blend Black Tea with Different Citrus Species

Citrus blend black teas are popular worldwide, due to its unique flavor and remarkable health benefits. However, the aroma characteristics, aroma profiles and key odorants of it remain to be distinguished and cognized. In this study, the aroma profiles of 12 representative samples with three different cultivars including citrus (Citrus reticulata), bergamot (Citrus bergamia), and lemon (Citrus limon) were determined by a novel approach combined head space-solid phase microextraction (HS-SPME) with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS). A total of 348 volatile compounds, among which comprised esters (60), alkenes (55), aldehydes (45), ketones (45), alcohols (37), aromatic hydrocarbons (20), and some others were ultimately identified. The further partial least squares discrimination analysis (PLS-DA) certified obvious differences existed among the three groups with a screening result of 30 significant differential key volatile compounds. A total of 61 aroma-active compounds that mostly presented green, fresh, fruity, and sweet odors were determined in three groups with gas chromatography-olfactometry/mass spectrometry (GC-O/MS) assisted analysis. Heptanal, limonene, linalool, and trans-β-ionone were considered the fundamental odorants associated with the flavors of these teas. Comprehensive analysis showed that limonene, ethyl octanoate, copaene, ethyl butyrate (citrus), benzyl acetate, nerol (bergamot) and furfural (lemon) were determined as the characterized odorants for each type.

Identifikacija isparljivih aromatičnih jedinjenja voćnih rakija metodom mikroekstrakcije na čvrstoj fazi u kombinaciji sa gasnom hromatografijom i masenom spektrometrijom

The optimization of the headspace solid-phase microextraction in combination with the gas chromatography-mass spectrometry (HS-SPME-GC/MS) for the qualitative identification of the aroma compounds in fruit spirits (Williams, plum spirit, grape spirit , apricot spirit) was the subject of the presented paper. The SPME extraction conditions (temperature, time, and NaCl amount) have been varied in order to achieve the more efficient chromatographic separation of the gas mixtures, to efficiently salt-out a higher number of less volatile compounds, and to save the energy during the sample preparation. Optimal parameters were determined as: T = 40 °C; m NaCl = 2 g; dilution = 10 times. According to the results obtained, the analyzed samples of Serbian fruit spirits produced from different fruits have a comparable composition of volatile aroma compounds to whiskey. The detection and definition of specific compounds that are "fingerprint" of fruit spirits could be an efficient method of the product authentication developing.

Analysis of the Volatile Components in Selaginella doederleinii by Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry.

Selaginella doederleinii (SD) is a perennial medicinal herb widely distributed in China. In this study, the volatile components of SD from two regions (24 batches), namely Zhejiang and Guizhou, were determined by combining headspace solid phase microextraction and gas chromatography-mass spectrometry (HS-SPME/GC-MS). After investigating different influence factors, the optimal conditions for extraction were as follows: The sample amount of 1 g, the polydimethylsiloxane-divinylbenzene (PDMS-DVB) fiber of 65 µm, the extraction time of 20 min, and the extraction temperature of 100 °C. Based on the above optimum conditions, 58 volatiles compounds, including 20 terpenes, 11 alkanes, 3 alcohols, 6 ketones, 3 esters, 11 aldehydes, 1 ether, 1 aromatic, 1 phenol, and 1 furan, were found and identified in SD. Furthermore, hierarchical cluster analysis and principal component analysis were successfully applied to distinguish the chemical constituents of SD from two regions. Additionally, anethol, zingerone, 2,4-di-tert-butylphenol, ledene, hexyl hexanoate, α-cadinol, phytone, hinesol, decanal, octadecene, cedren, 7-tetradecene, copaene, β-humulene, 2-butyl-2-octenal, tetradecane, cedrol, calacorene, 6-dodecanone, β-caryophyllene, 4-oxoisophorone, γ-nonanolactone, 2-pentylfuran, 1,2-epoxyhexadecane, carvacrol, n-pentadecane, diisobutyl phthalate, farnesene, n-heptadecane, linalool, 1-octen-3-ol, phytane, and β-asarone were selected as the potential markers for discriminating SD from 24 habitats in Zhejiang and Guizhou by partial least squares discrimination analysis (PLS-DA). This study revealed the differences in the components of SD from different regions, which could provide a reference for the future quality evaluation.

Ultrasensitive speciation analysis of mercury in waters by headspace solid-phase microextraction coupled with gas chromatography-triple quadrupole mass spectrometry

A sensitive, repeatable and inexpensive method combining headspace solid-phase microextraction (HS-SPME) with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was developed for the simultaneous speciation of mercury in water samples at trace and ultra-trace levels. The low-cost home-made polydimethylsiloxane (PDMS) fiber based on sol-gel method was used as a substitute for commercial one to extract and enrich the derivatives of inorganic mercury (Hg2+), methylmercury (MeHg) and ethylmercury (EtHg) in the headspace after derivatizing with sodium tetraphenylborate (NaBPh4) in situ. Some important parameters, such as preincubation and extraction temperature, preincubation time, extraction time and inlet temperature, were investigated. Under the optimized conditions, the limits of detection (LODs) of alkyl mercury and inorganic mercury were 0.03 and 6 ng L–1, respectively. The correlation coefficients were more than 0.994 in the range of 25.0–200 ng L–1 for Hg2+ and 0.12–80.0 ng L–1 for alkyl mercury. The recoveries of the analytes in real water samples spiked at three levels were all in the range of 76.6%-114.8%. The repeatability of all mercury species was good. For inorganic mercury spiked at the lowest quality control concentration (LQC) level, the relative standard deviation (RSD) was 12.1%, and it was less than 7.7% at higher spiked concentration. The RSDs of alkyl mercury were in the range of 3.0–8.5%. The method validation demonstrated the applicability of the proposed method, and it was finally used for the determination of mercury species in surface water and wastewater samples.

Inhibitory Abilities of Bacillus Isolates and Their Culture Filtrates against the Gray Mold Caused by Botrytis cinerea on Postharvest Fruit.

Botrytis cinerea, a major phytopathogenic fungus, has been reported to infect more than 200 crop species worldwide, and it causes massive losses in yield. The aim of this study was to evaluate the inhibitory abilities and effects of Bacillus amyloliquefaciens RS-25, Bacillus licheniformis MG-4, Bacillus subtilis Z-14, and Bacillus subtilis Pnf-4 and their culture filtrates and extracts against the gray mold caused by B. cinerea on postharvest tomato, strawberry, and grapefruit. The results revealed that the cells of Z-14, culture filtrate of RS-25, and cells of Z-14 showed the strongest biocontrol activity against the gray mold on the strawberry, grape, and tomato fruit, respectively. All the strains produced volatile organic compounds (VOCs), and the VOCs of Pnf-4 displayed the highest inhibition values. Based on headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry, esters accounted for the largest percentage of the VOCs produced by RS-25, MG-4, Z-14, and Pnf-4 (36.80%, 29.58%, 30.78%, and 36.26%, respectively). All the strains showed potent cellulase and protease activities, but no chitinase activity. RS-25, Z-14, and MG-4, but not Pnf-4, grew on chrome azurol S agar, and an orange halo was formed around the colonies. All the strains showed biofilm formation, fruit colonization, and lipopeptide production, which may be the main modes of action of the antagonists against B. cinerea on the fruit. This study provides the basis for developing natural biocontrol agents against the gray mold caused by B. cinerea on postharvest fruit.

Interrelation of Volatile Organic Compounds and Sensory Properties of Alternative and Torrefied Wood Pellets

The increasing demand for wood pellets on the market, which is caused by their excellent combustion properties, inspires the production as well as the utilization of alternative biomass pellets as fuel. However, the emission of volatile organic compounds gives pellet materials a distinct odor or off-odor, which is directly perceived by the end user. Thus, there is an urgent need for knowledge about the emitted volatile organic compounds and their potential formation pathways as well as their contributions to odor properties of the pellets. In this study, pellets made of biomass energy crops (i.e., straw or miscanthus), byproducts from the food industry (i.e., rapeseed, grapevine, or DDGS (dried distillers grains with solubles from beer production)), or eucalyptus, as well as torrefied pinewood and torrefied sprucewood were investigated with respect to the emitted volatile compounds and their possible impact on the pellet odor. Headspace solid-phase microextraction in combination with gas chromatography–mass spectrometry was used to enrich, separate, and identify the compounds. Techniques used in sensory science were applied to obtain information about the odor properties of the samples. A total of 59 volatile compounds (acids, aldehydes and ketones, alcohols, terpenes, heterocyclic compounds, and phenolic compounds) were identified with different compound ratios in the investigated materials. The use of multivariate statistical data analysis provided deep insight into product–compound interrelation. For pellets produced from bioenergy crops, as well as from byproducts from the food industry, the sensory properties of the pellets reflected the odor properties of the raw material. With respect to the volatiles from torrefied pellets, those volatiles that are formed during the torrefaction procedure dominate the odor of the torrefied pellets covering the genuine odor of the utilized wood. The results of this work serve as a substantiated basis for future production of pellets from alternative raw materials.

Zwitterionic polymeric ionic liquid-based sorbent coatings in solid phase microextraction for the determination of short chain free fatty acids

Five different zwitterionic sorbent coatings based on polymeric ionic liquids (PILs) were developed by the on fiber UV co-polymerization of the zwitterionic monomers 1-vinyl-3-(alkylsulfonate)imidazolium or 1-vinyl-3-(alkylcarboxylate)imidazolium and different dicationic ionic liquid (IL) crosslinkers. The developed sorbent coatings were applied in headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry for the determination of short chain free fatty acids in wine. The sorbent coatings were found to extract these analytes via a non-competitive extraction mechanism. The methodology was optimized for the two best zwitterionic PIL coatings and compared to the commercially-available carboxen/polydimethylsiloxane (CAR/PDMS) and polyacrylate (PA) fibers. The sorbent coating based on the 1-vinyl-3-(propanesulfonate)imidazolium IL (Fiber 1) was more sensitive than PA while providing similar limits of detection to CAR/PDMS for the determination of analytes in a diluted synthetic wine sample. At the same time, Fiber 1 required lower extraction times (only 20 min versus 60 min for CAR/PDMS and 40 min for PA), exhibited higher reproducibility (with relative standard deviation lower than 8.9% for a spiked level of 7 µM) and was more tolerant to ethanol present within the sample. The zwitterionic PILs were also applied for the analysis of red wine, and the results were in agreement with those obtained for CAR/PDMS. The analytes were detected and quantified in the concentration range from 0.18 ± 0.03 mg L−1 to 4.8 ± 0.9 mg L−1, depending on the analyte and fiber.

Robust Markers of Coffee Consumption Identified Among the Volatile Organic Compounds in Human Urine.

The human volatilome has gained high interest for the discovery of potential biomarkers of diseases. However, knowledge about the diet as a crucial factor affecting the volatilome is scarce. Therefore, the search for disease biomarkers, as well as the potential use of volatiles as dietary markers is so far limited. The aim of this study is to investigate the association of the diet with the urinary volatilome with the special task to find potential markers of coffee consumption in 24 h urine samples from the Karlsruhe Metabolomics and Nutrition (KarMeN) study. Acidified urine samples are analyzed using an approach combining headspace solid phase microextraction (HS-SPME) sampling with untargeted GC×GC-MS. Overall, 138 reliably occurring volatiles are detected. To account for the unequally concentrated urine samples, results of six different commonly used normalization methods are compared. Statistical analysis evidences six potential markers of coffee consumption, the most promising being 3,4-dimethyl-2,5-furandione. A correlation analysis between the 24 h dietary recall data and the urinary volatilome reveals further promising associations. The human urinary volatilome is highly affected by the diet, enabling access to a high level of information about potential diet-related biomarkers. Therefore, it is a very promising source for further investigations on dietary markers.

A volatilomics approach for off-line discrimination of minced beef and pork meat and their admixture using HS-SPME GC/MS in tandem with multivariate data analysis

Beef, pork and mixed (70% beef and 30% pork) minced meat samples were obtained from a meat processing plant in Athens during a two-year survey and analyzed both microbiologically and by headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry (HS-SPME/GC–MS). A validated method for the discrimination of minced meat was developed based on the volatile fingerprints. Unsupervised (PCA) and supervised (PLS-DA) multivariate statistical methods were applied to visualize, group and classify the samples. The data-set was divided 70% for model calibration and 30% for model prediction. During model calibration 99, 100 and 100% of the samples were correctly classified as beef, pork and mixed meat samples, respectively, while for model prediction the respective percentages were 100, 100 and 95% respectively. In both datasets, the overall correct classification rate amounted to 99% on average. Among the volatile compounds identified, heptanal, octanal, butanol, pentanol, hexanol, octanol, 1-penten-3-ol, 2-octen-1-ol, 3-hydroxy-2-butanone, 2-butanone and 2-heptanone were positively correlated with beef samples. Furthermore, pentanal, hexanal, decanal, nonanal, benzaldehyde, trans-2-hexenal, trans-2-heptenal, trans-2-octenal and 1-octen-3-one were positively correlated with pork. Lastly, the alcohols, 2-butanol and 1-octen-3-ol showed positive correlation with mixed samples. The results indicated that the volatilomics approach employed in this study could be used as an alternative method for robust and reliable discrimination and classification of meat samples in an off-line mode.

Odour-active compounds in baby banana Fruit (Musa acuminata AA Simmonds cv. Bocadillo)

ABSTRACTThe contribution of individual compounds to the typical aroma of baby banana cv. Bocadillo fruit would be useful to assess aroma changes caused in the course of fruit processing. Potent odourants in baby banana fruit were determined by combined headspace solid-phase microextraction GC–Olfactometry (HS-SPME-GC–O), solvent-assisted flavour evaporation, gas chromatography−olfactometry (GC–O), gas chromatography-mass spectrometry (GC-MS), aroma extract dilution analysis (AEDA) and calculation of odour activity values. Twenty-three constituents were considered as potentially odour-active compounds contributing to the typical fruit aroma, from which 2-pentyl acetate, 3-methylbutyl acetate, 3-methylbutyl butanoate, 3-methylbutyl 3-methylbutanoate, hexanal, (E)-2-hexenal and 2-pentyl 3-methylbutanoate were the most important contributors to the aroma. HS-SPME-GC-O has a great potential as fast and simple tool to control aroma quality of baby banana fruit.

Identification of volatile compounds in Antarctic krill (Euphausia superba) using headspace solid-phase microextraction and GC-MS

ABSTRACTAntarctic krill (Euphausia superba) has a very high economic value due to its enormous production, higher protein content, and nutritional value. This study presents a detailed optimization of the analysis of volatile flavor compounds from Antarctic krill by combining headspace solid-phase microextraction (HS-SPME) as the extracting method and gas chromatography/mass spectrometry (GC-MS) as the analysis. An optimal solid-phase microextraction (SPME) fiber was selected, and the microextraction conditions were optimized using the response surface method (RSM). The Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS) fiber showed the highest extraction efficiency and was selected for further optimization of extraction temperature, extraction time, and sodium chloride concentration. Forty-two types of volatile substances producing characteristic flavors were detected, seven of which contributed significantly to the flavor of Antarctic krill. Ethers, pyrazine, and aldehyde compounds contribute to the main flavor of Antarctic krill. The compounds 2-ethyl-3, 5-dimethyl-pyrazine, 2, 3, 5-trimethyl-6-ethyl-pyrazine, and 3-ethyl-2, 5-dimethyl- pyrazine produce the roasted flavor and the characteristic nutty odor. Moreover (E, Z)-2, 6-nonadienal adds a cucumber fragrance. The compounds 3-methyl-butanal and 3-methional play an important role in determining the overall flavor.

Characterization and geographical discrimination of saffron from Greece, Spain, Iran, and Morocco based on volatile and bioactivity markers, using chemometrics

In the present study saffron samples from Greece, Spain, Iran, and Morocco, collected during harvesting years 2005–2014, were characterized and classified according to geographical origin using volatile compounds and selected bioactivity parameters. The volatile compounds of saffron were semi-quantified using headspace solid-phase microextraction in combination with gas chromatography/mass spectrometry. Bioactivity parameters such as total phenolic content (TPC), radical scavenging activity (%RSA), and ferric reducing antioxidant power (FRAP) were determined using spectrophotometric assays. Results showed that significant variations (P < 0.05) in the volatile content, TPC, and antioxidant activity were observed according to geographical origin of saffron. Certain volatile compounds and bioactivity parameters were also affected by harvesting year (P < 0.05). Finally, strong positive Pearson’s correlations were obtained for TPC and %RSA (r = 0.90), TPC and FRAP (r = 0.90), highlighting that the methanolic fraction of saffron is rich in phytochemicals, contributing thus, to its overall antioxidant properties. The application of LDA to above combined parameters determined, enabled the correct geographical discrimination of saffron, resulting in a correct prediction rate of 95.5%. The use of a larger number of saffron samples will further validate present results.