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Cheese production is associated with the analysis of its nutritional composition as well as with the sensory evaluation of the acceptance of the products. The paper is aimed at the determination of basic chemical parameters such as the content of proteins, fat, dry matter, salt and, pH and also on the evaluation of sensory properties of hard cheeses by the sensory panel. The GC-MS analysis of cheeses, cheese spreads, and traditional butter was performed to evaluate the aroma profile of the dairy products analyzed. The dry matter in the analyzed cheeses varied between 56.75 and 71.83%, the fat content varied from 18.73 to 30.83%, and the salt from 1.21 to 2.61%. The presence of proteins was found between 27.76 and 32.61% and the pH of the cheeses ranged from 5.21 to 6.01. The results of the sensory analysis were processed using a PCA map. The results showed that sample no. 5 was rated within all attributes as the best. Sample 3, 2, and 1 followed. Sample 4 received the lowest score. The volatile aromatic compounds that contribute to a taste perception were analyzed by GC-MS in dairy products. The aroma profile was built by the volatile compounds that belonged to chemical families of alcohols, aldehydes, ketones, esters, amides, amines, imines, and terpenes. In particular, cheeses contained mostly alcohols (3-methyl-1-butanol), aldehydes (3-methylbutanal and benzaldehyde), and ketones (acetoin, 2,3,3-trimethylcyclobutanone, 2-heptanone, 2,3-butanedione, acetone, 2-butanone, 2-nonanone, 2- pentanone). The spreads most often contained alcohols (represented by 2-methyl-1-butanol, 3-methyl-1-butanol and cyclopropane-1,2,3-d3-methanol), aldehydes (2-methylbutanal, 3-methylbutanal, benzaldehyde) and ketones (acetoin, 2-heptanone, 2-pentanone, 2-butanone and 2,3-butanedione).

The evaluation of volatiles in food is an important aspect of food production. It gives knowledge about the quality of foods and their relationship to consumers’ choices. Alcohols, aldehydes, acids, esters, terpenes, pyrazines, and furans are the main chemical groups that are involved in aroma formation. They are products of food processing: thermal treatment, fermentation, storage, etc. Food aroma is a mixture of varied molecules. Because of this, the analysis of aroma composition can be challenging. The four main steps can be distinguished in the evaluation of the volatiles in the food matrix as follows: (1) isolation and concentration; (2) separation; (3) identification; and (4) sensory characterization. The most commonly used techniques to separate a fraction of volatiles from non-volatiles are solid-phase micro-(SPME) and stir bar sorptive extractions (SBSE). However, to study the active components of food aroma by gas chromatography with olfactometry detector (GC-O), solvent-assisted flavor evaporation (SAFE) is used. The volatiles are mostly separated on GC systems (GC or comprehensive two-dimensional GCxGC) with the support of mass spectrometry (MS, MS/MS, ToF–MS) for chemical compound identification. Besides omics techniques, the promising part could be a study of aroma using electronic nose. Therefore, the main assumptions of volatolomics are here described.

International audience; In order to encourage Western populations to increase their consumption of vegetables, we suggest turning legumes into novel, healthy foods by applying an old, previously widespread method of food preservation: fermentation. In the present study, a total of 55 strains from different microbial species (isolated from cheese or plants) were investigated for their ability to: (i) grow on a emulsion containing 100% pea proteins and no carbohydrates or on a 50:50 pea:milk protein emulsion containing lactose, (ii) increase aroma quality and reduce sensory off-flavors; and (iii) compete against endogenous micro organisms. The presence of carbohydrates in the mixed pea:milk emulsion markedly influenced the fermentation by strongly reducing the pH through lactic fermentation, whereas the absence of carbohydrates in the pea emulsion promoted alkaline or neutral fermentation. Lactic acid bacteria assigned to Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis and Lactobacillus casei species grew well in both the pea and pea:milk emulsions. Most of the fungal strains tested (particularly those belonging to the Mucor and Geotrichum genera) were also able to grow on both emulsions. Although most Actinobacteria and Proteobacteria did not compete with endogenous microbiota (Bacillus), some species such as Hafnia alvei, Acinetobacter johnsonii and Glutamicibacter arilaitensis grew strongly and appeared to restrict the development of the endogenous microbiota when the pea emulsion was inoculated with a combination of three to nine strains. In the mixed emulsions, lactic fermentation inhibited Actinobacteria and Proteobacteria (e.g. Brevibacterium casei, Corynebacterium casei, Staphylococcus lentos) to the greatest extent but also inhibited Bacillus (e.g. Bacillus subtilis and Bacillus licheniformis). Overall, this procedure enabled us to select two microbial consortia able to colonize pea-based products and positively influence the release of volatile compounds by generating a roasted/grilled aroma for the 100% pea emulsion, and a fruity, lactic aroma for the 50:50 pea:milk emulsion. Moreover, the fermentation in the pea-based emulsions reduced the level of hexanal, which otherwise leads to an undesired green pea aroma. Our present results show how the assembly of multiple microbial cultures can help to develop an innovative food product.

The aroma profile is a key component of Pinot noir wine quality, and this is influenced by the diversity, quantity, and typicity of volatile compounds present. Volatile concentrations are largely determined by the grape itself and by microbial communities that produce volatiles during fermentation, either from grape-derived precursors or as byproducts of secondary metabolism. The relative degree of aroma production from grape skins compared to the juice itself, and the impact on different yeasts on this production, has not been investigated for Pinot noir. The influence of fermentation media (Pinot noir juice or synthetic grape must (SGM), with and without inclusion of grape skins) and yeast choice (commercial Saccharomyces cerevisiae EC1118, a single vineyard mixed community (MSPC), or uninoculated) on aroma chemistry was determined by measuring 39 volatiles in finished wines using headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC-MS). Fermentation medium clearly differentiated the volatile profile of wines with and without yeast, while differences between EC1118 and MSPC wines were only distinct for Pinot noir juice without skins. SGM with skins produced a similar aroma profile to Pinot noir with skins, suggesting that grape skins, and not the pulp, largely determine the aroma of Pinot noir wines.

The volatile compounds from insects (Tenebrio molitor and Zophobas morio larvae) roasted at 160, 180, or 200 °C and fed with potato starch or blue corn flour were isolated by solid-phase microextraction (SPME), and identified by gas chromatography–mass spectrometry (GC-MS). In the tested material, 48 volatile compounds were determined. Among them, eight are pyrazines, aroma compounds that are formed in food products during thermal processing due to the Maillard reaction. Eleven of the identified compounds influenced the roast, bread, fat, and burnt aromas that are characteristic for traditional baked dishes (meat, potatoes, bread). Most of them are carbonyl compounds and pyrazines. To confirm the contribution of the most important odorants identified, their odor potential activity values (OAVs) and %OAV were calculated. The highest value was noted for isobuthylpyrazine, responsible for roast aroma (%OAV &gt, 90% for samples roasted at lower temperatures), and 2,5-dimethylpyrazine, responsible for burnt aroma (%OAV &gt, 20% for samples roasted at the highest temperature). According to the study, the type of feed did not significantly affect the results of the sensory analysis of roasted insects. The decisive influence was the roasting temperature. The highest scores were achieved for Tenebrio molitor larvae heat-treated at 160 °C.

Sourdough is an old example of a natural starter composed of a mixture of flour, water, and metabolites and is produced by naturally occurring lactic acid bacteria and yeasts that influence bread aroma. In this work, four types of sourdough were used to prepare bread: one sourdough with yeast beer and three with bacteria and yeasts. The physicochemical parameters (pH, moisture, water activity, and organic acids) of the bread and sourdoughs were assessed. Lactic, acetic, and succinic acids were found in considerable amounts in sourdoughs and the corresponding breads. The fermentation quotient (molar ratio between lactic and acetic acid) ranged from 0.39 to 3.4 in sourdoughs. Lactic acid was prevalent in all types of bread and showed the highest value in bread made from sourdough with a 1.5 bacteria/yeast ratio (8722.24 mg/kg). Moreover, volatile organic compounds were identified in bread samples. Alcohols, aldehydes, and acetic acid were mainly found. The alcohol concentration ranged from 140.88 to 401.20 ng/g. Aldehydes ranged from 185.01 to 454.95 ng/g, and acetic acid ranged from 91.40 to 173.81 ng/g. Bread prepared from sourdough with a 1.5 bacteria/yeast ratio showed a considerable amount of alcohols and acetic acid.

International audience; Haloanisoles (HAs) are known to compromise wine quality because of their mouldy off-flavours. Up to now no treatment exists to eliminate the presence of these unpleasant volatiles in wine. This research aimed i) to assess the alimentary plastic film efficacy to remove or lessen HAs content in polluted wines; and ii) to evaluate its impact on wine quality. The film-treatment reduced significantly (p < 0,05) the 2,4,6-trichloroanisole (TCA) content of initial wine. This decrease became more noticeable as the contact time film-wine increased.Chromatic characteristics, phenolic and proanthocyanidin contents, and woody aroma profile did not change because of the film-treatment. A significant sorption of certain esters was observed, but as HAs were removed under detection thresholds, fruity perception of wines was improved.Globally, the alimentary plastic film was able to improve the organoleptic quality of wines contaminated with HAs, by reducing the cork taint and enhancing their overall fruity aroma.

The aim of the research was to increase the efficiency of the hydrodistillation process and determine the volatile composition, biological activity, and aroma profile of essential oil from celery seeds (Apium graveolens L.). The essential oil was extracted from the plant material by ultrasonic hydrodistillation with higher efficiency when compared with classical hydrodistillation. The antimicrobial activity was evaluated using the impedimetric method for the bacteria Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and yeast Candida vini as well as moulds Aspergillus niger and Penicillium expansum with minimal inhibitory concentration (MIC) (&mu, L/mL) values: 30, 10, 20, 3, 30, 40, and 40, respectively. The oil possessed very weak 2,2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant activity with the half maximal inhibitory concentration (IC50) value of 81.6 g/L. Initial studies of the aroma profile indicated that the perception of the fragrance of the oil could be related to the sex of the panellists. According to women, the fragrance of celery seeds oil was intense herb-like. From the men&rsquo, s point of view, it had a fresh, mossy, and mushroom scent.

Pea protein isolate (PPI, from Pisum sativum L.) was fermented with six different lactic acid bacteria strains for 24 ​h and 48 ​h. The fermented samples were analyzed regarding their retronasal aroma and taste, their protein solubility, emulsifying and foaming capacity. Changes in the molecular weight distribution were analyzed to monitor potential effects of fermentation on the main allergenic protein fractions of PPI. After 24-h fermentation, PPI's characteristic aroma attributes and bitter taste decreased for all fermented PPI. However, after 48-h fermentation, cheesy aroma, and acid and salty tastes were increased. The PPI fermented with L. plantarum showed the most neutral taste and the panel's highest preference; instead, fermentation with L. fermentum led to a fecal aroma and was the least preferred. The protein solubility and emulsifying capacity decreased after PPI fermentation, while foaming capacity remained constant in comparison to the untreated PPI. The electrophoretic results showed a reduction in the intensity of the allergenic protein fractions; however, these changes might be attributed to the reduced protein solubility rather than to a high proteolytic effect of the strains. Fermentation of PPI for 24 ​h and 48 ​h might not be a suitable method for the production of highly functional pea proteins. Further modification methods have to be investigated in the future., Graphical abstract Image 1, Highlights • Fermentation with lactic acid bacteria changed the characteristic aroma profile of pea protein isolates. • Bitterness of pea protein isolates is reduced after 24-h and 48-h fermentation. • The functional properties are negatively affected after fermentation. • Electrophoretic results indicate a reduced intensity of the main allergenic protein fractions.

Summer truffles (Tuber aestivum) collected from Italy were evaluated for changes in chemical composition and hence in vitro bioactivity on the basis of their maturity. Truffles were classified as immature and mature based on the colour of glebum. Water and methanol extracts of freeze-dried mature truffles demonstrated higher total phenolics, in vitro antioxidant activity, and lower tannins than immature truffle extracts. Phenolics and flavonoids were detected by liquid chromatography–mass spectroscopy (LC–MS) analysis. Gas chromatography (GC)–MS analysis of hexane extracts showed differences in fatty acid composition. Linoleic acid content was highest in both samples, and lauric and myristic acids were prominently detected in hexane extracts of mature truffles. The aroma profiling of truffles by headspace—GC showed an increase in alcohols and decrease in aldehydes. Thus this study comprehends altered chemical composition and its manifestation in in vitro bioactivity on maturation of summer truffles. This would aid in development of techniques for identification of maturity of truffles.

This study investigates the effects of simultaneous inoculation of a selected Saccharomyces cerevisiae yeast strain with two different commercial strains of wine bacteria Oenococcus oeni at the beginning of the alcoholic fermentation on the kinetics of malolactic fermentation (MLF), wine chemical composition, and organoleptic characteristics in comparison with spontaneous MLF in Tempranillo grape must from Castilla-La Mancha (Spain). Evolution of MLF was assessed by the periodic analysis of L-malic acid through the enzymatic method, and most common physiochemical parameters and sensory traits were evaluated using a standardized sensory analysis. The samples were analyzed by GC/MS in SCAN mode using a Trace GC gas chromatograph and a DSQII quadrupole mass analyzer. Co-inoculation reduced the overall fermentation time by up to 2 weeks leading to a lower increase in volatile acidity. The fermentation-derived wine volatiles profile was distinct between the co-inoculated wines and spontaneous MLF and was influenced by the selected wine bacteria used in co-inoculation. Co-inoculation allows MLF to develop under reductive conditions and results in wines with very few lactic and buttery flavors, which is related to the impact of specific compounds like 2,3-butanedione. This compound has been also confirmed as being dependent on the wine bacteria used.

Shiikuwasha pulp is an important raw material for producing citrus essential oils. The volatile aroma composition of pulp essential oil was evaluated using gas chromatography (GC) methods, and its aroma profile was assessed using GC-olfactometry with an extended aroma extract dilution analysis (AEDA) technique in regard to alterations of odor strength and sensorial perception throughout serial dilution steps. The essential oil comprised a mixture of 55 aroma compounds, including monoterpene hydrocarbon, sesquiterpene hydrocarbon, alcohol, aldehyde, ester, and oxide compounds. The predominant compounds were limonene [57.36% (4462.80 mg/100 g of pulp)] and γ-terpinene [25.14% (1956.21 mg/100 g of pulp)]. However, linalool was identified as one of the key aroma components providing the highest flavor dilution factor in AEDA, whilst three sesquiterpene hydrocarbons (δ-elemene, germacrene B, and bicyclosesquiphellandrene) and two esters (heptyl acetate and decyl acetate) had superior relative flavor activities. The extended AEDA profile identified variations in assessed odor perceptions, intensity, and duration of aroma components over dilution, whereas the 12 most odor-active compounds showed comparable odor strengths.

Single-dose coffee capsules have revolutionized the coffee market, fueling espresso coffee popularity and offering access to a wide selection of coffee blends. Nevertheless, scarce information related to coffee powder and brew’s combined volatile characterization is available. In this study, it is hypothesized that coffee brew aroma characteristics can be predicted based on coffee powder’s volatile composition. For this, headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection (GC × GC-ToFMS) was used. The data were combined via chemometric tools to characterize in depth the volatile composition of eight blends of capsule-coffee powder and respective espresso brews, simulating the consumer’s perception. A total of 390 volatile compounds were putatively identified, 100 reported for the first time in roasted coffee or brews. Although the same chemical families were determined among the coffee powders and espresso brews, a different volatile profile was determined for each matrix. The Pearson correlation of coffee powders and respective brews allowed to identify 15 volatile compounds, mainly terpenic and esters recognized by their pleasant notes, with a strong relationship between the amounts present in both matrices. These compounds can be key markers to predict the volatile aroma potential of an espresso brew when analyzing the coffee powder.

The chemical composition of volatiles emitted in vivo from different plant parts of P. cerasifera and P. cerasifera ‘Pissardii’ were collected during the entire biological cycle of the plant growth and analyzed by gas chromatography mass spectrometry (GC-MS) after solid phase micro-extraction (SPME). All the data were submitted to multivariate statistical analysis evidencing many differences amongst the selected plant parts and growth stages. A total of 136 compounds were identified corresponding to 90.1–99.6% of the whole aroma profile of cherry plum samples. Non-terpenes were the most abundant class of constituents present in the volatile emission of all analyzed samples. In particular, the aroma of both fruit stages was mainly characterized by alcohols and esters in different amounts.

The volatiles emitted in vivo by different organs (leaf, bud flower, flower, green and red fruits) of Ziziphus jujuba were analysed using HS-SPME-GC/MS. A total of 144 compounds were identified corresponding to 94.6–99.4% of the whole aroma profile of jujube samples. The main constituents detected were (E, E)-α-farnesene, (E)-β-ocimene, perillene, γ-terpinene, cis-sabinene-hydrate, trans-sabinene-hydrate and 4-terpineol. The SPME analyses of the collected samples showed different patterns of emission and can contribute to understand their ecological interactions and fruit production management.

Nowadays, consumers require quality beer with peculiar organoleptic characteristics and fermentation management has a fundamental role in the production of aromatic compounds and in the overall beer quality. A strategy to achieve this goal is the use of non-conventional yeasts. In this context, the use of Torulaspora delbrueckii was proposed in the brewing process as a suitable strain to obtain a product with a distinctive aromatic taste. In the present work, Saccharomyces cerevisiae/T. delbrueckii mixed fermentation was investigated at a microbrewery plant monitoring the evolution of the main aromatic compounds. The results indicated a suitable behavior of this non-conventional yeast in a production plant. Indeed, the duration of the process was very closed to that exhibited by S. cerevisiae pure fermentation. Moreover, mixed fermentation showed an increase of some aromatic compounds as ethyl hexanoate, α-terpineol, and β-phenyl ethanol. The enhancement of aromatic compounds was confirmed by the sensory evaluation carried out by trained testers. Indeed, the beers produced by mixed fermentation showed an emphasized note of fruity/citric and fruity/esters notes and did not show aroma defects.

Modern viticulture requires the replacement of hazardous agrochemicals with eco-friendly, bio-based products such as microbial preparations that enhance grape and wine quality while protecting the grapevine from pest and disease attacks. This study investigated the effects of a commercially available Bacillusbased preparation on the volatile and sensory properties of wines made from Vitis vinifera, cv. Prokupac grapes. Three different concentrations of preparation based on Bacillus subtilis Ch-13 were applied to grapevines two weeks prior to harvest. The total soluble solids in the grapes was affected by the application of B. subtilis Ch-1 and the alcohol content of the wine made from these grapes was greater. Wines made from the B. subtilis Ch-13-treated grapes showed an average increase in total phenolic compounds of about 27%, compared to the wine made from the untreated control grapes. The colour intensity of wines from the treated grapes, independently of the concentration, was higher by more than 30% than for the wine from the control grape sample. The B. subtilis Ch-13 treatment also affected the content of 3-methyl-1-butanol, ethyl decanoate and ethyl octanoate in the wine, at about 35%, 40% and 20%, respectively. The latter compounds are responsible for floral and fruity aromas. Generally, wines made from the treated grapes showed similar sensorial characteristics but scored better overall than the control. Principal component analysis showed a clear differentiation between wine made from the control and that from the B. subtilis Ch-13-treated grapes. The results suggest that the application of B. subtilis Ch-13 to grapevines two weeks prior to harvest has a positive effect on wine quality.

Mandragora autumnalis Bertol. (Solanaceae family), synonym of M. officinalis Mill., occurs in North Africa and grows natively in Northern and Central Tunisia, in humid to sub-arid climates. The ripe fruits of mandrake are odiferous with a particular, indescribable, specific odor, shared, to a lesser extent, by the leaves and roots. We carried out an investigation of the essential oils (EOs) and of the aromatic volatiles emitted by fresh leaves, roots and ripe fruits of M. autumnalis growing wild in Central Tunisia. The EOs were obtained from freshly collected plant material by hydrodistillation, while the volatile emissions from the powdered M. autumnalis tissues were sampled by headspace solid phase microextraction (HS-SPME); both types of samples were analyzed by gas chromatography-mass spectrometry (GC/MS). Fifty-one compounds representing 96.2-98.6 % of the total oil compositions were identified in the three tissues and belonged to different chemical classes specifically in 16 esters, 12 alcohols, 12 hydrocarbons, 6 ketones, 3 aldehydes and 3 acids. The main constituents were pentadecanoic acid (34.2 %) and hexadecanol (26.3 %). A total of 78 volatile compounds emanating from M. autumnalis tissues, representing 94.1-96.4 % of the total volatile compositions, were identified: 22 esters, 11 alcohols, 9 aldehydes, 14 ketones, 7 nitrogen, 10 hydrocarbons, 2 lactones, 1 sulfur and 2 ethers. Ethyl hexanoate (12.3 %) and 1,3-butanediol (12.3 %) were at the highest relative percentages. This study characterizes and distinguishes M. autumnalis from Tunisia and attributes the compounds responsible for the intoxicating and particular odor of fruits. Chemosystematic of Mandragora autumnalis based on the identification of essential oils and headspace volatiles of each of its organ can be used to characterize this species according to its geographic distribution.

Feijoa is an aromatic fruit and the essential oil from feijoa peel could be a valuable by-product in the juicing industry. An initial comparison of the essential oil extraction methods, steam-distillation and hydro-distillation, was conducted. The volatile compounds in the essential oils from four feijoa cultivars were identified and semi-quantified by GC-MS and the aroma active compounds in each essential oil were characterized using SPME-GC-O-MS. Hydro-distillation, with a material to water ratio of 1:4 and an extraction time of 90 min, was the optimized extraction method for feijoa essential oil. The Wiki Tu cultivar produced the highest essential oil yield among the four selected cultivars. A total of 160 compounds were detected, among which 90 compounds were reported for the first time in feijoa essential oils. Terpenes and esters were dominant compounds in feijoa essential oil composition and were also major contributors to feijoa essential oil aroma. Key aroma active compounds in feijoa essential oils were &alpha, terpineol, ethyl benzoate, (Z)-3-hexenyl hexanoate, linalool, (E)-geraniol, 2-undecanone, 3-octanone, &alpha, cubebene, and germacrene D. This is the first report on the optimization of the extraction method and the establishment of the aroma profile of feijoa essential oils, with a comparison of four New Zealand grown cultivars.

Electronic nose with sensors is used in many industries and for various applications such as quality control, process monitoring, shelf life evaluation, origin or authenticity assessment. The aim of this work was to investigate the electronic nose with FID detectors applicability for characterization of steamed cheese and for the assessment of steamed cheese quality decay during storage. Samples of smoked and unsmoked steamed cheese varieties from 5 Slovak enterprises concerning different regions of Slovakia were analysed. Data from aroma profiles were processed by statistical technique PCA. Compounds like acetaldehyde, 1-propanal, propanoic acid, ethyl hexanoate, furfural, butan-2-one, isovaleric acid, 1-hexanol or α-pinene were determined as significant flavours in fresh steamed cheese samples. In the current study, no significant differences in aroma profiles between fresh and stored cheese samples were confirmed. Thus, differences in main odour substances composition of steamed cheese varieties, obtained from various producers in several geographic regions of Slovakia, were minor.

Saccharomyces cerevisiae remains the baker’s yeast of choice in the baking industry. However, its ability to ferment cereal flour sugars and accumulate CO2 as a principal role of yeast in baking is not as unique as previously thought decades ago. The widely conserved fermentative lifestyle among the Saccharomycotina has increased our interest in the search for non-conventional yeast strains to either augment conventional baker’s yeast or develop robust strains to cater for the now diverse consumer-driven markets. A decade of research on alternative baker’s yeasts has shown that non-conventional yeasts are increasingly becoming important due to their wide carbon fermentation ranges, their novel aromatic flavour generation, and their robust stress tolerance. This review presents the credentials of non-conventional yeasts as attractive yeasts for modern baking. The evolution of the fermentative trait and tolerance to baking-associated stresses as two important attributes of baker’s yeast are discussed besides their contribution to aroma enhancement. The review further discusses the approaches to obtain new strains suitable for baking applications.

The chemical composition of spontaneous volatile emission from Rubus ulmifolius flowers and fruits during different stages of development was evaluated by HS-SPME-GC/MS. In total, 155 chemical compounds were identified accounting 84.6 - 99.4% of whole aroma profile of flowers samples and 92.4 - 96.6% for fruit samples. The main constituents were α-copaene, β-caryophyllene, germacrene D, (E,E)-α-farnesene, 1,7-octadien-3-one,2-methyl-6-methylene, tridecane, (E)-2-hexenol acetate, (E)-3-hexenol acetate and cyperene. The results give a chemotaxonomic contribution to the characterization of the VOCs emitted from flowers and fruits during their ontogenic development.

The application of yeast strains that are low producers of sulfur compounds is actually required by winemakers for the production of organic wine. This purpose could be satisfied using a native Saccharomyces cerevisiae strain improved for oenological aptitudes. Moreover, to improve the aromatic complexity of wines, sequential fermentations carried out with S. cerevisiae/non-Saccharomyces yeast is widely used. For these reasons, in the present work an improved native S. cerevisiae low producer of sulfite and sulfide compounds was evaluated in pure and in sequential fermentation with a selected Torulaspora delbrueckii. Additionally, the influence of grape juices coming from three different vintages under winery conditions was evaluated. In pure fermentation, improved native S. cerevisiae strain exhibited a behavior related to vintage, highlighting that the composition of grape juice affects the fermentation process. In particular, an increase in ethyl octanoate (vintage 2017) and phenyl ethyl acetate (vintage 2018) was detected. Moreover, isoamyl acetate was highly consistent and could be a distinctive aroma of the strain. The sequential fermentation T. delbrueckii/S. cerevisiae determined an increase in aroma compounds such as phenyl ethyl acetate and ethyl hexanoate. In this way, it was possible to produce Verdicchio wine with reduced sulfites and characterized by a peculiar aromatic taste.

This paper reported for the first time the aroma profile and essential oil composition of eight species of Helichrysum endemic in South Africa but grown in Italy (CREA-Sanremo collection). The volatiles of all the studied Helichrysum were dominated by monoterpene hydrocarbons, except for H. basalticum, where sesquiterpene hydrocarbons was the main class of compounds with β-caryophyllene (13.7%) and α-guaiene (11.9%) as major components. Despite the great diversity of compounds obtained in the volatile emission (more than 130), only four compounds were responsible for at least 34% of the identified fraction. These compounds were: sabinene (16.0%), β-caryophyllene and α-guaiene in H. basalticum; sabinene (57.7%) in H. foetidum; (Z)-β-ocimene (34.6%), tricyclene (16.2%) and myrcene (10.0%) in H. incanatum; myrcene (29.3%), tricyclene (21.5%) and limonene in H. indicum; tricyclene (32.1%) and (E)-3-hexanol acetate (20.1%) in H. montanum; limonene (10.3%), sabinene (8.9%), 1-decene (7.6%) and 1-hexanol (7.0%) in H. mutabile; α- and β-pinene in H. patulum (27.6% and 44.9%, respectively) and α-pinene (36.3%) and α-fanchene(15.6%) in H. setosum. The EOs composition of these species was also different from each other with sesquiterpene compounds as the prevalent class. Valerianol (16.3%, os, in H. basalticum), ledol (16.3%, os, in H. foetidum), β-caryophyllene (11.0% and 13.4%, sh, in H. indicum and H. patulum, respectively), viridiflorol (18.3%, os, in H. montanum) and valerianol (30.1%, os in H. setosum) were found to be the main constituents. It is worthy to highlighting that the H. incarnatum EO showed a similar behaviour to that of the spontaneous emission with a predominance of monoterpene hydrocarbons (60.7% in EO vs 81.4% in VOC), both represented by (Z)-β-ocimene as main constituent.

Carbohydrates are important compounds in natural products where they primarily serve as a source of energy, but they have important secondary roles as precursors of aroma or bioactive compounds. They are present in fresh and dried (cured) tobacco leaves as well. The sugar content of tobacco depends on the tobacco variety, harvesting, and primarily on the curing conditions (temperature, time and moisture). If the process of curing employs high temperatures (flue-curing and sun-curing), final sugar content is high. In contrast, when air curing has a lower temperature, at the end of the process, sugar level is low. Beside simple sugars, other carbohydrates reported in tobacco are oligosaccharides, cellulose, starch, and pectin. Degradation of polysaccharides results in a higher yield of simple sugars, but at the same time reduces sugars oxidization and transfer into carbon dioxide and water. Loss of sugar producers will compensate with added sugars, to cover undesirable aroma properties and achieve a better, pleasant taste during smoking. However, tobacco carbohydrates can be precursors for many harmful compounds, including formaldehyde and 5-hydroxymethylfurfural. Keeping in mind that added sugars in tobacco production are unavoidable, it is important to understand all changes in carbohydrates from harvesting to consuming in order to achieve better product properties and avoid the formation of harmful compounds. This review summarizes current knowledge about tobacco carbohydrates, including changes during processing with special focus on carbohydrates as precursors of harmful compounds during smoking.

The free aromatic composition of must from Pedro Giménez grapes, grown in San Juan, Argentina, was characterised. Samples from the vintages of 2008 and 2009 were analysed by gas chromatography–mass spectrometry–solid phase microextraction (GC–MS–SPME). Higher alcohols, terpenes, C13-norisoprenoids, esters, aldehydes and ketones were quantified. The calculation of the odour activity values (OAVs) revealed that β-damascenone, α-ionone, β-linalool, geraniol, ethyl butanoate, hexanoate and octanoate were the most prevalent aroma-active compounds of the grape variety. However, the remaining 42 aromatic compounds that registered OAVs less than 1 could potentially contribute to the flavour of Pedro Giménez grapes. The measured monoterpene levels indicate that the Pedro Giménez grape can be considered a neutral variety. This is the first report describing the main potential free aroma contributors of Pedro Giménez grapes in two consecutive years. EEA Mendoza Fil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Nally, María Cristina. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Assof, Mariela Vanesa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; Argentina Fil: Toro, María Eugenia. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina Fil: Castellanos de Figueroa, Lucía Inés. PROIMI; Argentina. Universidad Nacional de Tucumán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Jofre, Viviana Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza. Laboratorio de Aromas y Sustancias Naturales; Argentina Fil: Vazquez, Fabio. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina

The aroma profiles of 10 traditional Italian fermented sausages were evaluated. The volatile organic compounds (VOCs) obtained by solid-phase microextraction and gas chromatograph-mass spectrometry were analysed using principal component analysis (PCA) and linear discriminant analysis (LDA). PCA allowed an acceptable separation but some sausage typologies were not well separated. On the other hand, the supervised approach of LDA allowed a clear grouping of the samples in relation to sausage size and starter culture. In spite of the extreme variability of the volatile profiles of the sausage typologies, this work showed the influence of diameter on VOC profile. The differences observed can be related to the effects that some fundamental physicochemical characteristics (such as water loss kinetics and oxygen availability) have on the results of ripening processes. Differences in VOC profiles were also observed due to the lactic acid bacteria used as starter cultures, with differences mainly attributable to compounds deriving from pyruvate metabolism.

Four batches of Milano-type dry fermented sausages were industrially produced to evaluate the effects of two different lactic acid bacteria starter cultures ( Lactobacillus sakei and Pediococcus pentosaceus ) and diameter on physico-chemical, microbiological and aroma characteristics during processing and in the final products. Values of a w and pH were similar in the final sausages. Lactic acid bacteria counts were high and slightly influenced by the diameter, while higher concentrations of staphylococci were found in small sausages. The diameter had a strong influence on the formation of volatile organic compounds, as revealed by PCA analysis. The main differences regarded ketones (acetone, 2-butanone, 3-hydroxy-2-butanone and 2,3-butandione) and aldehydes (mainly hexanal). The influence of starter cultures was less evident, also due to the presence of indigenous L . sakei in the sausages inoculated with pediococci. Nevertheless, the choice of L . sakei or P. pentosaceus as starter culture showed a direct effect on some of the main process parameters (fermentation and acidification rate) and generation of volatile compounds. The results evidenced the need to optimize the process to increase starter culture performances.

V. vinifera cv. Pinot Noir vines were grown in pots together with blackberry plants and the effect of this association on the grape aroma was assessed. Preliminary data showed that vines that cohabited with blackberry had a different aroma profile compared to vines grown alone. The association with blackberry increased the concentration of 30 out of 74 free aroma compounds and 24 out of 95 bound ones. No aroma compound was identified exclusively in the treated grapes.

Mixed fermentations with Starmerella bacillaris and Saccharomyces cerevisiae affect the chemical composition of wines, by modulating various metabolites of oenological interest. The current study was carried out to elucidate the effect of sequential inoculation of the above mentioned species on the production of white wines, especially on the chemical and aromatic characteristics of Chardonnay, Muscat, Riesling and Sauvignon blanc wines. Titratable acidity and glycerol content exhibited evident differences among the wines after fermentation. For volatile compounds, mixed fermentations led to a reduction of the total esters, including ethyl acetate, which is a compound responsible for wine deterioration. However, Sauvignon blanc wines fermented by mixed cultures contained significantly higher levels of esters and thiols, both associated with positive sensory attributes. These findings suggest that sequential inoculations possess great potential in affecting and modulating the chemical and aromatic profile of white wines, especially those produced from Sauvignon blanc grapes.

The aim of the present study was to investigate encapsulation of probiotic Lactobacillus casei ATCC 393 on alginates using the extrusion technique and to evaluate cell survival under simulated gastrointestinal conditions and during fermented milk production and storage at 4 °C for up to four weeks. Encapsulation of probiotic bacteria led to significantly higher viabilities compared to free cells under simulated gastrointestinal conditions, as well as after storage for 28 days in fermented milk (7.13 log cfu g−1). In addition, the effect of encapsulated L. casei ATCC 393 cells on aroma volatile compounds formation during milk fermentation was studied using the SPME GC/MS technique. The fermented milks presented improved aroma, containing characteristic compounds produced usually by L. casei in fermented dairy products. The results showed that the alginate matrix has a great potential as encapsulation material for probiotics and application of the encapsulated cells in fermented dairy products may result in effective maintenance of cell survival during refrigerated storage and improvement of sensory characteristics. From an economical point of view and under certain conditions, the application of encapsulated probiotic cells is a sustainable process for the production of fermented milk.

WOS: 000409154900021 Kefir grains consist of rich bacterial and fungal microflora responsible for the production of this traditional fermented milk beverage with unique flavour properties. Here, a pyrosequencing approach was applied for the identification of microbial flora of four kefir grains collected from different regions of Turkey and the volatile compounds in kefir samples produced with these grains were determined. Lactobacillus kefiranofaciens presented in all grains at important levels and Enterobacter, Acinetobacter, Enterococcus and Pseudomonas spp. were observed in traditional kefir grains. The fungal microflora of kefir grains was dominated by yeast species and Dipodascaceae family was dominant and Saccharomyces cerevisiae presented in all grains. Other yeast species belonging to Kazachstania, Candida, Issatchenkia and Rhodotorula species were also detected in kefir grains. Volatile compounds of kefir samples were also diverse related to the microbial diversity of kefir grains. This study revealed the rich microflora of Turkish kefir grains and their interactions with the aromatic properties of kefir. (C) 2017 Elsevier Ltd. All rights reserved. Bayburt University This study was supported by Bayburt University through an internal fund. We thank Htimeyra Ispirli and Zuhal Akay for technical assistance.

The aroma profile of shade-dried aerial part from Iranian dill (Anethum graveolens L.) and Savory (Satureja sahendica Bornm.) plants was analyzed by the gas chromatography–mass spectrometry (GC–MS) and gas chromatography–flame ionization detector (GC–FID). For the first time in these aromatic plants, the solvent-assisted flavour evaporation (SAFE) extraction method with dichloromethane was used prior to GC–MS. A total of 40 and 26 aroma compounds was identified in dill and savory. Dill contained 271.52 µg/g total amount of aroma compounds, which included terpenes (28), aldehydes (3), alcohol (1), acids (3), volatile phenols (3), ketone (1) and norisoprenoid (1). Savory possessed 10,547.16 µg/g total amount of aroma compounds, including terpenes (20), alcohol (1) and volatile phenols (5). Of all aroma compounds detected in both plants, terpenes were quantitatively the most dominant aroma volatiles. In the overall aroma volatiles, ?-phellandrene (160.0 µg/g) together with sabinene (26.5 µg/g), d-carvone (16.2 µg/g), dl-limonene (12.3 µg/g) and dill ether (7.8 µg/g) in dill and ?-terpinene (6236.83 µg/g) along with carvacrol (3239.19 µg/g), ?-pinene (267.08 µg/g), ?-thujene (219.36 µg/g) and ß-bisabolene (130.8 µg/g) in savory were the major compounds. © 2017, Springer Science+Business Media New York.

Since the early days of the specialty coffee movement, freshness has been one of its central pillars. Freshness is best defined as having original unimpaired qualities. In coffee, it is most often seen as freshly roasted, ground within a few days, immediately extracted, and consumed. But despite this pivotal role of freshness for high quality coffee, the objective and scientific measurement of freshness have often been vague and elusive. How can one measure the level of freshness of coffee? In this chapter we will outline two approaches. One is based on the degassing of the freshly roasted coffee and the other on the evolution of its aroma profile during storage. In terms of the evolution of the aroma profile, we will introduce one particular freshness index: the ratio of dimethyl disulfide to methanethiol, suited to assess the evolution of freshness of roasted coffee during storage. Although this ratio has been shown to increase during storage, the speed at which this freshness index increases depends on the packaging and storage temperature. This has opened the possibility to use this index to assess the freshness of roasted coffee and compare the quality of different packaging materials for preserving the freshness of the coffee inside.

Cantaloupensis melons are aromatic and fast senescing, whereas Inodorus have less odor and are slower senescing. Modified atmosphere packaging (MAP) is used to reduce respiration rate and extend shelf-life but may alter the synthesis of volatile compounds. We assessed the effects of passive MAP and controlled atmosphere (CA; 5 kPa O 2 + 10 kPa CO 2 ) upon quality and volatile production by fresh-cut 'Cantaloupe' and 'Honeydew' melons, stored at 5°C for 14 days. O 2 concentration inside the MAP packages decreased during the 14 days, to 11.1 and 14.2 kPa, in 'Cantaloupe' and 'Honeydew', respectively. CO 2 levels increased to 11.3 and 7.9 kPa during storage, for 'Cantaloupe' and 'Honeydew', respectively. In MAP, during the first 4 days of storage, cantaloupe cubes softened at a higher rate (2.0 N.day -1 ) than 'Honeydew' cubes (0.9 N.day -1 ). Conversely in CA, fresh-cut 'Honeydew' softened faster (1.9 N.day -1 ) than fresh-cut 'Cantaloupe' (0.9 N.day -1 ) which, softened faster between days 4 and 7 (2.1 N.day -1 ). Initial 'Cantaloupe' respiration was 17.5 ml CO 2 .kg -1 .h -1 , which increased to 63.8 and 43.4 ml CO 2 .kg -1 .h - 1 when stored in CA and MAP, respectively. Initial respiration of 'Honeydew' melon was 7.7 ml CO 2 .kg -1 .h -1 and increased to 55.5 and 30.0 ml CO 2 .kg -1 .h -1 when stored in CA and MAP, respectively. Volatile compounds that are known to be flavor-important in melons, were extracted using Stir Bar Sorptive Extraction (SBSE) and quantified via GC-MS. The production of acetate esters increased in both melons stored in MAP, but decreased in 'Cantaloupe' under CA conditions. Non-acetate esters increased in both cultivars and storage conditions. Alcohols, initially more abundant in 'Honeydew', underwent a decrease throughout storage. Aldehydes, initially more abundant in 'Cantaloupe', decreased in both melons for MAP but not in 'Honeydew' stored in CA. Lower O 2 availability in fresh-cut fruit, stored under CA conditions utilized in this experiment, likely suppressed some of the acetate esters relevant to the aroma of fresh-cut melon.

We evaluated dehydrofreezing in strawberries in terms of retention of healthy compounds (i.e. polyphenolics) and sensory qualities for direct consumption in substitution of fresh fruit. Different osmodehydration (OD at 30 °C and 5 °C), vacuum osmodehydration (VOD at 30 °C) and immersion chilling freezing (ICF) processes were applied in sucrose syrup. Samples were analyzed for dry matter, soluble solids, pH, titratable acidity, mass transfers, polyphenolic content by HPLC-DAD/MSD, volatile profile by SPME-GC/MSD and consumer acceptance. The results of sensory evaluation, in particular, confirmed the cryoprotective effects of osmotic processes of fruits with respect to untreated frozen control samples. The OD samples at 5 °C presented a water loss to solid gain ratio comparable to OD at 30 °C and VOD samples. Moreover, while osmo-dehydrofreezing at relatively high temperatures caused a slight depletion of phenolic compounds, the samples osmodehydrated at 5 °C showed higher polyphenolic retention. Data on aromatic compounds showed that some compounds increased (e.g. ethanol and acetaldehyde), while others did not appear to be affected by the pre-treatments.

The indigenous Lactobacillus rhamnosus DSA LR1 was isolated from milk that was obtained from a restricted geographical area in northeast Italy and it was chosen, among other isolated strains on the bases of its resistance to the pH of gastric juices, the bile salts, the antibiotics and its lipolytic and proteolytic activities. The indigenous isolated potential probiotic bacteria were then added in combination with starter bacteria to the milk used for yogurt production. The results showed that L. rhamnosus DSA LR1 was able to maintain its viability for the entire shelf-life period without affecting on the viability or acidification capacity of starter culture. At the end of the fermentation period, the yogurt that had been co-fermented with L. rhamnosus DSA LR1 presented an aroma profile that was qualitatively similar to the control yogurt but less intense from a quantitative point of view. However, all of the major volatile compounds tended to increase during storage at 4 °C for 20 days, yogurt with L. rhamnosus had absolute areas larger than the areas of the control yogurt for all major carbonyl compounds.

WOS: 000388819600003 Aroma, aroma-active compounds and fatty acid profiles of Iranian olive oil obtained from the cv. Mari were investigated for the first time in the current study. Aroma extracts were isolated from the oil by using a purge and trap extraction system and their compositions were analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O). A total of 35 aroma compounds comprising alcohols, aldehydes, acids, esters, ketones, terpenes and volatile phenols were identified and quantified in the assayed samples. Aldehydes were present at the highest levels, followed by ketones and alcohols. (E)-2-Hexenal was quantitatively (1589 A mu g kg(-1)) the main aroma compound in the analyzed oils, followed by hexanal and (E)-2-heptenal. The aroma-active volatiles were elucidated in the aromatic extract by applying aroma extract dilution analysis (AEDA). The results of AEDA revealed 17 aroma-active compounds. Under these condition it was possible to completely identify 16 of these compounds. Regarding to the flavor dilution (FD) factor, the most potent odorants with the highest FD factor were (E)-2-hexenal (512), followed by hexanal, 6-methyl-5-hepten-2-one, (E)-2-decenal and one unknown compound (LRI = 1871). The fatty acid profile of the tested oils was composed of thirteen compounds. Oleic acid was the main fatty acid (76.01 %) followed by palmitic acid.

Mead is a traditional alcoholic beverage obtained by the fermentation of diluted honey performed by yeasts. In this work the potential of application of immobilised yeast cells on single-layer Ca-alginate or double-layer alginateechitosan for mead production was assessed for the first time. The meads produced either with entrapped or free cells were evaluated in terms of quality and aroma profile. The immobilisation procedure had no adverse effect on cell viability, since minor differences were found in fermentation kinetics among the strains and immobilisation systems. The double-layer alginate-chitosan had no advantage compared with the single-layer Ca-alginate, as the number of free cells in the medium, resulting from cell leakage, was similar. Although meads obtained with entrapped yeast cells presented less ethanol and glycerol and more acetic acid, it exhibited larger amounts of volatile compounds. Immobilised cells produced meads with more compounds with fruity characteristics, such as ethyl octanoate and ethyl hexanoate; however the concentrations of undesirable compounds in such meads were also higher. The effect of immobilisation on the aroma profile was important, but the strain contribution was also of major importance. Thus, the sensory analysis of final product gives an important insight on the overall quality., The research presented in this paper was partially funded by the Fundacdo para a Ciencia e Tecnologia, (FCT) and by PTDC projects (contracts PTDC/AGR-ALI/68284/2006). A.P.P. is a recipient of a Ph.D. grant from the FCT (SFRH/BD/45820/2008).

The aim was to evaluate the effect of wine addition during manufacturing of dry fermented sausages, in terms of safety aspects (biogenic amine accumulation), aroma profile and sensory characteristics. Three batches of salami were produced: without wine addition and with 7.5% or 15% (v/w) of white wine. The fermented sausages showed characteristics that can increase product diversification. Some of the sensory features (i.e. increased salty perception) can represent an important strategy because of the trend to reduce salt intake for health reasons. The presence of wine immediately reduced the pH and is a source of ethanol, which can have an inhibitory effect against undesirable microflora. The microbiological results observed regarding Enterobacteriaceae and enterococci were encouraging. The addition of wine did not negatively affect the ripening time or increase the presence of biogenic amines. The samples containing wine showed reduced concentrations of putrescine.

Mead is a traditional drink that contains 8 % and 18 % (v/v) of ethanol, resulting from the alcoholic fermentation of diluted honey by yeasts. Mead fermentation is a time-consuming process and the quality of the final product is highly variable. Therefore, the present investigation had two main objectives: first, to determine the adequate inoculum size of two commercial wine-making strains of Saccharomyces cerevisiae for the optimisation of mead fermentation; and second, to determine if an increase in yeast pitching rates in batch fermentations altered the resulting aroma profiles. Minor differences were detected in the growth kinetics between the two strains at the lowest pitching rate. With increasing pitching rates net growth of the strain ICV D47 progressively decreased, whereas for the QA23 the increasing inoculum size had no influence on its net growth. The time required to reach the same stage of fermentation ranged from 24 to 96 h depending on the inoculum size. The final aroma composition was dependent on the yeast strain and inoculum size. Fourteen of the twenty-seven volatile compounds quantified could contribute to mead aroma and flavour because their concentrations rose above their respective thresholds. The formation of these compounds was particularly pronounced at low pitching rates, except in mead fermented by strain ICV D47, at 106 CFUs/mL. The esters isoamyl acetate, ethyl octanoate and ethyl hexanoate were the major powerful odourants found in the meads. The results obtained in this study demonstrate that yeast strain and inoculum size can favourably impact mead’s flavour and aroma profiles., The research presented in this paper was partially funded by the Fundacao para a Ciencia e Tecnologia, (FCT) and by PTDC projects (contracts PTDC/AGR-ALI/68284/2006). A.P.P. is a recipient of a Ph.D. grant from FCT (SFRH/BD/45820/2008).