Flavour and Fragrance Journal最新文献

Two commercial dry strains of Saccharomyces cerevisiae and their different inoculum levels were used to carry out cider fermentation to assess their impact on the quality and volatile flavour composition of cider. Analyses indicated that the composition and production of flavour compounds of ciders are generally significantly affected by the strains and inoculation levels. Additionally, the Uvaferm CM strain produced the lowest amount of relative and total flavour compounds compared to Actiflore PM. According to the PCA, differences in volatile components were observed in ciders obtained from both yeasts. While the 1st and 2nd concentrations of Actiflore PM yeast fall to the same region and the others to the different region, the 1st, 2nd and 3rd concentrations of the Uvaferm CM yeast are located in the same region and the others in the different region. It could be said that the Actiflore PM strain synthesizes compounds (such as ethyl alcohol, relative and total esters) that are effective on the quality of cider, the higher amount that Uvaferm CM. The data obtained can be useful for cider producers.

Numerous studies indicate that the efficiency of microwave extraction, a popular method for extracting essential oil, needs to be improved. In this study, we used fennel (Foeniculum vulgare) as the focused species, extracted its essential oil using three methods, including traditional hydrodistillation (HD), single-cooled microwave extraction (SCME) and dual-cooled microwave extraction (DCME), and then tested the chemical composition and antibacterial activity of the essential oils. The optimum parameters of DCME were liquid-solid ratio 5.6 mL/g, extraction time 27 min and irradiation power 600 W. The yield of fennel essential oil raised to 1.172%. The composition of essential oils obtained by both SCME and DCME was obviously different from that obtained by HD, such as higher monoterpene hydrocarbons in SCME and higher oxygenated monoterpenes in DCME. Furthermore, Salmonella Typhimurium and Escherichia coli were the most sensitive to fennel essential oil, followed by Staphylococcus aureus and Listeria monocytogenes. The activity of essential oil from different methods against four bacteria strains was similar. Our founding revealed that the improved microwave extraction greatly raised the yield of fennel essential oil, retained its fragrance and antibacterial activity. Overall, this study provides a theoretical basis for the separation and application of essential oils from natural aromatic plants.

Gas Chromatography/High-Resolution Mass Spectrometry (HRMS) was used to identify new compounds in Rosa damascena and Rosa centifolia absolutes. These compounds were esters derived from the main alcohols of rose absolute (phenylethyl alcohol, geraniol, citronellol, nerol, and (E,E)-farnesol). Based on low-resolution mass spectrometry (LRMS) and HRMS data of rose absolutes, hypotheses were first formulated. In a second stage, the standards of these candidate structures were synthetized and analyzed by LRMS using apolar and polar columns. LRMS spectra of these standards, and apolar and polar retention indices (RI) were compared with those of candidate structures. Only four out of nineteen molecules were validated by these three criteria mostly due to an important difference of polar RIs between the standards and the compounds detected in rose absolutes. In a third stage, absolutes were spiked with synthesized standards and were analyzed by HRMS on both apolar and polar columns to confirm the presence of these candidate structures. Finally, 19 new compounds were identified in Rosa damascena and Rosa centifolia absolutes.

A predictive tool called COSMO-RS, Conductor-Like Screening Model for Real Solvents, based on quantum chemistry, dielectric continuum models, electrostatics surface interactions, and statistical thermodynamics, has been used to predict five key physicochemical properties of raw materials used in perfumery industries. The prediction of boiling point (BP), octanol-water partition coefficient (log P), vapor pressure (VP), water solubility (WS), and Henry's law constant (HLC) of fragrance molecules has been validated with a reference data set of 166 organic compounds. Knowing these properties for a fragrance molecule is essential and being able to predict them precisely can be particularly useful in the development of new molecules or in the replacement of controversial molecules regarding safety issues without compromising the overall hedonic accord. Finally, mapping the vapor pressure versus the Henry's law constant and the octanol-water partition coefficient consistently predicts the note class of the molecules useful for release comparison of captives.

Donkey broth has a unique aroma and is affected by cooking time. Five donkey broth samples of different stewing time were prepared. The volatile components were extracted by solvent-assisted flavor evaporation (SAFE) and analyzed by gas chromatography-mass spectroscopy (GC-MS). According to the result, a total of 45 volatile aroma compounds were identified in five donkey broths (stewing time of 0 min, 1, 2, 3 and 4 h respectively). In terms of gas chromatography-olfactometry (GC-O) analysis, aroma extraction dilution analysis (AEDA) and calculating odor activity values (OAVs), respective 26 and 15 aroma active compounds were pointed out significantly in five donkey broths. Twelve odorants including 2-methyl pentanal, 3-hydroxyl-2-butanone, hexanal, dimethyl trisulfide, nonanal, 3-(Methylthio)propanal, 2-ethyl-1-hexanol, benzaldehyde, 4-methoxyallylbenzene, (E,E)-2,4-nonadienal, delta-hexalactone and octanoic acid were characterized as the common aroma active compounds existed in donkey broths with different stewing time. Principal component analysis (PCA) and sensory evaluation results characterized the difference of aroma profiles for the five different donkey broths, which showed that the duration of the stewing time had an important effect on the general flavor of donkey broth.

In China, Lu'an Guapian (LAGP) tea consists of tea leaves without tea buds or stems. In this study, we evaluated the aromatic characteristics of LAGP by sensory analysis, aroma extract dilution analysis (AEDA), and odor activity values. The sensory analysis revealed that LAGP had cooked soybean-like, cooked chestnut-like, roasted, cooked corn-like, fishy, fruity, floral, and grass aromas. Aroma-active compounds from LAGP were identified by solvent extraction-solid phase extraction (SE-SPE) and headspace-solid phase microextraction (HS-SPME), and subjected to AEDA. A total of 91 aroma-active compounds were identified by SE-SPE-AEDA with flavor dilution (FD) factors ranging from 1 to 4096. A total of 66 aroma-active compounds were identified by HS-SPME-AEDA with FD of 1 to 128. Nine compounds with FD ≥64 and OAVs ≥1 were major aroma-active compounds to the aroma of LAGP tea: raspberry ketone (raspberry), (E)-β-ionone (floral, raspberry), dimethyl sulfide (cooked corn-like), indole (animal), phenylacetaldehyde (floral, honey-like), 2-ethyl-3,5-dimethylpyrazine (roasted), (Z)-4-heptenal (cooked soybean-like, fishy), (Z)-jasmone (jasmine), and geraniol (rose).

Terpene hydroperoxides (THPs) have been reported to be skin sensitizers, so their elimination from citrus oils is desirable for consumer safety. Previously, we reported that treatment of citrus-based perfumes with pyruvic acid and α-ketoglutaric acid (AKG) or their salts was effective at removing existing THPs, measured by peroxide value (POV) titration. AKG salts, if soluble, were effective in neat citrus oil as well, but an insoluble AKG salt was only moderately effective. However, contact with an insoluble salt did prevent further autoxidation of the citrus oil. Herein, we report that coating an inert solid support with an insoluble AKG salt, made from either N-methyl diethanolamine or 1-[bis[3-(dimethylamino)propyl]amino]-2-propanol, produced an easily handled device for insertion into a container of citrus oil; the device was highly effective at maintaining a low POV in fresh orange oil for an extended storage period. Such devices offer a promising mode of preventing autoxidation in fresh citrus oil raw materials.

The aim of this study was to remove bitterness from cold-press produced grapefruit seed oil by adsorption principle. The 14 different materials and 5 different metal–organic frameworks (MOFs) were tested for this purpose. Best performing adsorbents were selected based on the analyses of sensory bitterness measurements, as well as oil loss, free fatty acidity (FFA), peroxide value (PV), and color measurements. The silica gel 60 and MIL-101 MOF were selected as the best performing adsorbents and tested against control oil. There were some changes in oil color. Oil FFA and unsaponifiable matter values were decreased, and PV and turbidities were enhanced after the treatments. Similarly, unsaturated fatty acid content and tocopherols were decreased expectedly. Although MIL-101 caused great sterol losses, it was in fewer quantities with silica gel 60 treatment. Silica gel 60 treatment resulted in the complete removal of the bitter-tasting flavonoids: naringin and neohesperidin. The non-bitter flavonoids were also decreased after both treatments. Most importantly, sensory descriptive analysis proved that after silica gel 60 treatment, the bitter taste was totally removed, and the astringent, menthol, and raw vegetable attributes significantly reduced compared with the control sample. Overall, the silica gel 60 treatment provided total success in removing bitterness from the oil. Further studies for the reusability of the silica gel 60 and possibly other similar adsorbents for the same purpose were suggested.

A series of novel-substituted cyclohexane derivatives has been prepared and their olfactory evaluation is presented. The different structures are derived from the cyclization of an unsaturated ketal under catalytic conditions. Its further functionalization allowed for the preparation of a series of 22 new compounds. Most of the new cyclic compounds present fruity and/or woody notes.

Salvia sclarea L. or clary sage is cultivated worldwide in temperate and sub-tropical climates, as an ornamental and essential oil (EO) bearing plant. EO is obtained from fresh spikes in full flowering stage and is recognized as an important commercial product for food, beverage and cosmetic industries. This study investigated the EO composition of S. sclarea grown in Serbia (Southeast Europe) obtained by two different methods, steam (SD) and hydrodistillation (HD). GC-MS analysis identified oxygenated monoterpenes as the main class of compounds for all EOs (between 81.8% and 88.2% depending on the distillation process). The most abundant oxygenated monoterpenes were linalyl acetate and linalool. In addition, in vitro antimicrobial (modified resazurin microtitre-plate assay) and antioxidant activities (DPPH^· assay) and total polyphenol content of obtained EOs were also evaluated. According to the assay used for the evaluation of the antibacterial activity, Gram-negative bacteria were more sensitive to S. sclarea EO in comparison to Gram-positive bacteria. EOs exhibited low antioxidant capacity, below 3% neutralized DPPH^· radicals, reaching up to approximately 400 µg AAE mL^-1. This study also investigated a possibility for predicting retention indices (RIs) of compounds isolated from EOs. In total, 78 experimentally obtained RIs were applied to construct the prediction model. The quantitative structure-chromatographic retention relationship (QSRR) model was used to anticipate the experimentally obtained RIs. Five molecular descriptors were selected by factor analysis and genetic algorithm to predict RIs. The obtained accuracy of the QSRR model reached r² = .912, which showed that these models might be applied for predicting retention indices.