Influence of Varying Fermentation Parameters of the Yeast Strain Cyberlindnera saturnus on the Concentrations of Selected Flavor Components in Non-Alcoholic Beer Focusing on (E)-ß-Damascenone.

The diversification of beer flavor is becoming increasingly popular, especially in the field of non-alcoholic beers, where sales are growing steadily. While flavor substances of traditional beers can largely be traced back to defined secondary metabolites, the production of non-alcoholic beers with non-Saccharomyces yeasts generates novel fruity flavors, some of which cannot yet be assigned to specific flavor substances. In a recently published study, besides pear, cool mint sweets, and banana-like flavor, distinctive red berry and apple flavors were perceived in a non-alcoholic beer fermented with the yeast strain Cyberlindnera saturnus TUM 247, whose secondary metabolites were to be elucidated in this study. The trials were carried out using response surface methodology to examine the fermentation properties of the yeast strain and to optimize the beer with maximum fruitiness but minimal off-flavors and ethanol content. It turned out that a low pitching rate, a moderate fermentation temperature, and an original gravity of 10.5 °P gave the optimal parameters. Qualitative analysis of the secondary metabolites, in addition to standard analysis for traditional beers, was first performed using headspace-gas chromatography with olfactometry. (E)-ß-damascenone emerged as the decisive substance for the red berry and apple flavor and so this substance was then quantitated. Although (E)-ß-damascenone is a well-known secondary metabolite in beer and this substance is associated with apple or cooked apple- and berry-like flavors, it has not yet been reported as a main flavor component in non-alcoholic beers.

Antioxidant Capacity of Free Volatile Compounds from Olea europaea L. cv. Oblica Leaves Depending on the Vegetation Stage.

Previous research on specialized metabolites of olive leaves has focused on the phenolic components and their biological role. The research in this article focuses on the metabolites that form free volatile compounds (FVCs). The composition of FVCs is divided into compounds isolated in the oil phase (essential oils; EO) and in the aqueous phase (hydrosols; Hy) from leaves of Olea europaea L. cultivar Oblica. Plant material was collected from the same olive tree over a six-month period, from December to May, and analyzed by gas chromatography-mass spectrometry (GC-MS). The compounds ß-caryophyllene, α-humulene, allo-aromadendrene, docosane, hexadecanoic acid and oleic acid were identified in all EO study periods. In the Hy in all studied periods, the major compounds are α-pinene, ß-ionone, myristicin, docosane, 1-hexanol, oleic acid and (E)-ß-damascenone. The differences in the qualitative composition of FVC are directly related to the phenological development of the leaves. Antioxidant capacity of the EOs and hydrosols was measured with two methods, ORAC and DPPH. Hydrosol extracts showed higher capacity than the EOs in all methods.

Characterization of the aroma-active compounds in black soybean sauce, a distinctive soy sauce.

Black soybean sauce's (BSS) aroma was scarcely investigated, which seriously affected BSS's quality and consumers' preference. Thus the aroma compounds in BSS were characterized using gas chromatography-mass spectrometry/gas chromatography-olfactometry coupling with recombination and omission experiments. Sensory evaluation showed the fruity odor was increased by 63% and the malty, alcoholic, floral, smoky, caramel-like and sour odors were decreased by 24-35% when compared to the control soy sauce (SS, p < 0.05). Totally, 126 volatile compounds, 44 aroma-active compounds and 22 vital aroma-active compounds were identified in BSS. Compared to SS, BSS exhibited a distinctive aroma characteristics which was caused by significantly higher odor activity values (OAVs) of 3-methylbutyl acetate (357%), ethyl propanoate (144%), ethyl 3-methylbutanoate (70%), ethyl 2-methylbutanoate (102%) and lower OAVs of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (52%), 4-hydroxy-2-ethyl-5-methyl-3(2H)-furan-3-one (50%), ethanol (48%), 4-vinylguaiacol (41%), 3-methylthiopropanal (37%), 3-methylbutanol (33%), 4-ethylguaiacol (28%). The results would contribute to BSS's quality control and aroma improvement.

Chemical composition, anti-nociceptive and anti-inflammatory activities of essential oil of Bougainvillea glabra.

ETHNOPHARMACOLOGICAL RELEVANCE: Bougainvillea glabra is widely used in Nigeria for the treatment of inflammatory-related conditions, and as remedy for pain ailments. AIM OF THE STUDY: Considering the lack of scientific studies focused on chemical constituents and pharmacological activity of B. glabra essential oil, this work was designed to characterize the volatile compounds and evaluate the anti-inflammatory and anti-nociceptive properties ascribed to this plant species. MATERIALS AND METHODS: The essential oil was extracted from the leaf of B. glabra by hydrodistillation in an all glass Clevenger-type apparatus and characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS) on HP-5 column. The anti-inflammatory property of the essential was established by measurement of carrageenan induced rat paw edema while the anti-nociceptive activity was determined by hot plate test, according to established procedures. RESULTS: The essential oil was obtained in a yield of 0.08% (v/w) calculated on dry weight basis. A total of 11 compounds representing 96.2% of the oil contents were identified by GC/MS. The main constituents of the essential oil were (E)-nerolidol (31.4%), (E)-ß-ionone (10.3%) and linalool (10.1%). The anti-nociceptive property of the essential oil was statistically significant p < 0.001 at all doses of when compared to the control while exhibiting an activity in tandem with the standard drug. For the 1st and 2nd h, at doses of 100 and 200 mg/kg, the anti-inflammatory activity was statistically very significant (p < 0.001), while at 3rd h the activity declined (p < 0.01) at a dose of 200 mg. The activity was non-significant at the 4th h experimental duration. CONCLUSIONS: This is first report on the chemical constituents and biological activity of essential oil of B. glabra from Nigeria. Overall, the results herein presented sustain and strengthen the anti-nociceptive and anti-inflammatory properties traditionally ascribed to B. glabra.

Characterization of free and bound volatile compounds in six Ribes nigrum L. blackcurrant cultivars.

This study investigated the profiles of free and bound volatile compounds of six currant cultivars grown in China. Results showed that 166 free and 111 bound volatiles were found in these cultivars with esters and terpenoids as the major volatiles. Additionally, 10 hydroxy esters were detected in these cultivars for the first time. Floral, fruity, and sweet flavors appeared to be the feature aroma in these cultivars, which resulted from the contribution of 17 volatiles. Principal component analysis indicated the cultivar "Fertodi", "Risagar" and "Liangye" had the similar profiles of free and bound volatile compounds, whereas the cultivar "Brodtrop" and "Yadrionaya" exhibited the similarity on their free and bound volatiles. The cultivar "Sofya" showed a different volatile composition. Cluster analysis revealed the cultivar "Fertodi", "Risagar", and "Liangye" had the similar profiles of free and bound volatile compounds, whereas the similar free and bound volatile compositions were observed in the cultivar "Sofya" and "Yadrionaya". This study could provide useful information on quality control of commercial currant products.

Decoding the combinatorial aroma code of a commercial Cognac by application of the sensomics concept and first insights into differences from a German brandy.

In the volatile fraction isolated from a commercial Cognac by means of extraction/SAFE distillation, 39 odor-active areas were detected, among which (E)-ß-damascenone showed the highest flavor dilution (FD) factor of 2048 followed by 2- and 3-methylbutanol, (S)-2-methylbutanol, 1,1-diethoxyethane, ethyl methylpropanoate, and ethyl (S)-2-methylbutanoate, as well as 4-hydroxy-3-methoxybenzaldehyde (vanilla-like) and 2-phenylethanol. The quantitation of 37 odorants by stable isotope dilution assays and a calculation of odor activity values (OAV; ratio of concentration to odor threshold) resulted in 34 odorants with OAVs > 1. Among them (E)-ß-damascenone, methylpropanal, ethyl (S)-2-methylbutanoate, ethyl methylpropanoate, and ethyl 3-methylbutanoate together with ethanol were established as key contributors to the Cognac aroma. Finally, the overall aroma of the Cognac could be mimicked by an aroma recombinate consisting of these 34 key odorants on the basis of their natural concentrations in the Cognac using an odorless matrix to simulate the influence of the nonvolatile constituents. A comparison of the FD factors of the key odorants identified in a German brandy to those in the Cognac suggested the pair (E)-ß-damascenone and ethyl pentanoate as indicators to differentiate various Cognacs from German, French, and Spanish brandies. This was confirmed by calculating a ratio of the concentrations of (E)-ß-damascenone to ethyl pentanoate for 12 Cognacs and 7 brandies from Germany and 2 from France and Spain, respectively.