Discovering the volatilome fingerprint of selected traditional Cuban wines elaborated with native grapes, tropical fruits, and rice using DHS-TD-GC-MS.

Cuban wine is a traditional alcoholic beverage elaborated with a wide variety of raw materials, such as native grapes, tropical fruits, and rice, and different winemaking processes. Research on Cuban wines is almost nonexistent, and therefore, a study of these wines is necessary to improve their quality. Dynamic headspace (DHS)-TD-gas chromatography-mass spectrometry (GC-MS) analysis was carried out to establish the different aroma fingerprints of different Cuban wines. A total of 42 volatile aroma metabolites (VAMs) were identified, including esters, alcohols, aldehydes, acids, volatile phenols, terpenes, and lactones. The odorant activity values (OAV) of each VAM were obtained, and the esters were the most relevant group due to their highest OAV. Ethyl octanoate, hexanoate, and butanoate stand out and are considered key odorants in the aromatic fingerprint. The VAMs were grouped into seven aromatic series. Fruity series showed the highest OAVs due to the contribution of ethyl esters and acetates. Principal component analysis was used to identify the specific parameters most accurately reflecting the differences between the wines. Showing that fruity, spicy, and chemical aromatic series allow distinguishing the wines into three aroma types. These results may provide useful information for the selection of raw materials and optimization of the traditional winemaking processes of Cuban wines. PRACTICAL APPLICATION: This research contributes to knowledge of the aroma and the oenological parameters of traditional and selected Cuban wines (rice wine, tropical fruit wine, and native grape varieties). The establishing of the aroma fingerprint of these wines provides useful information for the industrial development of a quality product that may then be promoted in other areas of the world.

Volatile, Microbial, and Sensory Profiles and Consumer Acceptance of Coffee Cascara Kombuchas.

Given the substantial world coffee production, tons of coffee fruit cascara rich in bioactive compounds are discarded annually. Using this by-product to produce potentially healthy and acceptable foods is a sustainable practice that aggregates value to coffee production and may help improve people's lives. This study aimed to elaborate kombuchas from coffee cascara tea, evaluate their microbial profile, and monitor the changes in the volatile profile during fermentation, together with sensory attributes and acceptance by consumers from Rio de Janeiro (n = 113). Arabica coffee cascaras from Brazil and Nicaragua were used to make infusions, to which black tea kombucha, a Symbiotic Culture of Bacteria and Yeasts (SCOBY), and sucrose were added. Fermentation of plain black tea kombucha was also monitored for comparison. The volatile profile was analyzed after 0, 3, 6, and 9 days of fermentation via headspace solid phase microextraction GC-MS. A total of 81 compounds were identified considering all beverages, 59 in coffee cascara kombuchas and 59 in the black tea kombucha, with 37 common compounds for both. An increase mainly in acids and esters occurred during fermentation. Despite the similarity to black tea kombucha, some aldehydes, esters, alcohols, and ketones in coffee cascara kombucha were not identified in black tea kombucha. Potential impact compounds in CC were linalool, decanal, nonanal, octanal, dodecanal, ethanol, 2-ethylhexanol, ethyl acetate, ethyl butyrate, ethyl acetate, ß-damascenone, γ-nonalactone, linalool oxide, phenylethyl alcohol, geranyl acetone, phenylacetaldehyde, isoamyl alcohol, acetic acid, octanoic acid, isovaleric acid, ethyl isobutyrate, ethyl hexanoate, and limonene. The mean acceptance scores for cascara kombuchas varied between 5.7 ± 0.53 and 7.4 ± 0.53 on a nine-point hedonic scale, with coffee cascara from three-day Nicaragua kombucha showing the highest score, associated with sweetness and berry, honey, woody, and herbal aromas and flavors. The present results indicate that coffee cascara is a promising by-product for elaboration of fermented beverages, exhibiting exotic and singular fingerprinting that can be explored for applications in the food industry.

Electroantennographic Responses of Wild and Laboratory-Reared Females of Xyleborus affinis Eichhoff and Xyleborus ferrugineus (Fabricius) (Coleoptera: Curculionidae: Scolytinae) to Ethanol and Bark Volatiles of Three Host-Plant Species.

Chemical ecology studies on ambrosia beetles are typically conducted with either wild or laboratory-reared specimens. Unlike laboratory-reared insects, important aspects that potentially influence behavioral responses, such as age, physiological state, and prior experience are unknown in wild specimens. In this study, we compared the electroantennographic (EAG) responses of laboratory-reared and wild X. affinis and X. ferrugineus to 70% ethanol and bark odors (host kairomones) of Bursera simaruba, Mangifera indica, and Persea schiedeana aged for 2, 24, and 48 h. Chemical analyses of each odor treatment (bark species x length of aging) were performed to determine their volatilome composition. EAG responses were different between laboratory-reared and wild X. ferrugineus when exposed to ethanol, whereas wild X. affinis exhibited similar EAG responses to the laboratory-reared insects. Ethanol elicited the strongest olfactory responses in both species. Among the bark-odors, the highest responses were triggered by B. simaruba at 48 h in X. affinis, and P. schiedeana at 24 and 48 h in X. ferrugineus. Volatile profiles varied among aged bark samples; 3-carene and limonene were predominant in B. simaruba, whereas α-copaene and α-cubebene were abundant in P. schiedeana. Further studies are needed to determine the biological function of B. simaruba and P. schiedeana terpenes on X. affinis and X. ferrugineus, and their potential application for the development of effective lures.

Antibacterial Activity of Volatile Organic Compounds Produced by the Octocoral-Associated Bacteria Bacillus sp. BO53 and Pseudoalteromonas sp. GA327.

The present research aimed to evaluate the antibacterial activity of volatile organic compounds (VOCs) produced by octocoral-associated bacteria Bacillus sp. BO53 and Pseudoalteromonas sp. GA327. The volatilome bioactivity of both bacteria species was evaluated against human pathogenic antibiotic-resistant bacteria, methicillin-resistant Staphylococcus aureus, Acinetobacter baumanni, and Pseudomonas aeruginosa. In this regard, the in vitro tests showed that Bacillus sp. BO53 VOCs inhibited the growth of P. aeruginosa and reduced the growth of S. aureus and A. baumanni. Furthermore, Pseudoalteromonas sp. GA327 strongly inhibited the growth of A. baumanni, and P. aeruginosa. VOCs were analyzed by headspace solid-phase microextraction (HS-SPME) joined to gas chromatography-mass spectrometry (GC-MS) methodology. Nineteen VOCs were identified, where 5-acetyl-2-methylpyridine, 2-butanone, and 2-nonanone were the major compounds identified on Bacillus sp. BO53 VOCs; while 1-pentanol, 2-butanone, and butyl formate were the primary volatile compounds detected in Pseudoalteromonas sp. GA327. We proposed that the observed bioactivity is mainly due to the efficient inhibitory biochemical mechanisms of alcohols and ketones upon antibiotic-resistant bacteria. This is the first report which describes the antibacterial activity of VOCs emitted by octocoral-associated bacteria.

Volatilome study of the feijoa fruit [Acca sellowiana (O. Berg) Burret.] with headspace solid phase microextraction and gas chromatography coupled with mass spectrometry.

Feijoa is a subtropical bush of the Myrtaceae family. It has unique fruit with organoleptic properties that make it an exotic fruit. Head space solid phase microextraction (HS-SPME) with a 65 µm divinylbenzene/polydimethylsiloxane (DVB/PDMS) fiber and gas chromatography coupled to mass spectrophotometry (GC-MS) was used to study the volatile fraction of feijoa fruit cultured in Caldas, Colombia. The profile analyzed included 134 volatile organic compounds (VOCs). 127 VOCs were classified based on the functional group using the spectral and structural networks correlation analysis. Methyl, ethyl and (Z)-3-hexenyl benzoate with 50% of the volatile composition, were the main compounds. Biosynthesis of the volatilome of feijoa fruit was associated with five main metabolic pathways. This study represents the first analysis of feijoa fruit commercialized in the region. This is an innovator view in elucidation of metabolic pathways that represent the biochemistry of the aroma of this fruit.

Influence of the culture preparation and the addition of an adjunct culture on the ripening profiles of hard cheese.

The aim of this work was to evaluate the impact of two factors on the ripening profiles of hard cooked cheeses: (F1) the growth medium for the primary and adjunct cultures, constituted by autochthonous strains: Lactobacillus helveticus 209 (Lh209) and Lactobacillus paracasei 90 (Lp90), respectively, and (F2) the addition of L. paracasei Lp90 as adjunct culture. Four types of cheeses were made: W and M cheeses in which only Lh209 was added after its growth in whey and MRS, respectively; Wa and Ma cheeses in which both strains (Lh209 and Lp90) were added after their growth in whey and MRS, respectively. Physicochemical and microbial composition, proteolysis and profiles of organic acids and volatile compounds were analyzed. According to the methodology of the cultures preparation, W and Wa cheeses showed a higher level of secondary proteolysis and lower level of primary proteolysis (P < 0·05), lower content of citric and acetic acids and higher amount of propionic acid (P < 0·05), in comparison with M and Ma cheeses. The incorporation of Lp90 increased the secondary proteolysis (P < 0·05), decreased the citric acid (P < 0·05), and increased the propionic acid only when was added after their growth in whey (P < 0·05). Both factors significantly modified the percentages of the volatile compounds grouped in chemical families; in addition, for the half of the compounds detected, significant differences were found. Based on the obtained results, the use of Lp90 as an adjunct in hard cooked cheeses, and the preincubation of the cultures in whey are strategies to accelerate the cheese ripening and to enhance the production of some characteristic compounds of this type of cheeses, such as propan-2-one, hexan-2-one, 2- and 3-methyl butanal, heptan-2-ol, acetic and 3-methylbutanoic acids and 3-hydroxy butan-2-one.

A breath of information: the volatilome.

Volatile organic compounds (VOCs) are small molecular mass substances, which exhibit low boiling points and high-vapour pressures. They are ubiquitous in nature and produced by almost any organism of all kingdoms of life. VOCs are involved in many inter- and intraspecies interactions ranging from antimicrobial or fungal effects to plant growth promotion and human taste perception of fermentation products. VOC profiles further reflect the metabolic or phenotypic state of the living organism that produces them. Hence, they can be exploited for non-invasive medicinal diagnoses or industrial fermentation control. Here, we introduce the reader to these diverse applications associated with the monitoring and analysis of VOC emissions. We also present our vision of real-time VOC analysis enabled by newly developed analytical techniques, which will further broaden the use of VOCs in even wider applications. Hence, we foresee a bright future for VOC research and its associated fields of applications.