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A disponibilidade hídrica afeta a biossíntese de compostos voláteis, com efeito dependente de aspectos relacionados ao vegetal e ao manejo hídrico. A cebolinha (Allium fistulosum L.) é uma hortaliça condimentar amplamente utilizada na culinária mundial e seu aroma se deve à presença de compostos voláteis sulforados. O objetivo deste trabalho foi avaliar os efeitos dos níveis de restrição hídrica sobre crescimento, fisiologia e produção de compostos voláteis em cebolinha. O experimento foi conduzido em ambiente protegido. Os tratamentos foram determinados de acordo com o fornecimento de água, relativos à reposição da água consumida tendo como referência o tratamento CONTROLE, i.e., reposição de 100% da água consumida (CONTROLE), reposição de 75% (MODERADO) e reposição de 50% (SEVERO). O experimento seguiu DIC, com unidades amostrais constituídas por três vasos com cinco plantas cada, e quatro repetições por tratamento. A colheita foi realizada aos 29 dias após início dos tratamentos. Foram avaliadas: taxa transpiratória, resistência estomática, temperatura foliar, massa fresca da parte área e da raiz, massa seca da parte aérea, número e diâmetro de perfilhos e a produção de compostos voláteis (hidrodestilação e análise GC-MS). O tratamento SEVERO resultou em aumento da temperatura foliar, redução da taxa transpiratória e maior resistência estomática. Quanto ao crescimento houve efeito da intensidade de estresse hídrico para o diâmetro de perfilhos, com redução significativa sob os tratamentos MODERADO e SEVERO. O composto dissulfeto de dipropenila foi negativamente influenciado pelo tratamento SEVERO. O diâmetro de perfilho mostrou-se como a característica mais sensível ao estresse hídrico.

To investigate the impact of various cooking methods on the volatile aroma compounds of button mushroom, gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-nose) were utilized for aroma analysis. The results indicated that the E-nose was able to effectively distinguish between the samples prepared using different cooking methods. In the raw, steamed, boiled and baked samples, 37, 23, 33 and 35 volatiles were detected, respectively. The roasting process significantly contributed to the production of flavor compounds, giving button mushroom its distinctive flavor. Sixteen differential aromas were identified based on the p-value and VIP value. Additionally, the cluster analysis of differential aroma substances revealed a stronger odor similarity between the steamed and raw groups, consistent with the results of the OPLS-DA analysis of overall aroma components. Seven key aromas were identified through OAV analysis and omission experiments. In addition, 1-octen-3-one was identified as the main aroma component of cooked button mushroom. The findings of the study can be valuable for enhancing the flavor of cooked button mushroom.

Jasmine tea is loved by most people who drink flower tea owing to its unique aroma, and it is known as the top of flower teas. In our study, the quantitative evaluation of the quality of jasmine tea and detection of aroma components were carried out. First, the flavor quality of 92 kinds of jasmine tea was evaluated using multiple sub‐factor quality evaluation methods. According to the evaluation results, jasmine tea was divided into three types: “fresh and lovely” (FL), “heavy and thick” (HT), and “fresh and heavy” (FH). Gas chromatography–mass spectrometry (GC–MS) was used to detect the aroma components of the three types of jasmine tea samples. α‐Farnesene, cis‐3‐hexenyl benzoate, acid phenylmethyl ester, linalool, methyl anthranilate, and indole were the main substances that constituted the basic aroma quality characteristics of jasmine tea. Compared to the FL type, the HT and FH types were weaker in the diversification of the characteristic aroma and accumulation of green, herb, sweet, and roast aroma substances. Green and herb aromas play crucial roles in the fresh and persistent qualities of the three types of jasmine tea, which are the key quality factors research focus of jasmine tea. Six components, a‐farnesene, cis‐3‐hexenyl benzoate, acetic acid phenylmethyl ester, linalool, methyl anthranilate, and indole, were considered to constitute important components of jasmine tea aroma quality.“Fresh and lovely” type of jasmine tea was richer in the diversity of characteristic aroma than the “heavy and thick” and “fresh and heavy” types of jasmine tea. Green and herb aroma played crucial roles in “fresh” and “persistence” quality of jasmine tea.

Introduction: There are various degrees of defects of cigar filler leaves after air drying. Methods: In order to improve the quality and plant-derived aroma content of cigar filler leaves, nine aroma-producing yeasts were applied in artificially solid-state fermentation of cigar filler leaves in this study. The differences with various yeasts application were compared by chemical composition and GC-MS analysis. Results and discussion: The results showed that 120 volatile components were identified and quantified in cigar filler leaves after fermentation, including aldehydes (25 types), alcohols (24 types), ketones (20 types), esters (11 types), hydrocarbons (12 types), acids (4 types) and other substances (23 types). Based on the analysis of odor activity value (OAV), the OVA of fruity and floral aroma components were higher. It was found that floral aroma are the representative aroma types of cigar filler leaves treated with Clavispora lusitaniae , Cyberlindera fabianii , Saccharomycosis fibuligera an d Zygosaccharomyces bailii R6. After being inoculated with Hanseniaspora uvarum J1, Hanseniaspora uvarum J4 and Pichia pastoris P3, the OAV of fruity aroma in cigar filler leaves was the highest, followed by tobacco aroma and woody aroma. The correlation between volatile components of cigar filler leaves with different yeasts was revealed after PCA analysis. It was concluded that the quality of cigar filler leaves was improved, and cigar filler leaves fermented with different yeasts showed different flavor.

En los vinos blancos el aroma es uno de los principales atributos de calidad, siendo los compuestos aportados por la uva los que determinan el perfil varietal. Tempranillo Blanco es una variedad derivada de Tempranillo Tinto por mutación natural, que desde el año 2008 está autorizada únicamente en la D.O.Ca. Rioja. Sus vinos manifiestan características organolépticas de alta calidad, con notas afrutadas y florales intensas. En este trabajo se estudió el perfil aromático varietal de Tempranillo Blanco en siete localizaciones geográficas de la D.O.Ca. Rioja durante la campaña 2016. Las parcelas se distribuyeron en las tres subzonas que integran la denominación, con características vitivinícolas diferenciadas debido a las condiciones de clima y suelo. Los resultados obtenidos mostraron diferencias notables en el contenido aromático de la uva procedente de las distintas ubicaciones del viñedo. Los compuestos más abundantes fueron los norisoprenoides (48-70%), seguidos por los bencenoides (8-29%) y los aldehídos y cetonas (3-18%); otros muchos volátiles fueron detectados en menores porcentajes (compuestos C6, alcoholes, terpenos, ésteres, ácidos…). A pesar de las diferencias observadas, el perfil aromático varietal se mantuvo, por lo que se puede concluir que Tempranillo Blanco es una variedad con amplias posibilidades de adaptación a diferentes entornos vitícolas.

Parallel application of an aroma extract dilution analysis (AEDA) to the volatiles isolated from a sample of fermented cocoa with an atypically pronounced coconut note and to the volatiles isolated from a reference cocoa sample revealed coconut-like smelling compounds δ-octalactone, δ-2-octenolactone, γ-nonalactone, γ-decalactone, δ-decalactone, and δ-2-decenolactone as potential causative odorants. Quantitation of these six compounds and calculation of odour activity values as ratios of the concentrations to the odour threshold values suggested δ-2-decenolactone as the crucial compound. Chiral analysis showed the presence of pure (R)-δ-2-decenolactone, commonly referred to as massoia lactone. Its key role for the coconut note was finally demonstrated in a spiking experiment: the addition of (R)-δ-2-decenolactone to the reference cocoa in an amount corresponding to the concentration difference between the two samples was able to provoke a coconut note in an intensity comparable to the one in the atypically smelling cocoa. To avoid an undesired coconut note caused by (R)-δ-2-decenolactone in the final products, the chocolate industry may consider its odour threshold value, that is 100 µg/kg, as a potential limit for the acceptance of fermented cocoa in the incoming goods inspection.

Background Nitrogen (N) plays an important role in the formation of tea quality-related compounds, like amino acids and flavor/aroma origin compounds. Lipids, which have been reported to be affected by N deficiency, are precursors to the generation of flavor/aroma origin compounds in tea plant. However, there is no literature about the lipid profiles of tea plant affected by N fertilization. Hence, we hypothesize that the biosynthesis of flavor-related compounds in tea was affected by N through its regulation of lipid metabolism. Results In this study, mature leaves and new shoots of tea plant grown under three N levels at the rates of 0, 285 and 474 kg/ha were applied for ultra-performance liquid chromatography-mass spectrometry (UPLC/MS) based lipidomic analysis. Totally, 178 lipid species were identified. The results showed that the composition of lipid compounds in mature leaves and new shoots varied dramatically, which was also affected by N levels. The higher content of the storage lipid TAG and higher carbon (C)/N ratio in mature leaves than that of new shoots in tea plants grown under low N level (0 kg/ha) suggested that tea plants could remobilize the C stored in TAG to maintain their C/N balance and help to improve the quality of tea. N fertilization resulted in a higher content of the compounds 36:6 MGDG and 36:6 DGDG. Since these compounds contain linolenic acid (18:3), a precursor to the formation of aroma origin compounds, we suggested their increase could contribute to the quality of tea. Conclusions Taken together, the present work indicated that appropriate application of N fertilizer could balance the lipid metabolism and the formation of flavor/aroma origin compounds, which help to improve the quality of tea. Moreover, excess N fertilization might deteriorate the aroma quality of made tea due to increases of precursors leading to grassy odor.

Headspace Solid-Phase Microextraction-Gas Chromatography-Mass Spectroscopy (HS–SPME–GC–MS) and Odor Activity Value (OAV) analysis were used to characterize the aroma components of Chuanhong congou black tea. The key aroma compounds were screened by combining Principal Component Analysis (PCA), Orthogonal Partial Least Squares Discrimination Analysis (OPLS-DA) model, and Variable Importance Projection (VIP). The perceived interactions among the key aroma compounds in the tea were analyzed using Feller summation model and S-curve. Thus, 89 volatile aroma compounds were identified in the samples. Thirty key aroma compounds (OAV > 1) were screened by OAV, PCA (R2Xcum = 0.941, Q2cum = 0.897), and OPLS-DA (R2cum > 0.9, Q2cum > 0.9). Results showed a good model fit and more effective clustering of the samples. Finally, eight key aroma compounds were screened, which included trans-2-Hexenal, 2-hexenal, linalool, hexanal, phenylacetaldehyde, methyl salicylate, benzaldehyde, and (E)-linalool oxide (furan type). The perceived interactive relationships among the key aroma substances showed that 12 of the 15 groups of binary compounds had masking effects and 3 groups had additive effects. The results would serve as a reference for improving the quality of Chuanhong congou black tea.

Abstract Aroma compounds provide attractiveness and variety to alcoholic beverages. We discuss the molecular biology of a major subset of beer aroma volatiles, fruity and floral compounds, originating from raw materials (malt and hops), or formed by yeast during fermentation. We introduce aroma perception, describe the most aroma-active, fruity and floral compounds in fruits and their presence and origin in beer. They are classified into categories based on their functional groups and biosynthesis pathways: (1) higher alcohols and esters, (2) polyfunctional thiols, (3) lactones and furanones, and (4) terpenoids. Yeast and hops are the main sources of fruity and flowery aroma compounds in beer. For yeast, the focus is on higher alcohols and esters, and particularly the complex regulation of the alcohol acetyl transferase ATF1 gene. We discuss the release of polyfunctional thiols and monoterpenoids from cysteine- and glutathione-S-conjugated compounds and glucosides, respectively, the primary biological functions of the yeast enzymes involved, their mode of action and mechanisms of regulation that control aroma compound production. Furthermore, we discuss biochemistry and genetics of terpenoid production and formation of non-volatile precursors in Humulus lupulus (hops). Insight in these pathways provides a toolbox for creating innovative products with a diversity of pleasant aromas.