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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.

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.

Molecules with very large rings—macrocycles—are often conformationally constrained, and some exhibit planar chirality when substituents of the ring cannot rotate freely. Restricted rotation is generally valued in macrocycles because it can hold the molecule in functional conformations. Using a well-established lipase enzyme, Gagnon et al. developed a synthesis of planar chiral macrocycles with handles that can be easily functionalized. Computational docking suggests how using an enzyme as the catalyst for sequential acylation reactions can impart the observed stereochemistry. Science , this issue p. 917 An enzymatic synthesis for macrocycle building blocks locks in planar chirality. Macrocycles can restrict the rotation of substituents through steric repulsions, locking in conformations that provide or enhance the activities of pharmaceuticals, agrochemicals, aroma chemicals, and materials. In many cases, the arrangement of substituents in the macrocycle imparts an element of planar chirality. The difficulty in predicting when planar chirality will arise, as well as the limited number of synthetic methods to impart selectivity, have led to planar chirality being regarded as an irritant. We report a strategy for enantio- and atroposelective biocatalytic synthesis of planar chiral macrocycles. The macrocycles can be formed with high enantioselectivity from simple building blocks and are decorated with functionality that allows one to further modify the macrocycles with diverse structural features.

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.

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.

Herbal spices are widely consumed as food additives owing to their distinct aroma and taste as well as a myriad of economic and health value. The aroma profile of four major spices including bay leaf, black pepper, capsicum, and fennel was tested using HS-SPME/GC–MS and in response to the most widely used spices´ processing methods including autoclaving and γ-radiation at low and high doses. Additionally, the impact of processing on microbial contamination of spices was tested using total aerobic count. GC–MS analysis led to the identification of 22 volatiles in bay leaf, 34 in black pepper, 23 in capsicum, and 24 in fennel. All the identified volatiles belonged to oxides/phenols/ethers, esters, ketones, alcohols, sesquiterpene and monoterpene hydrocarbons. Oxides/phenol/ethers were detected at high levels in all tested spices at ca . 44, 28.2, 48.8, 61.1%, in bay leaves, black pepper, capsicum, and fennel, respectively of the total blend and signifying their typical use as spices. Total oxides/phenol/ethers showed an increase in bay leaf upon exposure to γ-radiation from 44 to 47.5%, while monoterpene hydrocarbons were enriched in black pepper upon autoclaving from 11.4 in control to reach 65.9 and 82.6% for high dose and low dose of autoclaving, respectively. Cineole was detected in bay leaf at 17.9% and upon exposure to autoclaving at high dose and γ-radiation (both doses) its level increased by 29–31%. Both autoclaving and γ-radiation distinctly affected aroma profiles in examined spices. Further, volatile variations in response to processing were assessed using multivariate data analysis (MVA) revealing distinct separation between autoclaved and γ-radiated samples compared to control. Both autoclaving at 115 °C for 15 min and radiation at 10 kGy eliminated detected bioburden in all tested spices i.e., reduced the microbial counts below the detection limit (< 10 cfu/g).

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.

Black Périgord truffles ( Tuber melanosporum ) are the highest-priced edible fungus in the world due to their unique flavour, rarity, short growing season, difficulty in mass cultivating, and short shelf-life. The current industrial practices have not been effective in extending truffle shelf-life while preserving its aroma profiles. This study aimed to determine the effectiveness of several preservation methods on Australian-grown black Périgord truffles, which include assessing the changes in the volatile organic compounds (VOCs) of truffles treated with edible coatings, antimicrobial agents, or antioxidants such as chitosan, gum Arabic, kafirin, natamycin, tocopherol, vitamin C, and citric acid at the interval of 0, 7, and 14 days of storage. The study also aimed to assess the capability of gamma-cyclodextrin (γ-CD) in encapsulating truffle VOCs at the intervals of 0, 14, and 28 days of storage. Among all the edible coatings, chitosan-treated truffles had the least change in VOCs, especially the black truffle aroma volatile markers, 2-methyl-1-butanal, 2,4-dithiapentane, and dimethyl sulphide. Chitosan also resulted in no significant changes ( P  < 0.05) in the carbon dioxide emissions of truffle. The PCA plots showed that chitosan-coated samples displayed the least changes. The sole application of antimicrobial agents or antioxidants was ineffective in delaying the deterioration process. On the other hand, the results show that γ-CD was able to encapsulate 30 truffle’s VOCs, which included 3-methyl-1-butanal, 2-methyl-1-butanol, dimethyl sulphide, and 2,4-dithiapentane with no significant changes over the storage period.