Aroma Composition Research Articles

Identification of characteristic aroma compounds for spicy in Iris lactea var. chinensis.

Iris lactea var. chinensis (Fisch.) Koidz has a unique floral fragrance that differs from that of other Iris spp.; however, its characteristic aroma composition remains unknown. This study aimed to identify the floral fragrance components of I. lactea var. chinensis during different flowering stages using headspace solid-phase microextraction in conjunction with gas chromatography mass spectrometry, electronic nose, and sensory evaluation. During the three flowering phases (bud stage, bloom stage, and decay stage), 70 volatile organic compounds (VOCs), including 13 aldehydes, 13 esters, 11 alcohols, 10 alkanes, 8 ketones, 7 terpenes, 7 benzenoids, and 1 nitrogenous compound, were identified. According to principal component analysis, the primary VOCs were (-)-pinene, β-irone, methyl heptenone, phenylethanol, hexanol, and 2-pinene. A comparison of the differential VOCs across the different flowering stages using orthogonal partial least squares discriminant analysis and hierarchical clustering analysis revealed that 3-carene appeared only in the bud stage, whereas hexanol, ethyl caprate, ethyl caproate, linalool, (-)-pinene, and 2-pinene appeared or were present at significantly increased levels during the bloom stage. The phenylethanol, methyl heptenone, 3-methylheptane, and β-irone reached a peak in the decay stage. The odor activity value and sensory evaluation suggested that "spicy" is the most typical odor of I. lactea var. chinensis, mainly due to 2-methoxy-3-sec-butylpyrazine, which is rare in floral fragrances.

Elucidation and quantification health-promoting phenolic compounds, antioxidant properties and sugar levels of ultrasound assisted extraction, aroma compositions and amino acids profiles of macroalgae, Laurencia papillosa

Currently, sustainability is one of the most critical issues confronting society today. The growing of macroalgae in ocean farms appears more sustainable than agriculture on land due to it does not require any fresh water, chemical fertiliser, or soil. Macroalgae have been shown to be a sustainable marine source of amino acids, novel bioactive phenolic and aroma compounds that can be exploitation in food, cosmetic, nutraceuticals, pharmacological applications. Despite starting the huge cultivation of macroalgae in world, bioactive compounds in the edible macroalgae have not been well characterized. Ultrasound assisted extraction (UAE) and conventional extraction (CE) techniques were compared and red macroalgae, L. papillosa extracts were characterized. The highest amount of amino acid was glutamic acid (GLU) and composed of 35% was essential amino acids. UAE at 10% amplitude for 15 min showed significantly highest (p < 0.05) phenolic (212.03±3.03 mg gallic acid equivalent/100 g) as well as antioxidant activity determined by DPPH (105.69±3.02 µmol Trolox/100 g), ABTS (238.69±2.23 µmol Trolox/100 g) radical assay and FRAP value (72.47±3.13 µmol Trolox/100 g) when in comparison with CE. Furthermore, bioactive compounds in extracts were indicated as phlorotannins, flavonoids, phenolic acids and other polyphenols using liquid chromatography coupled to diode array detection and electrospray ionisation tandem mass spectrometry (LC-DAD-ESI-MS/MS). This result confirmed higher antioxidant capacity detected with the UAE. A total of 46 volatile organic compounds were identified and quantified by GC-FID/MS with HS-SPME system. This study emerges as first report to novel extraction method used and deeply characterization of L papillosa. The results seem that significant potential application in the functional food, active packaging and nutraceuticals industry.

Influence of Native Saccharomyces cerevisiae Strains on Malvasia aromatica Wines.

In the search of tools to deal with climate change-related effects along with the aim of avoiding the loss of aromatic typicity in wine, two native yeasts strains of Saccharomyces cerevisiae (CLI 271 and CLI 889) were evaluated to determine their influence on white Malvasia aromatica wines aroma composition and sensory characteristics. The strains were tested versus a commercial yeast strain (LSA). The fermentations were performed on grape must of the Malvasia aromatica variety previously macerated. Wine quality was studied by analysis of oenological parameters together with volatile aroma components using gas chromatography coupled to flame ionization detector (GC-FID) to quantify major volatiles compounds and headspace-solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) to determine terpenoids and C13-norisoprenoids. Sensorial analysis was also realized by an experienced taster panel. Wines from locally-selected yeasts strains used had lower volatile acidity levels and higher concentration of aromatic compounds compared to the commercial strain ones. The yeast strain S. cerevisiae CLI 271 provided wines with a higher concentration of esters related to fruity attributes, especially isoamyl acetate. The tasting panel highlighted the strong floral character of wines from S. cerevisiae CLI 889 fermentation. The use of microorganisms well adapted to climatic conditions can be used to produce quality wines of the Malvasia aromatica variety.

Aroma Composition of Wines Produced from Grapes Treated with Organic Amendments

The application to agriculture of wheat-straw spent mushroom substrate amendments (compost/vermicompost) used to grow Pleurotus ostreatus has been analyzed. The study was conducted in a vineyard where the effect on (1) the physicochemical properties of the soil and the leaf and (2) the analytical characteristics and the aromatic composition of the wine were analyzed. The application of the amendments resulted in an increase in organic matter and macronutrients (NO3−, P2O5 and K2O) in the soil. With regard to the leaves, the NO3− and K2O contents of those vines fertilized with vermicompost were higher, and the metallic content was the same regardless of the treatment applied. The analysis of the colorimetric parameters showed that there was a higher content of compounds with red and violet colorations in the case of wine obtained after treatment with vermicompost. In addition, for this type of wine, a higher concentration of volatile compounds was obtained. Thus, after grouping the aroma compounds into aroma series, the greatest differences among vermicompost wines and the rest were obtained in the fruit, floral, herbaceous, and green fruit series. The principal component analysis showed that the vermicompost treatment clearly differentiated the wine from the rest of the wines, in addition to its effects on the aromatic series, the values in the total polyphenol index, and the compounds responsible for brown tones.

Effects of cellulose nanofibrils treatment on antioxidant properties and aroma of fresh-cut apples.

Horticultural products tend to deteriorate during postharvest storage and processing. In this study, cellulose nanofibers (CNFs) were prepared from wood to investigate the effects of CNF treatment on the storage quality, aroma composition, and antioxidant system of fresh-cut apple (Malus domestica) wedges. Compared with control treatment, CNF coating treatment significantly improved the appearance of apple wedges; reduced the decay rate of apple wedges; and delayed the decline in weight loss, firmness, and titratable acid during storage. Gas chromatography-mass spectrometry showed that CNF treatment could maintain the aroma components of apple wedges (stored for 4days). Further investigations showed that CNF treatment increased the antioxidant system level and decreased reactive oxygen species content and membrane lipid peroxidation level of apple wedges. Overall, this study showed that CNF coating could effectively maintain the quality of fresh-cut apples during cold storage.

Urate oxidase treatment increases the quality of autumn Yellowish Yinghong 9 black tea

Microbes can be used to improve the quality of fermented beverages and food. Colletotrichum camelliae is one of the most dominant fungi associated with tea leaves. In the present study, black tea produced from the autumn leaves of Yellowish Yinghong 9 was treated with C. camelliae urate oxidase (CcUOX) to determine whether this treatment could improve tea quality. The effects of recombinant CcUOX on several black tea quality parameters were assessed, such as liquor color, aroma, and levels of theabrownins, thearubigins, total polyphenols, catechins, caffeine, xanthine, and hypoxanthine. CcUOX treatment significantly affected the aroma composition and volatile compound profiles. Specifically, volatiles in the benzenoid/phenylpropanoid, fatty acid metabolism, and amino acid pathways were increased in CcUOX-treated black tea, whereas levels of volatiles in the terpineol and carotenoid pathways were reduced. This suggested that the balance of aroma constituents in Yellowish Yinghong 9 black tea was affected by treatment with CcUOX. The present study provides evidence that pre-treatment of black tea with a single enzyme from a common tea-associated microbe could significantly improve autumn tea quality, validating this method for use in further studies of tea improvement.

Natural Appetite Control: Consumer Perception of Food-Based Appetite Regulating Aromas

According to the WHO, the number of overweight people (BMI ≥ 25) and obese people (BMI ≥ 30) is constantly growing. On the other hand, the number of elderly people (≥60 years old) in 2020 reached 1.4 billion worldwide. Both mentioned groups demonstrate their individual and characteristic appetite disorders. In light of the side effects of appetite stimulating drugs, which interfere with diabetics, hypertension and thrombosis medicines or diet supplements with doubtful effectiveness in reducing appetite, new and natural alternatives are highly demanded. Therefore, the present study focusses on the search for natural food aromas, which may have potential for appetite regulation. A survey was carried out among consumers with excess body weight (BMI ≥ 25) and the elderly (≥60 years old). Food products and meals pointed out by the survey participants were subjected to volatile analysis by HS-SPME Arrow followed by GC-MS. As a result, a group of volatiles and their odor characteristic were determined for appetite stimulation or reduction, which may suggest that the actual composition of food aroma is more significant than the character of the aroma. Those results may be a basis for designing appetite regulating agents, in which the mechanism of action will be based only on olfaction activity.

Methyl jasmonate elicitation effect on the metabolic profile of cambial meristematic cells culture derived from sweet basil (Ocimum basilicum L.) in relation to antioxidant activity: Untargeted metabolomics study in a time-based approach

The undifferentiated cambial meristematic cell (CMC) has been recognized as a value-added production platform for plant natural products in comparison to the dedifferentiated plant cell line (DDC). In a time-based approach at 0, 24, 48, and 72 h, the present study aimed at investigating the phytochemical metabolome of methyl jasmonate (MeJA)-elicited CMC cultures derived from sweet basil (Ocimum basilicum L.), including primary and secondary metabolites analyzed using GC/TOF-MS post-silylation and RP-UPLC-C18-FT-MS/MS, respectively, as well as the analysis of aroma composition using headspace SPME-GC-MS. The results revealed a stress response in primary metabolism manifested by an increase in amino and organic acids reaching their maximum levels after 48 (1.3-fold) and 72 (1.7-fold) h, respectively. In addition, phenolic acids (e.g., sagerinic acid, rosmarinic acid, and 3-O-methylrosmarinic acid) followed by flavonoid aglycones (e.g., salvigenin and 5,6,4′-trihydroxy-7,3′-dimethoxyflavone) were the most abundant with prominent increases at 48 (1.2-fold) and 72 (2.1-fold) h, respectively. The aroma was intensified by the elicitation along the time, especially after 48 and 72 h. Furthermore, multivariate data analyses, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) confirmed elicitation effect, especially post 48 and 72 h. The study further assessed the effect of MeJA elicitation on the antioxidant and polyphenolic content. The cultures at 48 h demonstrated a significant (p < 0.05) antioxidant activity concurrently with correlation with total polyphenolic content using Pearson's correlation. Our study provides new insights to the elicitation impact on primary and secondary metabolism, in addition to aroma profile, to orchestrate the stress response and in relation to antioxidant effect.

Sensory dimensions derived from competitive and creative perceptual interactions between fruity ethyl esters and woody odorants in wine-like models

The present study analyses the sensory effects associated with the interactions between different woody aroma compositions and a simple fruity ester vector in red wines. The semi-synthetic wine models contained a fixed aroma composition, the dearomatised non-volatile fraction of red wine and 21 different combinations of ethyl 2-methylbutyrate (fruity vector) plus 1 out of 3 woody aroma compositions (woody vectors) at 3 possible levels of concentration each. Woody vectors imitated a highly toasted American oak (HAO—elevated levels of whiskylactones and furaneol), a highly toasted French oak (HFO—low levels of whiskylactone and vanillin levels, high levels of eugenol and guaiacol) and a medium toasted French oak (MFO—low levels of whiskylactones, eugenol, guaiacol and furaneol and high levels of vanilla). Models were sensorily assessed by a sorting task and by descriptive analysis. The increase in woody notes causes a concomitant decrease in fruity notes by a competitive perceptual interaction. HAO models are richest in coconut and woody notes and poorest in fruity notes, while HFO models keep strawberry and apple notes. At certain specific fruity-woody vector ratios, particularly in the MFO model, blackcurrant notes emerge, which can be considered a creative perceptual interaction.

Exploring the Aroma Fingerprint of Various Chinese Pear Cultivars through Qualitative and Quantitative Analysis of Volatile Compounds Using HS-SPME and GC×GC-TOFMS.

To comprehensively understand the volatile compounds and assess the aroma profiles of different types of Pyrus ussuriensis Maxim. Anli, Dongmili, Huagai, Jianbali, Jingbaili, Jinxiangshui, and Nanguoli were detected via headspace solid phase microextraction (HS-SPME) coupled with two-dimensional gas chromatography/time-of-flight mass spectrometry (GC×GC-TOFMS). The aroma composition, total aroma content, proportion and number of different aroma types, and the relative quantities of each compound were analyzed and evaluated. The results showed that 174 volatile aroma compounds were detected in various cultivars, mainly including esters, alcohols, aldehydes, and alkenes: Jinxiangshui had the highest total aroma content at 2825.59 ng/g; and Nanguoli had the highest number of aroma species detected at 108. The aroma composition and content varied among pear varieties, and the pears could be divided into three groups based on principal component analysis. Twenty-four kinds of aroma scents were detected; among them, fruit and aliphatic were the main fragrance types. The proportions of aroma types also varied among different varieties, visually and quantitatively displaying changes of the whole aroma of the different varieties of pears brought by the changes in aroma composition. This study contributes to further research on volatile compound analysis, and provides useful data for the improvement of fruit sensory quality and breeding work.

Effect of Applying Organic Fertilizer to Tobacco Leaves on the Quality and Taste of Cigarettes

Tobacco production is a significant industry worldwide, and the quality of tobacco leaves is a crucial factor in determining the taste and quality of cigarettes. The use of synthetic fertilizers in tobacco production has been the traditional method for providing nutrients to tobacco plants. However, the use of synthetic fertilizers can have harmful effects on human health and the environment. In recent years, organic fertilizers have emerged as an alternative method that offers numerous benefits, including improved soil quality, enhanced nutrient content in tobacco leaves and reduced harmful chemicals. This paper aims to explore the impact of applying organic fertilizers to tobacco leaves on the quality and taste of cigarettes and to compare the benefits of organic fertilizers with those of synthetic fertilizers. The impact is analyzed by applying organic fertilizers to tobacco leaves on the taste and quality of cigarettes, sensory evaluation tests, and chemical analysis. These sensory evaluation test can provide data on the flavor, aroma, and chemical composition of cigarettes produced with organic and synthetic fertilizers. Then hypothesis testing is conducted to identify the significance of the organic fertilizers in improving the quality and taste of cigarettes produced from tobacco leaves grown with organic fertilizers versus synthetic fertilizers.

Effect of thermal treatments on volatile profiles and fatty acid composition in sweet corn (Zea mays L.).

This study analyzed the effects of thermal processing on volatiles and fatty acids in sweet corn. There were 27 volatiles measured in fresh samples, and 33, 21, and 19 volatiles identified in the steaming, blanching, and roasting groups, respectively. Relative odor activity values (ROAVs) showed that characteristic aroma-active volatiles of sweet corn after thermal treatments included: (E)-2-nonenal, 1-octen-3-ol, beta-myrcene, dimethyl trisulfide, 1-(4,5-dihydro-2-thiazolyl)-ethanone, and d-limonene. Thermal treatments significantly increased the unsaturated fatty acids (oleic acid and linolenic acid) of sweet corn by 110 to 183% compared to fresh samples. Meanwhile, many characteristic volatiles were found that derived from the oxidative cleavage of fatty acids. The sweet corn aroma obtained by steaming for 5min was considered the closest to fresh corn. Our research provided insight into aroma composition of different thermally processed sweet corn and laid the foundation for further exploring the sources of aroma compounds in thermally processed sweet corn.

The Combined Effect of Lactic Acid Bacteria and Galactomyces geotrichum Fermentation on the Aroma Composition of Sour Whey.

The increase in demand for food flavorings due to the shortening and simplification of food production technology also entails an increase in the demand for new technologies for their production. The biotechnological production of aromas is a solution characterized by a high efficiency, an independence from environmental factors and a relatively low cost. In this study, the influence of the implementation of lactic acid bacteria pre-fermentation into the production of aroma compounds by Galactomyces geotrichum on a sour whey medium on the intensity of the obtained aroma composition was analyzed. The monitoring of the culture in terms of biomass buildup, the concentration of selected compounds, and the pH resulted in the confirmation of interactions between the analyzed microorganisms. The post-fermentation product underwent a comprehensive sensomic analysis for the identification and quantification of the aroma-active compounds. The use of gas chromatography-olfactometry (GC-O) analysis and the calculation of odor activity values (OAVs) allowed 12 key odorants to be identified in the post-fermentation product. The highest OAV was found for phenylacetaldehyde with a honey odor (1815). The following compounds with the highest OAVs were 2,3-butanedione with a buttery aroma (233), phenylacetic acid with a honey aroma (197), 2,3-butanediol with a buttery aroma (103), 2-phenylethanol with a rosy aroma (39), ethyl octanoate with a fruity aroma (15), and ethyl hexanoate with a fruity aroma (14).

Selected Ion Flow Tube Mass Spectrometry (SIFT-MS): a promising technology for the high throughput phenotyping of grape berry volatile fingerprints

Over the last decade, there have been renewed efforts into wine grape breeding within the research community. Quick characterisation by phenotyping of quality traits, including aroma composition, remains challenging. Selected Ion Flow Tube Mass Spectrometry (SIFT-MS), a high throughput soft ionisation technology first available in 2008, could be particularly useful for this purpose. In light of this, this technical article summarises recent results obtained with SIFT-MS.

Combined LC-MS-based metabolomics and GC-IMS analysis reveal changes in chemical components and aroma components of Jujube leaf tea during processing.

Making tea from jujube leaves changed the chemical composition and aroma composition of jujube leaves. Here, Through LC-MS, GC-IMS, and GC-MS technology, we have revealed the effect of jujube leaf processing changes on metabolites. LC-MS identified 468 non-volatile metabolites, while GC-IMS and GC-MS detected 52 and 24 volatile metabolites, respectively. 109 non-volatile metabolites exhibiting more pronounced differences were screened. Most lipids and lipid-like molecules, organic acids, amino acids, and flavonoids increased significantly after processing. GC-IMS and GC-MS analysis revealed that the contents of aldehydes and ketones were significantly increased, while esters and partial alcohols were decreased after processing into jujube leaf tea. The main flavor substances of fresh jujube leaf and jujube leaf tea were eugenol and (E) - 2-Hexenal, respectively. Furthermore, amino acids and lipids were closely linked to the formation of volatile metabolites. Our study provided new insights into the changes in metabolites of jujube leaves processed into jujube leaf tea, and had great potential for industrial application. It laid a foundation for further research on fruit tree leaf tea.

Flavor Profile Evaluation of Soaked Greengage Wine with Different Base Liquor Treatments Using Principal Component Analysis and Heatmap Analysis.

The selection of base liquor plays a crucial role in the flavor of soaked greengage wine. This study aimed to investigate the effects of different base liquor treatments on the physicochemical characteristics and aroma composition of greengage wine. We carried out a comprehensive analysis using HPLC for the determination of organic acids and GC-MS for the determination of volatile aroma compounds, combined with sensory evaluation. The results showed that the red and yellow colors were the darkest in the high-alcohol group, while the citric acid content was the highest in the sake group (21.95 ± 2.19 g/L). In addition, the greengage wine steeped in 50% edible alcohol had more terpenes, a significantly higher concentration of acid-lipid compounds, and a more intense aroma compared to that of the low-alcohol group, whose typical aroma compounds were greatly reduced. The sensory results showed that the greengage wine treated with baijiu had a distinct alcoholic flavor, while almond flavors were more intense in the greengage wine treated with 15% edible alcohol. In this study, base liquor was used as the main influencing factor to provide new research ideas for the flavor optimization of soaked greengage wine.

Aroma Characterization of Roasted Meat and Meat Substitutes Using Gas Chromatography-Mass Spectrometry with Simultaneous Selective Detection and a Dedicated Software Tool, AromaMS.

The development of healthier and more sustainable food products, such as plant-based meat substitutes (PBMSs), have received significant interest in recent years. A thorough understanding of the aroma composition can support efforts to improve the sensory properties of PBMS products and promote their consumer acceptability. Here, we developed an integrated hardware and software approach for aroma analysis of roasted food based on simultaneous analysis with three complementary detectors. Following the standard procedure of aroma headspace sampling and separation using solid-phase microextraction-gas chromatography, the column flow was split into three channels for the following detectors for the selective detection of nitrogen and sulfur (N/S)-containing compounds: an electron ionization-mass spectrometry for identification through a library search, a nitrogen-phosphorous detector, and a flame-photometric detector (FPD)/pulsed-FPD. Integration of results from the different types of detectors was achieved using a software tool, called AromaMS, developed in-house for data processing. As stipulated by the user, AromaMS performed either non-targeted screening for all volatile organic compounds (VOCs) or selective screening for N/S-containing VOCs that play a major role in the aroma experience. User-defined parameters for library matching and the retention index were applied to further eliminate false identifications. This new approach was successfully applied for comparative analysis of roasted meat and PBMS samples.

Volatilomics of raspberry fruit germplasm by combining chromatographic and direct-injection mass spectrometric techniques.

The application of direct-injection mass spectrometric (DI-MS) techniques, like Proton Transfer Reaction Time of Flight Mass Spectrometry (PTR-ToF-MS) has been suggested as a reliable phenotyping tool for fruit volatilome assessment in both genetic and quality-related studies. In this study the complexity of raspberry aroma was investigated by a comprehensive untargeted VOC analysis, done by combining SPME-GC-MS and PTR-ToF-MS assessments with multi-block discriminant analysis using the DIABLO mixOmics framework. The aim was to acquire an exhaustive characterization of the raspberry volatilome according to different fruit ripening stages (pink, ripe, and overripe) and genetic variances (50 accessions), as well as to investigate the potential of PTR-ToF-MS as a rapid and high throughput VOC phenotyping tool to address issues related to raspberry fruit quality. Results of this study demonstrated the complementarity between SPME-GC-MS and PTR-ToF-MS techniques to evaluate the raspberry aroma composition. PTR-ToF-MS generates reliable raspberry VOC fingerprints mainly due to a reduced compound fragmentation and precise content estimation. In addition, the high collinearity between isomers of monoterpenes and norisoprenoids, discovered by GC analysis, reduces the main analytic limitation of PTR-ToF-MS of not being able to separate isomeric molecules. The high similarity between the VOC matrices obtained by applying PTR-ToF-MS and SPME-GC-MS confirmed the possibility of using PTR-ToF-MS as a reliable high throughput phenotyping tool for raspberry volatiolome assessment. In addition, results provided by the germplasm collection investigation enabled to distinguish the best performing accessions, based on VOCs composition, to be used as superior parental lines for future breeding programs.

Sugar profile and volatile aroma composition in fermented dried beans and roasted nibs from six controlled pollinated Cameroonian fine-flavor cocoa (Theobroma cacao L.) hybrids

The quality of chocolate products proven by consumer acceptability mostly depends on cocoa volatile compounds. In fact, aroma profile of cocoa or chocolate is correlated to cocoa genotype, culture conditions, postharvest practices, and chocolate manufacturing. To the best of our knowledge, no study has been published on both sugars and aromas of controlled cocoa hybrids from Cameroon. The present study aimed at analyzing biochemical and volatile composition of six hand-pollinated cocoa hybrids belonging to different traditional groups. Specifically, the sugar profile was obtained by high performance ion chromatography-electrochemical detector (HPIC-ED) and aroma composition was analyzed using headspace solid phase micro-extraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS) on fermented dried beans and roasted nibs. The content of sugars was variable among hybrids and fructose showed the highest concentration in all hybrids in the two matrices. Roasting decreased sugar content. However, the decrease in sugar content seemed genotype dependent. A total of 48 volatile aromas were classified in six groups according to their odor description (fruity, floral, chocolate/nutty, buttery/creamy, undesirable, and unknown). Fruity flavors were not specific to a given chemical group. However, floral volatiles were specific to terpenes, chocolate/nutty to pyrazines, buttery/creamy to lactones and undesirable to phenols and acids. Principal component analysis (PCA) showed specificity of each hybrid and the hierarchical cluster analysis (HCA) Heatmap presented four distinct groups. SCA12 × ICS40 with the highest pyrazine concentration was associated with important content of sugars. Roasting of nibs reduced total volatiles and particularly fruity volatiles whereas other flavor groups moderately increased. In fact, some volatiles such as 2,3-butanediol, 2-nonanol, linalool, β-myrcene, cis/trans-β-ocimene, 2-nonanone, 2-heptanol, methyl acetate, acetophenone could be used as markers in separating traditional cocoa groups in Cameroon.

Could foliar applications of methyl jasmonate and methyl jasmonate+urea improve must grape aroma composition?

Grape aromas are formed by a great number of volatile compounds. Methyl jasmonate (MeJ) and urea (Ur) foliar applications have been studied to improve grape quality, but their combined application has never been studied. In both seasons, MeJ application enhanced terpenoids and C6 compounds synthesis, whereas decreased alcohols content. Moreover, MeJ + Ur treatment reduced benzenoids and alcohols and did not affect C13 -norisoprenoids content. However, there was no clear effect of these treatments on the rest of volatile compounds. Multifactorial analysis showed a season effect on all volatile compounds, except terpenoids. Discriminant showed a good separation among samples under treatment criterion. The great effect of MeJ treatment on terpenoids was probably due to this elicitor influences their biosynthesis. Season has a strong influence on grapes aromatic composition since affected to all volatile compounds families but terpenoids. MeJ foliar application enhanced terpenoids, C13 -norisoprenoids and C6 compounds synthesis, whereas decreased alcohols content; however, MeJ + Ur foliar treatment did not affect C13 -norisoprenoids and C6 compounds, and decreased benzenoids and alcohols grape compounds. Therefore, no synergistic effect was observed between Ur and MeJ on grape volatile compounds biosynthesis. Foliar application of MeJ seems to be sufficient to improve the aromatic quality of grapes. This article is protected by copyright. All rights reserved.