Aroma Profile Research Articles

The quality difference in five oolong tea accessions under different planting management patterns in south Fujian of China

IntroductionOolong tea, celebrated for its significance in Chinese tea culture, was the subject of investigation in this study.MethodsFive varieties of Minnan oolong tea were sampled, each cultivated under two distinct management approaches: conventional management and natural growth methods. The study aimed to discern variations in sensory attributes, encompassing appearance and liquor color, alongside the analysis of chemical composition.Results and discussionThe results indicated that oolong tea cultivated through conventional manual management generally exhibited qualities in terms of shape and foliage appearance, in contrast to those grown naturally. However, naturally grown oolong tea tended to exhibit more favorable aroma and taste profiles compared to conventionally managed counterparts. Furthermore, the content of water extract, amino acids, polyphenols, caffeine, and other pivotal chemical constituents were typically higher in naturally grown tea varieties compared to conventionally managed ones. Conversely, catechin content was found to be more abundant in traditionally managed bushes than in those grown naturally. These findings emphasize the significance of implementing appropriate natural growth management practices to enhance the quality of Minnan oolong tea and maintain ecological sustainability.

Plant In Vitro Cultures of Coleus scutellarioides (L.) Benth. "Electric Lime" and Possibilities of Modification in the Biosynthesis of Volatile Compounds.

Coleus scutellarioides (L.) Benth. is a globally spread species, known for its characteristic spectacularly colorful leaves of decorative value. Thanks to its rich chemical composition, the plant is used in ethnopharmacology, and it is also regarded as having high medicinal potential. The application of in vitro cultures enables the acquisition of homogeneous certified material of high quality. Additionally, excluding the effect of biotic and abiotic factors on the plants is a way to fully recognize the influence of phytohormones on the plant morphology and the biosynthetic pathways of compound production. The best way to grow C. scutellarioides "Electric Lime" under in vitro conditions is to use the basic MS medium (Murashige and Skoog medium), enriched with naphthyl-1-acetic acid at a concentration of 0.5 mg dm-3. The analysis of volatile compounds demonstrated that the content of volatile compounds in the plants cultivated under in vivo conditions was expressed at a level of 2848.59 µg g-1, whereas in the plants bred in vitro without supplementation with phytohormones, the level was 8191.47 µg g-1. The highest content was noted for copaene, α-pinene, 1-octene-3-ol, α-selinene, sabinen, γ- and δ-cadinene, 3-octanol, and β-pinene. Aroma profiling revealed a lack of boranyl acetate, 2-hexenal, and 2-hexen-1-ol in the plants cultivated under in vivo conditions. Differences were found in the volatile composition between plants bred in vivo and in vitro, with the most significant recorded for the contents of 1-octen-3-ol and 3-octanol. The addition of plant growth regulators into the basic medium under in vitro conditions affected the percentage ratio and contents of specific compounds in plant tissues. The most intense biosynthesis of volatile compounds took place in the plants cultivated on the medium enriched with NAA at 10,579.11 µg g-1, whereas the least intense was noted for plants cultivated on the medium supplemented with BA, where it was recorded at the level of 5610.02 µg g-1. So far, there has been no research published which would pertain to the profiling of volatile compounds performed using the SPME (solid-phase microextraction) technique. Moreover, the very few studies conducted on the chemical composition of these compounds do not mention the specific variety of C. scutellarioides under analysis.

Difference comparison of characteristic aroma compounds between braised pork cooked by traditional open-fire and induction cooker and the potential formation cause under electromagnetic cooking

The characteristic aroma compounds of braised pork were identified through molecular sensory science and PLSR analysis, and the difference between two cooking methods, traditional open-fire (BPF) and induction cooker (BPC), was compared. Seventeen aroma compounds with odor activity values (OAVs) > 1 were identified in both samples. BPF revealed higher OAVs for most of the aroma compounds compared to BPC, and the higher aroma quality. Aroma recombination and omission experiments confirmed that twelve aroma compounds significantly contributed to the characteristic aroma of braised pork, and eight compounds such as hexanal, (E)-2-octenal, and methanethiol were further confirmed as important contributors by PLSR analysis. Furthermore, PLSR analysis clarified the role of aldehydes such as hexanal, (E)-2-octenal, and (E,E)-2,4-decadienal in contributing to fatty attribute, whereas methanethiol was responsible for the meaty aroma. These characteristic aroma compounds mainly derived from lean meat due to its high content of phospholipids, and the exogenous seasonings contributed to the balanced characteristic aroma profile of braised pork by altering the distribution of these characteristic aroma compounds. Variations in heating parameters affected the formation of lipid oxidation and Strecker degradation products, which might explain aroma discrepancy between braised pork cooked by two methods with different heat transfer efficiencies.

Effect of jujube powder addition on the aroma profile of quinoa snacks (QS).

Quinoa is a full-nutrition food; however, its poor flavor and small size make it not the best food option for direct consumption. In this study, a quinoa snack (QS, a cake) was developed, and the aroma profile of the products was improved by adding jujube fruit powder (made from dried jujube fruits, from 5% to 30%). Gas chromatography mass spectrum (GC-MS) combined with electronic nose (e-nose) was applied for characterizing the aroma profiles of QS samples. Results showed a total of 26 aroma compounds were identified in QS samples by GC-MS, and 3-methylbutanol (from 1525 μg/kg in QS-30 to 3487 μg/kg in QS-0), ethanol (from 1126 μg/kg in QS-0 to 3581 μg/kg in QS-30), hexanal (from 125.6 μg/kg in QS-30 to 984.1 μg/kg in QS-0), and acetaldehyde (from 531.9 μg/kg in QS-30 to 191.1 μg/kg in QS-0) were common. The e-nose response of W1S (sensitive to methane, from 17.50 of QS-0 to 93.85 of QS-30) and W1W (sensitive to sulfur-organic compounds of e-nose, from 15.57 of QS-0 to 39.50 of QS-30) were significantly higher, and significant differences were presented among QS samples. In conclusion, the aroma profile of the QS sample was significantly (p < .05) enhanced by the addition of jujube powder, and QS-30 with the highest jujube content (30%) presented the strongest aroma profile. Moreover, QS samples with different additions of jujube powders could be well distinguished by principal component analysis (PCA), and the combination of e-nose and GC-MS was effective in the volatile profile analysis of QS samples.

The influence of drying and storage conditions on the volatilome and cannabinoid content of Cannabis sativa L. inflorescences

The increasing interest in hemp and cannabis poses new questions about the influence of drying and storage conditions on the overall aroma and cannabinoids profile of these products. Cannabis inflorescences are subjected to drying shortly after harvest and then to storage in different containers. These steps may cause a process of rapid deterioration with consequent changes in precious secondary metabolite content, negatively impacting on the product quality and potency. In this context, in this work, the investigation of the effects of freeze vs tray drying and three storage conditions on the preservation of cannabis compounds has been performed. A multi-trait approach, combining both solid-phase microextraction (SPME) two-dimensional gas chromatography coupled to mass spectrometry (SPME-GC × GC–MS) and high-performance liquid chromatography (HPLC), is presented for the first time. This approach has permitted to obtain the detailed characterisation of the whole cannabis matrix in terms of volatile compounds and cannabinoids. Moreover, multivariate statistical analyses were performed on the obtained data, helping to show that freeze drying conditions is useful to preserve cannabinoid content, preventing decarboxylation of acid cannabinoids, but leads to a loss of volatile compounds which are responsible for the cannabis aroma. Furthermore, among storage conditions, storage in glass bottle seems more beneficial for the retention of the initial VOC profile compared to open to air dry tray and closed high-density polyethylene box. However, the glass bottle storage condition causes formation of neutral cannabinoids at the expenses of the highly priced acid forms. This work will contribute to help define optimal storage conditions useful to produce highly valuable and high-quality products.Graphical

Influence of Milk Pasteurization on the Key Aroma Compounds in a 30 Weeks Ripened Pilot-Scale Gouda Cheese Elucidated by the Sensomics Approach.

Gouda cheese was produced from pasteurized milk and ripened for 30 weeks (PM-G). By application of gas chromatography/olfactometry and an aroma extract dilution analysis on the volatiles isolated by extraction/SAFE distillation, 25 odor-active compounds in the flavor dilution (FD) factor range from 16 to 4096 were identified. Butanoic acid, 2- and 3-methylbutanoic acid, and acetic acid showed the highest FD factors, and 2-phenylethanol, δ-decalactone, and δ-dodecalactone were most odor-active in the neutral-basic fraction. Quantitations by stable isotope dilution assays followed by a calculation of odor activity values (OAVs) revealed acetic acid, 3-methylbutanoic acid, butanoic acid, and butane-2,3-dione with the highest OAVs. Finally, an aroma recombinate prepared based on the quantitative data well agreed with the aroma profile of the PM-G. In Gouda cheese produced from raw (nonpasteurized) milk (RM-G), qualitatively the same set of odor-active compounds was identified. However, higher OAVs of butanoic acid, hexanoic acid, and their corresponding ethyl esters were found. On the other hand, in the PM-G, higher OAVs for 3-methylbutanoic acid, 3-methylbutanol, 3-methylbutanal, and butane-2,3-dione were determined. The different rankings of these key aroma compounds clearly reflect the aroma differences of the two Gouda-type cheeses. A higher activity of lipase in the RM-G and higher amounts of free l-leucine in PM-G on the other side were responsible for the differences in the concentrations of some key aroma compounds.

Study on Ways to Improve the Quality of Black Goat Meat Jerky and Reduce Goaty Flavor through Various Spices.

In this study, we analyzed the physicochemical and sensory properties of black goat jerky marinated with various spices (non-spice, control; rosemary, RO; basil, BA; ginger, GI; turmeric, TU; and garlic, GA). The physicochemical properties of black goat jerky analyzed were pH, water holding capacity, color, cooking yield, shear force, and fatty acid composition. The sensory characteristics were analyzed through the aroma profile (electronic nose), taste profile (electronic tongue), and sensory evaluation. The pH and water holding capacity of the GI showed higher values than the other samples. GI and GA showed similar values of CIE L* and CIE a* to that of the control. The shear force of the GI and TU was significantly lower than that of other samples (p<0.05). Regarding fatty acid composition, GI showed high unsaturated and low saturated fatty acid contents compared with that of the other samples except for RO (p<0.05). In the aroma profile, the peak area of hexanal, which is responsible for a faintly rancid odor, was lower in all treatment groups than in the control. In the taste profile, the umami of spice samples was higher than that of the control, and among the samples, GI had the highest score. In the sensory evaluation, the GI sample showed significantly higher scores than the control in terms of flavor, aroma, goaty flavor, and overall acceptability (p<0.05). Therefore, marinating black goat jerky with ginger powder enhanced the overall flavor and reduced the goat odor.

Analysis of differences in microorganisms and aroma profiles between normal and off-flavor pit mud in Chinese strong-flavor Baijiu

The unique cellar fermentation process of CFSB is the reason for its characteristic “cellar aroma” flavor. The types, abundance, community structure and metabolic activity of microorganisms in the pit mud directly affect the microbial balance in the white spirit production environment, promoting the formation of typical aromas and influencing the quality of CFSB. During the production process, the production of off-flavor in the cellar may occur. The aim of this study is to elucidate the differences in microbiota and flavor between normal pit mud and abnormal pit mud (pit mud with off-flavor). A total of 46 major volatile compounds were identified, and 24 bacterial genera and 21 fungal genera were screened. The esters, acids, and alcohols in the abnormal pit mud were lower than those in the normal pit mud, while the aldehydes were higher. Indole, 3-methyl-, which have been proven to be responsible for the muddy and musty flavors, were detected in both types of pit mud, and for the first time, high levels of 4-Methylanisole were detected in the pit mud. The microbial composition of the two types of pit mud showed significant differences in the bacterial genera of Sporosarcina, Lactobacillus, Garciella, Anaerosalibacter, Lentimicrobium, HN-HF0106, Petrimonas, Clostridium_sensu_stricto_12 and Bacillus, and the fungal genera of Millerozyma, Penicillium, Mortierella, Monascus, Saccharomyces, Issatchenkia, Pithoascus, Pseudallescheria, and Wickerhamomyces. While we speculate that Sporosarcina is the predominant bacterial genus responsible for the imbalance of microbiota in pit mud.

Characterization of the key volatile compounds in longjing tea (Camellia sinensis) with different aroma types at different steeping temperatures by GC‒MS and GC‒IMS

Longjing tea (Camellia sinensis), an iconic agricultural product distinguished by its geographical indication status, has gained much acceptance and consumption in China. The aroma types and steeping conditions of green tea are important factors influencing consumer acceptance. However, the effects of steeping conditions on tea samples with different aroma types are still unknown. Explanation of the above unknowns can provide new insights into the flavor variations of tea when consumed for optimal sensory enjoyment. Here, the aroma profiles of Longjing green teas with bean-like (DX) and fresh aroma (QX) types were analyzed using gas chromatography‒mass spectrometry (GC‒MS), gas chromatography–ion mobility spectrometry (GC‒IMS), and quantitative descriptive analysis (QDA). Geraniol, (E, E)-2,4-heptadienal and other 11 compounds contributed to the bean-like aroma, while heptanal-d, hexanal-d and other 4 compounds contributed to the fresh aroma. Further, the release patterns of volatiles at different steeping temperatures were also revealed. 12 volatiles led to the differences between the two aroma types of Longjing teas at different steeping temperatures. Most volatiles exhibited their aroma characteristics when the steeping temperature exceeded 80 °C. These results enhance the comprehension of green tea's aroma profile, thereby enabling consumers to approach tea drinking from a more scientific perspective.

Flavour characterization of twelve species of edible algae

Integration of algae as ingredients in food products may contribute to the flavour characteristics, on top of providing nutritional requirements. In this study, characterization of the volatile and non-volatile flavour compounds was performed on 12 species of macroalgae and microalgae representing various groups of algae. Nine macroalgae species from three divisions were selected, namely Phaeophyta (brown alga): Laminaria japonica, Undaria pinnatifida, Sargassum fusiforme and Fucus vesiculosus; Rhodophyta (red alga): Porphyra haitanensis, Porphyra yezoensis, Palmaria palmata and Gelidium amansii, and Chlorophyta (green alga): Ulva lactuca. In addition, three microalgae species include Arthrospira platensis, Chlorella vulgaris and Dunaliella salina. Volatile compounds were analysed by solid-phase microextraction (SPME) and gas chromatography–mass spectrometry-flame ionization detector (GC–MS/FID). Amino acids and nucleotides were analysed using amino acid analyser and high-performance liquid chromatography (HPLC) respectively. Based on the identified volatile and non-volatile compounds, no obvious trend was found within each group of algae. However, some algae variants have been found to contain a unique aroma profile of selected volatile and non-volatile compounds. D. salina was found to be high in volatile aldehydes, ketones, and alcohols, primarily products of carotenoid degradation. U. lactuca contains the highest volatile sulfur content, while F. vesiculosus was found to be high in aldehyde and alcohol compounds, which are potentially fishy odours. C. vulgaris was found to have the highest value of equivalent umami concentration (EUC) followed by roasted P. haitanensis, indicating that both algae have the highest umami potential. Lastly, microalgae species A. platensis and C. vulgaris contained the highest amounts of sulfurous tasting amino acids cysteine and methionine respectively.

Aroma profiles of shalgam: Effect of purple carrot (Daucuscarota) amount.

Shalgam is a fermented product characterized by its color and aroma compounds. However, there is no standard regarding the amount of use of purple carrot, which is the major raw material in production and affects the fermentation and aroma compounds of the product. This present research was designed to examine the effect of purple carrot concentrations on aroma compounds, which are one of the most important characteristics that reflect the quality characteristics of shalgam and affect consumer preferences. Aroma compounds in shalgam juices produced using five different amounts of carrots were analyzed by gas chromatography-flame ionization detector-mass spectrometry (GC-FID-MS). As expected, since the difference between the produced shalgam beverages was only the amount of purple carrots, a qualitative similarity and a quantitative difference were determined in the aroma profiles in general. In the aroma categories defined, terpenes (26 compounds) were the most abundant compounds, followed by esters (17 compounds) and higher alcohols (11 compounds). 88 aroma compounds have been identified in shalgam, and a total of 28 ACs, including 7 terpenes, 7 esters, 3 alcohols, 4 volatile acids, 3 volatile phenols, 1 lactone, 1 norisoprenoid, and 2 naphthalenes, were detected for the first time. The concentration of aromas in the samples varied from 5471.5 to 6490.1 μg/L (p < .05). According to principal component analysis, it was determined that the correlation between the position of the shalgam samples in the coordinate system and the aroma groups was significant. This study shows that purple carrots also affect the aroma compounds of shalgam beverages.

Uncovering the flavor differences between black rice wine and glutinous rice wine by GC-MS, GC-IMS, HPLC, and electronic sensory analysis

The black rice bran component (BRBC) is the main difference between black rice and glutinous rice, but its influence on the flavor of rice wines brewed from them is ambiguous. To address this, the flavor profiles and compounds of four rice wines — brewed from glutinous rice (B), glutinous rice with BRBC (added), polished black rice (without BRBC), and whole black rice (HH) — were analyzed using e-nose, GC-MS and GC-IMS. The e-nose revealed significant aroma profile differences between B and HH, with 47 and 49 volatile compounds detected by GC-MS and GC-IMS, respectively. Orthogonal partial least-squares discrimination and fold change analysis highlighted the significant impact of BRBC on the aroma differences between HH and B. Chemometrics and odor activity values identified isoamyl acetate, ethyl caprylate, (E)-2-octenal, phenylethyl acetate, ethyl caproate, 2,4-heptadienal, and 1-octen-3-ol as key contributors to the fresh and fruity aroma in B, while ethyl butanoate, ethyl isoiautyrate, benzene acetaldehyde, (E)-2-octen-1-ol, guaiacol, and heptanal were predominant in HH, contributing to its rich and complex aroma. The e-tongue indicated significant taste distinctions between HH and B, potentially due to the influence of the black rice bran component on the regulation of organic acid and free amino acid content. This study provides new insights into the regulation of rice wine flavor through raw materials.

A comprehensive review of quantified flavour components in Chinese baijiu

Baijiu, a Chinese distilled liquor, plays an essential role in Chinese life and culture. The intricate flavour profile and distinguished quality of baijiu are closely linked to its organic components, which encompass an array of elements such as esters, acids, alcohols, aldehydes, phenols, pyrazines, terpenes, and others. Consequently, the analysis of these components has emerged as a fundamental cornerstone for the study and comprehension of baijiu. In the present review, we succinctly encapsulate the latest research endeavours aimed at the identification and precise quantification of pivotal components within a diverse array of Chinese baijiu exhibiting varying aroma profiles. The culmination of this collective effort has yielded an impressive compendium comprising 397 quantified components, each with meticulously determined concentrations within baijiu. These components are categorised into major, medium, minor, and trace components, based on their respective concentration levels in baijiu. Furthermore, the focal attention on trace components, with concentrations below 1 mg L-1 threshold, is deliberately underscored. This emphasis is ascribed to the pivotal roles of these trace elements in shaping the nuanced flavour and overall quality of baijiu. As a result, the present review not only provides the most comprehensive reference compendium of quantified baijiu components to date, but also furnishes invaluable insights into the multifaceted study of Chinese baijiu.

Maize landrace and post-harvest traits are reflected in the volatile profile and nutritional composition of Italian maize porridge (Polenta): A preliminary study

Maize porridge, known as "polenta" in Italy, is a global staple food. This study aims to characterize the quality of four Italian flint maize landraces by investigating physical properties and macronutrients composition. By using SPME GC–MS and PTR-ToF-MS we analyzed the flours volatilome and changes in aroma profile post- cooking. Cooking induced the formation of 5 compounds and the loss of up to 25 compounds, primarily through evaporation. Post-cooking, the concentrations of some sulphur compounds (methanethiol, dimethyl sulfide and dimethyl trisulfide), lipid oxidation compounds (2-pentylfuran and hexanal) and Maillard reaction compounds including some aldehydes (nonanal, benzaldehyde, phenylacetaldheyde), pyridine and furans (furfural and furfuryl alcohol) increased. Differences in volatilome and macronutrients contents among landraces were also observed with Marano samples having on average a significantly higher concentration of proteins (13.67 %), while the Nostrano samples had the highest fat content (5.00 %). Fatty acid profile differences were mirrored in the volatilome. Spin flours had the highest level of linoleic acid, leading to elevated levels in cooked polenta due to linoleic acid oxidation. The differences in volatilome and macronutrients contents among the samples confirmed that local landraces are not only important for biodiversity and cultural heritage but also lead to unique aroma compounds profiles.

Exploring the role of lactic acid bacteria involved in bread fermentation in improving flavor via intelligent sensory technologies and GC×GC-ToF-MS

The effect of individually mixing Lactobacillus paracasei C5 and Lactobacillus pentosus D1 with yeast as starter cultures on bread flavor was investigated via electronic-nose, electronic-tongue, and GC × GC-ToF-MS methods The electronic-nose results showed that the bread smell could be completely distinguished. Electronic-tongue analysis revealed that the taste of mixed-fermented bread was positively correlated with sourness, sweetness, saltiness, and umami, while the taste of yeast-fermented bread was positively correlated with bitterness and astringency. GC × GC-TOF-MS was used to further detect volatile organic compounds, from which 15 (L. paracasei bread) and 18 (L. pentosus bread) major contributing aroma compounds were screened (ROAV ≥1 and VIP >1). Additionally, Lactobacillus was found to be positively correlated with 35 flavor substances and positively regulated the aroma profile of the bread, especially sweet-caramel, coffee-like, and roasted aromas. In conclusion, LAB involved in fermentation can improve the flavor of bread.

Effect of roselle and purple rice powder on baking quality and aroma characteristic of bread

The effects of different dosages of roselle flour (0 %, 4 %, and 8 %) and purple rice flour (5 %, 10 %, and 15 %) on the properties of the dough, the quality of the bread, the phenolic compounds contained, the anthocyanin content and the aroma profile were investigated by adding roselle flour and purple rice flour to the wheat flour. The results showed that the addition of purple rice flour elevated the G′ and G″ of the dough and improved the viscoelasticity of the bread. The addition of roselle flour disrupted the gluten network structure in the bread, resulting in an increase in chewiness and hardness, but within acceptable limits. The color of the bread also changed significantly. In addition, increased polyphenol content in the bread, roselle flour, and purple rice flour significantly (p < 0.05) increased the aroma profile of bread, giving it a richer odor. In particular, the presence of more acids, alkanes and heterocyclic compounds associated with fruity flavors also adds a distinctive burnt and ‘roasted’ note. Therefore, the addition of moderate amounts of roselle flour and purple rice flour was beneficial in improving the baking quality of bread, especially positively affecting the flavor.

Differences in Volatile Profiles and Sensory Characteristics in Plum Spirits on a Production Scale

The specific sensory properties attributed to distillates from different plum varieties are intricately linked to aromatic substances, fruit quality, and technology employed during production. This study compares four plum brandies, each made from a renowned plum variety: Presenta, Valjevka, Čačanská lepotica, and Čačanská rodná on a production scale. Analytical and sensory profiles were assessed using GC-FID, an available analytical method advantageous for monitoring industrial fruit distillate production. Between 71 and 85 analytes were detected in the distillates, with the Presenta plum distillate containing the highest number of substances. Statistically significant differences in analyte concentration between plum varieties (p &lt; 0.05) were observed for 11 analytes. The comparison of analytical profiles and sensory evaluation revealed that a high concentration of 1-propanol, despite its negative sensory perception, significantly impacts the overall perception of a distillate, contrasting with substances like acetaldehyde and propyl acetate, which have positive sensory evaluations but lesser significance in content. Our work identified key compounds and procedures that can be used as benchmarks for production of plum brandy with positive sensory evaluation. These findings demonstrate the broad application potential of GC-FID in fruit distillate production as an independent tool for aromatic profile assessment and quality control.

GC-Olfactometric Analysis as a Tool for Comprehensive Characterization of Aromatic Profiles in Cocoa-Based Beverages with a Natural Chocolate Substitute

Cocoa is the third most important global agricultural export commodity. However, because it is a crop sensitive to climatic change, there has been an active search for cocoa substitutes worldwide. Roasted jackfruit seeds were previously described as having a chocolate aroma and are affordable and accessible. In this study, we characterized and identified by SPME-GC-O and SPME-GC-MS the aroma profile of cocoa-based beverages formulated with jackfruit seed flour as a natural cocoa substitute. Our analysis tentatively identified 71 odor-active aroma descriptors with some similarities between formulations. Overall, 15 odor-active aromas were present in all beverages. The formulation containing only cocoa/chocolate showed the following aroma descriptors: cocoa, hazelnut, peanut butter, earthy, and roast, which are mostly related to the presence of 2,3-dimethylpyrazine and 2,3-diethyl-5-methylpyrazine. The fermented beverage had a content of complex pyrazines such as 2,3,5-trimethyl-6-isopentylpyrazine and methylpropylpyrazine. Our data indicated that both the control and fermented beverages showed a similar aromatic profile, mainly earthy, pyrazine, and chocolate. Qualitative similarities in the pyrazine content were observed between the fermented jackfruit seed flour and cocoa beverages. In conclusion, fermented jackfruit seed flour can be incorporated into cocoa-based beverages as a natural chocolate substitute, offering the potential to elevate the chocolate aroma.

Autochthonous Ingredients for Craft Beer Production

Innovation in the beer market focuses on research into the different ingredients that make up this popular and sought-after beverage. Some of these innovations have focused on the use of autochthonous ingredients, which bring added value to products, reduce production costs and environmental impact, and provide beers with special organoleptic characteristics. This study focuses on the use of autochthonous ingredients from the Community of Madrid and the design of four recipes that are suited to these ingredients and consumer demand. In terms of the ingredients used, the micromalting of barley grown in the CM was carried out, while hops (Cascade variety for bittering hops and wild hops Rayo verde Tajuña and Torreta Tajuña for aroma) and yeast strains (Saccharomyces cerevisiae G 520 and G 354) were selected from previous studies, which were also sourced from the CM. For the barley malt, parameters such as protein content were determined, which was at the maximum limit but did not affect the final quality of the beers. The content of α- and β-acids in the hops was also determined, being higher in the Cascade variety. Different physicochemical analyses (GC, aromatic compounds, bitterness, colour, SO2, polyphenols, and antioxidant capacity) were carried out to determine the quality of the beers obtained from the four recipes designed, as well as tastings by a panel of experts and consumers. Finally, two recipes were rated the best by a panel of experts and consumers, where the cereal, hop, and fruit flavours stood out for their aromatic profile.

Fatty acid degradation driven by heat during ripening contributes to the formation of the “Keemun aroma”

Ripening refers to the process of chemical change during the refinement of Keemun black tea (KBT) and is crucial in the formation of Keemun Congou black tea’s quality. In this study, the aroma composition of KBT during the ripening was analyzed. Sensomics indicated that ripening strengthened the coconut and fatty aroma of KBT and contributed to the decrease of green aroma substances, resulting in a shift of the overall aroma type of KBT to an integrated aroma profile, which was consistent with sensory evaluation. Changes in fatty acid content and the results of in vitro addition simulation tests confirmed that heat causes highly degradation of fatty acids into fatty aroma volatiles, which is a key driver of the formation of “Keemun aroma” quality. This study revealed the mechanism behind the formation of KBT’s integrated “Keemun aroma” quality and the mode of thermal degradation of major fatty acids.