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BACKGROUND: The excessive salt intake associated with Douchi has become a topic of controversy. Addressing this concern and enhancing its market competitiveness necessitates the application of salt reduction fermentation in Douchi. Therefore, to promote the application of salt reduction fermentation in Douchi, a comprehensive study was undertaken aiming to investigate the differences in biogenic amines, volatile compounds and non‐volatile compounds in Douchi with varying salt content. RESULTS: The findings unequivocally demonstrate that salt hampers the formation of metabolites in Douchi. As the salt content increased, there was a significant decrease (P < 0.05) in the levels of total acid, amino‐type nitrogen and free amino acids in Douchi. Notably, when the salt content exceeded 80 g kg−1, there was a substantial reduction (P < 0.05) in putrescine, lactic acid and malic acid levels. Similarly, when the salt content surpassed 40 g kg−1, β‐phenethylamine and oxalic acid levels exhibited a significant decline (P < 0.05). Furthermore, the results of E‐nose and principal component analysis based on headspace solid phase microextraction gas chromatography–mass spectrometry revealed notable discrepancies in the volatile compound content between Douchi samples with relatively low salt content (40 and 80 g kg−1) and those with relatively high salt content (120, 160 and 200 g kg−1) (P < 0.05). By employing partial least squares discriminant analysis, eight distinct volatile compounds, including o‐xylene, benzaldehyde and 1‐octen‐one, were identified. These compounds exhibited higher concentrations in Douchi samples with relatively low salt content (40 and 80 g kg−1). The sensory results showed that Douchi samples with lower salt content exhibited higher scores in the soy sauce‐like and Douchi aroma attributes. CONCLUSION: In conclusion, this study significantly enhances our understanding of the impact of salt on metabolites in Douchi and provides invaluable insights for the development of salt reduction fermentation in this context. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The semi-dry fermentation processing (SFP) of Coffea arabica is a traditional primary processing method in the coffee industry, which crucially impacts the coffee's flavor. To further obtain useful information on microbial communities and chemical compounds during the SFP of C. arabica from Yunnan, China, the microbial community structures and the differentially changed non-volatile compounds (DCnVCs) were comprehensively analyzed. The results showed that Tatumella, Staphylococcus, Klebsiella, Brevundimonas, and Gluconobacter were the most prevalent bacteria genera, and Candida, Hannaella, Hanseniaspora, Pichia, and Lachancea were the most abundant fungal genera. Furthermore, 117 DCnVCs were found in the fermentation-finished samples compared to the raw materials. Therefore, this study can provide useful information for understanding the SFP of coffee beans, and its impact on coffee's quality parameters. [ABSTRACT FROM AUTHOR]

In the present study, bud yellow tea (BYT), small-leaf yellow tea (SYT) and large-leaf yellow tea (LYT) were produced from the same local “population” variety Huoshanjinjizhong (Camellia sinensis var. sinensis), and the effects of raw material tenderness on the chemical profile and bioactivities of these teas were investigated. The results showed that 11 crucial compounds were screened by headspace solid-phase microextraction-gas chromatography–mass spectrometry from 64 volatiles in these yellow teas, among which the heterocyclic compounds showed the greatest variations. In addition, 43 key compounds including organic acids, flavan-3-ols, amino acids, saccharides, glycosides and other compounds were screened by liquid chromatography-mass spectrometry from 1781 non-volatile compounds. BYT showed the best α-glucosidase inhibitory activity and antioxidant capacity among the selected yellow teas, which might be contributed by the higher content of galloylated catechins. These findings provided a better understanding of the chemical profile and bioactivities of yellow teas.

The enzymatic reaction stage (ECS) of oolong tea processing plays an important role in the formation of the flavor quality of the oolong tea. To investigate the dynamic changes in the volatile and non-volatile components in the leaves of oolong tea during the ECS, metabolomic studies were carried out using the leaf samples collected at different stages of the ECS of Aijiao oolong tea. Out of the identified 306 non-volatile metabolites and 85 volatile metabolites, 159 non-volatile metabolites and 42 volatile metabolites were screened out as key differential metabolites for dynamic changes during the ECS. A multivariate statistical analysis on the key differential metabolites showed that the accumulations of most metabolites exhibited dynamic changes, while some amino acids, nucleosides, and organic acids accumulated significantly after turning-over treatment. The evolution characteristics of 27 key precursors or transformed VOCs during the ECS of Aijiao oolong tea were clarified, and it was found that the synthesis of aroma substances was mainly concentrated in lipids as precursors and glycosides as precursor pathways. The results revealed the dynamic changes in the flavor metabolites in the ECS during the processing of Aijiao oolong tea, which provided valuable information for the formation of the characteristic flavor of Aijiao oolong tea. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lactic acid bacteria (LABs) are widely present in foods and affect the flavour of fermented cultures. This study investigates the effects of fermentation with Lactobacillus acidophilus JYLA-16 (La), Lactobacillus plantarum JYLP-375 (Lp), and Lactobacillus rhamnosus JYLR-005 (Lr) on the flavour profile of blueberry juice. RESULTS: This study showed that all LABs strains preferentially used glucose rather than fructose as the carbon source during fermentation. Lactic acid was the main fermentation product, reaching 7.76 g L-1 in La-fermented blueberry juice, 5.86 g L-1 in Lp-fermented blueberry juice, and 6.41 g L-1 in Lr-fermented blueberry juice. These strains extensively metabolized quinic acid, whereas oxalic acid metabolism was almost unaffected. Sixty-four volatile compounds were identified using gas chromatography--ion mobility spectrometry (GC--IMS). All fermented blueberry juices exhibited decreased aldehyde levels. Furthermore, fermentation with La was dominated by alcohols, Lp was dominated by esters, and Lr was dominated by ketones. Linear discriminant analysis of the electronic nose and principal component analysis of the GC--IMS data effectively differentiated between unfermented and fermented blueberry juices. CONCLUSION: This study informs LABs selection for producing desirable flavours in fermented blueberry juice and provides a theoretical framework for flavour detection. [ABSTRACT FROM AUTHOR]

To reveal the changes in the flavor quality of chicken osteopontin (CO) before and after enzymatic hydrolysis and a thermal reaction, the present study was carried out to evaluate the volatile compounds and non-volatile compounds in CO. The results show that the chicken boneset enzymatic solution (CBES) presented a notably richer aroma after the enzymatic hydrolysis treatment. At the same time, the concentrations of the total free amino acids (FAAs) and 5′-nucleotides in the CBES increased dramatically. The ERP (enzymatic reaction paste) scores and the ORC (osteopontin reactive cream) scores were exceptionally high in terms of the umami and salty flavor profiles. As precursors, FAAs and 5′-nucleotides also boosted the Maillard reaction, leading to the generation of wide volatile compounds. Compared to CO, CBES, and ORC, the sensory evaluation showed that ERP scored the highest. In summary, the enzymatic hydrolysis treatment coupled with the Maillard reaction significantly enhanced the flavor profile of CO. These findings offer valuable insights into the high-value utilization of bone by-products, making a significant advancement in the field. [ABSTRACT FROM AUTHOR]

Abstract Background Crown gall disease caused by Agrobacterium tumefaciens is a very destructive affliction that affects grapevines. Endophytic bacteria have been discovered to control plant diseases via the use of several mechanisms. This research examined the potential for controlling crown gall by three endophytic bacteria that were previously isolated from healthy cultivated and wild grapevines including Pseudomonas kilonensis Ba35, Pseudomonas chlororaphis Ba47, and Serratia liquefaciens Ou55. Result At various degrees, three endophytic bacteria suppressed the populations of A. tumefaciens Gh1 and greatly decreased the symptoms of crown gall. Furthermore, biofilm production and motility behaviors of A. tumefaciens Gh1were greatly inhibited by the Cell-free Culture Supernatant (CFCS) of endophytic bacteria. According to our findings, CFCS may reduce the adhesion of A. tumefaciens Gh1 cells to grapevine cv. Rashe root tissues as well as their chemotaxis motility toward the extract of the roots. When compared to the untreated control, statistical analysis showed that CFCS significantly reduced the swimming, twitching, and swarming motility of A. tumefaciens Gh1. The findings demonstrated that the endophytic bacteria effectively stimulated the production of plant defensive enzymes including superoxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), and total soluble phenols at different time intervals in grapevine inoculated with A. tumefaciens Gh1. The Ba47 strain markedly increased the expression levels of defense genes associated with plant resistance. The up-regulation of PR1, PR2, VvACO1, and GAD1 genes in grapevine leaves indicates the activation of SA and JA pathways, which play a role in enhancing resistance to pathogen invasion. The results showed that treating grapevine with Ba47 increased antioxidant defense activities and defense-related gene expression, which reduced oxidative damage caused by A. tumefaciens and decreased the incidence of crown gall disease. Conclusion This is the first study on how A. tumefaciens, the grapevine crown gall agent, is affected by CFCS generated by endophytic bacteria in terms of growth and virulence features. To create safer plant disease management techniques, knowledge of the biocontrol processes mediated by CFCS during microbial interactions is crucial.

To provide new insights into the development and utilization of Douchi artificial starters, three common strains (Aspergillus oryzae, Mucor racemosus, and Rhizopus oligosporus) were used to study their influence on the fermentation of Douchi. The results showed that the biogenic amine contents of the three types of Douchi were all within the safe range and far lower than those of traditional fermented Douchi. Aspergillus-type Douchi produced more free amino acids than the other two types of Douchi, and its umami taste was more prominent in sensory evaluation (P < 0.01), while Mucor-type and Rhizopus-type Douchi produced more esters and pyrazines, making the aroma, sauce, and Douchi flavor more abundant. According to the Pearson and PLS analyses results, sweetness was significantly negatively correlated with phenylalanine, cysteine, and acetic acid (P < 0.05), bitterness was significantly negatively correlated with malic acid (P < 0.05), the sour taste was significantly positively correlated with citric acid and most free amino acids (P < 0.05), while astringency was significantly negatively correlated with glucose (P < 0.001). Thirteen volatile compounds such as furfuryl alcohol, phenethyl alcohol, and benzaldehyde caused the flavor difference of three types of Douchi. This study provides theoretical basis for the selection of starting strains for commercial Douchi production.

Background: Crown gall disease caused by Agrobacterium tumefaciens is a very destructive affliction that affects grapevines. Endophytic bacteria have been discovered to control plant diseases via the use of several mechanisms. This research examined the potential for controlling crown gall by three endophytic bacteria that were previously isolated from healthy cultivated and wild grapevines including Pseudomonas kilonensis Ba35, Pseudomonas chlororaphis Ba47, and Serratia liquefaciens Ou55. Result: At various degrees, three endophytic bacteria suppressed the populations of A. tumefaciens Gh1 and greatly decreased the symptoms of crown gall. Furthermore, biofilm production and motility behaviors of A. tumefaciens Gh1were greatly inhibited by the Cell-free Culture Supernatant (CFCS) of endophytic bacteria. According to our findings, CFCS may reduce the adhesion of A. tumefaciens Gh1 cells to grapevine cv. Rashe root tissues as well as their chemotaxis motility toward the extract of the roots. When compared to the untreated control, statistical analysis showed that CFCS significantly reduced the swimming, twitching, and swarming motility of A. tumefaciens Gh1. The findings demonstrated that the endophytic bacteria effectively stimulated the production of plant defensive enzymes including superoxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), and total soluble phenols at different time intervals in grapevine inoculated with A. tumefaciens Gh1. The Ba47 strain markedly increased the expression levels of defense genes associated with plant resistance. The up-regulation of PR1, PR2, VvACO1, and GAD1 genes in grapevine leaves indicates the activation of SA and JA pathways, which play a role in enhancing resistance to pathogen invasion. The results showed that treating grapevine with Ba47 increased antioxidant defense activities and defense-related gene expression, which reduced oxidative damage caused by A. tumefaciens and decreased the incidence of crown gall disease. Conclusion: This is the first study on how A. tumefaciens, the grapevine crown gall agent, is affected by CFCS generated by endophytic bacteria in terms of growth and virulence features. To create safer plant disease management techniques, knowledge of the biocontrol processes mediated by CFCS during microbial interactions is crucial. [ABSTRACT FROM AUTHOR]

Effects of light or dark storage condition on the profile changes of volatile and non‐volatile compounds were evaluated in dried and baked laver for 60 days. Volatile and non‐volatile compounds were analyzed using gas chromatography–mass selective detection and high‐performance liquid chromatography–quadrupole‐time of flight–mass spectrometry, respectively. Baked laver stored in light conditions for 60 days produced the most volatile compounds, whereas dried laver stored in the dark produced the least volatile compounds. Total 11 classes of volatile compounds were detected, including alkanes, alkenes, and ketones, with aldehydes being most abundant in dried laver stored under light. Metabolite analysis of non‐volatile compounds led to the selection of 12 compounds with a higher variable importance projection (VIP) value of >1.0: 6 fatty acids (VIP 1.2–2.0), 2 flavanols (VIP 1.3–1.8), hydroxybenzoic acid (VIP 1.5), hydroxycinnamic acid (VIP 2.3), a phenolic acid ester (VIP 1.9), and phloroglucinol (VIP 1.2). Generally, levels of these compounds decreased more following storage in the light than under dark, irrespective of laver preparation. The content of linolenic acid was particularly affected by storage conditions, with light conditions causing a fourfold reduction in linolenic acid level compared with dark conditions, which could result in an increased formation of aldehydes. Gallic acid and sinapinic acid were detected in dried but not baked laver, as they are destroyed by heat treatment. Therefore, laver should be baked and stored in dark conditions to prevent the development of rancidity. Practical Application: Laver is one of the representative seaweeds, and the popularity among consumers increases. Although commercially available laver is prepared in dried or baked condition, scientific studies on the changes of metabolites, including volatile and non‐volatile compounds during storage, are scarce. The results of this study can be applied to improve proper storage methods to maintain the quality of laver, which can be beneficial for consumers and food industry. [ABSTRACT FROM AUTHOR]

The semi-dry fermentation processing (SFP) of Coffea arabica is a traditional primary processing method in the coffee industry, which crucially impacts the coffee’s flavor. To further obtain useful information on microbial communities and chemical compounds during the SFP of C. arabica from Yunnan, China, the microbial community structures and the differentially changed non-volatile compounds (DCnVCs) were comprehensively analyzed. The results showed that Tatumella, Staphylococcus, Klebsiella, Brevundimonas, and Gluconobacter were the most prevalent bacteria genera, and Candida, Hannaella, Hanseniaspora, Pichia, and Lachancea were the most abundant fungal genera. Furthermore, 117 DCnVCs were found in the fermentation-finished samples compared to the raw materials. Therefore, this study can provide useful information for understanding the SFP of coffee beans, and its impact on coffee’s quality parameters.

Herein, we used an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) system to investigate changes in the profile of non-volatile metabolites in green tea after different periods (15, 40, 80 and 120 days) of storage at 37 ℃. The color of green tea and tea infusion changed after 40 days of storage at 37 ℃ when compared with the control (stored at −80 ℃). During 40 days of storage, the content of catechins did not significantly change, but the content of free amino acids significantly decreased. A total of 684 non-volatile components were identified, 77 of which were found to be characteristic differential metabolites, the major ones being polyphenols, lipids and organic acids. The content of octadecadien-6-ynoic acid, an umami-related compound, significantly decreased after 40 days and was undetected after 80 days. The content of theaflavine-3-catechin, related to the color and taste of tea infusion, significantly increased with storage time. Similarly, the content of flavone glycoside increased with storage time. Moreover, the content of lipids such as triacylglycerols (TAGs) and diacylglycerol (DAGs) changed significantly after 15 days, and the content of free fatty acids increased with storage time. The findings from this study showed that the contents of lipids and flavonoids in green tea significantly changed during storage, which played an important role in the quality deterioration of green tea.

Massa Medicata Fermentata (MMF) is widely applied in feed additives and human medicine. The stir-frying is a commonly used method for process of MMF, which will improve its efficacy in invigorating the spleen. However, the dynamic change of physical properties and ingredients during stir-frying remain un-elucidated. Here, the appearance color, pH values, UV–visible and fluorescence spectroscopy, content of volatile and non-volatile compounds of MMF at different process stage of stir-frying were measured. The results indicated that with increasing stir-frying time, the appearance color deepened, and pH value decreased, while the UV absorbance and fluorescence exhibited rising trends. Additionally, we identified four non-volatile compounds from MMF, and three of them showed gradual increase in content during stir-frying (from 0 to 30 min). Regarding the volatile compounds, the content of alcohols decreased, while aldehydes increased evidently after 30 min. These results demonstrated that the physicochemical properties, types of compounds and their content all significantly changed during stir-frying. The study provides insights regarding the change in substance and appearance, which will provide a guidance for the judgment of the degree of stir-frying MMF.

Scenting tea with Jasminum sambac is beneficial to forming a unique taste of jasmine tea, which is regulated by numerous compounds. To investigate the relationship between metabolites in jasmine and jasmine tea, as well as the impact of metabolites on the characteristic taste of jasmine tea, the liquid chromatography-mass spectrometry, sensory evaluation, and multivariate analysis were applied in this study. A total of 585 and 589 compounds were identified in jasmine tea and jasmine, respectively. After scented, jasmine tea added 70 compounds, which were believed to come from jasmine flowers. Furthermore, seventy-four compounds were identified as key characteristic compounds of jasmine tea, and twenty-two key differential metabolite compounds were believed to be used to distinguish jasmine tea scented differently and contribute to the taste of jasmine tea. Additionally, the relationship between taste compounds and aroma quality was also explored, and it was found that five compounds were positively correlated with the aroma properties of jasmine tea and seven compounds were negatively correlated with the aroma properties of jasmine tea. Overall, these findings provided insights into the future study of the mechanism of taste formation in jasmine tea and provided the theoretical basis for the production of jasmine tea. [ABSTRACT FROM AUTHOR]

Daqu , a fermentation starter, was important source of key flavors of Chinese Baijiu. The quality of Chinese Baijiu could be significantly affected by the ester-synthesis microorganisms. In order to clarify the microbial community that promoted the ester formation in Daqu , the dynamic changes of microbial community and non-volatile profiles of Qing-flavor Daqu and Nong-flavor Daqu samples through the whole making process were investigated by Illumina MiSeq platform and liquid chromatograph-mass spectrometry (LC-MS). The non-volatile compounds related to ester synthesis were identified by comparing with ester synthesis pathway and partial least squares discriminant analysis (PLS-DA). Correlations between microbial community and non-volatile metabolites involved in ester synthesis of two types of Daqu were disclosed by Pearson correlation analysis. Results showed that a total of 50 key compounds involved in ester synthesis were identified and 25 primary functional microorganisms were screened in 39 samples. Among them, in Qing-flavor Daqu , the top three primary functional microorganisms that had strong correlations with ester-formation precursors were Lactobacillus , Pantoea , and Sphingomonas ; Lactobacillus and Pantoea had significantly positive interactions with various microorganisms, but Sphingomonas did not interact with others. In Nong-flavor Daqu , the top three primary functional microorganisms that had strong correlations with ester-formation precursors were Candida , Apiotrichum , and Cutaneotrichosporon. Candida showed strong positive correlation with other microorganisms, whereas Apiotrichum and Cutaneotrichosporon had no interaction with other microorganisms. The study could help our understanding of the microbial metabolism process in Daqu and provided a scientific basis for a controllable and feasible fermentation system. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae is commonly used for the production of alcoholic beverages, including cider. In this study, we examined indigenous S. cerevisiae and S. uvarum strains, both species commonly found in cider from Hardanger (Norway), for their strain-specific abilities to produce volatile and non-volatile compounds. Small-scale fermentation of apple juice with 20 Saccharomyces strains was performed to evaluate their aroma-producing potential as a function of amino acids (AAs) and other physicochemical parameters under the same experimental conditions. After fermentation, sugars, organic acids, AAs, and biogenic amines (BAs) were quantified using the HPLC–UV/RI system. A new analytical method was developed for the simultaneous determination of nineteen AAs and four BAs in a single run using HPLC–UV with prior sample derivatization. Volatile compounds were determined using HS-SPME-GC-MS. Based on 54 parameters and after the removal of outliers, the nineteen strains were classified into four groups. In addition, we used PLS regression to establish a relationship between aroma compounds and predictor variables (AAs, BAs, organic acids, sugars, hydrogen sulfide (H2S) production, CO2 release) of all 19 strains tested. The results of the VIP show that the main predictor variables affecting the aroma compounds produced by the selected yeasts are 16, belonging mainly to AAs. [ABSTRACT FROM AUTHOR]

In this study, the flavor compounds of ivory shell (Babylonia areolata) and their changes caused by ammonia and salinity stresses were studied. Ammonia stress improved the contents of free amino acids (FAAs), 5′-adenosine monophosphate (AMP), citric acid, and some mineral ions such as Na+, PO43−, and Cl−. The FAA contents decreased with increasing salinity, while the opposite results were observed in most inorganic ions (e.g., K+, Na+, Mg2+, Mn2+, PO43−, and Cl−). Hyposaline and hypersaline stresses increased the AMP and citric acid contents compared to the control group. The equivalent umami concentration (EUC) values were 3.53–5.14 g monosodium glutamate (MSG)/100 g of wet weight, and the differences in EUC values among treatments were mainly caused by AMP. Hexanal, butanoic acid, and 4-(dimethylamino)-3-hydroxy- and (E, E)-3,5-octadien-2-one were the top three volatile compounds, and their profiles were significantly affected when ivory shells were cultured under different ammonia and salinity conditions. [ABSTRACT FROM AUTHOR]

The enzymatic reaction stage (ECS) of oolong tea processing plays an important role in the formation of the flavor quality of the oolong tea. To investigate the dynamic changes in the volatile and non-volatile components in the leaves of oolong tea during the ECS, metabolomic studies were carried out using the leaf samples collected at different stages of the ECS of Aijiao oolong tea. Out of the identified 306 non-volatile metabolites and 85 volatile metabolites, 159 non-volatile metabolites and 42 volatile metabolites were screened out as key differential metabolites for dynamic changes during the ECS. A multivariate statistical analysis on the key differential metabolites showed that the accumulations of most metabolites exhibited dynamic changes, while some amino acids, nucleosides, and organic acids accumulated significantly after turning-over treatment. The evolution characteristics of 27 key precursors or transformed VOCs during the ECS of Aijiao oolong tea were clarified, and it was found that the synthesis of aroma substances was mainly concentrated in lipids as precursors and glycosides as precursor pathways. The results revealed the dynamic changes in the flavor metabolites in the ECS during the processing of Aijiao oolong tea, which provided valuable information for the formation of the characteristic flavor of Aijiao oolong tea.

In this study, the bacterial communities and flavor metabolites of 27 traditional naturally fermented sauerkraut samples collected from nine regions of Heilongjiang Province in Northeast China were investigated. The dominant genera were Lactobacillus, Pseudomonas, Alcaligenes, Arcobacter, Pseudarcobacter, Lactococcus, Comamonas, Pediococcus, Prevotella, and Insolitispirillum. A total of 148 volatile compounds were detected in seven categories; esters and acids were the most abundant volatiles. Additionally, the highest content (15.96 mg/g) of lactic acid was detected in YC1. Acetic acid, oleic acid, palmitic acid, elaidic acid, and dehydroacetic acid were the key differential volatile compounds, which may be related to the bacterial communities. Spearman’s correlation analysis revealed that Lactococcus and Lactobacillus were significantly positively correlated with flavor metabolites, suggesting that they may play a more significant role in flavor formation. The results of this study can help in the development of better quality of fermented vegetables.

China, the largest pomelo producer, has many famous pomelo varieties. However, there has been limited research on the comparative of chemical compositions and antioxidant activities among different pomelo varieties from China. In the work, five pomelo varieties and one grapefruit variety from China were studied by investigating their chemical composition and antioxidant activity. Volatiles in dichloromethane extract of pomelo peels were measured using gas chromatography - mass spectrometry. Shatianyu pomelo contained 27 volatile compounds, was the most abundant in volatiles. Total protein, phenols, and flavonoid were determined by spectrophotometry. Changshanhuyou grapefruit contained more phenols and flavonoids, while Shatianyu pomelo contained more protein. The amount of vitamin C, sugars, and organic acids were evaluated using liquid chromatography. Shatianyu pomelo had the highest amount of vitamin C and sugars, and the lower amount of organic acids. Guanximiyu pomelo had the highest amount of organic acids. Shatianyu pomelo and Changshanhuyou grapefruit possessed the higher antioxidant activities as compared to other four pomelo varieties. The antioxidant activities of pomelo pulp had no obvious correlation with the amount of total phenols, total falconoid, and vitamin C. This study is helpful to understand the nutritional value and health function of six Chinese famous pomelo varieties.

To explore the changes in the viability and taste compounds of Crassostrea gigas at different circulation stages after harvesting, the oysters were sampled at different times of depuration, induced dormancy and waterless live storage for evaluation of viability changes in terms of adenosine triphosphate (ATP) related compounds, adenylate energy charge (AEC) and free amino acids and evaluation of flavor quality changes with respect to contents and taste activity values (TAV) of taste compounds. The results showed that the viability and taste compounds of C. gigas were significantly influenced by postharvest transportation and environmental stress. All viability indicators were significantly restored by 24 h depuration, with ATP, AEC and the content of total free amino acids being significantly higher than before depuration (P < 0.05), indicating that the viability reached new levels. During the process from induced dormancy to waterless live storage, more energy substances were required to maintain the balance of the organism under low temperature and hypoxia stress, so all viability indicators were significantly lower than before depuration (P < 0.05) and remained stable at a lower level. Among the taste compounds, the content of umami amino acids increased and the content of bitter amino acids decreased in C. gigas after depuration, and the content of taste amino acids decreased slowly as the waterless live storage time increased. The umami?nucleotides inosine 5’-monphosphate (IMP) and adenosine 5’-monophosphate (AMP) were accumulated throughout the circulation process (P < 0.05); the total amount of organic acids showed a fluctuant downward trend, with the amount of lactic acid being significantly higher after than before depuration (P < 0.05) and showing a decreasing trend from dormancy to the end of waterless live storage (P < 0.05), while the amounts of succinic acid and malic acid showed an increasing trend during waterless live storage (P < 0.05). The levels of Na+ and K+, which play an auxiliary role in the umami taste of C. gigas, were higher after 9 days of waterless live storage than before depuration. The total amount of taste substances did not change overall. The TAV of taste compounds showed that Asp, Glu, Arg, Ala, IMP, lactic acid, succinic acid, Na+ and K+ contributed significantly to the taste of C. gigas. In conclusion, the viability and taste substances of C. gigas can be maintained at a high level by depuration for 24 hours + gradient cooling to induce dormancy + ecological ice temperature waterless live storage for 9 days after harvesting.

Shrimp sauce, one of the traditional salt-fermented food in China, has a unique flavor that is influenced by the resident microflora. The quality of salt-fermented shrimp sauce was evaluated in this work by determining the total volatile basic nitrogen (TVB-N), the amino acid nitrogen (AAN), organic acid, 5'-nucleotide and free amino acids (FAA). Moreover, the dynamics of microbial diversity during processing was investigated by using high-throughput sequencing technology. The results showed that the AAN, TVB-N, organic acid, 5'-nucleotide and FAA content were in range of 0.93–1.42 g/100mL, 49.91–236.27 mg/100mL, 6.65–20.68 mg/mL, 3.51–6.56 mg/mL and 81.27–102.90 mg/mL. Among the microbial diversity found in the shrimp sauce, Tetragenococcus, Flavobacterium, Polaribacter, Haematospirillum and Staphylococcus were the predominant genera. Correlation analysis indicated that the bacteria Tetragenococcus and Staphylococcus were important in the formation of non-volatile compounds. Tetragenococcus positively correlated with a variety of FAAs; Staphylococcus positively correlated with 5'-nucleotides. The analysis indicated that Tetragenococcus and Staphylococcus were the core genera affecting non-volatile components. These findings indicate the dynamics of the bacterial community and non-volatile components inter-relationships during shrimp sauce fermentation and provide a theoretical basis for improving the fermentation process of shrimp sauce.

To reveal the changes in the flavor quality of chicken osteopontin (CO) before and after enzymatic hydrolysis and a thermal reaction, the present study was carried out to evaluate the volatile compounds and non-volatile compounds in CO. The results show that the chicken boneset enzymatic solution (CBES) presented a notably richer aroma after the enzymatic hydrolysis treatment. At the same time, the concentrations of the total free amino acids (FAAs) and 5′-nucleotides in the CBES increased dramatically. The ERP (enzymatic reaction paste) scores and the ORC (osteopontin reactive cream) scores were exceptionally high in terms of the umami and salty flavor profiles. As precursors, FAAs and 5′-nucleotides also boosted the Maillard reaction, leading to the generation of wide volatile compounds. Compared to CO, CBES, and ORC, the sensory evaluation showed that ERP scored the highest. In summary, the enzymatic hydrolysis treatment coupled with the Maillard reaction significantly enhanced the flavor profile of CO. These findings offer valuable insights into the high-value utilization of bone by-products, making a significant advancement in the field.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Scenting tea with Jasminum sambac is beneficial to forming a unique taste of jasmine tea, which is regulated by numerous compounds. To investigate the relationship between metabolites in jasmine and jasmine tea, as well as the impact of metabolites on the characteristic taste of jasmine tea, the liquid chromatography-mass spectrometry, sensory evaluation, and multivariate analysis were applied in this study. A total of 585 and 589 compounds were identified in jasmine tea and jasmine, respectively. After scented, jasmine tea added 70 compounds, which were believed to come from jasmine flowers. Furthermore, seventy-four compounds were identified as key characteristic compounds of jasmine tea, and twenty-two key differential metabolite compounds were believed to be used to distinguish jasmine tea scented differently and contribute to the taste of jasmine tea. Additionally, the relationship between taste compounds and aroma quality was also explored, and it was found that five compounds were positively correlated with the aroma properties of jasmine tea and seven compounds were negatively correlated with the aroma properties of jasmine tea. Overall, these findings provided insights into the future study of the mechanism of taste formation in jasmine tea and provided the theoretical basis for the production of jasmine tea.

Saccharomyces cerevisiae is commonly used for the production of alcoholic beverages, including cider. In this study, we examined indigenous S. cerevisiae and S. uvarum strains, both species commonly found in cider from Hardanger (Norway), for their strain-specific abilities to produce volatile and non-volatile compounds. Small-scale fermentation of apple juice with 20 Saccharomyces strains was performed to evaluate their aroma-producing potential as a function of amino acids (AAs) and other physicochemical parameters under the same experimental conditions. After fermentation, sugars, organic acids, AAs, and biogenic amines (BAs) were quantified using the HPLC–UV/RI system. A new analytical method was developed for the simultaneous determination of nineteen AAs and four BAs in a single run using HPLC–UV with prior sample derivatization. Volatile compounds were determined using HS-SPME-GC-MS. Based on 54 parameters and after the removal of outliers, the nineteen strains were classified into four groups. In addition, we used PLS regression to establish a relationship between aroma compounds and predictor variables (AAs, BAs, organic acids, sugars, hydrogen sulfide (H2S) production, CO2 release) of all 19 strains tested. The results of the VIP show that the main predictor variables affecting the aroma compounds produced by the selected yeasts are 16, belonging mainly to AAs.

Rhodiola crenulata (RC) and Rhodiola fastigiata (RF) are representative species of Rhodiola with well-accepted health benefits; the roots are the medicinal part. However, prior to this study, the differences in phytochemicals between these two species and different parts of the same species remained unclear. Using LC-ESI-MS/MS, HS-SPME-GC–MS, chemical and sensory analyses, volatile compounds and non-volatile compounds, and antioxidant activities of the roots of Rhodiola crenulata and Rhodiola fastigiata and four parts (roots, leaves, flowers, and above-ground stems) of RC were investigated. The volatile compounds and non-volatile compounds of RC roots exhibited upregulation overall compared to those of RF roots, and the odorousness, phenolic content, and antioxidant activity were more pronounced in the RC roots. The phenolic content and antioxidant activity of roots and leaves, alongside the odorousness of roots and flowers, were more significant among the four parts of RC, and the RC roots and RC flowers exhibited similar odorousness. Comparison of non-volatile differential metabolites between RC roots and RC leaves showed upregulations of saccharides and phospholipids, and minor upregulations of flavonoids and phenylpropanoids in the roots; in addition, amino acids, organic acids, and vitamins were upregulated in the leaves. These results revealed the following: 1) RC roots are superior to RF roots regarding volatile compounds and non-volatile compounds, and antioxidant activity; 2) it is more favorable to select RC roots for exploiting volatile compounds compared with RC flowers in consideration of the biomass available; 3) in terms of non-volatile compounds, and antioxidant ability, RC leaves are also of great value in addition to RC roots, though these two parts show distinct characteristics.

In the present study, bud yellow tea (BYT), small-leaf yellow tea (SYT) and large-leaf yellow tea (LYT) were produced from the same local "population" variety Huoshanjinjizhong ( Camellia sinensis var. sinensis ), and the effects of raw material tenderness on the chemical profile and bioactivities of these teas were investigated. The results showed that 11 crucial compounds were screened by headspace solid-phase microextraction-gas chromatography-mass spectrometry from 64 volatiles in these yellow teas, among which the heterocyclic compounds showed the greatest variations. In addition, 43 key compounds including organic acids, flavan-3-ols, amino acids, saccharides, glycosides and other compounds were screened by liquid chromatography-mass spectrometry from 1781 non-volatile compounds. BYT showed the best α-glucosidase inhibitory activity and antioxidant capacity among the selected yellow teas, which might be contributed by the higher content of galloylated catechins. These findings provided a better understanding of the chemical profile and bioactivities of yellow teas., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Ltd.)

In this study, the flavor compounds of ivory shell (Babylonia areolata) and their changes caused by ammonia and salinity stresses were studied. Ammonia stress improved the contents of free amino acids (FAAs), 5′-adenosine monophosphate (AMP), citric acid, and some mineral ions such as Na+, PO43−, and Cl−. The FAA contents decreased with increasing salinity, while the opposite results were observed in most inorganic ions (e.g., K+, Na+, Mg2+, Mn2+, PO43−, and Cl−). Hyposaline and hypersaline stresses increased the AMP and citric acid contents compared to the control group. The equivalent umami concentration (EUC) values were 3.53–5.14 g monosodium glutamate (MSG)/100 g of wet weight, and the differences in EUC values among treatments were mainly caused by AMP. Hexanal, butanoic acid, and 4-(dimethylamino)-3-hydroxy- and (E, E)-3,5-octadien-2-one were the top three volatile compounds, and their profiles were significantly affected when ivory shells were cultured under different ammonia and salinity conditions.

Summary: Sweet pickled mango named Ma‐Muang Bao Chae‐Im is a traditional preserved mango from Hat Yai, Thailand. This study investigated (I) volatile and non‐volatile compound profiles of commercial Ma‐Muang Bao Chae‐Im and (II) their relationship to consumer preference. Untargeted metabolomics profiling was performed by gas chromatography‐mass quadrupole‐time of flight analysis. There were 117 volatile and 44 non‐volatile compounds annotated in six commercial brands of Ma‐Muang Bao Chae‐Im. Furthermore, 46 volatile and 19 non‐volatile compounds' discriminant markers were found by Partial least square discriminant analysis. Among those markers, sorbic and benzoic acid were observed in several brands; moreover, the combination of both compounds altered the volatile profile, especially the ester group. Partial least square regression revealed that overall consumer liking is correlated to 1‐heptanol; 1‐octanol; acetoin; acetic acid, 2‐phenylethyl ester; D‐manitol; terpenes and terpenoids, while firmness to sucrose and L‐(‐)‐sorbofuranose. On the other hand, most ester compounds were not related to consumer preference. [ABSTRACT FROM AUTHOR]

Wuyi Rock Tea (WRT) has different characteristics of "rock flavor" due to different production areas. In this study, we investigated the flavor characteristics and key components of "rock flavor" and the influence of microorganisms on the substances by combining metabolomics and microbiomics with the Rougui WRTs from the Zhengyan, Banyan, and Waishan production areas. The results showed that Rougui has a strong floral and fruity aroma, which is mainly brought by hotrienol, and the sweet, smooth, and fresh taste is composed of epicatechin gallate, epigallocatechin, epigallocatechin gallate, caffeine, theanine, soluble sugar, and sweet and bitter amino acids. Bacteria Chryseobacterium , Pedobacter , Bosea , Agrobacterium , Stenotrophomonas , and Actinoplanes mainly influence the production of hotrienol, epicatechin gallate, and theanine. Fungi Pestalotiopsis , Fusarium, Elsinoe , Teichospora and Tetracladium mainly influence the production of non-volatile compounds. This study provides a reference for the biological formation mechanism of the characteristic aroma of WRT's "rock falvor". [Display omitted] • The "rock flavor" is a rich floral aroma and a smooth, sweet, and fresh taste. • Hotrienol is the characteristic substance of floral and fruity aroma. • Rougui's taste is determined by catechins, caffeine, soluble sugars, and amino acids. • The characteristic flavor substances are basically produced in tea-making process. • Characteristic microorganisms and flavor substances have strong correlation. [ABSTRACT FROM AUTHOR]

In this study, metabolomics and proteomics were performed to investigate the fluctuations of non-volatile compounds and proteins in tea leaves from three tea cultivars with varying colours during withering. A total of 2798 compounds were detected, exhibiting considerable variations in amino acids, phenylpropanoids, and flavonoids. The ZH1 cultivar displayed increased levels of amino acids but decreased levels of polyphenols, which might be associated with the up-regulation of enzymes responsible for protein degradation and subsequent amino acid production, as well as the down-regulation of enzymes involved in phenylpropanoid and flavonoid biosynthesis. The FUD and ZH1 cultivars had elevated levels of flavanols and flavanol-O-glycosides, which were regulated by the upregulation of FLS. The ZJ and ZH1 cultivars displayed elevated levels of theaflavin and peroxidase. This work presents a novel investigation into the alterations of metabolites and proteins between tea cultivars during withering, and helps with the tea cultivar selection and manufacturing development. [Display omitted] • Multi-omics study on tea leaves from three different tea cultivars with distinct colours during withering. • The composition and contents of non-volatile chemicals varied with tea cultivars and withering times. • The amino acids biosynthesis was increased and the polyphenols biosynthesis was decreased in the ZH1 cultivar. • The flavonoid biosynthesis was increased in the FUD and ZJ cultivars during withering. • The levels of PODs and PPOs were elevated in the ZJ and ZH1 cultivars during withering. [ABSTRACT FROM AUTHOR]

Abalone (Haliotis spp.) is a shellfish known for its exceptional nutritional value and significant economic worth. This study investigated the dynamic characteristics of non-volatile compounds over a year, including metabolites, lipids, nucleotides, and free amino acids (FAAs), which determined the nutritional quality and flavor of abalone. 174 metabolites and 371 lipids were identified and characterized, while 20 FAAs and 11 nucleotides were quantitatively assessed. These non-volatile compounds of abalone were fluctuated with months variation, which was consistent with the fluctuations of environmental factors, especially seawater temperature. Compared with seasonal variation, gender had less influence on these non-volatiles. June and July proved to be the optimal harvesting periods for abalone, with the levels of overall metabolites, lipids, FAAs, and nucleotides in abalone exhibiting a higher value in June and July over a year. Intriguingly, taurine covered 60% of the total FAAs and abalone could be used as dietary taurine supplementation. • Non-volatile compounds and umami intensity in abalone over a year were analyzed. • Compared with season shift, gender had less influence on the nutrients and umami. • Taurine covered 60% of the total FAAs and could be used as dietary supplementation. • June and July were optimal abalone harvest months due to higher nutrient and umami. [ABSTRACT FROM AUTHOR]

Xinyang Maojian (XYMJ) green tea is one of the top ten teas in China, and the consumers prefer spring tea due to its umami taste and pleasurable aroma. However, the knowledge about temporal variation of the volatile compounds in XYMJ green teas harvested during different seasons is very limited. In the present work, the main non-volatile compounds that endowed the taste and volatile compounds responsible for the aroma in XYMJ green teas harvested during the spring and autumn seasons were determined. The average contents of free amino acids (FAA) were significantly higher and gradually declined in the spring teas, whereas the caffeine was significantly lower and gradually increased in the spring teas. A total of 39 volatile compounds of six chemical classes were detected in XYMJ green teas, and they displayed various change trends during the spring and autumn seasons, among which 15 volatile compounds were identified as the key odorants based on odor activity value (OAV). The highest OAV of 2195.05 was calculated for the violet-like smelling trans-β-ionone followed by decanal, nonanal, dimethyl sulfide, linalool, geraniol and naphthalene. The OAVs of geraniol, (Z)-3-hexenyl hexanoate, heptanal, benzaldehyde and hexanal in XYMJ spring teas were higher than XYMJ autumn teas. The hierarchical clustering analysis indicated that XYMJ green teas were divided into three clusters and the quality of XYMJ green teas changed greatly within spring season. Harvest season is a crucial factor affecting the flavor quality of XYMJ green teas. [ABSTRACT FROM AUTHOR]

BACKGROUND Red light withering significantly improves the sensory flavor qualities of tea, although changes in metabolites during this process have not been systematically studied until now. The present study comprehensively analyzes metabolites in withered tea leaves at 2‐h intervals up to 12 h under red light (630 nm) and dark conditions using ultra performance liquid chromatography‐high resolution mass spectrometry (untargeted metabolomics). RESULTS: Ninety‐four non‐volatile compounds are identified and relatively quantified, including amino acids, catechins, dimeric catechins, flavonol glycosides, glycosidically‐bound volatiles, phenolic acids and nucleosides. The results show that amino acids, catechins and dimeric catechins are most affected by red light treatment. Ten free amino acids, theaflavins and theasinensin A increase after red light irradiation, whereas epigallocatechin gallate and catechin fall. CONCLUSION: The present study provides a comprehensive and systematic profile of the dynamic effects of red light on withering tea and a rationale for its use in tea processing quality control. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Rice bran, a by-product of the rice milling process, has high nutritional and bioactive components. The fermentation process has been adopted to enhance the nutritional quality of rice bran. The objective of this study was to identify and compare non-volatile compounds of fermented and non-fermented Inpari 30 and Cempo Ireng rice bran and its blood pressure-lowering activity. Each sample of rice bran was fermented by Rhizopous oligosporus for 72 hours at 30 ℃, using solid-state fermentation. In this study, non-fermented rice bran was used as a control. Non-targeted analysis of samples was carried out by Ultra performance liquid chromatography-tandem mass spectrometry with electrospray ionization in positive ion mode. For animal study, we used stroke-prone spontaneously hypertensive rats (SHRSP)-a model of hypertension-related disorders similar to human essential hypertension. Principal component analysis was done to categorize non-volatile compounds, based on its relative concentration. Seventy-two non-volatile compounds were identified in fermented and non-fermented rice bran, classified into secondary metabolites (36 compounds), lipids (16 compounds), amino acids (8 compounds), vitamins and cofactors (7 compounds), peptides (3 compounds), nucleotides (1 compound), and carbohydrates (1 compound). Adenosine was the most dominant of the non-volatile compounds in all rice bran samples. Further, blood pressure-lowering activity was shown in Inpari 30 fermented rice bran after six hours of administration in SHRSP. This study revealed a diversity of non-volatile compounds in fermented and non-fermented versions of Inpari 30 and Cempo Ireng rice bran that have anti-hypertensive effects. This study may provide opportunities to promote the production of fermented RB as a functional ingredient with enhanced bioactivity.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Emmer is among the most ancient domesticated grains. In craft brewing, emmer is used in an adjunct, due to its tannic astringency and typical nutty aroma. The aim of this study was to evaluate the effects on the quality of emmer-based craft beers exerted by the employment of two novel brewing procedures (BP1 and BP2) and four oenological Saccharomyces cerevisiae starter strains, namely 17,290, 14,061, 9502, and 9518. The two technological approaches differed for water conductivity (570 and 440 μS/cm), protein rest (30 and 10 min), boiling step (90 and 55 min), and Irish moss addition (only in BP1). The highest total phenolic concentrations were detected in the beers fermented by 17,290 and 14,061 strains. The beers fermented by 14,061 showed the highest contents of volatile esters, alcohols, and terpenes (the latter if produced according to BP1). The beers produced according to BP2 had the highest concentrations of volatile acids, norisoprenoids, hydrocarbons, and phenols with significant effects of the utilized starter strain. The highest overall sensory score (∼4.5) was assigned to BP2-9502 beers and it was positively correlated with color, pH, foam amount and persistence, olfactory finesse, body/fullness, and negatively correlated with CO 2 , titratable and volatile acidity, saltiness, and sourness. [Display omitted] • Two brewings (BP1, BP2) and 4 oenological yeasts studied for emmer beer production. • BP1/BP2: water conductivity, 570/440 μS/cm; protein rest, 30/10min; boiling, 90/55min. • BP2-beers had the highest content of volatile acids, norisoprenoids, hydrocarbons, phenols. • Beers fermented by strains from Negroamaro grape had the highest phenolic contents. • BP2 and Susumaniello-yeast strain gave the best sensory scores. [ABSTRACT FROM AUTHOR]

The flavor attribute of Fragaria × ananassa Duch. would decide consumers' selection of preferred strawberry commercial cultivars. The roles of volatile compounds in strawberry aroma have been well-studied while knowledge regarding the non-volatile compounds is limited. Some non-volatile compounds which are involved in consumers preference of strawberry have been reported, contributions of non-volatile compounds for strawberry flavor remain ambiguous. This study explored the strawberry flavor influences of essential non-volatile compounds by comparing biosynthesis pathways of cultivars exhibiting distinct flavor characteristics. The widely targeted metabolome generated global profiles of three cultivars including 521 known non-volatile compounds. The differential accumulation analysis and precise quantification of soluble sugars, organic acids, polyphenols and free amino acids (FAAs) predicted fructose, citric acid, kaempferol and pelargonin-3-glucoside were key compounds involved in the sweetness, acidity and astringency of strawberries. Further, the conjoint analysis of metabolites and 824 differentially expressed genes revealed that flavonoid biosynthesis, phenylpropanoid metabolism and citrate cycle pathways decided the content difference of key flavor compounds. Within these pathways, several structure genes were predicted as potential regulators of organic acids, flavonoids and umami-taste FAAs. These findings would be helpful in identification of non-volatile compounds and genes responsible for strawberry flavor. • A comprehensive map of genes and flavor compounds of strawberry. • Key non-volatile compound candidates responsible for strawberry flavor. • Several structure genes regulating flavor compounds biosynthesizing. [ABSTRACT FROM AUTHOR]

The oyster is well-known for its delicious taste and nutritional benefits. However, the taste of oysters in the market is relatively monotonous at present. In order to develop more tastes of oysters, this study explored the taste compounds (organic-acids, 5′-nucleotides and free amino acids) of Pacific oysters (Crassostrea gigas, triploid oyster) obtained from aquaculture at three different salinities (25‰, 28‰ and 32‰). The results showed that the contents of 5′-nucleotides (52.59 mg/100 g) in the test samples from the aquaculture salinity of 28‰ were higher than those in the salinity of 25‰ and 32‰. The contents of free amino acids (1760.47 mg/100 g) in the 32‰ sample were higher than those in the salinity of 25‰ and 28‰ ones. In addition, the taste activity value (TAV) and equivalent umami concentration (EUC) of three samples were calculated. The relationship between EUC and sensory evaluation was also investigated. The results showed that the highest TAV of the major free amino acids and 5′-nucleotides was observed in the 28‰ salinity oyster sample. A positive relationship was established between EUC and sensory score of overall taste as well as umami, respectively. Our results suggested that 28‰ was the optimal aquaculture salinity with regards to the oyster's taste, and it was the most commonly accepted. The study may be helpful to guide rational development of diversified flavors of oyster. [ABSTRACT FROM AUTHOR]

Xinyang Maojian (XYMJ) green tea is one of the top ten teas in China, and the consumers prefer spring tea due to its umami taste and pleasurable aroma. However, the knowledge about temporal variation of the volatile compounds in XYMJ green teas harvested during different seasons is very limited. In the present work, the main non-volatile compounds that endowed the taste and volatile compounds responsible for the aroma in XYMJ green teas harvested during the spring and autumn seasons were determined. The average contents of free amino acids (FAA) were significantly higher and gradually declined in the spring teas, whereas the caffeine was significantly lower and gradually increased in the spring teas. A total of 39 volatile compounds of six chemical classes were detected in XYMJ green teas, and they displayed various change trends during the spring and autumn seasons, among which 15 volatile compounds were identified as the key odorants based on odor activity value (OAV). The highest OAV of 2195.05 was calculated for the violet-like smelling trans-β-ionone followed by decanal, nonanal, dimethyl sulfide, linalool, geraniol and naphthalene. The OAVs of geraniol, (Z)-3-hexenyl hexanoate, heptanal, benzaldehyde and hexanal in XYMJ spring teas were higher than XYMJ autumn teas. The hierarchical clustering analysis indicated that XYMJ green teas were divided into three clusters and the quality of XYMJ green teas changed greatly within spring season. Harvest season is a crucial factor affecting the flavor quality of XYMJ green teas.

Background: Lactic acid bacteria (LABs) are widely present in foods and affect the flavour of fermented cultures. This study investigates the effects of fermentation with Lactobacillus acidophilus JYLA-16 (La), Lactobacillus plantarum JYLP-375 (Lp), and Lactobacillus rhamnosus JYLR-005 (Lr) on the flavour profile of blueberry juice., Results: This study showed that all LABs strains preferentially used glucose rather than fructose as the carbon source during fermentation. Lactic acid was the main fermentation product, reaching 7.76 g L -1 in La-fermented blueberry juice, 5.86 g L -1 in Lp-fermented blueberry juice, and 6.41 g L -1 in Lr-fermented blueberry juice. These strains extensively metabolized quinic acid, whereas oxalic acid metabolism was almost unaffected. Sixty-four volatile compounds were identified using gas chromatography-ion mobility spectrometry (GC-IMS). All fermented blueberry juices exhibited decreased aldehyde levels. Furthermore, fermentation with La was dominated by alcohols, Lp was dominated by esters, and Lr was dominated by ketones. Linear discriminant analysis of the electronic nose and principal component analysis of the GC-IMS data effectively differentiated between unfermented and fermented blueberry juices., Conclusion: This study informs LABs selection for producing desirable flavours in fermented blueberry juice and provides a theoretical framework for flavour detection. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The selection of fine flavour cocoa and coffee varieties can lead to attractive niche markets but germplasm need to be analysed for non-volatile compounds and aroma precursors. In the present study, green beans of 202 Theobroma cacao L. accessions (acc.), 64 Coffea arabica L. acc., 35 C. canephora Pierre ex A. Froehner, 7 C. arabusta Capot & Aké Assi and 2 C. canephora × C. congensis A. Froehner hybrids cultivated in Santo, Vanuatu, and harvested at full maturity, were analysed using High Performance Thin Layer Chromatography (HPTLC). In cocoa, 11 compounds were quantified: two alkaloids, two catechins, five proanthocyanidins, and two anthocyanins. Multivariate analyses revealed that Amenolado acc. are differentiated from Criollo, Forastero and Trinitario acc. due to their low caffeine, catechins, and proanthocyanidins contents. Hybrids involving an Amenolado parent also produce low non-volatile compounds contents. In coffee, 11 compounds were quantified: sucrose, two alkaloids, and eight chlorogenic acids. The two major species were differentiated by their mean caffeine content (12.69 mg/g in C. arabica vs. 16.04 mg/g in C. canephora), which is highly correlated with CGA and other chlorogenic acids. Each of the eight chlorogenic acids presented higher values in C. canephora. The ratio sucrose/alkaloids + chlorogenic acids was significantly higher in C. arabica (3.24) than in C. canephora (1.68) which could be an explanation for its comparative sweetness. Coffea arabusta interspecific hybrids presented an intermediate value (2.64). Congusta hybrids were low in sucrose. HPTLC is a cost-efficient technique when applied to germplasm characterization of non-volatile compounds in green cocoa and coffee beans. Chemotype selection appears promising for the development of fine flavor varieties. [ABSTRACT FROM AUTHOR]

Bacterial biofilms have attracted much attention in the food industry since this phenotype increases microbial resistance to environmental stresses. In wine-making, the biofilm produced by Oenococcus oeni is able to persist in this harsh environment and perform malolactic fermentations. Certain viticultural practices are interested in the simultaneous triggering of alcoholic fermentation by yeasts of the species Saccharomyces cerevisiae and malolactic fermentation by lactic acid bacteria. As yet, no data is available on the ability of these micro-organisms to produce mixed biofilms and promote fermentations. Here, the ability of S. cerevisiae and O. oeni to form mixed biofilms on different surfaces found in vinification was observed and analyzed using scanning electron microscopy experiments. Then, following co-inoculation with biofilm or planktonic cells microvinifications were carried out to demonstrate that the mixed biofilms developed on oak allow the efficient completion of fermentations because of their high resistance to stress. Finally, comparisons of the different metabolic profiles obtained by LC-MS were made to assess the impact of the mode of life of biofilms on wine composition. • Formation of mixed biofilms by Oenococcus oeni and Saccharomyces cerevisiae is investigated • Micro-vinification and metabolome are compared for biofilms and planktonic cells • Yeast and bacterial strains form a metabolically active biofilm • The mode of life has an influence on wine composition. [ABSTRACT FROM AUTHOR]