Taste Activity Value Research Articles

Analysis of Taste Quality Differences Between High and Low Grades of Ninghong Tea: From the Perspective of Sensory, Metabolite, and Taste Activity Values.

In this study, the taste quality difference between high (Ninghong-Jinhao tea, JH, unfolded fresh leaves) and low (Ninghong-Congou tea, CG, unfurled fresh leaves) grades of Ninghong tea (unique black tea) was analyzed from the perspective of sensory omics, non-targeted metabolomics, and chemical dose. JH was characterized by sweetness and mellowness with umami, while CG was characterized by sweetness and thickness. A total of 94 differential metabolites contribute to the quality difference between two grades. Further quantitative analysis revealed that JH exhibited a high accumulation of amino acids, catechins, and theaflavins, while CG demonstrated a high accumulation of water extract, tea polyphenols, flavonol glycosides, and saccharides. Taste activity values (TAVs) analysis revealed that the key taste components of JH and CG were catechin, epigallocatechin gallate, three theaflavins, caffeine, myrictin-3-O-glucoside, quercetin-3-O-rutinoside, quercetin-3-O-glucoside, quercetin-3-O-galactoside, kaempferol-3-O-rutinoside, kaempferol-3-O-glucoside, and gallic acid. Among the identified compounds, the TAVs of five flavonol glycosides in Ninghong tea were found to be greater than 10 for the first time. This study is helpful to understand the taste quality difference between different grades of Ninghong tea from the molecular sensory level, providing a scientific foundation for quality improvement and targeted regulation.

Separation and characterization of sweet compounds in Baijiu by molecular distillation combined with molecular sensory science

Sweetness is a crucial taste component in Baijiu. However, comprehensive research on the sweetness of Baijiu remains limited, and traditional methods for flavor analysis are not well-suited for identifying the sweet compounds. To address this, a multi-stage molecular distillation method, combined with molecular sensory science, was developed to more effectively and scientifically analyze the key sweet compounds in Baijiu. The recovery rates of samples and compounds were 93.8 % ∼ 98.3 % and 81.6 % ∼ 118.3 %. 15 important compounds with a taste dilution factor (TD) value ≥64 were identified through gas chromatography–mass spectrometry (GC–MS) combined with taste dilution analysis (TDA). By calculating their taste activity values (TAV), 10 primary sweet compounds with TAV ≥1 were determined. Further taste recombination and omission experiments confirmed that ethyl hexanoate, ethyl heptanoate, ethyl octanoate, ethyl 2-methylbutyrate, 1-butanol, phenethyl alcohol, and ethyl acetate contribute significantly to Baijiu's sweetness and are identified as the key sweet compounds.

Revealing the formation mechanisms of key flavor components during the fermentation of bamboo shoots by combining flavoromics and metagenomics

Microbial metabolism plays a critical role in the flavor development of Guangxi fermented bamboo shoots (GFBS). To clarify the role of microorganisms in flavor formation and predict the metabolic pathways of key characteristic flavor compounds, this study employed metabolomics, Odor Activity Value (OAV), and Taste Activity Value (TAV) calculations, integrated with Partial Least Squares Discriminant Analysis (PLS-DA), to investigate changes in GFBS flavors—represented by volatile flavor compounds, organic acids, and free amino acids—across a 30-day fermentation period. Metagenomic datasets were used to identify taxonomic and functional changes in the microbial community. As a result, 26 characteristic flavor compounds (OAV or TAV > 1) were identified in mature GFBS, and 23 differential flavor compounds were identified at different fermentation stages using PLS-DA (VIP > 1.2). The top 10 microbial genera associated with these characteristic flavor compounds were identified, including Acinetobacter, Enterobacter, Raoultella, Enterococcus, Klebsiella, Lactococcus, Leuconostoc, Weissella, Lactiplantibacillus and Limosilactobacillus. Based on these findings, a predictive metabolic network of key flavor compounds in GFBS was constructed, providing a comprehensive understanding of the diverse metabolic roles of microorganisms during fermentation. This work lays a theoretical foundation for the standardized production and quality control of GFBS flavor.

Physicochemical properties, non-volatile flavor components and antioxidant activity analysis of Ganoderma lucidum (Curtis) P. Karst. extracts dried by different methods

The objective of this present study is to evaluate the effect of different drying methods (spray drying, freeze drying and hot-air drying) on physicochemical properties and antioxidant ability of G. lucidum extracts (GLEs) using various techniques. Meanwhile, combined with free amino acids (FAA) analysis, taste activity values (TAV) analysis and electronic tongue to investigate the relationship between the drying method and the sensory quality of GLEs. The study demonstrates that spray drying GLEs (SDE) has a high water solubility of 96.04% ± 0.10% due to its low crystallinity and hollow spherical microstructure. SDE and freeze drying GLEs (FDE) contain high levels of polysaccharides and proteins, which facilitates the formation of polysaccharide-protein chelates, thereby improving antioxidant capacity. However, SDE has higher antioxidant activity when its polysaccharide content is the same. SDE has higher thermal stability to maintain the molecular structure of GLEs. Meanwhile, FDE has a bitter FAAs content up to 65.84 ± 1.12 mg/g and TAV of Histidine is 178.70. Overall, the results suggest that spray drying is an appropriate and preferred drying method to maintain the bioactivity and bioavailability of GLEs. These findings may enhance the understanding of the GLEs flavor property and bioavailability associated with drying methods and provide a theoretical basis for G. lucidum processing.

Key non-volatile taste components and characteristics in abdominal muscle of Eriocheir sinensis under various thermal processing methods

This study identified the key non-volatile taste components and characteristics in the abdominal muscle (AM) of Eriocheir sinensis under various thermal processing methods: boiling at rising temperature (BO-R), boiling at constant temperature (BO-C), steaming with water vapor (ST) and salt-baked (BK). The results showed that arginine (Arg), alanine (Ala), glycine (Gly), glutamate (Glu), 5′-AMP, histidine (His), lysine (Lys), proline (Pro), K+, PO43−, betaine, succinic acid, and lactic acid were the key taste contributors, exhibiting taste activity values (TAV) higher than 1.0. Compared to BO groups, ST and BK group showed higher expression in SFAAs. BK exhibited the highest Arg, 5′-AMP contents, EUC (4.49 g MSG/100 g), and reduced BFAAs. The cluster and correlation analysis demonstrated that Arg, Ala, and His were identified as the primary differential components under various thermal degradation. These findings could deepen the understanding of taste for subsequent studies.

Feasibility analysis on the application of the Maillard reaction in developing Lentinula edodes umami seasoning: Based on the umami substances, sensory quality, physicochemical properties of the products

To elucidate the feasibility of applying the Maillard reaction (MR) to the development of Lentinula edodes umami seasoning, this study quantitatively analyzed the main umami substances in the products and evaluated their sensory quality. Simultaneously, the rheology, thermal stability, zeta potential, and particle size of the products were also studied. The results indicated that after the MR, the content of umami amino acids in Lentinula edodes hydrolysates (LEHs) decreased from 17.72 mg/g to 12.70 mg/g, while the content of umami nucleotides increased from 0.61 mg/g to 1.36 mg/g. The equivalent umami concentration of MR products was high, at 293.84 ± 11.05 g MSG/100 g. Taste activity value indicated that 5’-GMP, Asp, and Glu were the key umami substances. MR increased the umami sensory score, particle size, absolute zeta potential, and viscosity of LEHs, and altered their thermal stability. These results support the application of MR in the mushroom umami seasoning.

Molecular Sensomics Combined with Random Forest Model Can Reveal the Evolution of Flavor Type of Baijiu Based on Differential Markers.

Baijiu is popular with a long history and balanced flavor. Flavor type is the most widely used classification mode for Baijiu. However, the evolutionary relationships of Baijiu flavor types and the differential markers between flavor types are still unclear, significantly impacting the development of the Baijiu industry. In this study, a total of 319 trace components were identified using gas chromatography-olfactometry-mass spectrometry and gas chromatography-mass spectrometry. Among them, 91 trace components with high odor active values or taste active values were recognized as flavor components. Then random forests were conducted to screen differential markers between the derived and basic flavor types, while a principal component analysis assessed their effectiveness in distinguishing the flavor types of Baijiu. Finally, 19 differential markers (including 3-methylbutyric acid, pentanoic acid, 2-butanol, 2,3-butanediol, ethyl pro-panoate, isobutyl acetate, ethyl butanoate, ethyl hexanoate, ethyl heptanoate, ethyl lactate, ethyl 2-hydroxy butanoate, isopentyl hexanoate, ethyl nonanoate, isopropyl myristate, ethyl tetradecanoate, ethyl benzoate, 2,4-di-t-butylphenol, 2-methylbutanal and 3-octanone) were screened and proven to effectively reveal the evolution of Baijiu flavor types; these were further verified as key differential markers using addition tests and a correlation analysis.

Characterization of flavor profile of Steamed beef with rice flour using gas chromatography-ion mobility spectrometry combined with intelligent sensory (Electronic nose and tongue).

The intelligent senses (Electronic nose and tongue), were combined with headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) and free amino acid were used in combination to determine the aroma and taste components during the processing of Chinese traditional dish Steamed beef with rice flour (SBD). The findings revealed that E-nose and E-tongue, could clearly distinguish and identify the aroma and taste of SBD. A total of 66 volatile substances and 19 free amino acids were identified by HS-GC-IMS and amino acid analyzer, respectively. The highest contribution to aroma in the production of SBD was alcohols, esters and aldehydes. Further analysis of relative odor activity showed that 3-Methylbutanol-D, 3-Methylbutanol-M and 3-Methylthio propanal is the marinating stage (T2) main aroma components. Ethyl 3-methylbutanoate-M and Ethyl 3-methylbutanoate-D were the main aroma components in the seasoning stage (T3). Additionally, the calculation of the taste activity value showed that Glutamic contributed significantly to the umami of SBD. Alanine was a representative taste component in the marinating stage (T2), while Proline, Aspartic, Lysine, Glutamic, Valine, Arginine, and Histidine were characteristic amino acids of the seasoning stage (T3). Consequently, this study offers valuable insights into the industrial-scale production and flavor regulation of SBD products.

The changes of fungal community and flavor substances in Yunnan-style sausages: A comparative analysis of different drying methods

This study aimed to investigate alterations in the fungal community and flavor substances in Yunnan-style sausages subjected to natural air-dried fermentation (NF), variable-temperature drying (VT), and constant-temperature drying (CT) and analyze the potential relationship between fungal community and flavor substances. The findings revealed that the NF group and VT group were more conducive to enhancing the accumulation of dominant fungi and characteristic flavor substances in Yunnan-style sausages. Glu, Ala, His, and Lys were identified as key taste substances based on their taste activity values (TAV ≥ 1). A total of 272 volatile compounds(VOCS) were detected in the sausage samples, while 28 key aroma compounds were screened based on the odor activity value (OAV ≥ 1). Multivariate statistical analysis showed that 12 key aroma compounds (VIP > 1) could be considered discriminative compounds, including (E,E)-2,4-nonadienal, nonanal, heptanal, benzaldehyde, Dodecanal, cyclohexanol, and hexyl-Benzene, etc. Furthermore, Wickerhamoomyces and Debaryomyces were positively correlated with most of the key flavor substances and physicochemical indices (|r| > 0.6, P < 0.05), which were potential flavor-contributing fungi in Yunnan-style sausages.

Decoding the bitter taste of Idesia polycarpa var. vestita Diels fruit: Bitterness contribution and mechanisms

To comprehensively explore the contribution and mechanisms of identified low-threshold bitter substances in Idesia polycarpa var. vestita Diels (I. vestita) fruit, we performed quantification and elucidated their interactions with main bitter taste receptors through molecular docking. The established method for quantifying bitter compounds in I. vestita fruit was validated, yielding satisfactory parameters for linearity, stability, and accuracy. Idescarpin (17.71–101.05 mg/g) and idesin (7.88–77.14 mg/g) were the predominant bitter compounds in terms of content. Taste activity values (TAVs) exceeded 10 for the bitter substances, affirming their pivotal role as major contributors to overall bitterness of I. vestita fruit. Notably, idescarpin with the highest TAV, played a crucial role in generating the bitterness of I. vestita fruit. Hydrogen bonds and hydrophobic interactions were the main driving forces. This study holds potential implications for industrial development of I. vestita fruit by providing novel insights into the mechanism underlying its bitterness formation.

Sequential Enzymatic Hydrolysis and Ultrasound Pretreatment of Pork Liver for the Generation of Bioactive and Taste-Related Hydrolyzates.

In the study of protein-rich byproducts, enzymatic hydrolysis stands as a prominent technique, generating bioactive peptides. Combining exo- and endopeptidases could enhance both biological and sensory properties. Ultrasound pretreatment is one of the most promising techniques for the optimization of enzymatic hydrolysis. This research aimed to create tasteful and biologically active pork liver hydrolyzates by using sequential hydrolysis with two types of enzymes and two types of ultrasound pretreatments. Sequential hydrolyzates exhibited a higher degree of hydrolysis than single ones. Protana Prime hydrolyzates yielded the largest amount of taste-related amino acids, enhancing sweet, bittersweet, and umami amino acids according to the Taste Activity Value (TAV). These hydrolyzates also displayed significantly higher antioxidant activity. Among sequential hydrolyzates, Flavourzyme and Protana Prime hydrolyzates pretreated with ultrasound showed the highest ferrous ion chelating activity. Overall, employing both Alcalase and Protana Prime on porcine livers pretreated with ultrasound proved to be highly effective in obtaining potentially tasteful and biologically active hydrolyzates.

Combining multivariate statistical analysis to characterize changes in amino acids and volatiles during growth of Lou onion pseudostems.

The main edible part of the Lou onion is the pseudostem, which is highly valued for its distinctive flavour. However, harvesting decisions for the pseudostem are often based on size and market price, with little consideration given to flavour. By clarifying the growth of flavour in pseudostems, farmers and consumers may benefit from evidence-based insights that help optimize harvesting time and maximize flavour quality. This study employed amino acid analysis and gas chromatography-ion migration spectroscopy (GC-IMS) to elucidate the compounds of the pseudostem across different growth phases, and 17 amino acids and 61 volatile substances. Subsequently, analysis revealed that 18 compounds, including arginine (Arg), aspartic acid (Asp), glutamic acid (Glu), valine (Val), (E)-2-nonenal, decanal, 2,4-nonadienal, 2-octenal, (Z)-4-decenal, 2,4-decadienal benzeneacetaldehyde, linalool, eugenol, (Z)-6-nonen-1-ol, methyl anthranilate, 2-acetylpyridine, 3-sec-butyl-2-methoxypyrazine, and 2,6-dichlorophenol, were the key compounds in determining the flavour characteristics of the pseudostems, as assessed by taste activity value and relative odour activity value calculations. In addition, correlation analysis, focusing on five amino acids and 38 volatile compounds with variable importance for predictive components scores of >1, identified anisaldehyde, eugenol, (Z)-6-nonen-1-ol, 2,4-decadienal, 3-sec-butyl-2-methoxypyrazine, Arg, Asp, and Val as the key differentiators and contributors to the pseudostems flavour profile. During the rapid growth of Lou onions just before the emergence of flower stems, the pseudostem exhibited the most prominent flavour, making this stage most suitable for harvesting compared to the regreening growth stage and the rapid growth period of the aerial bulbs. © 2024 Society of Chemical Industry.

Comparative analysis of nutritional and non-volatile taste components of the Chinese mitten crab (Eriocheir sinensis)

This study investigated the differences among 20–20 individual crab samples from Chongming (CM) and Taixing (TX) origin in china through proximate composition, taste composition, and sensory analysis evaluation, to find out the key factors and contribute to the realization of the high-quality mitten crab culture industry. The results showed that the overall performance of TX group was better, and the contents of Ala, Gly, Arg and AMP were 6.33±1.25 mg/g, 4.67±0.87 mg/g, 4.53±0.69 mg/g and 68.68±22.88 mg/100 g, respectively. The key taste amino acids, whose taste activity value was over 1.0, detected in TX (5 kinds) and CM (4 kinds). The umami and sweet sensory scores of TX were 0.52 and 0.50 higher than that in CM group. Cluster analysis and principal component analysis showed that TX and CM crabs could be distinguished to a certain extent.

Exploring bitter characteristics of blue honeysuckle (Lonicera caerulea L.) berries by sensory-guided analysis: Key bitter compounds and varietal differences

The taste of blue honeysuckle (Lonicera caerulea L.) berries is wrapped in bitterness, and awareness about the essence of bitterness is lacking. In the current study, 7-ketologanin, sweroside and loganin were isolated and identified as key bitter compounds using sensory-guided analysis. The bitterness thresholds of these compounds were determined to be 11.9 μg/mL, 33.5 μg/mL and 60.2 μg/mL. Subsequently, the differences in bitterness among 16 blue honeysuckle varieties were evaluated. The wild varieties A1 and A2 exhibited the highest bitter intensity. 7-Ketologanin, with the highest concentration of 34.70–37.11 mg/100 g and taste activity values of 29.16–31.18 in A1 and A2, was first identified as a bitter contributor in blue honeysuckle. There was no significant difference in bitter intensity between the reconstitution model and the original sample, confirming the contribution of the three bitter compounds. This study lays the foundation for the bitter improvement and variety selection of blue honeysuckle resources.

The impacts of cold plasma on the taste and odor formation of dried silver carp products

This study investigated non-thermal pretreatment (cold plasma, CP) on the flavor (taste and odor) profiles of dried fish products. CP treatment of 5 min contributed to accumulation of umami nucleotides adenosine 5′-monophosphate (AMP) from 30.96 to 40.82 μg/g and inosine 5′-monophosphate (IMP) from 2009.29 to 2132.23 μg/g, and significant reduction of bitter hypoxanthine ribonucleoside (HxR) and hypoxanthine (Hx), respectively (P < 0.05) in the dried fish products. A noticeable enhancement in sweet glycine (from 429.41 to 490.03 mg/100 g) and umami glutamic acid (from 55.68 to 67.76 mg/100 g) accompanied with the CP treatment (P < 0.05) based on taste activity value (TAV > 1). And the characteristic odor volatiles (nonanal, hexanal and 1-octen-3-ol) were strengthened 2.13-, 2.16- and 2.17- folds, respectively (P < 0.05). The results of equivalent umami concentration and Gibbs free energy calculation, combining with the correlation analysis, indicate that nucleotides and free amino acids synergically enhanced the taste improvement of dried fish products. Moderate lipids oxidation favored the formation of characteristic volatiles. The CP pretreatment offered new strategies for enhancing flavor of dried fish products.

Investigation of different ingredients affected the flavor changes of Yu-Shiang shredded pork by using GC-IMS and GC-MS combined with E-nose and E-tongue

The objective of this study was to assess and compare the characteristics of Yu-Shiang Shredded Pork made with different ingredients by using physicochemical measurements and intelligent sensory analysis. The study revealed that there were 18 varied amino acids present, with the taste active values (TAVs) of Leu, Glu, Asp, Asn, and Ala all higher than 1.0. Intelligent sensory analysis showed that the samples lacking lettuce and fungus had similar aromas and flavors, while those lacking shredded pork and pickled chillies had distinct aromas and flavors. Moreover, VOCs (volatile organic compounds) were detected in five types of Yu-Shiang Shredded Pork, with 43, 42, 53, 36, and 50 identified in GC-MS (gas chromatography-mass spectrometry), respectively. Olefins (20.62 %–30.93 %) were the most abundant. GC-IMS (gas chromatography-ion mobility spectrometry) detected 68 volatiles flavor compounds, with esters having a significantly higher relative content than other compounds, indicating their significant role in the flavor formation process of Yu-Shiang Shredded Pork. Furthermore, the Orthogonal Partial Least Squares-discriminant analysis (OPLS-DA) model analysis identified 19 marker compounds that could differentiate the five types of Yu-Shiang Shredded Pork. These fundamental results lay the groundwork for future research on the connection between ingredients and the flavor characteristics of Yu-Shiang Shredded Pork.

Comparative study on the morphological characteristics, nutritional quality, and tastes of large yellow croaker from five cage culture areas: Relay farming improved fish quality

Relay culture of large yellow croaker from Fujian to Zhejiang is a good model for improved fish quality. However, there is a scarcity of information regarding the comprehensive evaluation of quality alterations following relay culture. In the present study, the large yellow croaker from Ningde (ND) was transferred to net cages in Dongtou (DT), Nanji (NJ), Dongji (DJ) and Dacheng (DC) for continued culture. The 15-month-old fish from ND, DJ, DC, DT, and NJ were sampled on-site for a subsequent comparative study on the morphological characteristics, nutritional quality, and tastes. Results showed that the fish from DJ, DC, DT, and NJ had a lower condition factor (CF) and a higher ratio of body length to height (L/H) than those from ND. The fish from DJ, DC, DT, and NJ, at rates of 77.8%, 91.3%, 95.7%, and 100%, exhibited different geometric morphometrics from those from ND using 10 typical landmarks and Morpho J software. Ralay culture also significantly affected the histology and ultrastructure of muscle fibers, as reflected by an increase in the muscle fiber density and decreases in the ratio of fiber area to gap, I band width, and sarcomere length in the relay culture fish compared to the ND fish. The relay culture fish showed low lipid content and high moisture content. Relay culture also significantly affected the levels of some nutritional composition, including deceases in the levels of hydrolyzed glycine, C16:0, C18:1n9c, C18:2n6c, Σn-6 PUFA (polyunsaturated fatty acids), Fe (iron), Mn (manganese), and Co (cobalt), and increases in the levels of C20:5n3 (EPA, eicosapentaenoic acid), C22:6n3 (DHA, docosahexaenoic acid), C18:0, Σn-3/Σn-6 PUFA, Σn-3 PUFA, Al (aluminum), Se (selenium), Na (sodium), and Ca (calcium). The levels of taste substances such as guanosine monophosphate (GMP) and most flavor amino acids sharply declined after relay culture. However, the ratio of taste activity value (TAV) of ΣDAA to ΣBAA (delicious amino acids/bitter amino acids) in the DT and NJ fish was higher than that in the ND fish. Significant negative relationships between market price and quality parameters were found, including CF, crude lipid, C18:1n9c, C18:2n6c, Σn-6 PUFA, Fe, Mn, and TAV of GMP, whereas there were positive relationships between market price and 4 quality parameters such as L/H, moisture, Σn-3/Σn-6 PUFA, and the ratio of TAC of ΣDAA to ΣBAA. In conclusion, relay culture improved large yellow croaker quality by changes in morphological characteristics, nutritional quality, and tastes, which provides a theoretical basis for quality improvement.

Characterization of the Non-Volatiles and Volatiles in Correlation with Flavor Development of Cooked Goat Meat as Affected by Different Cooking Methods.

Thai-Native×Anglo-Nubian goat meat cooked by grilling (GR), sous vide (SV), and microwave (MW), was compared to fresh meat (Raw) in terms of flavor development. Non-volatile [i.e., free amino acids, nucleotide-related compounds, taste active values (TAVs) and umami equivalency, sugars, lipid oxidation, Maillard reaction products] and volatile compounds, were investigated. Notably, inosine monophosphate and Glu/Gln were the major compounds contributing to umami taste, as indicated by the highest TAVs in all samples. Raw had higher TAVs than cooked ones, indicating that heat-cooking removes these desirable flavor and taste compounds. This could be proportionally associated with the increase in aldehyde, ketone, and nitrogen-containing volatiles in all cooked samples. GR showed the highest thiobarbituric acid reactive substances (1.46 mg malonaldehyde/kg sample) and browning intensity (0.73), indicating the greatest lipid oxidation and Maillard reaction due to the higher temperature among all cooked samples (p<0.05). In contrast, SV and Raw exhibited similar profiles, indicating that low cooking temperatures preserved natural goat meat flavor, particularly the goaty odor. The principal component analysis biplot linked volatiles and non-volatiles dominant for each cooked sample to their unique flavor and taste. Therefore, these findings shed light on cooking method selection based on desirable flavor and preferences.

Combination of virtual screening, machine learning, molecular dynamics simulations and sensory evaluation to discover novel umami peptides from fermented Atlantic cod

The aim of this study was to explore the effect of fermentation with Lactobacillus helveticus Lh191404 on the umami characteristics of Atlantic cod and to elucidate the umami mechanism of the peptide. Post-fermentation significant increases in sweet amino acids (Threonine (Thr), Serine (Ser), Proline (Pro), Glycine (Gly), Alanine (Ala)) and umami amino acids (Aspartic acid (Asp), Glutamic acid (Glu)) enhanced the palatability and umami intensity of surimi. The calculated taste activity value showed Glu as the highest at 2.598, indicating that umami was the most prominent taste after the Atlantic cod fermentation. A new approach was constructed to batch screen high abundance umami peptides. Combined with Nano Liquid Chromatography Tandem Mass Spectrometry (nLC/MS-MS), virtual screening and machine learning identified four highly abundant umami peptides (WGDL, FDDLP, VAQWR, and YGESDL). Molecular docking and molecular dynamics simulations determined that they stably bind to the receptor proteins through hydrogen bonding and electrostatic interactions, with Asp108, Arg151, and Arg277 as the key active amino acids. Sensory evaluation and electronic tongue confirmed that the screened peptides were all umami peptides and the umami intensity was consistent with the simulation results. This study not only revealed that Lactobacillus helveticus Lh191404 enhanced the taste of fermented Atlantic cod by releasing high abundance umami peptides but also provided a novel approach for identifying umami peptides from fermented marine foods.

Shrimp Cultured in Low-Salt Saline-Alkali Water has a Better Amino Acid Nutrition and Umami─Comparison of Flavors between Saline-Alkali Water- and Seawater-Cultured Litopenaeus vannamei.

The advantages of Litopenaeus vannamei farming in saline-alkali water have gradually attracted attention, but few studies have focused on its flavor. In this study, L. vannamei cultured in saline-alkali water (SS) and ordinary seawater (CS) (both have a breeding time of 120 days) were selected for analysis (n = 5). High-performance liquid chromatography (HPLC) was used to measure free amino acids and flavoring nucleotides in the muscles of L. vannamei, while the taste activity value (TAV) and equivalent umami concentration (EUC) were used to analyze the degree of umami. The total essential amino acids (TEAA) in the SS group were 238.41 ± 46.24 mg/mL, significantly higher than that in the CS group (107.06 ± 15.65 mg/mL). The total amount of flavor nucleotides in the SS group was 2948.51 ± 233.66 μg/mL, significantly higher than those in the CS group (2530.37 ± 114.67 μg/mL). The content and TAV of some free amino acids (Glu, Cys-s) in the SS group were significantly higher. Meanwhile, due to the significant increase in IMP, the synergistic effect of free amino acids and flavored nucleotides leads to higher EUC. The significant separation of SS and CS samples in principal component analysis (PCA) indicates a significant difference between the two groups. Our results indicate that shrimp cultured in saline-alkali water has a stronger umami. This study enriches the basic theories related to the flavor of salt-alkali water crustaceans.