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In this study, we established a new methodology for preparing 5-nucleotidase (5-NT) with the aim of enhancing our understanding of its enzyme activity and laying a basis for regulating the content of umami-enhancing nucleotides in pork. 5-NT was prepared with Sephadex gel filtration and reverse-phase high-performance liquid chromatography, and its enzymatic properties and catalytic activity were evaluated. The results show that the molecular weight of the prepared 5-NT was 57 kDa, the optimal catalytic temperature was 40 °C, and the optimal pH was 8. Zn2+, and sucrose showed inhibitory effects on the activity of 5-NT, while K+, Na+, Ca2+, Mg2+, glucose, fructose, and trehalose promoted the activity of the studied compound. The prepared 5-NT exhibited higher catalytic activity and selectivity against IMP compared with its commercial counterpart, while its catalytic activity against XMP was not significant (p > 0.05). In brief, we established a new methodology for preparing 5-NT, enhancing our understanding of its enzyme activity and providing a solid basis for regulating the content of umami-enhancing nucleotides in pork through the control of endogenous 5-NT activity.

Summary: Globally, consumers continue to seek out novel foods and ingredients from different cultures and regions. Shio‐koji is a fermented seasoning that is usually made by fermenting rice with koji (Aspergillus oryzae). It has been proposed that shio‐koji can be used as a flavour enhancer of foods. This study investigated consumers' (n = 96; generally unfamiliar with koji) liking (hedonic scales), emotional response (using the EsSense25 profile in check‐all‐that‐apply format), as well as their sensory perception (generalised Labelled Magnitude Scales and free comment) of shio‐koji additions to food items. Participants evaluated three different soups (chicken, vegetable and tomato), a familiar food product, with and without the addition of shio‐koji. The shio‐koji increased the consumers' liking of the vegetable soup and increased their perception of saltiness in the vegetable and tomato soups. The bitterness and sourness intensity of the chicken soup decreased with the addition of shio‐koji, while the sweetness increased. However, the umami taste of all soups was not impacted. The soups with shio‐koji were also associated with positive emotions. During the free comment task, shio‐koji led to an increased mention of meaty attributes to describe the vegetable soup, but the inverse occurred when the participants evaluated the chicken soup. The results indicate that shio‐koji impacted consumer perceptions of both animal‐ and plant‐based soups. Future studies should continue to investigate the use of shio‐koji to enhance the flavour of different food products. [ABSTRACT FROM AUTHOR]

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BACKGROUND: Carboxypeptidase is an exopeptidase that hydrolyzes amino acids at the C‐terminal end of the peptide chain and has a wide range of applications in food. However, in industrial applications, the relatively low catalytic efficiency of carboxypeptidases is one of the main limiting factors for industrialization. RESULTS: The study has enhanced the catalytic efficiency of Bacillus megaterium M32 carboxypeptidase (BmeCPM32) through semi‐rational design. Firstly, the specific activity of the optimal mutant, BmeCPM32‐M2, obtained through single‐site mutagenesis and combinatorial mutagenesis, was 2.2‐fold higher than that of the wild type (187.9 versus 417.8 U mg−1), and the catalytic efficiency was 2.9‐fold higher (110.14 versus 325.75 s−1 mmol−1). Secondly, compared to the wild type, BmeCPM32‐M2 exhibited a 1.8‐fold increase in half‐life at 60 °C, with no significant changes in its enzymatic properties (optimal pH, optimal temperature). Finally, BmeCPM32‐M2 significantly increased the umami intensity of soy protein isolate hydrolysate by 55% and reduced bitterness by 83%, indicating its potential in developing tasty protein components. CONCLUSION: Our research has revealed that the strategy based on protein sequence evolution and computational residue mutation energy led to an improved catalytic efficiency of BmeCPM32. Molecular dynamics simulations have revealed that a smaller substrate binding pocket and increased enzyme–substrate affinity are the reasons for the enhanced catalytic efficiency. Furthermore the number of hydrogen bonds and solvent and surface area may contribute to the improvement of thermostability. Finally, the de‐bittering effect of BmeCPM32‐M2 in soy protein isolate hydrolysate suggests its potential in developing palatable protein components. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Bekasam is a fish that is spontaneously fermented by adding salt and a source of carbohydrates (such as cooked white rice). This traditional food is often found in several regions of Indonesia, especially in South Sumatra, South Kalimantan, and North Sulawesi. Bekasam is traditionally produced to preserve fish during the harvest season. This review aims to present information on the historical background of bekasam, its manufacturing process, chemical characteristics, the types of microflora that exist within it, and the potential utilization of bekasam as a source of umami in dishes. The methodology for this study included a combination of literature review, observational interviews with traditional bekasam producers, experimental bekasam processing, and thorough documentation. A total of 60 articles were collected and chosen based on appropriate criteria. The results of the review article offer several explanations, based on historical aspects bekasam is an adaptation of Chinese cuisine introduced by traders who visited Sriwijaya. In the South Sumatra region, especially among the Ogan and Komering tribes, clay jars left by the Chinese are used to store bekasam in the kitchen. The Komering tribe refers to the fermentation of bekasam as sam-sam. Various microbes are found in bekasam, with the main constituent being Lactobacillus spp., and a significant presence of Lactobacillus plantarum. During fermentation, the proteins in the raw materials of bekasam are degraded into simple compounds, mainly amino acids. Glutamate and aspartate had the highest values in the total composition of the other amino acids. These two amino acids contribute to the umami taste of food products. After exceeding the threshold for glutamate and aspartate, bekasam has the potential to contribute to the umami taste. Due to its umami potential, bekasam has been developed into various cuisines, including fried bekasam, sautéed bekasam, and chili sauce.

Previous studies have reported the development of a taste sensor using a surface modification approach to evaluate umami taste, specifically substances like monosodium L-glutamate (MSG) and monosodium L-aspartate. The sensor was modified with 2,6-dihydroxyterephthalic acid (2,6-DHTA). However, the mechanism underlying umami substance detection in the 2,6-DHTA- treated sensor remains unidentified, as does whether the specific detection is due to an intermolecular interaction between the modifier and the analyte. In this study, 1H-NMR measurements were conducted for a variety of modifiers and analytes in terms of structures, along with taste sensor measurements. By comparing the 1H-NMR spectra and the results of the taste sensor, we suggested that both modifiers and analytes need to meet certain molecular structure conditions to produce intermolecular interactions. The modifier needs to possess intramolecular H-bonds and have carboxyl groups in the para position of the benzene ring, i.e., two carboxyl groups. In conclusion, we validated that the response mechanism of the taste sensor for umami substance measurement proposed in previous studies is reasonable and predicted the binding form of 2,6-DHTA and MSG. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the umami characteristics of soy sauce using electronic tongue evaluation and amino acid composition and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI−TOF MS) analysis. The soy sauce peptides were isolated from soy sauce using XAD−16 macroporous resin combined with ethanol solution. The results showed that the soy sauce peptide fraction eluted by 60% ethanol (SS−60%) exhibited a prominent umami taste, and the umami scores were highly positively correlated with the amino acid nitrogen contents of soy sauces. The umami scores of SS−60% were significantly positively correlated with the contents of free amino acids. Especially, Phe showed the highest positive correlation with the umami scores. In addition, five characteristic ion peaks with m/z at 499, 561, 643, 649, and 855 were identified in the peptide mass fingerprinting. Therefore, this study provides new insights into the umami characteristics for the taste evaluation and reality identification of soy sauce. [ABSTRACT FROM AUTHOR]

Plant-based meat analogs require improvements in taste and texture to better replicate traditional meat. L-theanine and tannin, abundant in green tea, influence food taste and physicochemical properties. This study evaluated the quality characteristics of green tea extract (GE)-supplemented plant-based patties (PP) and the mechanisms affecting taste and texture. Green tea was extracted with water (GWE) or 70 % ethanol (GEE). GEE contained higher tannin and lower L-theanine levels than GWE. Both GWE and GEE reduced protein deterioration and lipid oxidation in PP throughout the 28-day storage period. PP with 1.0 % GEE (PP-GEE1.0) showed improved emulsion stability and texture due to non-covalent interactions including hydrophobic interaction and hydrogen bonds, and increased β-sheet structures between tannin and pea protein. PP-GEE1.0 also had superior sensory characteristics due to an optimal balance of L-theanine and tannin. Overall, the incorporation of GE, particularly GEE significantly improved physicochemical properties, sensory quality, and storage stability of PP.

In this study, we established a new methodology for preparing 5′−nucleotidase (5′−NT) with the aim of enhancing our understanding of its enzyme activity and laying a basis for regulating the content of umami−enhancing nucleotides in pork. 5′−NT was prepared with Sephadex gel filtration and reverse−phase high−performance liquid chromatography, and its enzymatic properties and catalytic activity were evaluated. The results show that the molecular weight of the prepared 5′−NT was 57 kDa, the optimal catalytic temperature was 40 °C, and the optimal pH was 8. Zn2+, and sucrose showed inhibitory effects on the activity of 5′−NT, while K+, Na+, Ca2+, Mg2+, glucose, fructose, and trehalose promoted the activity of the studied compound. The prepared 5′−NT exhibited higher catalytic activity and selectivity against IMP compared with its commercial counterpart, while its catalytic activity against XMP was not significant (p > 0.05). In brief, we established a new methodology for preparing 5′−NT, enhancing our understanding of its enzyme activity and providing a solid basis for regulating the content of umami−enhancing nucleotides in pork through the control of endogenous 5′−NT activity. [ABSTRACT FROM AUTHOR]

BackgroundThe World Health Organization (WHO) and the Food and Agriculture Organization (FAO) recommend the consumption of less than 2,000 mg of sodium/day to reduce blood pressure and the risk of conditions such as cardiovascular disease and coronary heart disease. The sodium intake among Vietnamese was reported to be 7,200 mg/d or more. Free L-glutamate enhances flavor when it is added to food and improves the taste of sodium-reduced foods.ObjectiveThis study aims to investigate whether the intake of free L-glutamate-rich seasonings contributes to maintaining a low sodium intake in a cross-over study.MethodsFrom a total of 145 subjects, 42 participants were screened for participation in the cross-over design study. Subjects were randomly allocated to the Low free L-glutamate group (Low free L-Gl) and the Normal free L-glutamate group (Normal free L-Gl). Both received a direct educational guideline to reduce sodium intake. The Low free L-Gl group started with a restriction in the variety of free L-glutamate-rich seasonings, and the Normal free L-Gl group had no restriction in the variety of seasonings. Blood pressure was measured at week 0 (baseline), week 2, week 4, and week 6, while body weight, height, urine sodium and potassium excretion, chromogranin-A (CgA pmol/mg protein) from saliva, and free L-glutamate from food were measured at week 0, week 3, and week 6.ResultsIn Low free L-Gl, the amount of free L-glutamate in food decreased significantly from baseline to week 6 (p 0.05). However, the reduction of sodium excretion at week 6 was 22% in Low free L-Gl (5,875 mg/d vs. 4,603 mg/d, p

The search to improve the quality of meat while maintaining its nutritional value and flavor profile has driven the investigation of emerging clean-label non-thermal technologies in the field of meat processing. Ultrasound (US) and pulsed electric field (PEF) treatments have emerged as promising tools for producing high-quality meat products. This study investigated the combined effects of ultrasound and PEF on chicken breast meat quality, focusing on cooking loss, texture, and taste-related amino acids. Ultrasound (24.5 kHz, 300 W, 10 min) combined with PEF for 30 s (1.6, 3.3, and 5.0 kV/cm as US + PEF 1, US + PEF 3, and US + PEF 5, respectively) significantly reduced cooking losses (up to 28.78 %), potentially improving the product yield. Although US + PEF significantly (p

Efficient cold-chain delivery is essential for maintaining a sustainable global food supply. This study used metabolomic analysis to examine meat quality changes during the "wet aging" of crossbred Wagyu beef during cold storage. The longissimus thoracic (Loin) and adductor muscles (Round) of hybrid Wagyu beef, a cross between the Japanese Black and Holstein–Friesian breeds, were packaged in vacuum film and refrigerated for up to 40 days. Sensory evaluation indicated an increase in the umami and kokumi taste owing to wet aging. Comprehensive analysis using gas chromatography-mass spectrometry identified metabolite changes during wet aging. In the Loin, 94 metabolites increased, and 24 decreased; in the Round, 91 increased and 18 decreased. Metabolites contributing to the umami taste of the meat showed different profiles during wet aging. Glutamic acid increased in a cold storage-dependent manner, whereas creatinine and inosinic acid degraded rapidly even during cold storage. In terms of lipids, wet aging led to an increase in free fatty acids. In particular, linoleic acid, a polyunsaturated fatty acid, increased significantly among the free fatty acids. These results provide new insight into the effects of wet aging on Wagyu-type beef, emphasizing the role of free amino acids, organic acids, and free fatty acids generated during cold storage. [ABSTRACT FROM AUTHOR]

Cold aging of fish has gained substantial attention because of improving its taste quality. However, fish aging typically requires approximately 2 weeks to 2 months. Thus, the production of aged fish has several challenges, such as food hygiene concerns and refrigeration costs, preventing its commercialization. In response to these challenges, this study aimed to develop a novel technology to promote the aging of greater amberjack Seriola dumerili meat by low-temperature heating. Proteolysis, an indicator of fish aging, was promoted by heating at ≥ 30 °C. Heating at 25–30 °C did not induce fish meat discoloration, which is caused by protein unfolding. The free amino acid (FFA) content increased with heating time at 30 °C. The fish samples were sufficiently softened at 30 °C for 120 min. Inosine-5′-monophosphate (IMP) content and total viable bacteria count were relatively constant at 30 °C, independent of heating time (0–120 min). Therefore, low-temperature heating at 30 °C for 120 min was optimal for promoting the aging of greater amberjack meat, resulting in improved taste and texture. This novel technology significantly enhanced proteolysis and consequently achieved the required properties, such as texture softening and increased FAA, for the aged fish with prevention of protein denaturation typically caused by conventional low-temperature heating. Furthermore, it is more useful than conventional aging because it significantly shortens the aging duration, contributes to safety, and maintains the IMP content. [ABSTRACT FROM AUTHOR]

IntroductionMonosodium glutamate (MSG), an umami substance, stimulates the gut-brain axis communication via gut umami receptors and the subsequent vagus nerves. However, the brain mechanism underlying the effect of MSG ingestion during the developmental period on aggression has not yet been clarified. We first tried to establish new experimental conditions to be more appropriate for detailed analysis of the brain, and then investigated the effects of MSG ingestion on aggressive behavior during the developmental stage of an ADHD rat model.MethodsLong-Evans, WKY/Izm, SHR/Izm, and SHR-SP/Ezo were individually housed from postnatal day 25 for 5 weeks. Post-weaning social isolation (PWSI) was given to escalate aggressive behavior. The resident-intruder test, that is conducted during the subjective night, was used for a detailed analysis of aggression, including the frequency, duration, and latency of anogenital sniffing, aggressive grooming, and attack behavior. Immunohistochemistry of c-Fos expression was conducted in all strains to predict potential aggression-related brain areas. Finally, the most aggressive strain, SHR/Izm, a known model of attention-deficit hyperactivity disorder (ADHD), was used to investigate the effect of MSG ingestion (60 mM solution) on aggression, followed by c-Fos immunostaining in aggression-related areas. Bilateral subdiaphragmatic vagotomy was performed to verify the importance of gut-brain interactions in the effect of MSG.ResultsThe resident intruder test revealed that SHR/Izm rats were the most aggressive among the four strains for all aggression parameters tested. SHR/Izm rats also showed the highest number of c-Fos + cells in aggression-related brain areas, including the central amygdala (CeA). MSG ingestion significantly decreased the frequency and duration of aggressive grooming and attack behavior and increased the latency of attack behavior. Furthermore, MSG administration successfully increased c-Fos positive cell number in the intermediate nucleus of the solitary tract (iNTS), a terminal of the gastrointestinal sensory afferent fiber of the vagus nerve, and modulated c-Fos positive cells in the CeA. Interestingly, vagotomy diminished the MSG effects on aggression and c-Fos expression in the iNTS and CeA.ConclusionMSG ingestion decreased PWSI-induced aggression in SHR/Izm, which was mediated by the vagus nerve related to the stimulation of iNTS and modulation of CeA activity.

With the aim of exploring the correlation between instrumental analysis and sensory evaluation of chicken soup umami-aroma characteristics, 110-day-old Xue Shan hens and 60-day-old 817 broilers were used as raw materials to prepare chicken soup, and four commercially available chicken soup products (C, G, T and W) were also selected to make analysis. The above six samples were tested with free amino acids, nucleotides, electronic tongue, electronic nose, free fatty acids, volatile substances, fuzzy sensory evaluation. Then partial least squares regression was used to explore the correlation between sensory evaluation and instrument analysis indexes. The results showed that the chicken soup of 817 broilers (S60) and Xue Shan hens (S110) was significantly lower in fresh amino acids, umami, and saltiness response values than the other four chicken soups (P

ABSTRACTEdible mushrooms are important in the human diet as a source of nutritive compounds with an appreciated taste. The split gill mushroom (Schizophyllum commune) is popularly consumed in Asia owing to its umami taste relating to a meaty flavor. Typically, blanching and drying are performed to preserve food quality and extend shelf-life and may affect the taste characteristics and bioactivity of mushrooms. This work investigated the effect of different methods of blanching – hot-water (HW) or microwave-assisted (MW) – and drying – hot air drying (HAD) and freeze-drying (FD) – on the characteristics, taste profile, and bioactivity of S. commune. The results showed that S. commune contained umami-related compounds, and the umami level was influenced by the processing conditions. Compared to HW blanching, MW blanching was more efficient at prohibiting polyphenol oxidase activity and maintaining the umami taste of the mushroom. Drying, particularly FD, successfully improved the umami level of S. commune. Nevertheless, HAD tended to provide the mushroom with higher bioaccessibility to phenolic compounds and antioxidant activity levels. The results suggested that S. commune could be promising as a functional ingredient with an umami taste. Pre-treatment using MW blanching, followed by FD could preserve appropriately the umami taste and quality of the mushroom.

To characterize the quality of widely consumed pork in China, the chemical compositions and other indexes of five breeds of pork were compared. The results indicated that the moisture content, sensory flavor, and overall acceptability of Pipa pork (PPP) were superior to other breeds. The fat content and essential amino acids (EAA) of Yihao native pork (YNP) were significantly (p < 0.05) higher than in other breeds. The protein content, the total amount of amino acids, and perceptible flavor of Tibetan black pork (TBP) were higher than in other breeds. The protein nutrition profiles of manor black pork (MBP) and TBP were better than in others. The equivalent umami concentration (EUC) value of white pork (WP) was significantly (p < 0.05) higher than in others; however, the health risk of its fatty acid content was higher. There were unique protein and flavor chemicals in YNP, TBP, and PPP, which may be useful for distinguishing their authenticity.

Previous studies have reported the development of a taste sensor using a surface modification approach to evaluate umami taste, specifically substances like monosodium L-glutamate (MSG) and monosodium L-aspartate. The sensor was modified with 2,6-dihydroxyterephthalic acid (2,6-DHTA). However, the mechanism underlying umami substance detection in the 2,6-DHTA- treated sensor remains unidentified, as does whether the specific detection is due to an intermolecular interaction between the modifier and the analyte. In this study, 1H-NMR measurements were conducted for a variety of modifiers and analytes in terms of structures, along with taste sensor measurements. By comparing the 1H-NMR spectra and the results of the taste sensor, we suggested that both modifiers and analytes need to meet certain molecular structure conditions to produce intermolecular interactions. The modifier needs to possess intramolecular H-bonds and have carboxyl groups in the para position of the benzene ring, i.e., two carboxyl groups. In conclusion, we validated that the response mechanism of the taste sensor for umami substance measurement proposed in previous studies is reasonable and predicted the binding form of 2,6-DHTA and MSG.

The objective of this study was to investigate the umami characteristics of soy sauce using electronic tongue evaluation and amino acid composition and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI−TOF MS) analysis. The soy sauce peptides were isolated from soy sauce using XAD−16 macroporous resin combined with ethanol solution. The results showed that the soy sauce peptide fraction eluted by 60% ethanol (SS−60%) exhibited a prominent umami taste, and the umami scores were highly positively correlated with the amino acid nitrogen contents of soy sauces. The umami scores of SS−60% were significantly positively correlated with the contents of free amino acids. Especially, Phe showed the highest positive correlation with the umami scores. In addition, five characteristic ion peaks with m/z at 499, 561, 643, 649, and 855 were identified in the peptide mass fingerprinting. Therefore, this study provides new insights into the umami characteristics for the taste evaluation and reality identification of soy sauce.

The salt (NaCl) content in processed meats must be reduced because of its adverse effects on cardiovascular health. However, reducing salt in meat products typically leads to a lower taste intensity and, thus, consumer acceptability. Industry interventions must reduce salt content while maintaining taste, quality, and consumer acceptability. In this context, high-pressure processing (HPP) has been proposed to enhance saltiness perception, though there are contradictory reports to date. The present work aimed to conduct a targeted experiment to ascertain the influence of HPP (300/600 MPa) and cooking (71°C) on saltiness perception and sensory acceptability of meat products. HPP treatment (300/600 MPa) did enhance those two sensory attributes (approx. +1 on a 9-point hedonic scale) in raw (uncooked) cured pork loins but did not in their cooked counterparts. Further, the partition coefficient of sodium (PNa+), as an estimate of Na+ binding strength to the meat matrix, and the content of umami-taste nucleotides were investigated as potential causes. No effect of cooking (71°C) and HPP (300/600 MPa) could be observed on the PNa+ at equilibrium. However, HPP treatment at 300 MPa increased the inosine-5′-monophosphate (IMP) content in raw cured pork loins. Finally, hypothetical HPP effects on taste-mediating molecular mechanisms are outlined and discussed in light of boosting the sensory perception of raw meat products as a strategy to achieve effective salt reductions while keeping consumer acceptability.

This study aimed to evaluate umami taste in Hanwoo with different feed by chemical analysis, sensory evaluation and an electronic tongue system. Hanwoo cattle were divided into three groups: control group (fed only total mixed ration [TMR]), T1 (fed soybean meal + TMR), and T2 (fed soybean meal + corn-dried distiller’s grain with solubles [Corn DDGS] + TMR). The three most abundant fatty acids (C18:1n-9, C16:0, and C18:0) in the T1, T2, and control groups accounted for 83.63%, 86.07%, and 85.52% of the total fatty acid content, respectively. Umami taste-related glutamic acid levels were significantly high in T1 (109.89 mg/kg), followed by T2 (66.66 mg/kg) and control (47.27 mg/kg). Fatty acid levels showed a high correlation with umami taste. The results of this study showed that the amino acid and fatty acid levels had been affected by feed types and soybean- or Corn DDGS-based feed potentially enhanced Hanwoo’s umami flavor.

Edible mushroom has attracted increasing attention as a natural flavor enhancer. This research studied sensory flavor profiles and identified umami taste-related compounds in split gill mushroom extract (SGME) using descriptive analysis and chemical analysis, respectively. The effects of SGME on taste enhancement as perceived by trained descriptive panelists and general consumers were evaluated in salt solutions and clear chicken soups. The results showed that SGME had mushroom, bitter aromatic, dark brown, meaty, and musty flavor notes and salty and umami tastes. Glutamic acid, aspartic acids, adenosine 5′-monophosphate (5′-AMP), and guanosine 5′-monophosphate (5′-GMP) contributed to SGME's umami taste. As perceived by trained panelists, saltiness enhancement caused by SGME in aqueous solutions occurred only at relatively low salt concentrations (0.3 and 0.5%), while its umami enhancement effect was more pronounced. When SGME was added into reduced-salt seasoned clear chicken soups, it helped to enhance both the salty and umami tastes of the soups. The 20–31.25% reduced-salt soups with 12.5% of SGME were rated as salty as (p > 0.05) the control soup with regular salt content as perceived by both trained panelists and general consumers. The results suggest that SGME could be used as a natural flavor enhancer in the development of reduced-salt foods. [ABSTRACT FROM AUTHOR]

In order to investigate the nonvolatile taste-active components in crayfish, free amino acids, nucleotides, organic acids, soluble sugars and alkaloids in cooked crayfish muscle were qualitatively and quantitatively analyzed by 1H nuclear magnetic resonance (1H NMR). Their taste activity values (TAVs) and equivalent umami concentration (EUC) were calculated to evaluate the key taste-active compounds and umami attributes, respectively. The results suggested that a total of 33 taste-active compounds were detected, among which arginine, histidine, glutamic acid, alanine, lysine, glycine, adenosine 5’-monophosphate (AMP), inosine 5’-mononucleotide (IMP), succinic acid and lactic acid were the key taste-active compounds with TAVs greater than 1.0, and they played an important role in the taste of crayfish. The EUC of crayfish was 9.1 g monosodium glutamate (MSG)/100 g, indicating very intense umami taste.

Currently, compound umami products in China are in the initial stage of development, which have not formed a systematic study yet. Hence, 12 kinds of commercially available compound umami products were analyzed for 17 free amino acids. It was found that the taste activity values (TAV) of glutamic acid (Glu) contributed the most, with TAV ranging from 4.12 to 228.86. The correlation analysis showed a significant positive correlation between other amino acids, except for Glu. Meanwhile, three principal components were extracted, with the cumulative variance contribution of 93.19%, which could effectively reflect most of information on the free amino acids in compound umami products. Partial least squares (PLS) analysis revealed a consistency between evaluation of umami taste and equivalent umami concentrations (EUC). This paper systematically evaluated the taste characteristics of compound umami products and provided a theoretical reference for research and development of compound umami products.

Abstract Background Evidence has demonstrated that excess sodium intake is associated with development of several non-communicable diseases. The main source of sodium is salt. Therefore, reducing salt intake in foods is an important global public health effort to achieve sodium reduction and improve health. This study aimed to model salt intake reduction with 'umami' substances among Japanese adults. The umami substances considered in this study include glutamate or monosodium glutamates (MSG), calcium diglutamate (CDG), inosinate, and guanylate. Methods A total of 21,805 participants aged 57.8 years on average from the National Health and Nutrition Survey was used in the analysis. First, we employed a multivariable linear regression approach with overall salt intake (g/day) as a dependent variable, adjusting for food items and other covariates to estimate the contribution of salt intake from each food item that was selected through an extensive literature review. Assuming the participants already consume low-sodium products, we considered three scenarios in which salt intake could be reduced with the additional umami substances up to 30%, 60% and 100%. We estimated the total amount of population-level salt reduction for each scenario by age and gender. Under the 100% scenario, the Japan’s achievement rates against the national and global salt intake reduction goals were also calculated. Results Without compromising the taste, the 100% or universal incorporation of umami substances into food items reduced the salt intake of Japanese adults by 12.8–22.3% at the population-level average, which is equivalent to 1.27–2.22 g of salt reduction. The universal incorporation of umami substances into food items changed daily mean salt intake of the total population from 9.95 g to 7.73 g: 10.83 g to 8.40 g for men and 9.21 g to 7.17 g for women, respectively. This study suggested that approximately 60% of Japanese adults could achieve the national dietary goal of 8 g/day, while only 7.6% would meet the global recommendation of 5.0 g/day. Conclusions Our study provides essential information on the potential salt reduction with umami substances. The universal incorporation of umami substances into food items would enable the Japanese to achieve the national dietary goal. However, the reduced salt intake level still falls short of the global dietary recommendation.

Abstract Taste plays an essential role in the evaluation of food quality by detecting potential harm and benefit in what animals are about to eat and drink. While the affective valence of taste signals is supposed to be innately determined, taste preference can also be drastically modified by previous taste experiences of the animals. However, how the experience-dependent taste preference is developed and the neuronal mechanisms involved in this process are poorly understood. Here, we investigate the effects of prolonged exposure to umami and bitter tastants on taste preference using two-bottle tests in male mice. Prolonged umami exposure significantly enhanced umami preference with no changes in bitter preference, while prolonged bitter exposure significantly decreased bitter avoidance with no changes in umami preference. Because the central amygdala (CeA) is postulated as a critical node for the valence processing of sensory information including taste, we examined the responses of cells in the CeA to sweet, umami, and bitter tastants using in vivo calcium imaging. Interestingly, both protein kinase C delta (Prkcd)-positive and Somatostatin (Sst)-positive neurons in the CeA showed an umami response comparable to the bitter response, and no difference in cell type-specific activity patterns to different tastants was observed. Meanwhile, fluorescence in situ hybridization with c-Fos antisense probe revealed that a single umami experience significantly activates the CeA and several other gustatory-related nuclei, and especially CeA Sst-positive neurons were strongly activated. Intriguingly, after prolonged umami experience, umami tastant also significantly activates the CeA neurons, but the Prkcd-positive neurons instead of Sst-positive neurons were highly activated. These results suggest a relationship between amygdala activity and experience-dependent plasticity developed in taste preference and the involvement of the genetically defined neural populations in this process.

Sunflower seeds are rich in protein and can be an excellent raw material for the production of umami peptides. In this study, sunflower seed meal, which was defatted at a low temperature, was taken as the raw material, and proteins were separated, followed by hydrolyzation for 4 h by flavourzyme® to obtain hydrolysates with strong umami intensity. These hydrolysates were deamidated using glutaminase to increase the umami intensity. The highest umami value of 11.48 was recorded for hydrolysates deamidated for 6 h, and the umami intensity was determined. The umami hydrolysates mixed with 8.92 mmol IMP + 8.02 mmol MSG showed the highest umami value of 25.21. Different concentrations of ethanol were used for further separation of hydrolysates, and the highest umami value of 13.54 was observed for 20% ethanol fraction. The results of this study provide utilization method for sunflower seed meal protein and a theoretical basis for the preparation of umami peptides. Practical Application: A large number of sunflower seed meals after oil production are used as feed for livestock and poultry. Sunflower seed meal is rich in protein, and umami amino acid composition in sunflower seed meal is up to 25%–30%, which is potentially an excellent raw material for the production of umami peptides. The umami flavor and synergistic effect of obtained hydrolysates, with MSG and IMP, were analyzed in the present study. We intend to provide a novel way for utilization of protein from sunflower seed meal along with a theoretical basis for the preparation of umami peptides. [ABSTRACT FROM AUTHOR]

Umami (2015) by the Mexican author Laia Jufresa deals with the themes of loss, mourning and identity through several interrelated stories. Residents of an apartment complex in Mexico City live in separate flats and experience individual traumas linked to the loss of loved ones. In their daily interactions, they recognize each other's pain while processing their own grief and exploring creative transformations in their identities and communities. Jufresa shows the intimate and personal process of mourning as a counterpart to stories of massive violence and narco-terrorism by presenting detailed examples of "ordinary grief." Jufresa also explores the cultural dimensions of more traditional types of mourning in Mexico. The characters in Umami recognize each other, keep each other company, and experience collective vulnerability, recreating what Barbara Fredrickson, Judith Butler, and Iona Heath attribute to the roles of mutual support in grief and the key role of positive emotion in individual and community transformation. Through these perspectives from psychology, psychotherapy, and medicine, our essay reads Umami as a literary representation of the complex relationship between the personal and the communal in the creative-affective exchanges that allow us to navigate the turbulent waters of everyday mourning. [ABSTRACT FROM AUTHOR]

The general consensus about four basic tastes, sweet, bitter, sour and salty, is rooted in Aristotle's writings. This inventory was expanded with the addition of umami (or savoury) in the early years of last century, a taste that wasn't fully scientifically recognized until the mid-1980s. Work on this area of human cognition from various fields – psychology, physiology, chemistry and particularly food science – has led to new discoveries that allow us to have a better understanding of the mechanism of taste. However, linguistic work on this aspect of human perception is lacking. Questions remain to be asked as to the size of the vocabulary of basic tastes, and how language can reflect the organization of the taste domain. This paper proposes to look at basic tastes by examining Chinese historical texts with an aim to reveal how the ancient Chinese people classified and categorized tastes. It will be demonstrated that the Chinese concept of "taste" boasts a long history, going back to pre-historic times. The word for "taste", 味 wèi, can also refer to "smell; flavour." The term is primarily used as a category noun, which gets borrowed into Japanese to become the head element -mi of the compound word umami in Japanese. Significantly, a form with a similar sound shape, 美 měi, was found in ancient Chinese with the meaning "tasty", an adjective describing the taste, flavour of fresh meat, akin to "savoury." This indicates that we are dealing with a morphological process or doublet in this semantic field. It also indicates that the idea of "good taste, tasty, savoury" existed long before that of umami. Equally important is the form with related meaning, 鲜 xiān, which is made up of two graphic forms, "fish" （鱼） + "lamb" （羊）. This form etymologically denotes the flavour of fresh fish, now carrying the sense of "fresh, delicious, tasty, savoury" in Chinese, which further illustrates the point. Still another form, 旨 zhǐ "(n) good flavour; pleasant taste," is the source of the meaning of umami, as defined in Japanese dictionaries. Several other tastes are also analysed. Their implications for the expansion of basic tastes are discussed. The connections between the taste domain and olfaction domain are explored, with insights from some neighbouring languages. [ABSTRACT FROM AUTHOR]

As one of the five basic tastes, umami has the advantages of making the overall taste of food more harmoniously. Although various umami substances in food have been isolated and identified, in recent years, there are limit studies on the processing technology for improving food umami. Therefore, it is necessary to explore novel efficient umami improvement technologies to meet the urgentment of the food industry. This experiment was designed to study the effect of 0.1% (w/w) sodium bicarbonate (NaHCO3) combined with different power (0, 120, 180, 240, and 300 W) ultrasound treatment on the taste and flavor of chicken broth. Results demonstrated that the chicken broth under the power of 120 W ultrasound treatment combined with 0.1% (w/w) NaHCO3 was the most umami, and contained the largest amount of IMP. The chicken broth under the treatment of 180 W ultrasound combined with 0.1% (w/w) NaHCO3 has better flavor and sensory evaluation as the umami improved. In summary, 180 W ultrasound combined with 0.1% (w/w) NaHCO3 pretreatment is a simple and low‐cost processing technology, which is inclined to apply in industry. Practical Applications: Compared with the traditional umami improvement method, ultrasound can significantly reduce the cost of food umami‐enhancing with the characteristics of high safety, environmental protection, low operating cost, and high instantaneous efficiency. Sodium bicarbonate is an inorganic salt. Moderate intake is beneficial to the body. It can help neutralize stomach acid and supplement sodium for the body. In this study, low‐power ultrasound combined with low‐concentration of sodium bicarbonate solution was used to cook chicken soup, and the umami taste was improved to a large extent, which provided a novel method for industrial application. [ABSTRACT FROM AUTHOR]

Abstract Objective: Excessive salt intake raises blood pressure and increases the risk of non-communicable diseases (NCD), such as CVD, chronic kidney disease and stomach cancer. Reducing the Na content of food is an important public health measure to control the NCD. This study quantifies the amount of salt reduced by using umami substances, i.e. glutamate, inosinate and guanylate, for adults in the USA. Design: The secondary data analysis was performed using data of the US nationally representative cross-sectional dietary survey, the National Health and Nutrition Examination Survey (NHANES) 2017–2018. Per capita daily salt intake corresponding to the NHANES food groups was calculated in the four hypothetical scenarios of 0 %, 30 %, 60 % and 90 % market share of low-Na foods in the country. The salt reduction rates by using umami substances were estimated based on the previous study results. Setting: The USA Participants: 4139 individuals aged 20 years and older in the USA Results: Replacing salt with umami substances could help the US adults reduce salt intake by 7·31–13·53 % (7·50–13·61 % for women and 7·18–13·53 % for men), which is equivalent to 0·61–1·13 g/d (0·54–0·98 g/d for women and 0·69–1·30 g/d for men) without compromising the taste. Approximately, 21·21–26·04 % of the US adults could keep their salt intake below 5 g/d, the WHO’s recommendation in the scenario where there is no low-Na product on the market. Conclusions: This study provides essential information that the use of umami substances as a substitute for salt may help reduce the US adults’ salt intake.

Tilapia is a freshwater fish group with a sustainable prospect but suffers off-notes appearing during cooking processes. To promote pleasant odorants by thermal cooking processes, tilapia fillets were cooked in different ways (roasting, microwave-heating, boiling and steaming). Their aroma profiles were analysed with special focus on off-notes and umami-enhancing odorants by principal component analysis, and correlated with the heating time, colour, moisture and water activity by partial least squares regression analysis. Results showed that the “green” and “earthy” off-notes were highly correlated with the boiling process (excess of water, short heating time), while most of the umami-enhancing odorants had a high association with the roasting process (low water content, long heating time, better Maillard reaction). This study indicated that roasting is the most adapted cooking process promoting Maillard-derived aromas, umami-enhancing aromas and meanwhile, reducing off-notes. This research helps in understanding the off-note generation in tilapia and promoting desirable umami-enhancing odorants.

Elucidating taste sensing systems in chickens is an important step toward understanding poultry nutrition. Amino acid taste receptors, type 1 taste receptors 1 and 3 (T1R1 and T1R3, respectively), are expressed in chicken taste cells, and chicken T1R1/T1R3 is activated by L-alanine (L-Ala) and L-serine (L-Ser), but not by L-proline (L-Pro). However, it is not clear whether chickens have a gustatory perception of L-amino acids. Here, we found that chickens conditioned to avoid either L-Ala, L-Ser, or L-Pro solutions could successfully learn to avoid the corresponding L-amino acid solution in the conditioned taste aversion (CTA) test. Because CTA is a well-established learning paradigm generated specifically by pairing gustatory perception and gastrointestinal malaise, the present study suggests that chickens can sense L-amino acids by gustatory perception. In addition, we found that the expression of the T1R1 and T1R3 genes was significantly downregulated in response to chronic exposure to L-Ala solution, but not to acute oral stimulation. Taken together, the present study suggests that chickens have a gustatory perception of L-amino acids, and the expression of T1R1/T1R3 mRNAs in the oral cavity can be regulated by L-amino acid intake. Since chickens can detect L-Pro solutions, additional amino acid receptors, other than T1R1/T1R3, may be involved in L-amino acid taste detection in chickens.

As the relevance between left and right brain neurons when transmitting electrical signals of umami taste is unknown, the aim of this work was to investigate responsive regions of the brain to the umami tastant monosodium glutamate (MSG) by using scalp-electroencephalogram (EEG) to identify the most responsive brain regions to MSG. Three concentrations of MSG (0.05, 0.12, 0.26 g/100 mL) were provided to participants for tasting while recoding their responsive reaction times and brain activities. The results indicated that the most responsive frequency to MSG was at 2 Hz, while the most responsive brain regions were T4CzA2, F8CzA2, and Fp2CzA2. Moreover, the sensitivity of the brain to MSG was significantly higher in the right brain region. This study shows the potential of using EEG to investigate the relevance between different brains response to umami taste, which contributes to better understanding the mechanism of umami perception.

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In this study, umami-rich seasoning powder was produced from the offcuts of Taiwanese tilapia (Oreochromis mossambicus) by cooking concentration and spray drying of granules while yielding an abundance of glutamic acid (0.23 mg/100 g), glycine (0.10 mg/100 g), aspartic acid (0.11 mg/100 g), lysine (0.10 mg/100 g), and 11 other aminic acids. It exhibited water content (3.81%), water activity (0.3), powder yields (68.83%), and a good water solubility index (99.89%), while the particle microstructure was a spherical powder. Additionally, it received the highest overall preference score (7.53) in the consumer-type sensory evaluation compared to commercially available seasonings. This study proves that offcuts may be part of the human diet after proper processing and can be widely used to flavor savory food. The producers involved could increase their economic returns while meeting the environmental challenges. The practical contribution could create incremental value for products to critical stakeholders at each point in the tilapia supply chain with an operational guide for transitioning from inefficient to innovative circular practices. [ABSTRACT FROM AUTHOR]

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.)

Salt is widely overconsumed. Among the strategies used in low-salt foods, the addition of flavor enhancers to improve saltiness perception through an umami taste is a viable and promising technique. This study investigated using split-gill mushroom (SGM) powder containing umami taste to increase saltiness in a clear soup for two different heating conditions: steaming under high pressure and microwave heating. According to the E-tongue results, the addition of 0.2–0.8% SGM produced a different taste in the soup compared to the addition of salt, and the addition of 0.2–0.8% SGM yielded a similar taste to the addition of 0.4–0.6% MSG in a plain, clear soup. In flavored soup, SGM at a high concentration had a taste-enhancing impact comparable to 0.4% MSG, whereas SGM at a low concentration had no taste-enhancing effect. The flavored soups containing 0.4 or 0.8% SGM consisted of two umami 5′-nucleotides: adenosine 5′-monophosphate (5′-AMP) and guanosine 5′-monophosphate (5′-GMP); however, inosine 5′-monophosphate (5′-IMP) was not detected. The major umami amino acids were glutamic acid, aspartic acid, and arginine. Microwave heating increased the salinity and total nucleotides and could maintain the umami amino acids, whereas aspartic acid (one of the umami amino acids) was reduced by 8.23% after steaming under high pressure. Thus, after microwave heating and steaming under high pressure, the equivalent umami concentration was reduced by 43.11 and 44.53%, respectively. In conclusion, the addition of SGM and volumetric heating using microwaves could be an alternative method for reducing the amount of salt in soup by increasing the umami taste intensity and salinity. [ABSTRACT FROM AUTHOR]

Dictyophora rubrovolvata is a typical edible fungus of Guizhou Province and is very popular due to its unique taste and texture. In this study, the effect of a controlled atmosphere (CA) on fresh-cut D. rubrovolvata shelf life was investigated. Firstly, this study addresses the influence of different O2 concentrations (5%, 20%, 35%, 50%, 65%, 80%, or 95%) with N2 balance on fresh-cut D. rubrovolvata quality while stored at 4 ± 1 °C for 7 d. Then, on the basis of the determined O2 concentration (5%), CO2 (0%, 5%, 10%, 15%, or 20%) was involved and stored for 8 d at 4 ± 1 °C. Evaluations of physiology parameters, texture, browning degree, nutritional, umami, volatile components, and total colony numbers were determined in fresh-cut D. rubrovolvata. From the results of water migration, the sample of 5% O2/5% CO2/90% N2 was closer to 0 d than other groups at 8 days. Meanwhile, the polyphenol oxidase (2.26 ± 0.07 U/(g·min)), and catalase activity (4.66 ± 0.08 U/(g·min·FW)) were superior to the samples of other treatment groups on the eighth day (3.04 ± 0.06 to 3.84 ± 0.10 U/(g·min), 4.02 ± 0.07 to 4.07 ± 0.07 U/(g·min·FW)). Therefore, we found that a gas environment with 5% O2/5% CO2/90% N2 could ensure the membrane integrity, oxidation, and prevent the browning of fresh-cut D. rubrovolvata, thus better maintaining the physiological parameters. Meanwhile, it also maintained the samples' texture, color, nutritional value, and umami taste. Furthermore, it inhibited the increase in total colony numbers. The volatile components were closer to the initial level compared with other groups. The results indicate that fresh-cut D. rubrovolvata could maintain its shelf life and quality when stored in 5% O2/5% CO2/90% N2 at 4 ± 1 °C. [ABSTRACT FROM AUTHOR]

Background: Evidence has demonstrated that excess sodium intake is associated with development of several non-communicable diseases. The main source of sodium is salt. Therefore, reducing salt intake in foods is an important global public health effort to achieve sodium reduction and improve health. This study aimed to model salt intake reduction with 'umami' substances among Japanese adults. The umami substances considered in this study include glutamate or monosodium glutamates (MSG), calcium diglutamate (CDG), inosinate, and guanylate. Methods: A total of 21,805 participants aged 57.8 years on average from the National Health and Nutrition Survey was used in the analysis. First, we employed a multivariable linear regression approach with overall salt intake (g/day) as a dependent variable, adjusting for food items and other covariates to estimate the contribution of salt intake from each food item that was selected through an extensive literature review. Assuming the participants already consume low-sodium products, we considered three scenarios in which salt intake could be reduced with the additional umami substances up to 30%, 60% and 100%. We estimated the total amount of population-level salt reduction for each scenario by age and gender. Under the 100% scenario, the Japan's achievement rates against the national and global salt intake reduction goals were also calculated. Results: Without compromising the taste, the 100% or universal incorporation of umami substances into food items reduced the salt intake of Japanese adults by 12.8–22.3% at the population-level average, which is equivalent to 1.27–2.22 g of salt reduction. The universal incorporation of umami substances into food items changed daily mean salt intake of the total population from 9.95 g to 7.73 g: 10.83 g to 8.40 g for men and 9.21 g to 7.17 g for women, respectively. This study suggested that approximately 60% of Japanese adults could achieve the national dietary goal of 8 g/day, while only 7.6% would meet the global recommendation of 5.0 g/day. Conclusions: Our study provides essential information on the potential salt reduction with umami substances. The universal incorporation of umami substances into food items would enable the Japanese to achieve the national dietary goal. However, the reduced salt intake level still falls short of the global dietary recommendation. [ABSTRACT FROM AUTHOR]