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The objective of the study was to assess the efficacy of monoammonium glutamate (MAG) in reducing the sodium chloride (NaCl) content (CCRD) of food matrices, including shoestring potatoes, requeijão cheese, and beef burgers. To this end, a time intensity (TI) analysis, temporal dominance of sensations (TDSs), and acceptance tests were employed to evaluate the NaCl reduction in various food items. The TI analysis showed that all experimental units had a mean salty taste intensity that equaled or exceeded the control. The TDS profiles of shoestring potatoes and requeijão cheese and the control were similar. However, the requeijão cheese exhibited significantly lower acceptance than the controls. The food matrices influenced the potential use of MAG and the CCRD. The addition of 2% MAG to the formulation reduced the NaCl content by up to 50% in shoestring potatoes and 65% in beef burgers without compromising the temporal perception of a salty taste and sensory acceptance. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office 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.)

Lentil protein hydrolysates (LPH) and lentil protein hydrolysates cross‐linked (LPHC) were grafted with gum Arabic (GA) through a wet Maillard reaction at 100°C for 2 h and called MLPH and MLPHC. The samples were assessed for absorption, degree of grafting (DG), surface hydrophobicity, antioxidant activity, molecular weight (MW) profile, chemical alteration, volatile compounds, functional and sensory properties. Results showed that Maillard grafting led to increase in absorption and DG (maximum value: MLPHC), and led to the reduction of the surface hydrophobicity and antioxidant activity (minimum value: MLPHC). MW profiles indicated that MLPH and MLPHC formed new bands at MW >250 kDa. Regarding the Fourier transform infrared spectroscopy (FTIR), Maillard conjugation led to the occurrence of peaks at 1759 and 1765 cm−1, while the intensities of amide I bands at 1637 and 1659 cm−1 and amide II bands at 1498 and 1495 cm−1 were decreased. Hydrolysis, cross‐linking, and especially Maillard grafting provided well‐balanced content of volatile components. Indeed, the proportions of alcohols, ketones, aldehydes, and acids were changed, thereby, the inherent grassy and planty tastes were diminished while new umami taste was developed. Maillard grafting led to significant improvement of functional properties, while MLPH and MLPHC indicated the highest emulsifying activity at pH 10.0 (73.76 and 70.12 m2/g, respectively) and stability (369.64 and 288.22 min), foaming capacity (88.57% and 142.86%) and stability (60.57% and 72%). Sensory analysis has demonstrated that umami taste was highly developed in MLPH and MLPHC, which can be well considered as meat proteins and flavor enhancers such as monosodium glutamate (MSG). [ABSTRACT FROM AUTHOR]

Sweet and umami taste receptors recognize chemicals such as sugars and amino acids on their extracellular side and transmit signals into the cytosol of the taste cell. In contrast to ligands that act on the extracellular side of these receptors, little is known regarding the molecules that regulate receptor functions within the cytosol. In this study, we analysed the interaction between sweet and umami taste receptors and calmodulin, a representative Ca2+-dependent cytosolic regulatory protein. High prediction scores for calmodulin binding were observed on the C-terminal cytosolic side of mouse taste receptor type 1 subunit 3 (T1r3), a subunit that is common to both sweet and umami taste receptors. Pull-down assay and surface plasmon resonance analyses showed different affinities of calmodulin to the C-terminal tails of distinct T1r subtypes. Furthermore, we found that T1r3 and T1r2 showed the highest and considerable binding to calmodulin, whereas T1r1 showed weaker binding affinity. Finally, the binding of calmodulin to T1rs was consistently higher in the presence of Ca2+ than in its absence. The results suggested a possibility of the Ca2+-dependent feedback regulation process of sweet and umami taste receptor signaling by calmodulin. [ABSTRACT FROM AUTHOR]

The aim was to study the changes in flavor compounds hydrolyzed by different proteases in fish soup boiled with fish scraps The odor compounds were extracted by solid-phase microextraction (SPME) and analyzed by two-dimensional comprehensive gas chromatography-olfactometry-mass spectrometry (GC×GC-O-MS). The state of the distribution of free amino acids, 5'-nucleotides, peptides and equivalent umami concentration (EUC) were investigated. It was found that enzymatic hydrolysis significantly reduced off-flavor compounds, and the umami taste increased significantly. The synergistic effect between FlavourzymeTM and ProtamexTM (F-P) made the flavor of enzymatic hydrolysis better than that of other enzymes. [ABSTRACT FROM AUTHOR]

This study investigated the effect of low-salt processing on the umami peptide profile of dry-cured hams. Peptidomics data showed 633 umami peptides in the low- and full-salt groups. Among them, 36.2% and 26.5% of shared umami peptides in the low-salt group were significantly down- and up-regulated in relative abundance. Multivariate statistical analysis showed 1011 significantly different umami peptides (SDUPs) in the low- and full-salt groups. Creatine kinase M-type (CKM) and fast skeletal muscle troponin T (TnTf) were the main precursor proteins of these SDUPs. At the end of processing, the relative expression of CKM was lower in the low-salt group than in the full-salt group (P < 0.05), but there was no significant difference in TnTf. More dipeptidyl peptidase cleavage sites were observed in CKM and TnTf proteins in the low-salt group. • Umami peptides in dry-cured hams were screened using peptidomics. • Low- and full-salt hams could be distinguished using 1011 SDUPs. • The 62.7% of shared umami peptides changed significantly in relative abundance. • Degradation of TnTf and CKM was closely associated with SDUPs formation. [ABSTRACT FROM AUTHOR]

To evaluate the storage stability and flavor changes of marinated pork treated with chili and pepper essential oils, the contents of total sulfhydryl, malondialdehyde, total volatile base nitrogen (TVBN), Ca2+ATPase activity, and total viable counts of marinated pork were determined. Further, the non-volatile (umami, numb, and spicy) and volatile flavor compounds of marinated pork were analyzed. Based on the results, the chili and pepper essential oils had limited effects on the storage stability of marinated pork. However, these essential oils could inhibit the oxidation of lipids and proteins and reduce the number of microorganisms and TVBN in marinated pork within 6 days. The non-volatile flavors of the marinated pork decreased as the refrigeration time increased. It was concluded that the decomposition of umami-enhancing nucleotides (GMP, IMP, XMP), the number of flavor substances (hydroxyl-α-sanshool, hydroxyl-β-sanshool), and spicy (capsaicin) tasting compounds caused the decrease in non-volatile flavors. [ABSTRACT FROM AUTHOR]

• The aroma characteristics of chaya leaves were investigated for the first time. • 3-Methylbutanal, with a malt-like aroma, is the key volatile in dried chaya leaves. • Oven drying (120 °C) enhances 5′-ribonucleotide content 3-fold in dried chaya leaves. • Umami taste was most pronounced in oven-dried (120 °C) and pan-roasted samples. • Freeze-dried chaya leaves exhibited the highest antioxidant activity levels. Chaya (Cnidoscolus chayamansa) leaves are known for their strong umami taste and widespread use as a dried seasoning. This study aimed to assess the impact of different drying methods [freeze drying (FD), vacuum drying, oven drying at 50 °C and 120 °C (OD120) and pan roasting (PR)] on the metabolome using mass spectrometry, umami intensity, and antioxidant properties of chaya leaves. The predominant volatile compound among all samples, 3-methylbutanal, exhibited the highest relative odor activity value (rOAV), imparting a malt-like odor, while hexanal (green grass-like odor) and 2-methylbutanal (coffee-like odor) are the second highest rOAV in the FD and PR samples, respectively. OD120 and PR samples possessed the highest levels of umami-tasting amino acids and 5′-ribonucleotides as well as the most intense umami taste, whereas FD samples exhibited the highest antioxidant capacity. These findings enhance our understanding of the aroma characteristics, umami taste, and antioxidant potential of processed chaya leaves. [ABSTRACT FROM AUTHOR]

Temperature is one of the most important factors for drying edible mushrooms. To evaluate the effects of different hot‐air drying (HAD) temperatures on the umami taste and aroma profile of Suillus granulatus (S. granulatus) mushrooms, we measured umami substances and volatile compounds of S. granulatus dried at 40°C, 50°C, 60°C, 70°C, and 80°C. Results showed that when dried at 60°C, S. granulatus exhibited significantly higher (p < 0.05) equivalent umami concentration, taste activity values of glutamic acid (Glu) and 5′‐guanosine monophosphate (5′‐GMP), and electronic tongue umami sensory scores. The results identified a total of 71 volatile components of which geranylacetone, benzaldehyde, phenylethyl alcohol, and 3‐methylbutanoic acid were the dominant compounds. Sensory evaluation and relative odor activity values (ROAVs) revealed that 16 volatile compounds were the key volatile organic compounds contributing mushroom‐like and sweet odor to the overall aroma of S. granulatus; these included 1‐octen‐3‐ol (ROAV: 15.11‐62.06) and ethyl phenylacetate (ROAV: 13.62‐79.11). The drying temperature changed the aroma profile of S. granulatus. Furthermore, the mushroom dried at 60°C had a more desirable mushroom‐like and almond odor. It was, therefore, proposed that HAD at 60°C was optimal for retaining a pleasant flavor in S. granulatus. This study provides a theoretical basis for the optimal drying condition selection for the mushroom processing industry. Practical Application: Hot‐air drying at 60°C can significantly retain the flavor of S. granulatus and is an optimal temperature for mushroom drying. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine the effect of supplement fish protein hydrolysate-based to broiler feed on sensory properties and meat quality. A total of 400 pieces of 1-day-old male broiler chicks (Ross 308) received 4 dietary levels (0, 2.5, 5.0, 7.5%) of fish protein hydrolysate-based supplement (FPHS) in the basal diet mix for 42 days. Quality index-derived method (QIM) was used for assessment of chicken carcass. Quantitative descriptive analysis method was applied to study sensory properties of the chicken fillets. Water holding capacity (WHC), cook loss, color, meat texture were also determined. The carcass odor and flavor in broilers received 2.5, 5.0, and 7.5% FPHS were significantly different from those of control. The highest intensity of darkness, reddish pink, and yellowness of the legs and breast was observed in the carcass of control treatment. The highest fat content (1.34%) and WHC (70.36%) were reported in treatments received 7.5% FPHS. The umami taste was detected in chicken broth and cooked fillets of broilers fed received FPHS, which was not detected in the control treatment. The umami (a pleasant savory taste) was sensed more strongly in the cooked fillet followed by chicken broth. Breast fillet of birds received FPHS had a better texture, which was confirmed by shear stress measurement. The results could be helpful in application of FPHS in the poultry farming especially in the countries looking for local feed protein products as soybean meal replacement. [ABSTRACT FROM AUTHOR]

To understand the relationship between flavor and energy, the flavor, energy, and enzyme activity related to energy metabolism in shiitake mushrooms harvested at different developmental stages were investigated. The results indicated that the adenosine triphosphate level increased significantly in developing mushrooms and was strongly correlated with the fresh weight. The levels of equivalent umami concentration (EUC), total aroma compounds, energy charge, adenosine triphosphatase, cytochrome c oxidase, and succinic dehydrogenase varied with maturity. In addition, a strong correlation was observed between aroma compounds, EUC, and energy status (p < 0.05). Our results suggest that the unique flavor of developing shiitake mushroom is closely related to energy. The findings may provide a new strategy to improve the flavor of mushrooms by regulating their energy levels. Practical Application: The unique flavor of shiitake mushroom, which has a significant impact on consumer preferences, is one of its key characteristics. This research paper provides a theoretical foundation for determining the optimal harvest period for shiitake mushrooms with high quality and a new strategy to improve the flavor of mushrooms by regulating their energy levels. [ABSTRACT FROM AUTHOR]

Improving the umami taste of seasoning is an important topic of discussion in the current scenario based on the conventional technology of using soybean protein isolates (SPI) as proposed as the base material for seasoning. In this study, a novel SPI seasoning was created by fermenting the SPI hydrolysate of Corynebacterium glutamicum to increase the umami taste of its fermented products. The differences between traditional SPI enzymatic hydrolysate fermentation (Sample S), traditional C. glutamicum fermentation (Sample F), and the aforementioned novel fermentation (Sample SF) were investigated. The results showed that Sample SF had the best umami taste, saltiness, and richness, which was compared with sample S and F showing significant differences, respectively (P < 0.05). Succinic acid, lactic acid, and acetic acid were the main organic acids in the seasonings, accounting for 92.24% of the total organic acids. The total fresh-sweet free amino acids content of sample SF was 7.22 and 2.15 times that of samples S and F, respectively, and 5′-nucleotide content was 2.85 and 2.35 times that of Samples S and F, respectively. Glu, 5′-inosine monophosphate, and 5′-guanosine monophosphate contents contributed remarkably to the umami taste of the seasoning (P < 0.05). Furthermore, among all the detected umami compounds, 18 conformed the variable important projection (VIP) values > 1.0. Therefore, SPI hydrolysate fermentation by C. glutamicum may improve the umami flavor of fermented products. This study presents a novel method for producing new SPI-containing seasonings on a commercial scale. • The content of SPI seasonings' OAs, FAAs, and 5′-nucleotides rises as a result of C. glutamate fermentation. • The umami taste of SPI seasonings is enhanced by C. glutamate fermentation. • The umami of SPI seasonings was strongly correlated with OAs, FAAs, and 5′-nucleotides, according to PCA. • Important elements influencing the umami of SPI seasonings are Glu, 5′-IMP, and 5′-GMP. [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.)

Affiliated Program for Children Development at University of George Town says, there are 6 types of eating difficulties in children, about 27.3% of children only want to eat liquid or crushed food and 24.1% of children have difficulty in sucking, chewing or swallowing. The hardness of food is important for determining one's appetite. The umami taste is the fifth sense of taste that is acknowledged as one of the basic tastes. Umami is considered a delicious taste that can arouse the appetite. The aims of this study to determine umami taste receptor TAS1R1 and TAS1R3 expression on rats (Rattus novergicus) that fed with different levels of food hardness. Post-weaned wistar rats (Ratttus novergicus) were divided into three groups, Group1 standard diet, group2 soft diet, group3 hard diet. The rats were sacrificed in 8th weeks and tongue was observed through scorring count TAS1R1 expression in fungiform and TAS1R3 expression in foliate with immunohistochemistry method using polyclonal antibody. The mean and standard deviation (± SD) of TAS1R1 expression on Group1 was 7.82 ± 1.66, Group2 was 7.37 ± 1.33, and Group3 was 4.84 ± 1.44. In group3 was significantly lower than group2 and group1. TAS1R3 expression on Group1 was 5.17 ± 2.58, Group2 was 8.55 ±1.85, and Group3 was 7.37± 2.32). In group2 was significantly higher than group1 and not significantly higher than group3. Hard diet group showed lower TAS1R1 expression, and soft diet group showed higher TAS1R3 expression. [ABSTRACT FROM AUTHOR]

Umami taste is the most recent confirmed basic taste in addition to sour, sweet, bitter, and salty. It has been controversial because of its effects on human nutritional benefit. Based on the available literatures, this review categorized 13 positive and negative effects of umami taste on human health. On the positive side, umami taste can improve food flavor and consumption, improve nutrition intake of the elderly and patients, protect against duodenal cancer, reduce ingestion of sodium chloride, decrease consumption of fat, and improve oral functions. On the other hand, umami taste can also induce hepatotoxicity, cause asthma, induce migraine headaches, damage the nervous system, and promote obesity. Due to its novelty, there are many functions and effects of umami taste waiting to be discovered. With further investigation, more information regarding the effects of umami taste on human health will be discerned. [ABSTRACT FROM AUTHOR]

Red oncom, a fermented product from solid waste of soybean curd process, and black oncom, a similar fermented product but made from defatted peanut cake, have been known to have umami taste. Umami fractions of red oncom and black oncom that are responsible for umami taste have not been investigated yet. The objective of this research was to characterize umami fractions obtained by ultrafiltration and chromatography of both oncoms. The first step, water‐soluble extracts of oncoms were ultrafiltered using a membrane with cutoff 3,000 Da and followed by gel filtration chromatography (Sephadex G‐25) to obtain umami fractions. Ultrafiltration fractions of red oncom (molecular weight [MW] less than 3,000 Da) and black oncom (MW more than 3,000 Da) had an intense umami taste. The further fractionation by gel filtration chromatography linked to taste dilution analysis yielded umami fractions. Chemical characterization revealed that free glutamic acid, free phenylalanine, and peptides containing their residual amino acids were present in the fractions. Practical Application: Umami fractions of red and black oncoms can be used as a source of umami compounds for food industries and food services. The information from this paper can be used by other researchers who will explore umami peptides. [ABSTRACT FROM AUTHOR]

Edible mushrooms have been used as food and medicine materials for thousands of years, and the yield of cultivatable edible mushrooms has increased in recent years. The increased consumption of edible mushrooms is not only due to their nutritional value, but also to their unique taste and specific flavor. As consumer awareness of food sensory qualities increases, umami taste and aroma have become important factors affecting consumer choices. There are many factors affecting umami taste and aroma of edible mushrooms, such as cultivation conditions, species, maturity, grading, parts of mushrooms, and processing and storage methods. However, the mechanisms underlying the variations in umami taste and aroma components of different mushrooms are still unclear. In this review, traditional umami components, novel umami peptides, and aroma compounds are discussed, as well as the perception of umami taste and aroma. Based on a combination of human sensory evaluation and instrumental analysis, changes in the composition of these components in edible mushrooms are summarized, and the metabolic pathways and biochemical reactions involved in these changes are also discussed. The umami taste and aroma of edible mushrooms were closely related to nucleotide metabolism, amino acid metabolism, fatty acid metabolism, and the Maillard reaction. Umami peptides and the synergy between these compounds contribute to overall umami taste. There are differences in umami taste and aroma between cultivated and wild mushrooms. The selection of processing and storage techniques is, therefore, based on the established demand for umami taste and aroma of edible mushrooms. • The aroma of edible mushrooms was reviewed for the first time. • The novel umami peptides in edible mushrooms were reviewed. • The metabolism pathways of umami taste and aroma components were described. • The variation of umami and aroma components in edible mushrooms were summarized. • Future research trends for umami taste and aroma of mushrooms were proposed. [ABSTRACT FROM AUTHOR]

Different species and processing methods have different impacts on the flavor quality of dried Lentinus edodes. To investigate the effect of species (four species of Qingyuan: 241-4, Qingke 20, Qingke 212, and Qingke 135) and drying method (slow charcoal roasting and natural drying) on dried L. edodes, the present study quantitatively analyzed the volatile compounds, particularly lenthionine, 1-octen-3-ol, and cyclic sulfur compounds, and compared 10 L. edodes varieties using solid-phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). A total of 136 volatiles from the 10 L. edodes varieties were quantitatively identified. 1-Octen-3-ol, lenthionine, and associated dispersion products, including dimethyl disulfide, dimethyl trithioether, and dimethyl tetrathioether, were selected as L. edodes flavor indexes. In addition, the electronic tongue results were consistent with the results of the sensory evaluation. The flavor quality of the dried L. edodes could be objectively evaluated by GC–MS and the electronic tongue for 1-octen-3-ol and lenthionine, their dispersion products, and the umami taste. The results showed that the flavor quality of L. edodes after a long period of charcoal roasting was improved. Although the quantity of volatile substances was reduced during charcoal roasting, the variety of volatiles was increased and the umami was improved. [ABSTRACT FROM AUTHOR]

Highlights • Umami taste and energy status of P. geesteranus during storage were evaluated. • Higher umami taste value of P. geesteranus could be obtained at 5 °C in late storage. • AMP, connecting umami and energy, significantly related to EUC and sensory score. • ATP content, SDH and CCO activity at 5 °C were significantly higher in late storage. • Higher umami taste related to higher ATP level and mitochondrial ATPase activity. Abstract Pleurotus geesteranus has recently been gaining popularity due to its strong umami taste. In the present study, umami taste, energy level, and energy metabolism-related enzymes activity in harvested P. geesteranus , stored at 20, 10, 5, and 0 °C, were investigated to evaluate the relationship between umami taste and energy status. Results showed that the mushroom at 5 °C exhibited significantly higher (p < 0.05) equivalent umami concentration (EUC), higher content of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), and higher activity of succinic dehydrogenase (SDH) and cytochrome c oxidase (CCO) in late storage. AMP, associating umami taste with energy, presented a significantly positive correlation with EUC and umami determined by electronic tongue at 5 °C. Furthermore, there were better correlations between umami taste and energy status of mushroom at 5 °C. The results suggest that higher energy status of post-harvest P. geesteranus contributes to better umami taste. [ABSTRACT FROM AUTHOR]

Highlights • Low molecular weights fraction (less than 1500 Da) contributed to the umami taste of asam sunti. • Umami fractions were obtained from ultrafiltration step followed by gel filtration separation. • Glutamic acid and succinic acid are the main umami compounds in the umami fractions. Abstract Salted fermented fruit known as asam sunti ( Averrhoa bilimbi L.) in Indonesia has been used as a source of umami taste. This study was aimed to characterize the three types of asam sunti and their water soluble extracts, and to trace the compounds responsible for umami taste in umami fractions. Umami fractions were obtained by ultrafiltration followed by Sephadex G-15 chromatographic separation. The three types of samples could be differentiated by physicochemical and sensory analyses. Low molecular weight fraction had the highest umami intensity. Further chromatographic separation revealed three umami fractions, F-II, III and IV. Umami taste of F-III was due to the presence of free l -glutamic acid at 6 times, while FII and FIV were due to succinic acid at more than 30 times their respective umami thresholds. Organic acid as well as amino acid seemed to play an important role in the intense umami taste of asam sunti. [ABSTRACT FROM AUTHOR]

• Sensory-guided fractionation revealed umami compounds in pea protein isolate. • Monosodium glutamate (MSG) was found at subthreshold concentrations. • Ribonucleotides were identified as umami enhancing compounds with MSG. • Ribonucleotides reported synergistic umami enhancing activity. The umami taste of pea protein ingredients can be desirable or undesirable based on the food application. The compounds contributing to the umami perception of pea protein isolate (PPI) were investigated. Sensory-guided prep-liquid chromatography fractionation of a 10% aqueous PPI solution revealed one well-known compound, monosodium glutamate (MSG), however, it was reported at a subthreshold concentration. Two umami enhancing compounds 5′-adenosine monophosphate (AMP) and 5′-uridine monophosphate (UMP) were subsequently identified after the LC fractions were re-evaluated with MSG. Sensory recombination studies, utilizing the aqueous PPI solution as the base, confirmed AMP and UMP were umami enhancers of MSG and contributed approximately 81% of the perceived umami intensity. However UMP was only reported to enhance umami perception in combination with AMP (not individually) indicating synergistic interactions were observed between the two enhancer compounds. Therefore the presence of all three compounds are important for umami perception and provide an improved basis to tailor the flavor profile in PPI products. [ABSTRACT FROM AUTHOR]

Four umami peptides were separated and purified by ultrafiltration, gel filtration chromatography and identified by ultra-performance liquid chromatography tandem mass-spectrometry (UPLC-MS/MS), the amino acid sequences of four peptides are Val-Pro-Tyr (VPY), Thr-Ala-Tyr (TAY), Ala-Ala-Pro-Tyr (AAPY) and Gly-Phe-Pro (GFP). The result illustrates that the umami amino acids are not the content of umami peptides, but bitter amino acids are included. The threshold of VPY, TAY, AAPY and GFP were 1.65 mmol/L, 1.76 mmol/L, 2.97 mmol/L and 6.26 mmol/L, respectively. The peptide TAY, VPY and AAPY had an umami-enhancement effect on the monosodium glutamate (MSG) + sodium chloride (NaCl) solution, their concentrations were 2.5 g/L, 5 g/L and 5 g/L, respectively, while GFP has no significant umami-enhancement effect in solution. In addition, the peptides have better taste than its composing amino acids, which indicates that the taste of peptide does not depend on its composing amino acids. [ABSTRACT FROM AUTHOR]

The bottle gourd or calabash [ Lagenaria siceraria (Mol.) Standl .] (2n = 2x = 22), also known as opo squash or long melon, is an important cucurbit crop worldwide. Commonly used as a vegetable, bottle gourd fruits have a peculiar umami taste that is important for their market value. To date, the umami chemical ingredients of bottle gourd fruits and their genetic determinants remain unidentified. In the current study, the relationship between umami flavor and free amino acid (FAA) contents was analyzed using a representative panel of twenty-eight accessions. Among the FAAs identified, free glutamate (Glu) was found to have the most significant association with umami taste, suggesting that free Glu is the main umami-conferring ingredient of bottle gourd. To further identify the genetic regions associated with umami taste, a genome-wide association study (GWAS) for free Glu content was conducted in a diversity panel consisting of 139 inbred lines, each sequenced with a restriction site-associated DNA sequencing (RAD-Seq) technology. Seventeen SNPs were identified as associated with free Glu content, each accounting for 7.5% to 15.1% of the phenotypic variation. The number of the favored alleles for each line varied from 0 to 13. Free Glu content exhibited a significant positive correlation with the number of the favored alleles. These results indicated that there is considerable genetic potential to develop new varieties with stronger umami taste through targeting more favored alleles of free Glu content. To our knowledge, this is the first GWAS study in bottle gourd. Our work reveals the genetic architecture of umami taste in the bottle gourd and will help facilitate molecular breeding of cultivars with improved flavor. [ABSTRACT FROM AUTHOR]

Sodium chloride (NaCl) is the most commonly used ingredient to provide salty taste to foods. However, excess sodium in the bloodstream has been associated with the development of several chronic noncommunicable diseases. In order to limit sodium intake to levels considered safe, the World Health Organization ( WHO) recommends for adults a daily intake of not more than 5 g of NaCl (less than 2 g of sodium). One of the strategic actions recommended by the to reduce sodium intake is reformulation of processed foods. This recommendation indicates there is an urgent need to find salt substitutes, and umami compounds have been pointed as an alternative strategy. Like salty, umami is also a basic taste and the major compound associated to umami is monosodium L-glutamate ( MSG). The available scientific data on the toxicity of MSG has been evaluated by scientific committees and regulatory agencies. The Joint FAO/ WHO Expert Committee on Food Additives and the Scientific Committee on Food of the European Commission established an acceptable daily intake ( ADI) not specified, which indicated that the substance offers no health risk when used as a food additive. The United States Food and Drug Administration and the Federation of American Societies for Experimental Biology classified MSG as a Generally Recognized as Safe ( GRAS) substance. In this paper, an overview about salty and umami taste physiology, the potential applications of MSG use to reduce sodium content in specific industrialized foods and safety aspects of MSG as food additive are presented. [ABSTRACT FROM AUTHOR]

BACKGROUND Bitter taste is the main limiting factor for various applications of protein hydrolysates. Frequently used physicochemical methods for debittering protein hydrolysates come with some undesired side effects. Deamidation-induced modification would be a very promising technique to improve the flavor of wheat gluten hydrolysates ( WGHs). This study was designed to determine the effect of deamidation with certain enzymes or acid treatment on the chemical composition, bitterness and umami properties of WGHs. The difference between umami peptide and free glutamic acid on the suppression of bitterness is emphatically discussed. The optimal scheme is proposed based on the flavor of WGHs and the yield of peptides. RESULTS The generation of umami substances suppressed bitter signal transduction. When the content of umami substances was relatively high, the umami-enhancing properties of umami peptides were obviously effective. The intensity of umami taste was high enough to further suppress bitter taste in the course of neurocognitive functioning. CONCLUSION When WGHs were treated with Glutaminase for 180 min, the umami taste score increased from 1.62 to 4.27 and the bitter taste score decreased from 1.33 to 0.65. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

• Pyruvate mainly contributed to pH of pork stored at ice temperature. • Ice temperature storage was effective in delaying decrease of umami nucleotides. • Endogenous enzymes induced umami nucleotides decomposition of pork stored at 4 °C. To study new methods to delay the umami taste attenuation of the conditioned pork, the ice temperature of pork, the content of nucleotides, lactic acid, pyruvate, glycogen, and activity of key endogenous enzymes were determined for the conditioned pork stored at 4 °C and ice temperature. The results indicated that the ice temperature of the pork ham bicipital muscle was −1.4 °C. The content of umami-enhancing nucleotides in pork stored at 4 °C decreased significantly (p < 0.05) with increasing aging time, but all umami-enhancing nucleotides in pork stored at ice temperature were decreased significantly (p < 0.05), but the decrease rates were lower than those in pork stored at 4 °C. A possible reason for this was that the storage temperature influenced the activity of endogenous enzymes and glycolysis. Ice temperature storage was an effective method to inhibit the decrease in umami taste nucleotides in conditioned pork. [ABSTRACT FROM AUTHOR]

Five tasty peptides were separated from soy sauce, by sensory-guided fractionation, using macroporous resin, medium-pressure liquid chromatography and reverse phase-high performance liquid chromatography, and identified by ultra-performance liquid chromatography tandem mass-spectrometry as ALPEEV, LPEEV, AQALQAQA, EQQQQ and EAGIQ (which originated from glycinin A1bB2-445, glycinin A1bB2-445, cobyric acid synthase, leucine-tRNA ligase and glycoprotein glucosyltransferase, respectively). LPEEV, AQALQAQA and EQQQQ tasted umami with threshold values of 0.43, 1.25 and 0.76 mmol/l, respectively. ALPEEV and EAGIQ had minimal umami taste, but ALPEEV, EAGIQ and LPEEV showed umami-enhancement with a threshold estimated at 1.52, 1.94 and 3.41 mmol/l, respectively. In addition, the synthetic peptides showed much better sensory taste than mixtures of their constitutive amino acids. It indicated that peptides might play an important role in the umami taste of soy sauce. [ABSTRACT FROM AUTHOR]

Seventeen edible mushrooms commercially available in Korea were analysed for their umami taste compounds (5′-nucleotides: AMP, GMP, IMP, UMP, XMP; free amino acids: aspartic, glutamic acid) and subjected to human sensory evaluation and electronic tongue measurements. Amanita virgineoides featured the highest total 5′-nucleotide content (36.9 ± 1.50 mg/g), while monosodium glutamate-like components (42.4 ± 6.90 mg/g) were highest in Agaricus bisporus . The equivalent umami concentration ( EUC ) ranged from 1.51 ± 0.42 to 3890 ± 833 mg MSG/g dry weight; most mushrooms exhibited a high umami taste. Pleurotus ostreatus scored the highest in the human sensory evaluation, while Flammulina velutipes obtained the maximum score in the electronic tongue measurement. The EUC and the sensory score from the electronic tongue test were highly correlated, and also showed significant correlation with the human sensory evaluation score. These results suggest that the electronic tongue is suitable to determine the characteristic umami taste of mushrooms. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antler fungus had the highest umami taste intensity. • Umami amino acids and nucleotides enhanced the salty intensity of NaCl. • Antler fungus enzymatic hydrolysate increased the salty intensity of NaCl. The demand for low-salt foods is increasing due to their health benefits. Umami is known to enhance salty, and a large amount of umami components have been identified in edible fungi. 5′-nucleotides and umami amino acids from nine species of edible fungi were quantified. The equal umami concentration (EUC) in nine edible fungi was within the range of 37.7–1317.72 g MSG/100 g, and umami intensity as determined by electronic tongue and sensory evaluation was within the range of 11.22–13.53 and 2.85–5.55, respectively. Antler fungus had the highest umami intensity. Umami amino acids and nucleotides could increase salty intensity of NaCl at medium and high concentrations. The enzymatic hydrolysate of Antler fungus at higher concentrations could more effectively enhance salty taste of NaCl at lower concentration. This synergistic effect between umami and salty indicates that Antler fungus can potentially be used as an ingredient in low-salt foods. [ABSTRACT FROM AUTHOR]

Umami taste is responsible for sensing monosodium glutamate, nucleotide enhancers, and other amino acids that are appetitive to vertebrates and is one of the five basic tastes that also include sour, salty, sweet, and bitter. To study how ecological factors, especially diets, impact the evolution of the umami taste, we examined the umami taste receptor gene Tas1r1 in a phylogenetically diverse group of bats including fruit eaters, insect eaters, and blood feeders. We found that Tas1r1 is absent, unamplifiable, or pseudogenized in each of the 31 species examined, including the genome sequences of two species, suggesting the loss of the umami taste in most, if not all, bats regardless of their food preferences. Most strikingly, vampire bats have also lost the sweet taste receptor gene Tas1r2 and the gene required for both umami and sweet tastes (Tas1r3), being the first known mammalian group to lack two of the five tastes. The puzzling absence of the umami taste in bats calls for a better understanding of the roles that this taste plays in the daily life of vertebrates. [ABSTRACT FROM AUTHOR]

Abstract: Effects of chronic restraint stress on the taste responses to five basic taste qualities were investigated electrophysiologically in the rat chorda tympani. In addition, the mRNA expression for T1R3, the common G-protein-coupled receptor (GPCR) for sweet and umami tastes, was studied quantitatively by RT-PCR after such stress. Rats were restrained in a small cylindrical restrainer made of steel wire for 8h daily for 14 successive days. The integrated responses to sweet and umami tastes, as recorded from the chorda tympani, were significantly suppressed after such stress, but the other three basic taste responses were unaffected. Expression of T1R3 mRNA in the fungiform papillae, as estimated by RT-PCR, was slightly reduced by the stress, and a quantitative real time RT-PCR study revealed a significant suppression of T1R3 mRNA expression in the stress group. These results suggest that the observed stress-induced changes in taste sensation could be caused by a peripheral disorder of the transduction mechanism in taste-receptor cells, involving in particular a stress-induced inhibition of T1R3 expression. [Copyright &y& Elsevier]

Abstract: The shrimp paste called belacan is a traditional umami taste condiment extensively used in Malaysia that is rich in glutamate and 5′-nucleotides. The aim of this study was to determine the concentration of glutamate and 5′-nucleotides of various types of foods prepared with belacan and to measure their sensory attributes. The concentration of free glutamic acid found in different brands of belacan was 180–530mg/100g and in local dishes 601–4207mg/100g. The total amount of 5′-nucleotides in belacan samples ranged from 0.85 to 42.25μg/g. A Quantitative Descriptive Analysis (QDA) using a list of 17 sensory attributes showed a good correlation between belacan concentration in the final food and a range of positive sensory attributes, except for bitter, sweet, sour taste and astringency. Belacan also contains bitter, sweet and sour compounds that change the positive attributes of belacan at higher concentrations. The highest aroma attributes were linked to nasi goreng belacan (belacan fried rice) while the highest flavour attributes were found in sambal belacan. There was a 32 folds significant increase of umami attributes with the addition of belacan to final foods. The optimum amount of belacan was 0.45% for asam pedas (tamarind flavoured dish with belacan), 18% for sambal belacan (chilli belacan), 1.5–2.5% for kangkong goreng belacan (stir fried water convolous with belacan), and 2% for nasi goreng belacan. [Copyright &y& Elsevier]

Soy sauce taste has become a focus of umami taste research. Umami taste is a 5th basic taste, which is associated to a palatable and pleasurable taste of food. Soy sauce has been used as an umami seasoning since the ancient time in Asia. The complex fermentation process occurred to soy beans, as the raw material in the soy sauce production, gives a distinct delicious taste. The recent investigation on Japanese and Indonesian soy sauces revealed that this taste is primarily due to umami components which have molecular weights lower than 500 Da. Free amino acids are the low molecular compounds that have an important role to the taste, in the presence of sodium salt. The intense umami taste found in the soy sauces may also be a result from the interaction between umami components and other tastants. Small peptides are also present, but have very low, almost undetected umami taste intensities investigated in their fractions. [ABSTRACT FROM AUTHOR]

The impact of salt reduction and addition of Umami Ingredient, obtained from shiitake stipes, on the physicochemical and technological properties of beef burgers was evaluated. Seven treatments were performed: one control (regular salt content) and six low-salt formulations with different levels of salt and Umami Ingredient. Cooked burgers with salt reduction and Umami Ingredient addition showed a slight increase in lightness and yellowness, but no effect was found for redness, pH, and water activity. There was no decrease in cooking loss and diameter reduction in any of the formulations and only samples with 70% salt reduction were significantly less hard and chewy in comparison to the control. An increase in the free amino acids proline and phenylalanine was observed in treatments with Umami Ingredient. In general, the treatments did not affect amino acid profiles compared to the control and the most abundant amino acids were those related to the umami taste (glutamic and aspartic acids). The volatile profile of beef burgers showed a slight increase in compounds also found in the Umami Ingredient, mainly 3-methylbutanal, (S)-(+)-1,2-Propanediol and dimethyl sulfide. Based on physicochemical and technological parameters, the Umami Ingredient can be considered a promising natural flavor enhancer for low-salt beef burgers. • Umami Ingredient (UI) obtained from shiitake stipes was studied as a flavor enhancer. • Low-salt beef burger with UI addition showed slight color changes. • Cooking properties of the burgers were not affected by sodium reduction and UI addition. • 35 and 52.5% salt reductions and UI addition did not affect the texture of the burgers. • UI can be a promising natural flavor enhancer for low-salt beef burgers. [ABSTRACT FROM AUTHOR]

• Dried S. granulatus had better umami taste and aroma in transparent packaging. • The umami taste and aroma were better after four to six months of storage. • Light could be used as a treatment technology to improve the umami taste and aroma. • Ketones and pyrazines were more abundant in transparent packaging. Umami and aroma are important flavor qualities of edible mushrooms, and packaging can maintain or improve the flavor during storage. This study explored the effects of light-proof packaging (LPP), light-transparent packaging (LTP), vacuum light-proof packaging (VLPP), and vacuum light-transparent packaging (VLTP) on umami taste and aroma of dried Suillus granulatus. Monosodium glutamate-like amino acid content, equivalent umami concentration, and electronic tongue umami sensory scores in VLTP were higher at 2, 4, and 6 months and higher in LTP at 8 and 10 months. Principal component analysis of aroma components showed that the comprehensive scores were higher for the transparent packaging. Ketones and pyrazines were more abundant in transparent packaging. Flavor quality was better at 4–6 months, based on the equivalent umami concentration and the concentration of eight-carbon compounds that contribute to aroma. Transparent packaging is a promising way to optimize the flavor of dried Suillus granulatus. [ABSTRACT FROM AUTHOR]

In the Western world, consumers have only recently learned to discriminate the Umami taste, although they have enjoyed its contribution to the palatability of traditional dishes for centuries. The flavor enhancing properties of MSG have been scientifically investigated in European subjects. By adding MSG to such foods as soups, their content in sodium can be decreased without altering palatability, thus favoring a net decrease in sodium intake. Consumers presented with a novel food often have to get accustomed to the new taste before they acquire a preference for the food. A study showed that when such novel foods are added with some appropriate amount of MSG, consumers acquire a preference for them more rapidly. In elderly persons, the addition of MSG to nutritionally valuable foods (soups, vegetables, starches) did induce an increase of intake of MSG-added foods. Total meal size, however, was not affected, since the increased intake of MSG-containing foods was followed by a decreased consumption of foods served later in the meal, such as desserts. The same observations were repeated in hospitalized diabetic patients. Again, the patients ingested more healthy MSG-containing foods and less of other foods, with the same total meal energy intake. These two studies suggested that MSG could be used to stimulate appropriate food choices in certain populations. [ABSTRACT FROM AUTHOR]

We have performed a comprehensive evaluation of single-nucleotide polymorphisms (SNPs) and haplotypes in the human TAS1R gene family, which encodes receptors for sweet and umami tastes. Complete DNA sequences of TAS1R1-, TAS1R2-, and TAS1R3-coding regions, obtained from 88 individuals of African, Asian, European, and Native American origin, revealed substantial coding and noncoding diversity: polymorphisms are common in these genes, and polymorphic sites and SNP frequencies vary widely in human populations. The genes TAS1R1 and TAS1R3, which encode proteins that act as a dimer to form the umami (glutamate) taste receptor, showed less variation than the TAS1R2 gene, which acts as a dimer with TAS1R3 to form the sweet taste receptor. The TAS1R3 gene, which encodes a subunit common to both the sweet and umami receptors, was the most conserved. Evolutionary genetic analysis indicates that these variants have come to their current frequencies under natural selection during population growth and support the view that the coding sequence variants affect receptor function. We propose that human populations likely vary little with respect to umami perception, which is controlled by one major form of the receptor that is optimized for detecting glutamate but may vary much more with respect to sweet perception. [ABSTRACT FROM AUTHOR]

• The application of STPD treatment on mushroom was investigated. • The storage quality and umami taste in mushroom were examined. • STPD treatment decreased respiration and maintained a high firmness of mushroom. • STPD-2 effectively delayed the browning of fresh mushroom. • Mushroom treated with STPD-2 had higher level of umami taste. The effects of short-time partial dehydration (STPD) on quality of shiitake mushroom were evaluated. Quality properties included respiration, texture, color and umami taste. Results showed that STPD treatment (STPD-2 and STPD-3) can slow down respiration rate and delay respiration peak, thus providing more than 7 days of storage time stored at 20 ± 1 °C. Mushroom subjected to STPD-2 and STPD-3 treatments also maintained better firmness. The STPD-2 treatment effectively delayed the browning of fresh mushroom. Compared to other groups, the content of flavor 5′-nucleotides and total 5′-nucleotides in STPD-2 and STPD-3 samples were higher, and STPD-2 sample had higher total amino acid content during storage. Higher equivalent umami concentration (EUC) values were found in STPD-2 sample (17.58 – 38.69 g MSG 100 g −1) compared to STPD-3 sample (13.80 – 27.51 g MSG 100 g −1) and STPD-1 sample (5.11 – 14.19 g MSG 100 g −1). Thus, it indicated that STPD-2 treatment could effectively preserve monosodium glutamate-like (MSG-like) components and nucleotides in mushroom. Results suggested that STPD treatment, especial STPD-2, could maintain mushroom overall quality. [ABSTRACT FROM AUTHOR]

Umami-taste loss and unpleasant odor are the restrictive factors of consumer acceptance of mushrooms (Flammulina velutipes). Pre- and postharvest 1-methylcyclopropene (1-MCP) treatments were applied to evaluate the sensory score, ethylene release, respiration rate, umami taste and aroma profiles in mushrooms at 10 °C storage. The results showed that preharvest treatment resulted in a stronger inhibition of respiration and ethylene production than postharvest treatment. Preharvest treatment also had the highest sensory score and flavor 5′-nucleotides content. The EUC values of preharvest and postharvest treatments were 10.5 and 1.4 times of CK on day 0, respectively. Preharvest treatment improved overall flavor by increasing umami scores in electronic tongue analysis and maintaining volatile compounds compared with postharvest treatment. Thus, preharvest 1-MCP treatment could be considered as an alternative approach to preserve the umami taste and aroma profiles in Flammulina velutipes. • 1-MCP effectively extended Flammulina velutipes shelf-life for up to 10 days. • Preharvest 1-MCP treatment was first applied to mushroom preservation. • Preharvest 1-MCP treatment achieved the highest level of umami taste. • Preharvest 1-MCP treatment maintained more aroma volatiles. [ABSTRACT FROM AUTHOR]

Although it is not an easy task, sodium reduction in food is necessary, and in this scenario, the research for tasty food with reduced sodium content has an extremely relevant role. In this study, sodium reduction in corn extruded snacks was evaluated. Four snack samples were evaluated: one control sample (with salt and monosodium glutamate) and three reduced-sodium formulations. To minimize sensory losses caused by sodium reduction, monosodium glutamate (MSG) and Umami Ingredient (a new flavor enhancer ingredient obtained from shiitake mushroom byproducts) were used as flavor enhancers, since the utilization of Umami Ingredient enables the development of MSG-free and low-sodium products. The physical (expansion ratio, density and cutting force) and sensory (acceptance through hedonic scale, Just-about-right scale and characterization by the Rate-All-That-Apply method) characteristics of the snacks were investigated. Snacks with lower sodium content exhibited lower acceptance compared to the control sample, but they were not rejected by the consumers. Umami Ingredient performed similarly to MSG on seasoning flavor, salty and umami tastes. From this result, Umami Ingredient can be considered a potential alternative to replace MSG in low-sodium food, acting as a flavor enhancer and contributing to reducing the use of additives in the product formulation. • Sodium reduction changed the sensory acceptance and profile of the snacks. • The Umami Ingredient performed similarly to monosodium glutamate (MSG). • Umami Ingredient can contribute for sensory improvement. • The use of Umami Ingredient is an option for development of low-sodium products. [ABSTRACT FROM AUTHOR]

• Shiitake byproducts (stipes) are source of umami compounds for food application. • A valuing alternative for shiitake stipes use was developed. • Umami Ingredient is a likely option to low sodium food, helping flavor maintenance. An alternative use of shiitake stipes, usually treated as waste, was proposed for the production of a powder ingredient, rich in umami compounds, aiming its application in food. The extraction of umami compounds was optimized through the Response Surface Methodology (RSM), in order to obtain an extract with high umami taste intensity. From the optimized condition, a comparative analysis of shiitake stipes dehydration method was performed. Stipes were dehydrated by hot air drying (HD) and freeze drying (FD), submitted to extraction and the umami compounds in the extracts were compared. The comparative analysis showed that the 5′ - nucleotides are more sensitive to prolonged heating, while the release of free amino acids (FAA) was favored by hot air drying. The HD samples extract showed higher Equivalent Umami Concentration (EUC). The spray drying of the HD samples extract allowed the production of a newly powder ingredient rich in umami compounds (Umami Ingredient) that can be applied in diverse food matrices. Due to the presence of umami compounds, Umami Ingredient can be a potential alternative to help in the process of sodium reduction by enhancing food flavor. [ABSTRACT FROM AUTHOR]

Summary: Taste loss is a major cause of morbidity in patients undergoing head and neck irradiation. Previous studies have reported the alteration of the four basic tastes in patients with head and neck cancer during radiotherapy. However, only a few studies have been conducted on the effects of irradiation on the function of umami taste, a novel and basic taste recently recognized. In a prospective study, 52 patients undergoing radical head and neck irradiation were assessed for taste loss. Taste ability was measured by the taste threshold for umami quality using the whole-mouth taste method in patients before, during, and immediately after radiotherapy. Umami taste declined of the 3rd week after the start of radiotherapy and improved of the 8th week. [Copyright &y& Elsevier]