Search

In our diet, we ingest a variety of compounds that are TRPV1 modulators. It is important to understand if these compounds alter neural and behavioral responses to taste stimuli representing all taste qualities. Here, we will summarize the effects of capsaicin, resiniferatoxin, cetylpyridinium chloride, ethanol, nicotine, N-geranyl cyclopropylcarboxamide, Kokumi taste peptides, pH, and temperature on neural and behavioral responses to taste stimuli in rodent models and on human taste perception. The above TRPV1 agonists produced characteristic biphasic effects on chorda tympani taste nerve responses to NaCl in the presence of amiloride, an epithelial Na+ channel blocker, at low concentrations enhancing and at high concentrations inhibiting the response. Biphasic responses were also observed with KCl, NH4Cl, and CaCl2. In the presence of multiple stimuli, the effect is additive. These responses are blocked by TRPV1 antagonists and are not observed in TRPV1 knockout mice. Some TRPV1 modulators also increase neural responses to glutamate but at concentrations much above the concentrations that enhance salt responses. These modulators also alter human salt and glutamate taste perceptions at different concentration ranges. Glutamate responses are TRPV1-independent. Sweet and bitter responses are TRPV1-independent but the off-taste of sweeteners is TRPV1-dependent. Aversive responses to acids and ethanol are absent in animals in which both the taste system and the TRPV1-trigeminal system are eliminated. Thus, TRPV1 modulators differentially alter responses to taste stimuli. [ABSTRACT FROM AUTHOR]

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]

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.

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]

Copyright of Food Research & Development is the property of Food Research & Development 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.)

As one of the most appealing edible mushrooms, the quality of Flammulina velutipes can be affected by the cultivation substrate, which has an impact on the mushroom umami taste and nutrients. In our study, the effect of mushroom root fermentation broth (MRFB) based substrate on umami taste and nutrients of F. velutipes were evaluated; four proportions of MRFB were conducted (CK 0%, E1 6.7%, E2 13.4%, E3 20.1%). Results indicated that MRFB was an effective nutrient supplement for mushroom cultivation substrate. E2 and E3 showed higher crude fiber, crude fat, and soluble protein. Compared to CK, the content of monosodium glutamate-like (MSG-like) amino acids, essential amino acids, total amino acids, and total 5′-nucleotides in E2 and E3 were higher. The equivalent umami concentration (EUC) values in E1, E2 and E3 were 1.70, 2.43 and 1.56 times that of CK, respectively. Higher umami, saltness and sweetness taste values were found in E2. Thereby, it signified that better umami and richer nutrients were achieved by using substrate with proper volume of MRFB, especially, E2 with 13.4% of MRFB. Overall, better mushroom quality could be derived from the application of MRFB in cultivation. MRFB was a favorable nutrient supplement for F. velutipes cultivation substrate.

The molecular mechanisms of energy status related to the umami taste of postharvest shiitake mushrooms during spore release remain poorly understood. In this study, the variations of energy status and umami taste of mushrooms were measured at 25 °C. At 24 h storage, slight spore prints of mushrooms were first pictured, respiration peaked. Significant ATP decrease and ADP increase were also observed as the initiation of postharvest senescence (P < 0.05). Meanwhile, the activities of phosphohexose isomerase, succinate dehydrogenase, glucose-6-phosphate dehydrogenase and cytochrome c oxidase and the contents of umami nucleotides and amino acids were maintained at higher levels in mushrooms with spore release. Notably, the equivalent umami concentration (EUC) was strongly correlated with energy levels (R = 0.80). Fifteen related gene expression levels in the energy metabolism pathway were downregulated. LecpdP1 and LeAK were significantly expressed in the conversion of ATP into AMP and played key roles in connecting the energy state and umami level. These results provided valuable insights on the umami taste associated with energy metabolism mechanism during postharvest mushroom spore release.

This study was aimed to compare the effects of thermal treatment (70, 90 ℃) and non-thermal treatment (room temperature, ultrasound treatment, homogenization and high hydrostatic pressure) on the umami taste and antioxidant capability of water extracts of Morchella esculenta. The content of 5’-nucleotide (5’-CMP, 5’-UMP, 5’-XMP, 5’-GMP, 5’-IMP and 5’-AMP) and free amino acid (17 kinds) in these extracts were analyzed by high performance liquid chromatography and amino acid analyzer respectively, and their corresponding value of Equivalent Umami Concentration (EUC) were calculated. Antioxidant properties of each water extract of Morchella esculenta were comprehensively evaluated by DPPH, FRAP and ABTS methods. Except for the treatment of RT (room temperature), other treatment on finely pulverized Morchella esculenta powder (P2 or P3, 35.52 and 6.28 μm, respectively) increased the contents of total 5'-nucleotides while decreased the contents of umami amino acids and total free amino acids (FAA) in their corresponding water extract. Therefore, the EUC values of the Morchella esculenta extracts were changed from 106.58 g MSG/100 g~493.97 g MSG/100 g to 74.70 g MSG/100 g~364.35 g MSG/100 g. Compared with the room temperature treatment, other treatments improved the EUC value of the water extracts. However, thermal treatment decreased the antioxidant capacity of the extract, and non-thermal treatment of HHP displayed the highest EUC value and ideal antioxidant effect. Especially, the original Morchella esculenta powder without superfine grinding had the highest EUC value and the best antioxidant capacity after HHP treatment, which might be suitable for the further processing of Morchella esculenta.

Nucleotide is a kind of important substrate for the biosynthesis of nucleic acid and caffeine in tea, which is also one of the most important umami substances in tea infusion. Ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry was used for the determination of nucleotide contents. Five types of flavored nucleotides including cytidine 5'-monophosphate (CMP), uridine 5'-monophosphate (UMP), adenosine 5'-monophosphate (AMP), inosine 5'-monophosphate (IMP) and guanosine 5'-monophosphate (GMP) in tea were determined within 4 min, and dynamic changes of the above nucleotide contents in the making green process of 'Tieguanyin' Oolong tea were analyzed. The results show that the detection limits of the five nucleotides were 0.87-1.47 µg⋅g-1, with the limits of quantification of 2.62-4.41 µg⋅g-1 and a linear range of 50-1 000 ng⋅mL-1. The intra-day and inter-day precisions were 2.17%-4.17% and 2.95%-4.74%, with a recovery rate of 72.89%-91.98%. Three types of nucleotides, AMP, CMP and UMP, were detected in tea cultivar 'Tieguanyin', with the UMP content of 16.98-26.78 µg⋅g-1, the CMP content of 14.31-17.56 µg⋅g-1, and the AMP content of 7.80-9.91 µg⋅g-1. The UMP, CMP, and AMP in 'Tieguanyin' were ranked in order from high to low and the CMP content increased slowly in late stages of making green process. The total amount of flavored nucleotides in the making green process varied from 40.78 to 56.69 µg⋅g-1, showing the trend of mild and stable fluctuation. The method is rapid, accurate and sensitive with high stability and precision, which can be used as an analytical technique for the study of flavor chemistry in tea processing. [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]

• 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]

Spent hens are egg‐laying chicken reaching the end of their egg‐laying cycle and are seen as a by‐product to the egg industry. A spent hen muscle protein hydrolysate prepared by food‐grade thermoase PC10F (SPH‐T) has previously shown antihypertensive potential. In the present work, we further investigated its antihypertensive effect and underlying mechanisms in spontaneously hypertensive rats. There are three groups: untreated, low dose (250 mg SPH‐T/kg/day body weight), and high dose (1,000 mg SPH‐T/kg/day body weight). Oral administration of SPH‐T over a period of 20 days reduced systolic blood pressure by 25.7 mm Hg (p < 0.001) and 11.9 mm Hg (p < 0.05), respectively, for the high‐ and low‐dose groups. The high‐dose treatment decreased the circulating level of angiotensin II (from 25.0 to 5.7 pg/ml) while increased angiotensin‐converting enzyme 2 (ACE2) (from 1.3 to 3.3 IU/ml) and angiotensin (1–7) (from 37.0 to 70.1 pg/ml) significantly (p < 0.05). Furthermore, the high‐dose group doubled the aortic expression of ACE2 while reduced the expression of angiotensin (Ang) II type 1 receptor (by 35%). Circulating inflammatory cytokines including tumor necrosis factor alpha and monocyte chemoattractant protein‐1 as well as vascular inflammatory proteins including inducible nitric oxide synthase and vascular cell adhesion molecule‐1 were attenuated by ∼15%–50% by the treatment; nitrosative stress (35%) and type I collagen synthesis (50%) in the aorta were also attenuated significantly (p < 0.05). Moreover, SPH‐T possessed an umami taste (no obvious bitter taste) as analyzed by electronic tongue. Practical Application: Hypertension is a global health concern, afflicting more than 20% of adults worldwide. Uncovering the antihypertensive effect of spent hen protein hydrolysate underpinned its functional food nutraceutical applications for the prevention and treatment of hypertension. [ABSTRACT FROM AUTHOR]

The cryptophyte Rhodomonas salina is widely used in aquaculture due to its high nutritional profile. This study aims to investigate the effect of salinity and pH on the growth, phycoerythrin concentrations, and concentrations of non-volatile umami taste active compounds of R. salina, using a design of experiment approach. Rhodomonas salina was cultivated in a flat-panel photobioreactor in turbidostat mode in a range of salinity (20–40 ‰) and pH (6.5–8.5). The strain was able to grow steadily under all conditions, but the optimal productivity of 1.17 g dry weight L−1 day−1 was observed in salinity 30 ‰ and pH 7.5. The phycoerythrin concentration was inversely related to productivity, presenting higher values in conditions that were not optimal for the growth of R. salina, 7% of dry weight at salinity 40 ‰, and pH 8.5. The identification of the umami taste of R. salina was based on the synergistic effect of umami compounds 5′-nucleotides (adenosine 5′-monophosphate, guanosine 5′-monophosphate, inosine 5′-monophosphate) and free amino acids (glutamic and aspartic acids), using the equivalent umami concentration (EUC). The results indicated that an increase in pH induces the accumulation of 5′-nucleotides, resulting in an EUC of 234 mg MSG g−1 at a salinity of 40 and pH 8.5. The EUC values that were observed in R. salina were higher compared to other aquatic animals, a fact that makes R. salina promising for further research and application in the food and feed sectors. [ABSTRACT FROM AUTHOR]

The effects of different doses of selenized yeast on growth performance and beef quality of Xinjiang brown cattle were determined. Healthy Xinjiang brown cattle were divided randomly into five experimental groups. They were fed with yeast containing different doses of selenium. The body weight (BW), organ weight, and selenium content of beef samples from the muscles and organs of the cattle were measured. Physicochemical parameters and nutritional values of the longissimus dorsi muscle sample were also determined. The results showed that selenized yeast-fed cattle had reduced weight gain compared with the cattle from the control group. The beef samples of different body parts and organs of the selenized yeast-fed cattle exhibited significantly higher selenium content than the control cattle. The selenium supplementation improved the beef quality by increasing water holding capacity. It also reduced the percentages of water loss and shear force. The beef samples of the cattle fed with the highest dosage of selenized yeast contained the lowest crude protein content. The total essential amino acids of the beef samples of the supplemented cattle were significantly higher than the control cattle. The selenized yeast supplementation was also found to improve the fatty acid composition of the beef samples. The addition of selenized yeast in feed improved the beef quality of Xinjiang brown cattle. The recommended dose of selenized yeast for cattle feeds was 0.9 mg/kg BW. [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]

Soy sauce is a traditional Japanese condiment produced from the fermentation of soybeans, wheat, and salt by three types of microorganisms, namely koji molds, halophilic lactic acid bacteria, and salt-tolerant yeast. The delicate balance between taste, aroma, and color contributes to the characteristic delicious flavor imparted by soy sauce. In soy sauce brewing, protein and starch of the raw materials are hydrolyzed into amino acids and sugars by enzymes derived from koji molds. These enzymatically hydrolyzed products not only directly contribute to the taste but are further metabolized by lactic acid bacteria and yeasts to most of organic acids and aromatic compounds, resulting in its distinctive flavor and aroma. The color of the soy sauce is also due to the chemical reactions between amino acids and sugars during fermentation. Therefore, koji mold, which produces various enzymes for the breakdown of raw materials, is an essential microorganism in soy sauce production and plays an essential role in fermenting the ingredients. In this review, we describe the manufacturing process of Japanese soy sauce, the characteristics of koji molds that are suitable for soy sauce brewing, and the key enzymes produced by koji molds and their roles in the degradation of materials during soy sauce fermentation, focusing on the production of umami taste in soy sauce brewing. [ABSTRACT FROM AUTHOR]

In the current scenario, considerable attention is being given to the enzyme L-glutaminase (EC 3.5.1.2). It belongs to the amidohydrolase class adherent to the family of serine-reliant β-lactamases and the penicillin-binding proteins due to its higher affinity to polymerize and modify peptidoglycan synthesis. However, based on the catalytic proficiency, L-glutaminase is characterized as a proteolytic endopeptidase that cleaves peptide linkage and emancipates various byproducts, viz. ammonia along with glutamate. L-glutamine is considered the key amino acid reportedly involved in multiple metabolic pathways such as nitrogen metabolism. The present review is focused on the recent development and aspects concomitant to the biotechnological applicability of L-glutaminase predominantly from the marine habitat. Additionally, a majority of L-glutaminases finds application in cancer therapy as therapeutic agents, especially for acute lymphocytic leukaemia. The in vitro studies have been effective against various human cancer cell lines. L-glutaminase enhances the growth of probiotic bacteria. Apart from all these applications, it is suitably applicable in fermented foods as a flavour enhancer especially the umami flavour and content. Marine habitats have largely been exploited for their bio-catalytic potential but very scarcely for therapeutic enzymes. Some of the reports of such marine bacterial isolates from Bacillus sp., Pseudomonas sp. and Vibrio sp. are in the domain, but none highlights the therapeutic applications predominantly as anticancer and anti-proliferative agents. Key points: The exploration of marine habitats along the Gujarat coasts mainly for bacteria secreting L-glutaminase is scarcely reported, and even more scarce are the amidohydrolases from these marine niches as compared to their terrestrial counterparts. Microbial sourced amidohydrolase has wide bio-applicability that includes food, cosmetics and therapeutics especially as anticancer/anti-proliferative agent making it of immense biotechnological significance. [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.)

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.

Taste is one of the five senses that detect vital information about what we are eating. Comprehending taste is crucial for enhancing the flavor of foodstuffs and high-protein foods like meat. Umami has global recognition as the fifth elementary taste, alongside sweetness, sourness, saltiness, and bitterness. Umami compounds are known to enhance the sensation of recognized flavors such as salty, sweet, bitter, and others. This could end up in greater food consumption by consumption by consumers. With the rising global population, meat consumption is rising and is projected to double by 2025. It is crucial to comprehend the umami mechanism of meat and meat products, identify novel compounds, and employ laboratory methodologies to gather varied information. This knowledge will aid in the development of new consumer products. Although very limited information is available on umami taste and compounds in meat through research data. This article discusses recent advancements in umami compounds in other foodstuff as well as meat to aid in designing future research and meat product development. Moreover, another objective of this review is to learn present techniques in foodstuffs to enhance umami taste and utilize that knowledge in meat products., Competing Interests: The authors declare no potential conflicts of interest., (© Korean Society for Food Science of Animal Resources.)

The fifth basic taste—umami—is based on hydrophilic monosodium L-glutamate (L-Glu), and, to a smaller extent, on L-aspartate (L-Asp), which can be found in free form in seaweeds. The umami taste can be elicited by the synergistic effect of 5′-nucleotides, guanosine-5′-monophosphate (GMP), and inosine-5′-monophosphate (IMP). In this work, twelve edible seaweeds, two green (Codium tomentosum, Ulva rigida), six red (Chondracanthus teedei var. lusitanicus, Chondrus crispus, Gracilaria gracilis, Grateloupia turuturu, Nemalion helminthoides, Osmundea pinnatifida), and four brown (Bifurcaria bifurcata, Fucus vesiculosus, Saccorhiza polyschides, Undaria pinnatifida), from the Portuguese seashore, were selected for the analysis of umami amino acids and 5′-nucleotides. To determine the concentrations of umami free compounds, L-Glu, L-Asp, GMP, and IMP, the usual procedure for the preparation of seaweed's broth was carried out, and the resulting extracts were analyzed by HPLC-DAD. The effect of the seaweed's pretreatment, oven-dried and lyophilized, was also studied. Results showed that all seaweed species contained free amino acids in broad range, whereas umami 5′-nucleotides were not detected. The lyophilized C.crispus and G. gracilis contained the highest amounts of free L-Glu (627 ± 109 mg (100 g)−1 and 398 ± 67 mg (100 g)−1, respectively) and L-Asp (520 ± 102 mg (100 g)−1 and 270 ± 10 mg (100 g)−1, respectively). Two-factor PCA explained quantitatively (90%) the variance of seaweed species based on umami L-Glu content after different drying techniques applied. The results indicate that lyophilization constitutes a superior procedure for increasing the umami potential in most of the selected seaweeds. [ABSTRACT FROM AUTHOR]

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]

Sigumjang is a traditional Korean fermented barley bran consumed in the Gyungsang-do area. In this study, pork loin was marinated with sigumjang, and its physicochemical and textural properties were investigated. Sigumjang-marinated pork loin (SMPL) displayed an attractive yellowish-brown overall color. SMPL's pH marginally increased during storage and finally equilibrated to the pH of sigumjang, 5.5, on day 14. The amino-type nitrogen content of SMPL increased linearly during the marination period. Due to the lower extractability and higher pH compared to the control, the volume of myofibrillar fragments in SMPL decreased during the marination period. SMPL showed an increase in free amino acids related to umami (Asp and Glu) and sweet (Ser, Thr, Ala and Gly) tastes compared to the control. These may indicate improvement of sensory qualities of SMPL. The results also provide valuable information for the use of sigumjang in the development of novel meat products. [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]

We evaluated the temporal profile of the flavor enhancers monosodium glutamate (MSG), disodium inosinate (IMP), disodium guanylate (GMP), and monoammonium glutamate (MAG). We also evaluated the ability of these flavor enhancers to enhance salty taste in solutions containing different reductions of sodium chloride. Four experiments were conducted using Central Composite Rotational Design (CCRD) with focus on two objectives: concentration of flavor enhancers (0% to 1%) and reduction of sodium chloride content (0% to 100%). A 0.75% saline solution of NaCl was used as a control. In each experiment, the treatments were evaluated by the intensity of salty and umami tastes using an intensity scale. Treatments, selected according to the results of CCRD, were analyzed using time‐intensity (TI) and temporal dominance of sensations (TDS) analyses. Glutamates (MSG/MAG) showed greater capacity to enhance salty taste than treatments containing nucleotides (IMP/GMP). The intensity of umami taste, using all the examined flavor enhancers, showed a similar sensory profile. Temporal perception curves (TI and TDS) of salty and umami tastes also showed a similar temporal profile. The glutamic acid amino acids were better able to improve salty taste than nucleotides in any range of sodium chloride reduction. Flavor enhancers showed greater ability to increase salty taste in smaller reductions in sodium chloride content. Practical Application: This research expand the knowledge about the ability to enhance the salty taste of flavor enhancers in different reductions in sodium content, Beside that, will provide information about the time profile of flavor enhancers. This study provides scientific technical information on the ability to intensify the salty taste of flavor enhancers and can assist the industry to develop new low sodium products and encourage the scientific community to conduct future research on this subject. [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]

This is the first report on the effect of low temperature stress applied during initial moromi fermentation on the quality and taste of soy sauce. Koji was prepared to yield initial moromi under three comparative fermentation conditions over 9 days: (1) 4 °C and 0% brine (i.e., water) (LTSF); (2) 4 °C and 16% w/w brine (LTSH); (3) 25 °C and 16% w/w brine (the control, CRTH). Greater extent of autolysis in samples was found under low temperature stress conditions (i.e., at 4 °C, a temperature much lower than the normal temperature range like 25 °C for natural microbial growth and performance). Compared to CRTH, LTSF had a two-fold increase of glutaminase activity in dregs and 65.17% increase in supernatant, and after 60 days of moromi fermentation, a 5.73% and 3.47% increase, respectively, in the contents of glutamic acid (Glu) and aspartic acid (Asp). LTSF had the highest total free amino acid content due to both the low temperature stress and absence of salt. The intensity ranking of umaminess and kokumi sensation (LTSF > LTSH > CRTH) revealed by sensory analysis followed the changing trends of their umami and sweet amino acid contents with a trend reversal in the bitter amino acid content. Low temperature (4 °C) without brine for initial moromi fermentation seemed beneficial, leading to a soy sauce product with desired taste and amino acid contents. [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]

Background/Aims: Taste perception is one of the most important primary oral reinforcers, driving nutrient and energy intake as well as toxin avoidance. Taste receptors in the gastrointestinal tract might as well impact appetitive or aversive behavior and thus influence learning tasks and a close relation of neural taste processing and working memory networks seems plausible. Methods: In the present pilot study, we determined the effects of five taste qualities “bitter” (quinine), “sweet” (glucose), “sour” (citric acid), “salty” (NaCl) and “umami” (monosodium glutamate, MSG) on working memory processing using functional MRI and their effect on plasma insulin and glucose levels. On six separate occasions, subjects received one of the following test substances dissolved in 200 mL tap water via a nasogastric tube (to circumvent the oral cavity): 1) 2g citric acid corresponding to 52 mM, 2) 2g NaCl; 171 mM, 3) 0.017g quinine; 0.26 mM, 4) 1g monosodium glutamate; 30 mM, 5) 25g glucose; 694 mM and 6) 200 mL tap water (placebo). Results: The taste qualities “bitter” and “umami” significantly altered brain activation patterns in the primary gustatory cortex as well as in subcortical structures, previously reported to be involved in emotional learning and memory. In contrast, glucose did not reveal any statistically significant brain activation difference. Working memory performance was not different over the six treatments. Plasma insulin and glucose levels were not affected by the different taste substances (MSG, quinine, NaCl and citric acid). Conclusions: in this pilot trial, we demonstrate that acute intragastric administration of different taste substances does not affect working memory performance in humans. However, “umami” and “bitter” have effects on brain areas involved in neural working memory, overpowering the effects of “sweet”, “salty” and “sour” reception.