Novel umami peptides from two Termitomyces mushrooms and molecular docking to the taste receptor T1R1/T1R3

Wild edible Termitomyces mushrooms are popular in Southwest China and umami is important flavor qualities of edible mushrooms.This study aimed to understand the umami taste of Termitomyces intermedius and Termitomyces aff.bulborhizus.Ten umami peptides from aqueous extracts were separated using a Sephadex G-15 gel filtration chromatography.The intense umami fraction was evaluated by both sensory evaluation and electronic tongue.They were identified as KLNDAQAPK,DSTDEKFLR,VGKGAHLSGEH,MLKKKKLA,SLGFGGPPGY,TVATFSSSTKPDD,AMDDDEADLLLLAM,VEDEDEKPKEK,SPEEKKEEET and PEGADKPNK.Seven peptides,except VEDEDEKPKEK,SPEEKKEEET and PEGADKPNK were selectively synthesized to verify their taste characteristics.All these 10 peptides had umami or salt taste.The 10 peptides were conducted by molecular docking to study their interaction with identified peptides and the umami taste receptor T1R1/T1R3.All these 10 peptides perfectly docked the active residues in the T1R3 subunit.Our results provide theoretical basis for the umami taste and address the umami mechanism of two wild edible Termitomyces mushrooms.

Three novel umami peptides derived from the alcohol extract of the Pacific oyster(Crassostrea gigas):identification,characterizations and interactions with T1R1/T1R3 taste receptors

Oyster(Crassostrea gigas),the main ingredient of oyster sauce,has a strong umami taste.In this study,three potential umami peptides,FLNQDEEAR(FR-9),FNKEE(FE-5),and EEFLK(EK-5),were identified and screened from the alcoholic extracts of the oyster using nano-HPLC-MS/MS analysis,i Umami-Scoring Card Method(i Umami-SCM)database and molecular docking(MD).Sensory evaluation and electronic tongue analysis were further used to confirm their tastes.The threshold of the three peptides ranged from 0.38 to 0.55 mg/m L.MD with umami receptors T1R1/T1R3 indicated that the electrostatic interaction and hydrogen bond interaction were the main forces involved.Besides,the Phe592 and Gln853 of T1R3 were the primary docking site for MD and played an important role in umami intensity.Peptides with two Glu residues at the terminus had stronger umami,especially at the C-terminus.These results contribute to the understanding of umami peptides in oysters and the interaction mechanism between umami peptides and umami receptors.

Umami taste components in chicken-spices blends and potential effect of aroma on umami taste intensity

In this study,umami taste intensity(UTI)and umami taste components in chicken breast(CB)and chickenspices blends were characterized using sensory and instrumental analysis.Our main objective was to assess the aroma-umami taste interactions in different food matrices and reconcile the aroma-taste perception to assist future product development.The impact of key aroma,including vegetable-note"2-pentylfuran",meaty"methional",green"hexanal",and spicy-note-estragole and caryophyllene"on UTI was evaluated in monosodium glutamate and chicken extract.We found that spices significantly decreased UTI and umami taste components in CB.Interestingly,the perceptually similar odorants and tastants exhibited the potential to enhance UTI in food matrices.Methional was able to increase the UTI,whereas spicy and green-note components could reduce the UTI significantly.This information would be valuable to food engineers and formulators in aroma selection to control the UTI perceived by consumers,thus,improving the quality and acceptability of the chicken products.

Studies of the Variability of Primary Metabolites in the Epicarp, Mesocarp and Seed of Dacryodes edulis Fruit at Taste Maturity

The fruits of Dacryodes edulis are rich in biologically active substances, which makes them of great interest in terms of validation. In this study, we targeted the primary metabolites in the epicarp, the mesocarp and the seed of the fruit of Dacryodes edulis at taste maturity, which were selected for their nutritional quality and its appreciation throughout the Gulf of Guinea area, which is very popular because of its large size, texture and special taste. The evaluation of total carbohydrates, total lipids and soluble proteins in the epicarp, mesocarp and seed of the fruit at taste maturity was made from spectrophotometer measurements. The overall analysis of the results of the present study shows that total carbohydrates, total lipids and proteins accumulate more in the seed with respectively 251.33 ± 1.15 mg/g DM;9.92 ± 0.201 mg/g DM and 55.075 ± 0.024 mg/g DM. Likewise, the results indicate low concentrations of total carbohydrates and total lipids in the epicarp with respectively 245 ± 1 mg/g DM and 4.77 ± 0.047 mg/g DM, on the other hand, it is the mesocarp which presents the lowest content of soluble proteins: 28.075 ± 3.231 mg/g DM. This variation could be linked to the nature of the compartment, more particularly to the storage location. This comparative study could lead to the valorization of the seed of the fruit of Dacryodes edulis for its richness in metabolites and arouse significant interest in nutrition.

First report of the histopathological effect of electrocautery using on the urethral taste rosea during glans penis injury by incision in rabbits

Objective:Currently,electrocautery devices have frequently been used in penile surgical procedures.We hypothesized that electrocautery using during penile surgical procedures may harm the taste rosea and the dorsal nerve of the penis or clitoris.Methods:Eighteen young age male New Zealand rabbits were studied:five in the control(Group I,n=5),five in the penile surgery without using electrocautery(sham group,Group II,n=5),eight in the monopolar cautery(study group,Group III,n=8)groups under general anesthesia.The animals were followed for 3 weeks and sacrificed.Penile tissue—pudendal nerve root complexes and dorsal root ganglion of sacral 3 level were examined using stereological methods.The results were compared statistically.Results:The live and degenerated taste bud-like structures and degenerated neuron densities of pudendal ganglia(mean±standard deviation,n/mm^(3))were estimated as 198±24/mm^(3),4±1/mm^(3),and 5±1/mm^(3) in Group I;8±3/mm^(3),174±21/mm^(3),and 24±7/mm^(3) in Group II;and 21±5/mm^(3),137±14/mm^(3),and 95±12/mm^(3) in Group III,respectively.Neurodegeneration of taste buds and pudendal ganglia was significantly different between groups.Conclusion:Intact spinal cord and normal parasympathetic and thoracolumbar sympathetic networks are crucial for human sexual function.The present study indicates that the glans penis injury by using electrocautery may lead to pudendal ganglia degeneration.Iatrogenic damage to taste rosea and retrograde degeneration of the pudendal nerve may be the cause of sexual dysfunction responsible mechanism.

Genetic mutation of Tas2r104/Tas2r105/Tas2r114 cluster leads to a loss of taste perception to denatonium benzoate and cucurbitacin B

Background:Bitter taste receptors(Tas2rs)are generally considered to sense various bitter compounds to escape the intake of toxic substances.Bitter taste receptors have been found to widely express in extraoral tissues and have important physiological functions outside the gustatory system in vivo.Methods:To investigate the physiological functions of the bitter taste receptor cluster Tas2r106/Tas2r104/Tas2r105/Tas2r114 in lingual and extraoral tissues,multiple Tas2rs mutant mice and Gnat3 were produced using CRISPR/Cas9 gene-editing technique.A mixture containing Cas9 and sgRNA mRNAs for Tas2rs and Gnat3 gene was microinjected into the cytoplasm of the zygotes.Then,T7EN1 assays and sequencing were used to screen genetic mutation at the target sites in founder mice.Quantitative real-time polymerase chain reaction(qRT-PCR)and immunostaining were used to study the expression level of taste signaling cascade and bitter taste receptor in taste buds.Perception to taste substance was also studied using twobottle preference tests.Results:We successfully produced several Tas2rs and Gnat3 mutant mice using the CRISPR/Cas9 technique.Immunostaining results showed that the expression of GNAT3 and PLCB2 was not altered in Tas2rs mutant mice.But qRT-PCR results revealed the changed expression profile of m Tas2rs gene in taste buds of these mutant mice.With two-bottle preference tests,these mutant mice eliminate responses to cycloheximide due to genetic mutation of Tas2r105.In addition,these mutant mice showed a loss of taste perception to quinine dihydrochloride,denatonium benzoate,and cucurbitacin B(CuB).Gnat3-mediated taste receptor and its signal pathway contribute to CuB perception.Conclusions:These findings implied that these mutant mice would be a valuable means to understand the biological functions of TAS2Rs in extraoral tissues and investigate bitter compound-induced responses mediated by these TAS2Rs in many extraoral tissues.

Role of bitter contributors and bitter taste receptors:a comprehensive review of their sources,functions and future development

Bitterness,one of the 5“basic tastes”,is usually undesired by humans.However,abundant literature reported that bitter fruits and vegetables have beneficial health effects due to their bitter contributors.This review provided an updated overview of the main bitter contributors of typical bitter fruits and vegetables and their health benefits.The main bitter contributors,including phenolics,terpenoids,alkaloids,amino acids,nucleosides and purines,were summarized.The bioactivities and wide range of beneficial effects of them on anti-cancers,anti-inflammations,anti-microbes,neuroprotection,inhibiting chronic and acute injury in organs,as well as regulating behavior performance and metabolism were reported.Furthermore,not only did the bitter taste receptors(taste receptor type 2 family,T2Rs)show taste effects,but extra-oral T2Rs could also be activated by binding with bitter components,regulating physiological activities via modulating hormone secretion,immunity,metabolism,and cell proliferation.This review provided a new perspective on exploring and explaining the nutrition of bitter foods,revealing the relationship between the functions of bitter contributors from food and T2Rs.Future trends may focus on revealing the possibility of T2Rs being targets for the treatment of diseases,exploring the mechanism of T2Rs mediating the bioactivities,and making bitter foods more acceptable without getting rid of bitter contributors.

基于学习活动观的小学英语课堂TASTE教学模式探究

针对当前部分教师对于如何在小学英语课堂上落实学习活动观的困惑,文章通过大量案例研究提炼出一种基于学习活动观的TASTE教学模式。TASTE教学倡导教师基于单元整体视域,根据单元主题与单元目标,确立课时目标,以目标为导向设计连续性话题,并以连续性话题为支点,建构以探究答案、共享表现、真实表达为主要内容的活动流程,从而在课堂上落实学习理解、应用实践、迁移创新等三类活动。

Identification of key taste components in Baccaurea ramiflora Lour.fruit using non-targeted metabolomics

Among the numerous fruit species of Baccaurea ramiflora Lour.,‘LR’(white flesh)and‘BR’(pink flesh)are two kinds of local strains with high edibility.In order to study the metabolic causes of taste differences,we performed the non-targeted metabonomics analysis of‘LR’and‘BR’using LC-MS/MS.541 metabolites were totally identified,and 45 kinds of metabolites(carbohydrates,fatty acids,flavonoids and terpenoids,etc.)were different between the two strains.The results indicate L-sorbose,D-(+)-glucose,citric acid,L-phenylalanine and oleamide,α-eleostearic acid were the main primary metabolites.The significant difference existed in pathways of unsaturated fatty acids between the studied two strains by pathway enrichment analysis.The results demonstrate that the different in composition,as well as the abundance of primary and secondary metabolites may be the potential causes of taste differences,which provides a new insight into the possible metabolic factors setting off the changing taste of B.ramiflora.

Untargeted UHPLC-Q-Exactive-MS-based metabolomics reveals associations between pre-and post-cooked metabolites and the taste quality of geographical indication rice and regular rice

Geographical indication(GI)rice refers to the rice of specific geographical origin,which tends to have a good taste quality and a high commodity price.Rice is favored for its soft texture and chewiness after cooking.However,GI rice is also plagued by rice fraud.Understanding the reasons for the excellent taste quality of GI rice and identifying its geographical origin can help maintain the stability of the rice market and promote the development of the rice industry.In this study,we determined the taste quality of rice.Untargeted metabolomics based on UHPLC-Q-Exactive-MS was used to identify metabolites in GI and regular rice before and after cooking.Our findings suggested that GI rice showed lower protein and amylose content,resulting in higher starch gelatinization properties and taste quality.This study identified 520 metabolites,among which 142 and 175 were significantly different between GI and regular rice,before and after cooking,respectively.The increased variety of metabolites after cooking was significantly negatively correlated with the taste quality of rice.GI rice was lower in amino acids and lipid metabolite content before and after cooking,which may be the reason for the excellent taste quality.Through linear discriminant analysis,we found that the differential metabolites of rice after cooking were more accurate in discriminating rice from different geographic origins,up to 100%.This work gained new insights into the metabolites of GI rice,which explains its excellent taste quality.The rice metabolites after cooking could be used for more accurate geographical identification of rice.

Dry matter production and panicle characteristics of high yield and good taste indica hybrid rice varieties

Indica hybrid rice(Oryza sativa) production aims to achieve two crucial targets: high yield and good taste. This study selected three types of indica hybrid rice according to grain yield and taste value, including high yield and good taste(HYGT), low yield and good taste(LYGT), and high yield and poor taste(HYPT), to analyze yield components,corresponding growth characteristics, and rice taste quality. When values were averaged across varieties and years,there were almost no differences in taste value between HYGT and LYGT;HYGT showed a significant increase in yield,owing to a higher number of panicles and spikelets per panicle, with a respective increment of 16.2 and 20.6%. The higher grain yield of HYGT compared with LYGT was attributed to three key factors: a higher leaf area index(LAI) during heading, a higher ratio of grain to leaf, and a higher biomass accumulation at maturity. HYGT and HYPT achieved similar high yields;however, HYGT had more panicle numbers and lower grain weight. In addition, HYGT showed a significantly higher taste value than HYPT, attributed to its significantly lower protein and amylose contents, with reductions of 8.8and 15.7%, respectively. Lower protein and amylose contents might be caused by a proper matter translocation from vegetative organs to panicle. This study suggested that reasonable panicle characteristics and translocation efficiency from vegetative organs to panicle during heading to maturity are the key factors in balancing yield and rice taste quality.These results will provide valuable insights for rice breeders to improve the grain yield and quality of indica hybrid rice.

Discovery of the relationship between bitter taste and bitter flavor (efficacy) based on hTAS2Rs

Objective:To explore the relationship between bitter taste and bitter flavor(efficacy),their character-istics were analyzed at the target and pharmacodynamic points.Methods:Compounds with bitter receptor activity were obtained by high-throughput screening models of the human bitter taste receptors(hTAS2Rs),which were used to analyze bitter taste.The efficacy of anti-asthma medications was used as an example to research bitter flavor(efficacy).The pharmacological effects of bitter taste and bitter flavor(efficacy)were classified according to the functional modules.The coverage for the same targets or pharmacological effects in the overall protein interaction network(PIN)of bitter taste and bitter flavor(efficacy)was analyzed to reveal their relationship.The effect of the compound polydatin with anti-asthma activation on hTAS2R14 was studied to verify the reliability of the aforementioned idea.Results:A total of 121 Chinese materia medica(CMM)compounds that activate hTAS2R10,hTAS2R14,and hTAS2R49 were obtained.The analysis results indicated that 108 same targets for bitter taste and bitter flavor(efficacy)were obtained,accounting for 13.9%in the PIN of bitter taste and 72.5%in the PIN of bitter flavor(efficacy).The pharmacological effects shared by bitter taste and bitter flavor(efficacy)accounted for 79%of the PIN of bitter taste and 81%of the PIN of bitter flavor(efficacy).The activating effect of the anti-asthma compound polydatin on hTAS2R14 was dose-dependent with EC 50 of 4.3 m M.Conclusion:In this study,the relationship between bitter taste and bitter flavor(efficacy)has been demonstrated from the target and pharmacodynamic points,which are based on hTAS2Rs and anti-asthma effect.Bitter taste and bitter flavor(efficacy)exhibited a high correlation.This study provides a theoretical and scientific basis for the hypothesis that“the property theory of CMM is the clinical pharmacodynamics of CMM.”

Study on the Influencing Factors of Chemotherapeutic-Related Taste Changes in Cancer Patients

Objective: To investigate the current situation of chemotherapy-related taste changes of cancer patients in Jingzhou area, and analyze the influencing factors of chemotherapy-related taste changes of cancer patients. Methods: In this study, 233 patients with malignant tumors who were confirmed by pathological examination and expected survival time of more than 6 months after admission to a tertiary general hospital in Jingzhou from January 2018 to October 2018 were selected by convenience sampling method. The Chinese version of The chemotherapy-induced Taste Alternation Scale (CiTAS) was used to investigate the baseline data and occurrence status, and multiple regression analysis was used to explore the influencing factors. Results: In this study, 171 tumor patients experienced chemotherapy related taste changes, accounting for 73.4% (171/233);The vast majority of chemotherapy patients have different types and severity of taste changes;Multiple regression analysis showed that the duration of chemotherapy, the number of consecutive days of chemotherapy, and dry mouth were the main influencing factors for chemotherapy related taste changes in cancer patients (p Conclusion: Nursing personnel should pay attention to the occurrence of chemotherapy-related taste changes in tumor patients, and provide predictive nursing interventions to improve their taste experience for tumor patients who have a long course of chemotherapy, many consecutive days of chemotherapy, or have dry mouth conditions.

杨振宁论taste风格与科学研究

一、taste与科学研究爱因斯坦在青少年时代就对世界的统一性怀有深挚的信念和强烈的感情,可以说,他一生的科学研究工作都是在这种很早就产生的信念和感情的支配下进行的。

中国英语学习者“TASTE”使用情况的调查分析——基于语料库的对比研究

"Taste"意为五种感官中的味觉,属于英语的基本词汇。通过中国英语学习者语料库(CLEC)和美国英语语料库(BROWN)对比,调查分析了中国英语学习者和本族语者在使用"taste"的频数、搭配、类连接方面存在的差异,揭示出中国学习者"taste"的使用特点,以期对该词的教学提出合理化建议。

EFFECTS OF SUCROSE/NaCl MIXTURES STIMULATION ON C-FOS-LIKE IMMUNOREACTIVITY IN THE TASTE-RELATED NUCLEI IN RATS

Objective To investigate the changes of neuronal activation in taste related nuclei following intraoral taste stimulation with binary taste mixtures of sucrose and NaCl. Methods Neuronal activation in response to intraoral taste stimulation with 0.5 mol·L -1 sucrose, 0.3 mol·L -1 NaCl, sucrose+NaCl mixture and distilled water was evaluated in taste related nuclei by using c Fos like immunoreactivity in the rats deprived of water overnight. Results The consumption of sucrose+NaCl mixture was lower than that of sucrose solution. Intraoral sucrose or NaCl stimulation induced more c FLI than distilled water in the external lateral subnucleus of the rostral parabrachial nucleus (PBN), but the c FLI induced by intraoral sucrose+NaCl mixture stimulation was less than that induced by sucrose solution in this subnucleus. Compared with distilled water, the intraoral sucrose or sucrose+NaCl mixture stimulation induced more c FLI in the central amygdala. ConclusionThese results suggest that salty taste has a suppressive effect on the neuronal activations induced by sweet taste in the external lateral subnucleus of rostral PBN in rats.

Shrinkage of ipsilateral taste buds and hyperplasia of contralateral taste buds following chorda tympani nerve transection

The morphological changes that occur in the taste buds after denervation are not well under- stood in rats, especially in the contralateral tongue epithelium. In this study, we investigated the time course of morphological changes in the taste buds following unilateral nerve transection. The role of the trigeminal component of the lingual nerve in maintaining the structural integrity of the taste buds was also examined. Twenty-four Sprague-Dawley rats were randomly divided into three groups： control, unilateral chorda tympani nerve transection and unilateral chorda tympani nerve transection ＋ lingual nerve transection. Rats were allowed up to 42 days of re- covery before being euthanized. The taste buds were visualized using a cytokeratin 8 antibody. Taste bud counts, volumes and taste receptor cell numbers were quantified and compared among groups. No significant difference was detected between the chorda tympani nerve transection and chorda tympani nerve transection ＋ lingual nerve transection groups. Taste bud counts, volumes and taste receptor cell numbers on the ipsilateral side all decreased significantly compared with control. On the contralateral side, the number of taste buds remained unchanged over time, but they were larger, and taste receptor cells were more numerous postoperatively. There was no evidence for a role of the trigeminal branch of the lingual nerve in maintaining the structural integrity of the anterior taste buds.

Conditioned Taste Aversion Diminishes Sugar Intake

Animals learn to avoid particular food when some of its sensory properties are associated with gastrointestinal discomfort. Twenty rats were exposed to free access to food and a sugar solution for ten days in first phase. During second phase, experimental group received a dose of LiCl. Control group received an injection without LiCl. Both groups had free access to a sugar solution and food restriction for three days. In the final phase, both groups returned to the conditions of first phase. Results showed a significant decrease in sugar intake after aversive conditioning regarding the intake registered in the initial phase in experimental group. Control group did not show any differences in its sugar intake before and after the experimental manipulation. The procedure carried out is discussed as a means to decrease sugar intake.

Comprehensive comparison on the chemical metabolites and taste evaluation of tea after roasting using untargeted and pseudotargeted metabolomics

Roasting is a common manufacture technology for processing various teas.It is not only used in decreasing the water content of finished tea,but also improving the flavor of teas.In the present study,the roasted and non-roasted teas were compared by liquid-chromatography mass spectrometry and sensory evaluation.The roasted tea tasted less bitter and astringent.The content of main galloylated and simple catechins,caffeine and theobromine in roasted were significantly lower than non-roasted teas.Targeted taste-compounds metabolomics revealed that(-)-epigallocatechin gallate,kaempferol-glucose-rhamnose-glucose and(-)-epicatechin gallate were main contributors tightly correlated to astringent intensity.Flavonol glycosides including kaempferol-glucose,quercetin-glucose,kaempferol-glucose-rhamnose-glucose,and quercetin-glucose-rhamnose-glucose in roasted teas were also significantly less than non-roasted teas.To study the chemical changes during roasting,tea with a strong astringency was roasted under 80,100,120,140,and 160°C.With the increase of roasting temperature,the bitter and astringent intensity of tea was gradually decreased,but the main astringent compounds including(-)-epigallocatechin,(-)-epigallocatechin gallate and kaempferol/quercetin glycosides were irregularly varied with temperature.The Pearson correlation coefficient analysis suggested procyanidin B2,coumaroylquinic acids and gallotannins were tightly correlated to the astringent and bitter perceptions,while N-ethyl-2-pyrrolidonesubstituted flavan-3-ols were negatively correlated.

Evaluation of umami taste components of mushroom (Suillus granulatus) of different grades prepared by different drying methods

Suillus granulatus is a valuable wild edible mushroom with a strong umami taste.Different grades of S.granulatus were dried by different methods,including natural air drying(ND),hot air drying(HAD),vacuum drying(VD),and freeze drying(FD).Results showed that VD samples of all grades had the highest equivalent umami concentration(EUC)value(P<0.05).The second grade of ND samples showed the highest EUC value(P<0.05).The first grade of HAD samples showed the highest EUC value(P<0.05).The third grade of FD samples showed the highest EUC value(P<0.05).The third grade of VD samples had a higher EUC value than the other grades of samples dried by VD.Electronic tongue results indicated no significant differences between samples of all grades dried by all methods.Thus,umami taste components are affected by drying method and grade.VD is an appropriate drying method for all sample grades.ND,HAD,and FD are suitable for second-,first-,and third-grade samples,respectively.