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.

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.

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.

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。

Comparing the difference in enhancement of kokumi-tastingγ-glutamyl peptides on basic taste via molecular modeling approaches and sensory evaluation

γ-Glutamyl peptides can enhance basic taste sensations such as saltiness,sweetness,and umaminess,while the molecular mechanism and the difference in taste enhancement remain elusive.Thus,two complex conformations:taste type 1 receptor 1(T1 R1)-MSG and taste type 1 receptor 2(T1 R2)-sucrose were constructed to form binding receptors.These peptides showed affinity for the two receptors,but a higher affi nity scores and more binding amino acid residues for the T1 R1-MSG receptor,implying that they may exhibit a higher umami-enhancing effect.Thereinto,γ-glutamyl alanine(γ-EA)displayed the highest affi nity for the two receptors through mobilizing multiple amino acid residues to form hydrophobic and hydrogen bonds,indicating it had the highest enhancement for umaminess and sweetness among these peptides.Sensory evaluation demonstrated the enhancement ofγ-EA on umaminess was superior to that of sweetness.Generally,γ-glutamyl peptides could enhance basic taste sensation via activating taste receptor,and exhibited a highest umami-enhancing effect.

Subdiaphragmatic vagotomy reduces intake of sweet-tasting solutions in rats

Studies have shown that there are strong interactions between gustatory and visceral sensations the central nervous system when rats ingest sweet foods or solutions. To investigate the role of th subdiaphragmatic vagi in transmitting general visceral information during the process of drinking sweet-tasting solutions, we examined the effects of subdiaphragmatic vagotomy on the intake of 0.5 mol/L sucrose, 0.005 mol/L saccharin or distilled water over the course of 1 hour in rats depriv~ of water. Results showed no significant difference in consumption of these three solutions in vagotomized rats. However, rats in the sham-surgery group drank more saccharin solution than sucrose solution or distilled water. Moreover, the intake of distilled water was similar between vagotomized rats and sham-surgery group rats, but significantly less sucrose and saccharin were consumed by vagotomized rats compared with rats in the sham-surgery group. These findings indicate that subdiaphragmatic vagotomy reduces intake of sweet-tasting solution in rats, and suggest that vagal and extravagal inputs play a balanced role in the control of the intake of sweet-tasting solutions. They also suggest that subdiaphragmatic vagotomy eliminates the difference in hedonic perception induced by sweet-tasting solutions compared with distilled water II E

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.

Tasting the World with a New Perspective

IN the 1990s,Fuchsia Dunlop decided to visit China after reading articles about the country for several months.The ensuing one-month backpacking trip exposed the English woman to a wide range of Chinese food.“The dishes and soups I had even in the cheapest and plain eateries were better than what I had in the U.K.,”Dunlop recalled.

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.”

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.

重庆针形绿茶滋味特征及主要贡献物质

滋味是评定茶叶品质的重要指标,为探索重庆针形绿茶滋味特征,该文通过检测分析绿茶主要呈味物质组分及含量,结合主成分及滋味物质贡献度进行分析。结果表明,重庆针形绿茶味感表现浓醇而鲜爽,总体品质较好。主要品质指标:水浸出物含量在45.2%~49.6%,多酚含量在14.7%~21.6%,游离氨基酸含量在2.8%~5.6%,咖啡碱含量在3.4%~4.7%(均为质量分数)。主成分分析表明,天冬氨酸、苏氨酸、丝氨酸、天冬酰胺、丙氨酸、蛋氨酸、异亮氨酸、亮氨酸、酪氨酸、组氨酸、赖氨酸、精氨酸12种氨基酸组分和没食子酸(gallic acid,GA)、表没食子儿茶素(epigallocatechin,EGC)、表儿茶素没食子酸酯(epicatechin gallate,ECG)3个组分为重庆针形绿茶滋味主要特征成分。而通过滋味物质贡献度[浓度/阈值(dose-over-threshold,Dot)]分析出天冬氨酸、谷氨酸、GA、表没食子酸儿茶素没食子酸酯(epigallocatechin gallate,EGCG)、ECG、EGC、儿茶素(catechin,D/L-C)对滋味的形成有重要贡献。滋味成分聚类分析表明永川、巴南两地的针形绿茶聚类效果较好。该研究为重庆针形绿茶品质成因及品质改善研究提供参考。

Tasting South Africa

During the Year of South Africa in China, ChinAfrica presents an introduction of different aspects of South African culture. This month we look at some of the country＇s better known dishes

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.

口感番茄新品种“潍科玉玲珑”的选育

“潍科玉玲珑”是潍坊科技学院用自交系WKFQ015作母本、自交系YLL48作父本杂交选育而成的口感番茄新品种。该品种长势旺盛,早熟,果圆形底部略扁,未成熟果实带绿肩,成熟后果实亮深粉色,色泽亮丽,平均单果质量120 g,皮薄且有韧性,肉厚汁多,酸甜适度,风味浓郁,香味独特,维生素C含量22.1 mg·(100g)^(-1),番茄红素含量80.9 mg·kg^(-1),可溶固形物含量7.4%,品质优良。2020年1月通过国家非主要农作物品种登记,适合山东省、河北省等大部分地区早春设施种植。

基于无人机多光谱影像的寒地水稻品质估测

【目的】在稻谷收获前准确估测稻米品质,为改善水稻养分管理、实现优质优价提供参考。【方法】试验在黑龙江省佳木斯市大兴农场和青龙山农场进行,两个地点土壤肥力具有较大差异。每个农场选择一块稻田,以20 m×20 m间隔采集土壤样品分析碱解氮含量,通过变量施氮形成产量水平、长势差异明显的水稻群体。利用大疆精灵4四旋翼多光谱无人机获取水稻分蘖期、拔节期、抽穗期和成熟期冠层多光谱数据。成熟期采集长势具有明显差异的水稻样品和对应的土壤样品,测定土壤有机质和速效氮、磷、钾含量,水稻籽粒蛋白质和直链淀粉含量,产量和食味值,随机选择其中67%的数据通过逐步多元线性回归构建不同生育时期的品质估算模型,其余33%的数据用于模型的验证。【结果】大兴农场水稻成熟期土壤有机质、碱解氮、有效磷和速效钾含量的变异系数分别为11.65%、14.44%、37.66%和11.60%,青龙山农场分别为14.45%、14.32%、36.37%和28.51%。成熟期两个地点水稻产量和食味值的变异系数均大于10%,青龙山农场水稻蛋白质含量变异系数也超过10%,而两地稻米直链淀粉含量的变异系数仅为1.11%~1.83%,因此,水稻直链淀粉含量不适合用于后续的品质估测分析。分蘖期至抽穗期,大兴农场和青龙山农场水稻蛋白质多元回归模型的R~2和RMSE分别为0.262~0.794和0.259~0.686,食味值多元回归模型的R~2和RMSE分别为0.240~0.755和4.211~7.588,估测效果不理想。成熟期,大兴农场和青龙山农场水稻蛋白质多元回归模型的R~2和RMSE分别为0.791~0.874和0.166~0.365,食味值多元回归模型的R~2和RMSE分别为0.786~0.852和2.836~4.039。成熟期基于植被指数的蛋白质和食味值估测精确度优于抽穗期。在抽穗期,将土壤pH、有机质、碱解氮、有效磷、速效钾等指标与植被指数一起建立与蛋白质和食味值的多元回归模型,大兴农场水稻蛋白质模型的R~2由0.585提高到0.720,RMSE由0.301降低至0.247;两农场食味值模型的R~2由0.565~0.755提高到0.706~0.787,RMSE由4.318~4.854降低至3.993~4.029,基本可以满足对稻米品质估测的精度,而在成熟期加入上述土壤指标提升精度不明显。【结论】水稻成熟期利用多光谱无人机对稻米品质进行原位估测的精度较高,如果将估测时期提前到抽穗期,除植被指数外,还需配合土壤有机质和速效养分含量数据来提高多光谱无人机预测稻米品质的精度。