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.

Effects of prebiotics on the fermentation of traditional suancai of Northeast China

Suancai is a traditional fermented vegetable widely consumed in Northeast China.In this study,different prebiotics were used to improve the quality of suancai.Four prebiotics(inulin(INU),xylooligosaccharide(XO S),galactooligosaccharide(GOS),and stachyose(STA))were shown to reduce the pH value and increase the content of total titratable acidity(TTA)in suancai,while the contents of most organic acids were also increased.The addition of prebiotics had significant effects on the bacterial microbiota during the suancai fermentation process.All prebiotics were shown to contribute to the growth of Lactobacillus.The suancai sample with fructooligosaccharides(FOS)had the highest relative abundance of Lactobacillus.Besides,INU and XOS could increase the abundance of Weissella.To evaluate the quality of suancai fermented with prebiotics,profiles of volatile flavor compounds(VOCs)and free amino acids(FAA)were analyzed.The prebiotics affected the VOCs and FAA profiles via transforming the bacterial microbiota.In addition,the addition of prebiotics also changed the taste profiles of the suancai samples.This study is among the first attempts to reveal the effects of different prebiotics on suancai fermentation,and the findings provide a foundation to develop new ways for improving the quality of suancai.

Emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate obtained by Corolase PP under high hydrostatic pressure

Enzymatic hydrolysis of proteins can enhance their emulsifying properties and antioxidant activities.However,the problem related to the hydrolysis of proteins was the generation of the bitter taste.Recently,high hydrostatic pressure(HHP)treatment has attracted much interest and has been used in several studies on protein modification.Hence,the study aimed to investigate the effects of enzymatic hydrolysis by Corolase PP under different pressure treatments(0.1,100,200,and 300 MPa for 1-5 h at 50℃)on the emulsifying property,antioxidant activity,and bitterness of soybean protein isolate hydrolysate(SPIH).As observed,the hydrolysate obtained at 200 MPa for 4 h had the highest emulsifying activity index(47.49 m^(2)/g)and emulsifying stability index(92.98%),and it had higher antioxidant activities(44.77%DPPH free radical scavenging activity,31.12%superoxide anion radical scavenging activity,and 61.50%copper ion chelating activity).At the same time,the enhancement of emulsion stability was related to the increase of zeta potential and the decrease of mean particle size.In addition,the hydrolysate obtained at 200 MPa for 4 h had a lower bitterness value and showed better palatability.This study has a broad application prospect in developing food ingredients and healthy foods.

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.

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.

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.

Analysis of flavor and widely metabolomics differences in black sesame before and after processing

The objective of this study was to determine the differences of aroma and taste in three black sesame originsbefore and after processing via flavor and widely metabolomics.By analyzing the sensory characteristics and metabolites of raw and treated black sesame from China,Vietnam,and Myanmar,treated Chinese sesame have the most significant change in hardness after thermal processing,low viscosity and was easy to chew.The electronic nose could distinguish between raw and treated sesame due to the aroma distribution.The reason of treated sesame from China was“fragrant”is due to the highest content(2545.50μg/kg)of total pyrazines including 2,5-dimethylpyrazine,2-ethyl-5-methylpyrazine,2,3,5-trimethylpyrazine,3-ethyl-2,5-dimethylpyrazine.933 metabolites were detected via a wide targeted metabolomics in the taste of raw and treated sesame.Based on the analysis of metabolites related to bitterness,145 substances were selected.The main bitter contributors may be amino acids,dipeptides and organic acids.

口腔外甜味受体生物学作用的研究进展

甜味受体(STR)是1型味觉受体的一种主要类型,可感知甜味并与不同的糖类和人工甜味剂相结合。虽然它最初被发现于口腔味蕾,但近来许多研究表明其在心脏、肾脏、胰腺、胃肠道、呼吸道和大脑等口腔外组织中均有表达,并发挥多种口外味觉效应,如参与摄食活动、能量稳态调节、内分泌代谢调节、内皮通透性调节、免疫防御调控和认知功能调节等。对此,本文综述STR的信号途径及其在口外组织中生物学作用的研究进展,旨在为STR相关的深入研究提供参考。

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.

Preparation and Characterization of Vitamin-D Incorporated Marshmallow

This project looks at a novel way to enhance the sensory experience of vitamin D ingestion by incorporating it into marshmallows. This investigation used a human panel taste test with twelve individuals, an index of swelling, and a stability evaluation. Samples of vitamin D infused marshmallows were prepared and given to participants in the human panel taste test, which evaluated mouthfeel and flavor. By analyzing dissolving behavior, the swelling index test revealed unexpected erosion. In addition, a temperature threshold for storage conditions was found through a temperature sensitivity test. All of these techniques assessed the feasibility and palatability of vitamin D supplementation with marshmallow flavor, offering insights into both the possible advantages and difficulties. The marshmallow infusion technique effectively covered up the disagreeable taste of vitamin D pills, leading to reviews that were overwhelmingly favorable (“Moderate Sweet”) and that indicated a pleasant mouthfeel. During the swelling index test, it showed erosion behavior, suggesting a certain kind of dissolution that is advantageous for nutritional absorption. Furthermore, the study discovered a temperature sensitivity threshold, highlighting how crucial proper storage conditions are.

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。

鄂温克族与鄂伦春族的群体遗传学研究(续)

本次调查采印了645名鄂温克族和424名鄂伦春族中、小学生和部分牧民、猎民的指纹和掌纹。观察了各型指纹出现率、指纹总嵴数、atd角和掌褶纹等指标。 1.各型指纹出现率 弓(A)、尺侧箕(L^u)、桡侧箕(L^r)和斗(W)的出现频率见表11。额左旗和陈旗鄂温克人中斗多于箕,与汉族相似。有些指纹型在某个手指上较为多见。

个性化网络教学资源系统

随着教育信息呈指数增长,用户在拥有丰富的教育信息的同时,也面临着信息过载的困扰。如何从大量的教学资源中快速有效地找到自己感兴趣的信息成为当前信息化研究的热点。根据教学资源的特点,设计并实现了基于个性化推荐技术的网络教学资源系统,希望借此能够有效提高教学资源的利用率。

Adsorption Dynamics of Calyx Aroma onto Basic Tea in Scenting Process of Calyx-scented Tea

[Objective] The paper was to study adsorption dynamics of calyx aroma onto basic tea in scenting process of calyx-scented tea, so as to increase aroma and quality of products. [Method] Adsorption experiment was carried out in a hermetic container, and the effect of calyx amount, contact time, moisture content of basic tea and temperature on the scenting process was studied. [Result] The optimal moisture and temperature for scenting process was 4% and 10 ℃, respectively. [Conclusion] The scenting process accorded pseudo-first-order kinetic model, and the adsorption dynamic data of total process could better fit pseudo-second-order kinetic model.

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。

Turbo TAST译码的降维方法研究

Turbo TAST译码的主要问题是降低其维数。该文研究了几种方法:零空间法、投影法、Thread分解法、SISO法。不同的方法导致其性能差异非常大。零空间法降维不适合TAST码。在所有的次优方法中,MMSE均衡转化为SISO子系统,在复杂度和性能之间取得了最好的平衡。推导了几种方法的链路级信道容量,该容量大小与实际性能之间呈一一对应关系。

使用TAST码的BI-STCM-ID系统中的星座映射分析

研究了BI-STCM-ID系统中的星座映射问题。证明了在使用TAST空时编码方案的BI-STCM-ID系统中,基于最大化编码增益的高维星座映射设计优化问题等价于基于最大化欧式距调和均值的一维星座映射设计优化问题。

Influence of Huizhou Culture on Plant Landscapes in Huizhou-style Gardens

Huizhou-style gardens have been greatly influenced by Huizhou culture, their plant landscapes have also been integrated with various aspects of Huizhou culture, which demonstrated the ideology, historical and cultural connotation of the society in an abstract and impalpable way. In this study, Huizhou-style miniature landscapes, plants of virtual implications, flowers or fruit trees of special connotations are taken for examples to analyze the influence of Xin’an Neo-Confucianism on plant landscapes in Huizhou-style gardens, the demonstration of Huizhou businessmen’s aesthetic tastes, as well as folk cultures of Huizhou, which implies that plant landscapes in Huizhou-style gardens are those incorporating with humanistic spirits, ornamental and practical uses. This study aims to provide references for further researches in the present situation of ancient Huizhou areas, protection of ancient Huizhou-style gardens and construction of new-style Huizhou gardens.