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.

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.

The Effect of Umami Stimulation on Salivary Secretion Rate and Duration

Purpose: Umami reportedly promotes salivation. We aimed to investigate the effects of taste stimuli on slow and fast salivary secretion in humans using umami, sweet, and sour stimuli. Methods: Eight healthy women participated between 14:00 and 15:00, taking the circadian rhythm of salivary secretion into account. The types and concentrations of the taste solutions were glutamic acid (1.7 × 10−3 M), inosinic acid (9.8 × 10−3 M), and guanylic acid (9.8 × 10−3 M) for umami stimulation, citric acid (6.5 × 10−3 M) for acidity stimulation, and sucrose (1.6 × 10−2 M) for sweetness stimulation. First, the unstimulated salivary flow rate was measured. Then, 3 ml of a flavor solution was dropped under the tongue using a syringe. The saliva was expelled into an aluminum cup every minute and weighed. The first minute’s value minus 3 ml flavor solution was the stimulated salivary secretion rate produced by each flavor. The time-to-return to the initial unstimulated salivary flow rate was the duration of the stimulated saliva secretion rate. Results: The mean unstimulated salivary flow rate across participants was 0.64 ± 0.25 ml/min (range: 0.23 - 1.03 ml/min). The highest amount of saliva was induced by citric acid. There were significant differences between citric acid and the other flavor solutions (p < 0.05 for glutamic acid, inosinic acid, and sucrose;p < 0.01 for guanylic acid). There were no significant differences in duration of salivation between the flavor solutions. When the participants were divided into slow (0.45 ± 0.16 ml/min) and fast groups (0.83 ± 0.15 ml/min) based on their median resting salivary secretion rate, there were no significant differences between the two groups in the amount of saliva secreted at 1 minute after stimulation and the duration of the salivary secretion rate. Conclusion: Umami stimulation was effective in slowing salivary secretion and sustaining salivary secretion after stimulation.

Virtual screening,molecular docking and identification of umami peptides derived from Oncorhynchus mykiss

Oncorhynchus mykiss is delicious and contains abundant flavor substances.However,few studies focused on umami peptides of O.mykiss.In the current work,umami peptides derived from O.mykiss were identified using virtual screening,molecular docking,and electronic tongue analysis.First,the O.mykiss protein was hydrolyzed using the PeptideCutter online enzymolysis program.Subsequently,water-soluble and toxicity screening were performed by Innovagen and ToxinPred software,respectively.The potential peptides were docked with umami receptor T1R1/T1R3.Furthermore,taste properties of potential peptides were validated by electronic tongue.Docking results suggested that the three tetrapeptide EANK,EEAK,and EMQK could enter the binding pocket in the T1R1 cavity,wherein Arg151,Asp147,Gln52,and Arg277 may play key roles in the production of umami taste.Electronic tongue results showed that the umami value of EANK,EEAK,and EMQK were stronger than monosodium glutamate.This work provides a new insight for the screening of umami peptides in O.mykiss.

Effect of cooking processes on tilapia aroma and potential umami perception

Tilapia is a freshwater fish group with a sustainable prospect but suffers off-notes appearing during cooking processes.To promote pleasant odorants by thermal cooking processes,tilapia fillets were cooked in different ways(roasting,microwave-heating,boiling and steaming).Their aroma profiles were analysed with special focus on off-notes and umami-enhancing odorants by principal component analysis,and correlated with the heating time,colour,moisture and water activity by partial least squares regression analysis.Results showed that the“green”and“earthy”off-notes were highly correlated with the boiling process(excess of water,short heating time),while most of the umami-enhancing odorants had a high association with the roasting process(low water content,long heating time,better Maillard reaction).This study indicated that roasting is the most adapted cooking process promoting Maillard-derived aromas,umami-enhancing aromas and meanwhile,reducing off-notes.This research helps in understanding the off-note generation in tilapia and promoting desirable umami-enhancing odorants.

Energy status regulated umami compound metabolism in harvested shiitake mushrooms(Lentinus edodes)with spores triggered to release

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℃.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.

酵母抽提物鲜味(umami)及浓厚味(kokumi)滋味活性的评价与研究

酵母抽提物（YE）是一种极佳的风味增强食品,具有极强的鲜味（umami）增强和浓厚味（kokumi）效果.对三种酵母抽提物（高纯YE,高I＋G YE,普通YE）的umami及kokumi滋味进行了评价和描述.通过超滤、凝胶层析对YE滋味组分进行了分离,初步得出分子质量处于200～1 000u的肽类,本身具有苦味及强烈刺舌滋味,对MSG-NaC1、I＋G＋NaC1、鸡汤-NaC1模型溶液具有增鲜,增加复杂口感及持续的满口感的kokumi效果.随后对三种YE的粗分质子量分布、肽分布、核苷酸含量、GSH含量进行了测定.结果得出,YE中＜1 000u分子量寡肽含量较高（约70％）,为其主要滋味物质,相对而言,YE中呈味核苷酸含量较低（3.530mg/g）,而不能与其中的kukumi活性物质起到协同效果.通过YE对MSG-NaCl、I＋G＋NaCl模型溶液的反馈感官鉴评实验,得出YE浓度分别达到0.25g/L、0.05g/L时开始体现出增鲜效果,而在两种模型溶液中YE分别达到2.5g/L,5g/L浓度时达到最大增鲜效果,超过这一浓度时,溶液开始呈现一定的苦味,鲜味也不再增强.此外,对于I＋G＋NaCl模型溶液,YE对其鲜味提升更为明显,增鲜阈值也较低.

Umami型酵母抽提物对无添加酱油的品质提升作用

文章概述了国内无添加酱油的发展历程和现状,列举了零添加酱油的几点品质不足,详细的阐述了Umami型酵母抽提物对无添加酱油的品质提升作用。

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.

Umami: An Alternative Japanese Approach to Reducing Sodium While Enhancing Taste Desirability

COVID-19 has highlighted the underlying global burden from non-communicable diseases (NCDs) and the lack of resiliency in health systems to tackle highly preventable risk factors, which have left populations vulnerable to acute health crises. The persistent issue of unhealthy behaviors, particularly those related to a high-sodium diet, suggests inadequate policy attention and insufficient funding for public health and behavioral research. This year, Japan will host the Tokyo Nutrition for Growth (N4G) Summit 2021. The summit is being held in the era of COVID-19, offering a historic opportunity to make a difference on the global health agenda for food and nutrition and to reaffirm the global commitment to prevent future health crises by addressing the growing burden of NCDs and building better prepared and more resilient health systems. This perspective article suggests that we, global health researchers and decision-makers, should rethink the value of using “Umami” substances as candidates for a practical salt-reducing alternative that originated in Japan (while maintaining the affordability, accessibility, availability, and desirability of healthy food). Reduced salt intake will help address the global syndemic of COVID-19 pandemic and high rates of hypertension, heart diseases, diabetes, and other NCDs. By addressing these issues, it will make countries more resilient to future pandemic threats.

Remodeling of the ryanodine receptor isoform 1 channel regulates the sweet and umami taste perception of Rattus norvegicus

Sweet and umami tastes are elicited by sweet and umami receptors on the tongue and palate epithelium,respectively.However,the molecular machinery allowing the taste reaction remains incompletely understood.Through a phosphoproteomic approach,we identified the key proteins that trigger taste mechanisms based on phosphorylation cascades.Ryanodine receptor isoform 1(RYR1)was further verified by sensory and behavioral assays.We propose a model of RYR1-mediated sweet/umami signaling in which the RYR1 channel,which mediates Ca^(2+)release from the endoplasmic reticulum,is closed by dephosphorylation in bud tissue after sweet/umami treatment.The alteration in Ca^(2+)content in the cytosol induces transient membrane depolarization and generates a cell current for taste signal transduction.We demonstrate that RYR1 is a new channel involved in the regulation of sweet/umami signal transduction and propose a“metabolic clock”notion based on sweet/umami sensing.Our study provides a valuable foundation for a system-level understanding of the taste perception mechanism.

Effect of mushroom root fermentation broth on the umami taste and nutrients of Flammulina velutipes

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%,E16.7%,E213.4%,E320.1%).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.

大球盖菇酶解液中鲜味肽的分离鉴定及其协同增鲜效果分析

利用超滤、凝胶过滤色谱结合感官评价和电子舌分析技术,分离大球盖菇酶解液中鲜味肽组分,对鲜味最强组分F3中的鲜味肽进行反向高效液相色谱-串联质谱鉴定,并将鉴定得到的鲜味肽合成后进一步探讨其呈味特性。结果表明,大球盖菇酶解液F3组分中鉴定得到8条鲜味肽段,分别为ELWR、RLVDR、KPDNR、AHLRF、LDWDR、LAEWR、DDWWR和EGHKGW,它们均具有鲜味特征和鲜味增强作用,阈值分别为0.30~1.33mmol/L和0.53~2.43 mmol/L;除LDWDR外,7条多肽对味精溶液均有不同程度的鲜味提升,提升幅度0.18%~61.12%,ELWR、RLVDR、KPDNR、AHLRF和EGHKGW 5条多肽在低浓度时表现出良好的鲜味提升效果。RLVDR和KPDNR协同增鲜的鲜味峰值质量浓度为5mg/mL,LDWDR、LAEWR、DDWWR和EGHKGW在4mg/mL时达到鲜味峰值。鲜味肽的氨基酸组成和空间结构会影响其味觉属性。本研究结果为大球盖菇鲜味肽的开发利用提供了理论依据。

不同黄曲霉菌株强化发酵对浏阳豆豉鲜味形成的影响

为了探究不同黄曲霉菌株强化发酵对浏阳豆豉鲜味的影响,本研究对比了自然发酵(natural fermentation,NF)和优势黄曲霉菌株(Aspergillus flavus 7214、A. flavus 7622、A. flavus 6112、A. flavus 5322和4种菌株等比例混合M4)强化发酵下浏阳豆豉的蛋白质降解情况和鲜味差异。结果表明4株菌中均以丝氨酸蛋白酶为主,其中A.?flavus?5322总蛋白酶活力最强,且酸性蛋白酶活性远高于其余3株菌。5种强化发酵豆豉氨基酸态氮和水溶性蛋白质量分数在渥堆结束后均高于NF,进一步进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳,结果显示6种豆豉蛋白质降解趋势一致,均在渥堆阶段出现迅速降解。感官评价和电子舌分析结果表明,A.?flavus?5322强化发酵豆豉滋味最为浓郁,其中鲜味相较于NF增长明显。利用超高效液相色谱-电喷雾/四极杆飞行时间串联质谱联用技术结合相关性和肽组学分析共筛选出43条鲜味多肽,其中A.?flavus?6112强化发酵豆豉潜在鲜味肽的总峰面积最高,其次为A.?flavus?5322,两者差异较小,且明显大于NF。综上,A.?flavus?5322菌株强化发酵可通过促进蛋白质降解和潜在鲜味肽的释放提升豆豉的鲜味,本研究可为浏阳豆豉的鲜味提升和工业化生产菌株的应用开发提供理论指导。

猪肉鲜味物质及其形成机理研究进展

鲜味是猪肉中最受人们关注的滋味特征,解析猪肉鲜味形成的物质基础和鲜味物质生成机理对猪肉风味品质改良与调控具有重要意义。本文从食品鲜味与感知过程切入,综述了游离氨基酸、呈味核苷酸和呈味肽及其互作效应对猪肉鲜味形成的贡献,从活体和宰后2个层次解析了氨基酸代谢、能量代谢与肌纤维类型等对猪肉鲜味物质生成的影响,并探讨了相关控制基因与分子通路,期望为优质猪肉风味育种与营养调控提供新的科学依据和思路。

冻融循环对食用菌预制菌汤品质的影响

为探究冻融循环对食用菌预制菌汤的品质影响,本文以鲜菌汤为参照,对比了冻融过程中微生物数量、菌汤色泽、可溶性蛋白、还原糖、总酚含量等基本指标的变化,并基于超高效液相检测和气相色谱-质谱法分析冻融过程菌汤等鲜度和挥发性风味物质差异。研究表明,首次冻融大幅减少了菌汤的还原糖、总酚和总氨基酸含量,显著降低了菌汤等鲜度和挥发性成分含量,综合影响了菌汤的成分与风味。进一步通过冻融次数(1~5次)之间的对比,反复冻融3次菌汤可溶性蛋白含量相较于冻融1~2次显著降低(P<0.05),此外,等鲜度由1~2次冻融的0.441~0.450 g MSG/100 g直接下降至0.407 g MSG/100 g,同时微生物开始检出。在此后4~5次冻融过程中,虽然菌汤总酚、总氨基酸含量和等鲜度相对稳定,但核苷酸、可溶性蛋白和挥发性成分不断减少且菌落总数不断升高。因此,预制菌汤若需冻融处理则应控制在2次内为宜。

云南盐津乌骨鸡肉中鲜味肽的提取与鉴定

利用超滤和凝胶过滤色谱法对盐津乌骨鸡肉中的鲜味肽进行分离纯化,结合感官评价得到鲜味最佳的组分F1,进一步采用液相色谱-串联质谱联用技术从F1组分中鉴定出鲜味肽,对鉴定出的鲜味肽进行条件筛选、氨基酸组成和活性片段预测分析。结果表明,从盐津乌骨鸡肉中鉴定出921条多肽,筛选后得到551条多肽,通过鲜味活性预测得到鲜味片段出现频率大于1的10条多肽,其中DTEEVEHGEE、EVHEEEVH、HEAEEVHEE、HEKLSEESEE、KVED、TPIPDLP 6条多肽可能具有较强的鲜味。

海鲜菇美拉德肽的制备及其风味特性研究

以海鲜菇(Hypsizygus marmoreus)蛋白肽为原料,采用响应面法分析优化海鲜菇美拉德肽制备工艺,并通过褐变程度、产物分子量分布、感官评价、电子舌及超滤等特征性指标和评价手段,明确美拉德反应对海鲜菇蛋白肽风味特性的影响。结果表明,海鲜菇美拉德肽的最佳制备条件为葡萄糖与D-木糖质量比4∶1、反应温度110℃和反应时间56 min。与海鲜菇蛋白肽相比,制备的海鲜菇美拉德肽咸味强烈,并伴有鲜味产生,整体接受度好,在294 nm和420 nm下吸光值显著增加,并推测分子量大于180~500 Da的组分可能为美拉德反应的主要活性肽段。超滤结果表示,海鲜菇美拉德肽呈咸鲜味的肽分子量主要集中在500 Da以下。该研究结果证明美拉德反应可有效提升海鲜菇蛋白肽的咸鲜味,使其风味层次更加丰富,可为扩展可替代钠盐的新型食用菌调味领域的研究和应用提供理论基础。

鹅骨鲜味肽的发酵工艺优化及多肽组学分析

以鹅骨为原料,采用可溶性肽含量和鲜味强度双指标,通过响应面试验设计优化发酵法制备鹅骨鲜味肽的工艺条件,并通过纳米液相色谱-串联质谱(nano liquid chromatography-tandem mass spectrometry,nanoLC-MS/MS)分析鹅骨鲜味肽的性质和组成。结果表明,采用植物乳杆菌LP-12发酵,接种量3%、底物添加量8.5%、发酵温度36℃、发酵24 h效果最佳,该条件下发酵得到的可溶性肽含量为45.86 mg/g,鲜味强度为14.03。通过蛋白质数据库的比对,检索出胶原蛋白等多种蛋白。