不同结构改性与美拉德反应前后鲜味二肽(Asn-Pro和Ala-His)呈味特性的对比分析

本文为了探讨不同结构改性(氨基酸顺序改变、增加鲜味氨基酸、串联肽)与美拉德反应对鲜味二肽(Asn-Pro和Ala-His)鲜味与增鲜效果的影响,利用电子舌分析了Asn-Pro和Ala-His及其结构改性后获得的新肽和美拉德反应产物的呈味特性,评价了Asn-Pro和Ala-His结构改性前后以及美拉德反应对味精(MSG)和酱油的增鲜效果。结果表明,Ala-His序列改性后获得的新二肽His-Ala的鲜味评分由4.09分上升到5.08分,对MSG和酱油具有明显的增鲜作用,其鲜味评分分别提高了1.40分和0.48分,而其他结构改性获得的9条新肽(Pro-Asn、Glu-Asn-Pro、Asn-Pro-Glu、Asp-Asn-Pro、Asn-Pro-Asp、Asn-Pro-Asn-Pro、Ala-His-Ala-His、Asn-Pro-Ala-His和Ala-His-Asn-Pro)相对于原二肽的鲜味均有所下降,对MSG和酱油具有明显的鲜味抑制作用。美拉德反应可显著提升Asn-Pro和Ala-His的鲜味特性,其鲜味评分分别由7.65分和4.09分上升到9.48分和6.37分,美拉德反应产物对MSG和酱油具有明显的增鲜作用,MSG的鲜味评分分别提高了3.96分和2.29分,酱油的鲜味评分分别提高了3.77分和1.49分。氨基酸序列改变、增加鲜味氨基酸以及串联肽能显著影响多肽鲜味及增鲜效果,美拉德反应是提升多肽鲜味与增鲜效果的有效途径。     

Suppression of Umami Aftertaste by Polysaccharides in Soy Sauce

Umami is one of 5 basic tastes that make foods savory and palatable. The umami aftertaste is a long‐lasting taste sensation that is important for Japanese broth (dashi) utilized for various Japanese foods. Soy sauce is usually added when making dashi‐based dishes; however, different soy sauces produce distinct effects on the umami aftertaste. In this study, we attempted to identify the substances that cause the suppression of the umami aftertaste in soy sauce by combining sensory analysis, size fractionation, chemical analysis, and enzymatic treatment. The suppressive substance was revealed to be polysaccharides with molecular weights between 44900 and 49700. The results of acid hydrolysis and enzymatic treatment suggested that the polysaccharides were cellulose. These results indicate that a type of water‐soluble cellulose derived from soybean, wheat, or microorganisms has a suppressive effect on the umami aftertaste of soy sauce. Future studies should focus on developing a strategy that regulates the amount of these polysaccharides generated during soy sauce production, to maintain or enhance the umami aftertaste.     

Umami Increases Consumer Acceptability,and Perception of Sensory and Emotional Benefits without Compromising Health Benefit Perception

This study was undertaken to understand how consumers in the United States perceive umami‐rich products, specifically low sodium chicken noodle soup. Results suggest that the addition of monosodium l ‐glutamate (MSG) at a concentration of 0.1% to 0.5%, alone or in synergy with 5’‐ribonucleotides of inosine monophosphate (IMP) at 0.1% not only increases consumer acceptance but also positively impacts other aspects of consumer perception. Regardless of concentration of MSG and IMP, samples enhanced in umami compounds were perceived as more savory, flavorful, and less bland while providing a more homemade, fresh, and healthy wholesome taste than a control sample. From a functional and emotional benefit standpoint, when consuming umami‐rich samples, consumers reported feeling significantly higher general satisfaction (they felt more content, relaxed, satisfied, less disappointed, dissatisfied…) and heightened positive emotions (happy, excited, indulgent…) than under the control condition. The feeling of being healthy while consuming the dish was not compromised. Last, when asked how they would feel if serving the soup sample to their family or friends, consumers projected feeling more positively under the umami‐rich conditions (more happy, competent, loving, less dissatisfied or disappointed) compared to the control condition.     

Evaluation of Peptide Contribution to the Intense Umami Taste of Japanese Soy Sauces

ABSTRACT: Koikuchi and tamari shoyu are 2 types of traditional Japanese soy sauce whose low-molecular-weight fractions (less than 500 Da) are known to have the most intense umami taste. Given that peptides were also abundant in some umami fractions of both shoyu, further investigation was conducted to evaluate the precise contribution of peptides to the soy sauce tastes. To locate and isolate peptide fractions, separation procedures using Sephadex G-25 SF, Sephadex G-10, and reversed-phase high-performance liquid chromatography (RP-HPLC) linked to sensory evaluation (by taste dilution analysis), as well as amino acid analysis were performed. Peptides having glutamyl residue were present in most peptide fractions. However, they all revealed negligible contributions to the intense umami taste of the soy sauces. On the other hand, free Glu, in the presence of sodium salt, as well as free Asp and several sweet-taste eliciting free amino acids were considered to be the main contributors to the umami taste of the soy sauces. This study of Japanese soy sauces gives a clear explanation of the frequently questioned peptide contribution to the taste of savory food product.     

Soy sauce odour induces and enhances saltiness perception

Developing products with reduced sodium content is one alternative for consumers interested in reducing their daily sodium intake. In this research, we determined whether soy sauce odour could induce and enhance salty taste perception in salt solution models. The sensory threshold technique (ASTM E679‐04, the ascending forced choice method of limits) was used to determine thresholds at 25 °C. Group best estimate threshold geometric means of soy sauce odour were expressed as parts‐per‐billion (ppb, v/v). At 28.45 ppb (recognition threshold), soy sauce odour could induce salty taste in 0.03 mm NaCl solution (in which salty taste was undetectable without soy sauce odour) and at 122.71 ppb (difference threshold), it enhanced salty taste (i.e. saltier) perception in 20 mm NaCl solution. Through the odour–taste interaction concept, this study demonstrated that the soy sauce odour could induce and enhance salty taste perception, which could be applied in the development of reduced‐sodium foods.     

Analysis of binary taste-taste interactions of MSG,lactic acid,and NaCl by temporal dominance of sensations

Temporal dominance of sensations (TDS) is a relatively novel sensory evaluation technique that measures the temporal evolution of sensory perception. The sensory properties of food or drink products have been described by TDS; however, basic sensory data on TDS are still lacking. We analyzed TDS data for solutions of three basic tastes (umami, salty, and sour) and their binary combinations. The duration of TDS for the main taste of each type of solution (monosodium glutamate [MSG] for umami, sodium chloride [NaCl] for saltiness, and lactic acid for sourness) increased in a concentration-dependent manner. In addition, the duration of the umami taste of MSG was longer than that of MSG/inosine 5′-monophosphate solution with an umami taste of equivalent intensity. The duration of NaCl saltiness was increased by coexistence with MSG and decreased by coexistence with lactic acid. On the other hand, the duration of the umami taste of MSG was suppressed by coexistence with NaCl but not lactic acid, while the duration of the sour taste of lactic acid was suppressed by MSG but not NaCl. These findings provide novel insight into the temporal sequence of basic taste perception during food consumption.     

Soy Sauce and Its Umami Taste: A Link from the Past to Current Situation

ABSTRACT: Soy sauce taste has become a focus of umami taste research. Umami taste is a 5th basic taste, which is associated to a palatable and pleasurable taste of food. Soy sauce has been used as an umami seasoning since the ancient time in Asia. The complex fermentation process occurred to soy beans, as the raw material in the soy sauce production, gives a distinct delicious taste. The recent investigation on Japanese and Indonesian soy sauces revealed that this taste is primarily due to umami components which have molecular weights lower than 500 Da. Free amino acids are the low molecular compounds that have an important role to the taste, in the presence of sodium salt. The intense umami taste found in the soy sauces may also be a result from the interaction between umami components and other tastants. Small peptides are also present, but have very low, almost undetected umami taste intensities investigated in their fractions.     

pH值对酱油中呈味肽种类和呈味特性的影响

利用固相萃取技术结合超高效液相色谱-串联质谱法对不同pH值发酵酱油的酸性组分进行分离、鉴定和呈味特性分析.结果表明,从调控pH值发酵的酱油中鉴定出14 种呈味肽,从自然pH值发酵的酱油中鉴定出12 种呈味肽,其中8 种呈味肽在两种酱油中均鉴定出来.调控pH值发酵的酱油中含有较多良好呈味效果的小分子肽,其中ED、EE、E...     

不同鲜味物质对干腌马鲛鱼鲜味的贡献与比较分析

以8?种市售干腌马鲛鱼为研究对象,通过比较不同产品中鲜味物质成分和含量差异,并结合其滋味强度值和味精当量的分析计算,以确定对干腌马鲛鱼鲜味贡献最大的物质。结果表明：干腌马鲛鱼具有突出的咸、鲜味和浓厚味感,而其鲜味主要是由谷氨酸、鲜味肽等鲜味物质和乳酸等增鲜物质赋予。在其鲜味物质中,谷氨酸的滋味强度值大于1（除3、5、7号样品）,显示出它对干腌马鲛鱼鲜味的突出贡献,超滤组分的感官分析和肽分子质量分布测定结果表明,分子质量小于1?000?Da的小分子肽对样品的鲜味具有重要贡献。此外,长时间的风干可能会促进乳酸和鲜味肽的生成,但随着水分的流失,其苦味和咸味也增高;而辅料蔗糖和白酒的添加将抑制乳酸的产生,且蔗糖能在一定程度上促进谷氨酸的生成。值得强调的是,8?种样品的核苷酸均已降解为肌苷（inosine,HxR）和次黄嘌呤（hypoxanthine,Hx）等苦味物质,且长时间的风干可能会促进HxR和Hx的积累。     

酱油中鲜味二肽的分离鉴定及其呈味特性研究

为了明确酱油中鲜味肽的结构序列,本文对酱油中鲜味肽进行分离鉴定,并系统地研究了其呈味特性。酱油经超滤膜(膜通量:5 ku、3 ku和1 ku)分离获得4个组分(F1,F2,F3和F4),通过感官评定筛选出鲜味最强的组分F4(1 ku)。该组分通过Sephadex G-15凝胶层析色谱继续分离得到8个组分(P1、P2、P3、P4、P5、P6、P7和P8),经感官评定筛选出鲜味最强的组分P2。采用超高压液相色谱串联质谱技术对P2组分进行多肽结构鉴定,通过手动De novo测序得到4条新的鲜味肽,其序列分别是Asn-Pro(230.1135 u)、Ala-His(227.1026 u)、Gly-Pro(173.0929 u)和Gly-Leu(189.1230 u)。然后采用固相合成技术合成四条肽并通过感官评定和电子舌分析,结果表明四条肽均具有明显的鲜味或鲜味增强作用。进一步研究发现,酱油的鲜味不仅来自于谷氨酸和天冬氨酸等鲜味氨基酸,小分子肽类也是构成酱油鲜味的重要成分之一。     

“厚味”γ-谷氨酰-缬氨酸增味作用差异性机制

γ-谷氨酰-缬氨酸（γ-Glu-Val）具有多变的呈味特性,在水溶液中呈现涩味,可以增强基本味觉物质的味感强度,赋予奶酪、鸡汤、酱油等食物厚味味感。目前对于γ-Glu-Val呈味特性的机理研究甚少,尤其是鲜见它对于味觉增强效果的差异性机制的研究。本实验利用感官实验和分子模拟对γ-Glu-Val增味作用的差异性机制进行研究。感官实验结果显示,γ-Glu-Val对于基本味感（鲜味、甜味、咸味和酸味）均有一定的提升作用,而对于鲜味的提升效果最为明显。分子模拟实验的结果表明,γ-Glu-Val对基本味感受体（T1R1、T1R2和T1R3）均有一定的亲和力,其中对于鲜味受体T1R1的亲和力最强、结合自由能最高,与此相反,γ-Glu-Val对甜味受体T1R2的亲和力最弱、结合自由能最低,暗示其增鲜作用强于增甜作用。分子动力学结果显示,在味精存在的前提下,γ-Glu-Val可通过氢键和疏水键与鲜味受体T1R1上的氨基酸残基（Phe-274、Ser-275、Ser-300、Trp-303、Ala-147、Ala-170）相互作用,激活鲜味受体,以实现其增鲜作用。本实验解析了γ-Glu-Val增味作用差异性分子机制,为进一步验证其呈味机理提供理论支撑;同时为小分子物质的增味作用研究提供了思路。     

Molecular insights into human taste perception and umami tastants: A review

Understanding taste is key for optimizing the palatability of seaweeds and other non-animal-based foods rich in protein. The lingual papillae in the mouth hold taste buds with taste receptors for the five gustatory taste qualities. Each taste bud contains three distinct cell types, of which Type II cells carry various G protein-coupled receptors that can detect sweet, bitter, or umami tastants, while type III cells detect sour, and likely salty stimuli. Upon ligand binding, receptor-linked intracellular heterotrimeric G proteins initiate a cascade of downstream events which activate the afferent nerve fibers for taste perception in the brain. The taste of amino acids depends on the hydrophobicity, size, charge, isoelectric point, chirality of the alpha carbon, and the functional groups on their side chains. The principal umami ingredient monosodium l -glutamate, broadly known as MSG, loses umami taste upon acetylation, esterification, or methylation, but is able to form flat configurations that bind well to the umami taste receptor. Ribonucleotides such as guanosine monophosphate and inosine monophosphate strongly enhance umami taste when l -glutamate is present. Ribonucleotides bind to the outer section of the venus flytrap domain of the receptor dimer and stabilize the closed conformation. Concentrations of glutamate, aspartate, arginate, and other compounds in food products may enhance saltiness and overall flavor. Umami ingredients may help to reduce the consumption of salts and fats in the general population and increase food consumption in the elderly.     

The effect of the Corynebacterium glutamicum on the shortening of fermentation time,physicochemical and sensory properties of soy sauce

This study for the first time explores the possibility of using Corynebacterium glutamicum Ⅲ (C. glutamicum) to shorten the soy sauce fermentation period without compromising product quality. C. glutamicum was added to soy sauce that had been fermented with Aspergillus oryzae for 30 days (SS30) to initiate a further 3-day fermentation (yielding SS33). The 3-day fermentation exerted similar impacts on SS30 as the standard fermentation for further 60 days (yielding SS90): that is, increased the contents of total nitrogen, total free amino acids (FAAs), umami FAAs, acids, esters, ketones, furans and sulphur-containing compounds, whilst decreasing the contents of alcohols and phenols. This explained the similarities in taste, aroma and overall liking between SS33 and SS90. The SS90 was the darkest among the three soy sauces. Compared with SS90, SS33 was less salty and smoky, more umami and kokumi, softer and more mellow, higher overall liking, with more 0.5–1 kDa peptides and fewer peptides <0.5 kDa. Therefore, a 3-day fermentation with C. glutamicum after an initial 30 days of a normal soy sauce fermentation represents a simple and effective way to shorten the soy sauce production time from 90 to 33 days whilst increasing greatly the umami taste and mellow sensation. This approach enhances product competitiveness via lowering manufacturing cost.     

甜油和酱油中氨基酸和还原糖含量的比较研究

探讨甜油和酱油中两种关键营养成分氨基酸和还原糖的含量差异,分析原料不同、工艺相近的两种调味品特征指标存在差异的原因,并提出甜油和酱油存在的优势和缺点。结果表明,甜油中氨基酸总量和鲜味氨基酸谷氨酸低于酱油,甜油和酱油中氨基酸总量分别为15.86～23.21 mmol/L和31.69～46.04 mmol/L,其中谷氨酸含量分别为2.94～7.54 mmol/L和20.62～35.34 mmol/L;但每类氨基酸含量差距不大,比较协调;甜油中甜味氨基酸比例较大,为49.41%,酱油中的鲜味氨基酸比例较大,为71.19%;甜油中还原糖含量（14.24～27.53 g/L）高于酱油（4.80～8.26 g/L）。因此,酱油因高氨基酸和谷氨酸含量鲜味明显、口感厚重,适合烧制菜肴,而甜油口感协调、丰满,适合炒菜和凉拌菜;另外,甜油中高含量的还原糖含量能够改善菜肴质量、色泽和口感。     

厚味γ-Glu-Ile肽的谷氨酰胺酶酶法合成

Glu-Ile可通过解淀粉芽孢杆菌源谷氨酰胺酶酶法合成。结果表明:反应得最佳底物浓度比Gln∶Ile为100∶200(mmol/L∶mmol/L),最适pH值在9~10之间,最适温度为37℃,反应时间为10h,最大产量为21.58mmol/L。γ-Glu-Ile可以增加鸡汤、牛肉汤和酱油的鲜味、厚味、酸味和甜味,且γ-Glu-Ile在鸡汤、牛肉汤和酱油中的厚味阈值分别为(0.62±0.20),(0.83±0.37),(0.91±0.29)mmol/L。商用解淀粉芽孢杆菌源谷氨酰胺酶可用于γ-Glu-Ile的酶法合成,γ-Glu-Ile因能增加鸡汤、牛肉汤和酱油中的呈味感受而作为呈味添加剂。     

酱油的风味物质

酱油是一种大众调味品,传统的酱油酿造工艺是复合微生物菌群共生、多种生物酶共发酵的复杂过程,由此产生酱油特有的颜色、香气、味道,同时,在酿造过程中产生了许多生理活性物质。酱油的滋味由鲜、酸、甜、苦、咸等组成,酱油的香味主要来源于酮类、醇类、酯类、酚类、醛类等物质。该综述从分子层面阐述了酱油的呈味物质及风味物质,探讨了这些呈味物质的来源,并对这些香味物质的鉴定检测及它们所产生的生理活性进行简略阐述,旨在深入了解酱油酿造的生化反应过程和工艺机理,对于改善酱油的风味和提高酱油品质具有重要的意义。     

Salt Reduction in Foods Using Naturally Brewed Soy Sauce

ABSTRACT:  In recent years, health concerns related to salt/sodium chloride consumption have caused an increased demand for salt-reduced foods. Consequently, sodium chloride (NaCl) reduction in foods has become an important challenge. The more so, since a decrease in NaCl content is often reported to be associated with a decrease in consumer acceptance. The objective of the present study was to investigate whether or not it would be possible to reduce the NaCl content in standard Western European foods by replacing it with naturally brewed soy sauce. Three types of foods were investigated: salad dressing ( n  = 56), soup ( n  = 52), and stir-fried pork ( n  = 57). In the 1st step, an exchange rate (ER) by which NaCl can be replaced with soy sauce without a significant change in the overall taste intensity was established per product type, by means of alternative forced choice tests. In the 2nd step, the same consumers evaluated 5 samples per product type with varying NaCl and/or soy sauce content on pleasantness and several sensory attributes. The results showed that it was possible to achieve a NaCl reduction in the tested foods of, respectively, 50%, 17%, and 29% without leading to significant losses in either overall taste intensity or product pleasantness. These results suggest that it is possible to replace NaCl in foods with naturally brewed soy sauce without lowering the overall taste intensity and to reduce the total NaCl content in these foods without decreasing their consumer acceptance.
PRACTICAL APPLICATION: Health concerns related to salt consumption cause an increased demand for salt-reduced foods. Consequently, the development of foods with reduced salt content without decreasing the consumer acceptance is an important challenge for the food industry. A new possible salt reduction approach is described in the present article: The replacement of salt with naturally brewed soy sauce.     

米曲霉葡萄糖代谢抑制菌株的选育及发酵性能研究

选择对2-脱氧葡萄糖（2-DG）抗性较强的米曲霉A2-104为出发菌株,通过原生质体诱变育种,进一步获得了葡萄糖代谢抑制突变株A2-104-166-小试规模的酱油酿造实验结果显示：A2-104-166的蛋白酶和谷氨酰胺酶等主要酶系的活力均有不同程度的提升,碳水化合物消耗量下降33％,全糖／全氮、谷氨酸态氮／全氮、游离氨基态氮／全氮均有明显优势;感官鉴评结果表明A2-104-166菌株的酱油成味弱,甜味和鲜味加强。     

Chemical and sensory characteristics of low molecular weight fractions obtained from three types of Japanese soy sauce (shoyu) – Koikuchi, tamari and shiro shoyu

Three typical forms of Japanese soy sauce (shoyu), koikuchi, tamari and shiro shoyu, can be differentiated, primarily due to their different compositions of soybeans and wheat used for their productions. To evaluate and compare the chemical characteristics of the low molecular weight (MW) fractions of three types of shoyu with their sensory data, gel filtration fractions of ultrafiltration products with MW less than 500 Da (F-500) were subjected to chemical and sensory analyses. The results showed that salty and umami tastes were characteristic of all F-500 fractions, however, the umami taste intensities of those of koikuchi and tamari shoyu were found to be twice as large as that of shiro shoyu. After separation by gel filtration, it was found that the tastiest fractions of the three types of shoyu were those containing sodium salt, free l-glutamic acid and most other free amino acids, especially sweet taste-eliciting amino acids, at concentrations above their thresholds. In some umami fractions of koikuchi and shiro shoyu, that predominantly contained salt and phenylalanine but had a relatively low free l-glutamic acid content, a potential synergistic effect among free l-glutamic acid, salt and phenylalanine was obvious. This first report offers new insights into soy sauce research.