Non-volatile taste active compounds in the meat of Chinese mitten crab (Eriocheir sinensis)

The non-volatile taste active compounds, including soluble sugars, succinic acid, free amino acids and flavour 5′-nucleotides in the meat of Chinese mitten crab (Eriocheir sinensis) were analyzed, and their taste impacts were evaluated by taste active values (TAVs) and equivalent umami concentration (EUC) methods. The total free amino acid content of crab meat was 20.9 mg/g. Arginine, glycine and alanine were the major free amino acids, accounting for more than 70% of the total free amino acids. 5′-Adenosine monophosphate (AMP) was the main flavour 5′-nucleotide (75.3 mg/100 g), followed by 5′-inosine monophosphate (IMP) (34.4 mg/100 g) and 5′-guanosine monophosphate (GMP) (2.3 mg/100 g). Arginine, glycine, alanine, glutamic acid, IMP and AMP were of high TAV (greater than one), and they had strong taste impacts on the crab meat flavour. Glycine and alanine contributed to the major sweet taste, while glutamic acid, IMP and AMP contributed to the strong umami taste. As the TAVs of soluble sugar, succinic acid and bitter free amino acids were lower than one, thus those compounds are likely to have insignificant impact on the taste of the crab meat. The EUC was 4.2 g MSG/100 g crab meat, which meant that the umami taste of the crab meat was very intense.     

通电加热过程中凡纳滨对虾虾肉糜的游离氨基酸和核苷酸含量变化研究

为研究通电加热过程中不同加热温度(40、55、65、75、85和95℃)对凡纳滨对虾虾肉糜中主要非挥发性滋味成分的影响,采用氨基酸自动分析仪和高效液相色谱仪分别检测了虾肉糜中的游离氨基酸和核苷酸及其关联产物含量,并采用味道强度值(TAV)确定其中主要的呈味物质及贡献程度,最后通过味精当量(EUC)分析鲜味氨基酸和呈味核苷酸之间的协同作用,并对其鲜味进行评价。结果表明,与鲜虾相比,通电热处理的虾肉糜中游离氨基酸总量均有不同程度的减少。随着温度的升高,鲜味氨基酸、甜味氨基酸和苦味氨基酸的含量均呈现先减少后增加的趋势,且在65℃达到最小值(鲜味氨基酸、甜味氨基酸和苦味氨基酸的总TAV值分别为0.86、4.40、4.46)。通电加热并不影响ATP的降解途径只是会改变核苷酸及其关联产物的相对含量,尤其是促进Ado的产生。甘氨酸、精氨酸、谷氨酸、AMP和IMP在不同加热温度下其TAV几乎都大于1,是虾肉糜滋味的主要贡献者。味精当量以谷氨酸钠质量计,40℃最能促进虾肉糜鲜味的产生(EUC值为5.54 g MSG/100 g),在85℃处虾肉糜风味损失最小(EUC值为4.02 g MSG/100 g)。     

北海沙蟹特征滋味成分的分析

为研究沙蟹中的非挥发性滋味物质,采用氨基酸自动分析仪、高效液相色谱仪和电感耦合等离子体发射光谱仪检测沙蟹的游离氨基酸、5’-呈味核苷酸、有机酸以及无机离子等呈味物质的含量,并采用味道强度值（taste activity value,TAV）确定其中主要的呈味物质及贡献,最后通过味精当量（equivalent umami concentration,EUC）分析鲜味氨基酸和呈味核苷酸之间的协同作用,并对其鲜味进行评价。结果表明,精氨酸、组氨酸、甘氨酸、丙氨酸、谷氨酸、5’-单磷酸肌苷二钠、5’-单磷酸鸟苷二钠和Na＋的TAV大于1,是沙蟹滋味的主要贡献者。EUC值以谷氨酸钠质量计,结果表明沙蟹样品的EUC值为6.4?g/100?g,说明沙蟹具有强烈的鲜味特点。     

广西北部湾3 种贝类中主要呈味物质的测定及呈味作用评价

测定广西北部湾牡蛎(Crassostrea rivularis)、文蛤(Meretrix meretrix)和波纹巴非蛤(Paphia undulata) 3种贝类中的呈味核苷酸(AMP、GMP、IMP)、糖原等非挥发性呈味物质的含量,并采用味道强度值和等价鲜味值(或味精当量)评价这些非挥发性呈味物质的呈味作用鲜味强度。结果表明：牡蛎、文蛤和波纹巴非蛤的味精当量分别为3.2、1.9、2.7g MSG/100g,对应的味精当量的味道强度值分别是106.7、63.3、90,均远大于1,是其呈强烈鲜味的主要原因。     

Reducing the Influence of the Thermally Induced Reactions on the Determination of Aroma-Active Compounds in Soy Sauce Using SDE and GC-MS/O

A method based on simultaneous distillation extraction (SDE) coupled with gas chromatography–mass spectrometry/olfactometry (GC-MS/O) was developed for the analysis of volatile profiles in soy sauce. Its optimum operating conditions were as follows: 100 mL soy sauce plus 100 mL saturated brine; 2 h extraction using 50 mL dichloromethane. Eighty-eight volatile compounds were identified. Of these, 26 aroma-active compounds were detected by GC-O including 3-(methylthio)propanal, 2-methoxy-4-vinylphenol, 2-methoxyphenol, 2-methylbutanoic acid, 2,3-butanedione, phenylacetaldehyde, 2-ethyl-6-methylpyrazine, 3-methylbutanal, 2-methylbutanal, 3-methyl-1-butanol, and 2-methyl-1-butanol (which occurred at a high odor intensity in both high-salt liquid-state fermentation soy sauce (HLFSS) and low-salt solid-state fermentation soy sauce (LSFSS). SDE analysis of the odorless soy sauce indicated 12 volatiles (mainly Strecker aldehydes and α-dicarbonyl compounds). Thus, the proportions of these compounds (1.94–54.07 %) shown in previous GC-MS results could result from thermal degradation of non-volatile compounds in soy sauce. Especially, the contribution of 3-methylbutanal, 2-methylbutanal, phenylacetaldehyde, 3-(methylthio)propanal, and 2,3-butanedione to the aroma of soy sauce could be overestimated by conventional SDE-GC-O. With a full consideration of such limitations, this study will improve the application of SDE on aroma analysis of complex food matrix.     

17种市售广式酱油中风味物质的检测分析

广式酱油是国内产销量最大的一类酱油,不仅风味独特而且调味效果好。为进一步明晰广式酱油的风味构成,该实验运用气相色谱-质谱联用仪（GC-MS）、高效液相色谱仪（HPLC）与全自动氨基酸分析仪对酱油中的挥发性风味物质、氨基酸、有机酸进行分析。结果表明,苯乙醇（69.79～11 079.31 μg/kg）、苯乙醛（43.62～92 052.78 μg/kg）、4-乙基愈创木酚（71.47～13 086.21 μg/kg）、愈创木酚（79.78～11 542.93 μg/kg）与3-苯基-呋喃（52.61～10 009.73 μg/kg）对广式酱油香气活性值（OAV）贡献较大;谷氨酸（4.85～77.24 mg/g）对酱油滋味活度值（TAV）贡献最大且远高于其他氨基酸,其次是缬氨酸（1.58～4.21 mg/g）、丙氨酸（1.28～5.07 mg/g）与赖氨酸（1.46～3.74 mg/g）等;TAV贡献最大的有机酸是丁二酸（23.78～193.16 mg/mL）,其次是柠檬酸（7.29～173.24 mg/mL）。     

网箱海养卵形鲳鲹肌肉中呈味物质分析评价

测定网箱海养卵形鲳鲹肌肉中呈味核苷酸、游离氨基酸、无机离子和甜菜碱等主要呈味物质的含量,并采用味精当量值和呈味强度值来评价这些呈味物质的呈味强度。结果表明：网箱海养卵形鲳鲹肌肉的呈味核苷酸总量为379.9 mg/100 g,其中以5’-肌苷酸（5’-inosine monophosphate,IMP）含量最高,高达373.59 mg/100 g;游离氨基酸总量为256.60 mg/100 g,以甘氨酸（136.34 mg/100 g）、丙氨酸（27.47 mg/100 g）、谷氨酸（16.84 mg/100 g）贡献最大;K＋、Na＋、PO43－和IMP为主要呈味离子,甜菜碱含量为1.95 mg/g;呈味核苷酸和鲜味氨基酸具有一定的协同效应,其味精当量值为7.92 g MSG/100 g,呈味强度高达264。结果表明：IMP、甘氨酸、谷氨酸、丙氨酸、K＋和PO43－等为网箱海养卵形鲳鲹肌肉中主要滋味贡献物质,且IMP与甘氨酸和丙氨酸具有协同交互作用,这些是卵形鲳鲹肌肉呈现鲜味的物质基础。     

基于多元统计学解析我国四大烧鸡菜肴制品滋味物质图谱

以我国典型民族菜肴四大烧鸡为研究对象,系统分析其游离氨基酸和5’-核苷酸滋味物质,并计算其味精当量值和滋味活度值（taste activity value,TAV）,结合主成分分析（principal component analysis,PCA）、偏最小二乘判别分析（partial least squares discrimination analysis,PLS-DA）和聚类分析（hierarchical cluster analysis,HCA）等多元统计分析方法,解析我国四大烧鸡菜肴的滋味图谱。结果表明：我国四大烧鸡菜肴中游离氨基酸含量差异较大,其中沟帮子熏鸡菜肴中总氨基酸含量最高,为363.66～396.96 mg/100 g;通过TAV分析发现,谷氨酸对沟帮子熏鸡菜肴呈鲜味特征有显著贡献,肌苷酸对道口烧鸡菜肴呈鲜味特征有显著贡献;电子舌结果表明,我国四大烧鸡菜肴滋味存在差异;通过PCA、PLS-DA和HCA均可直观对我国四大烧鸡菜肴进行有效区分,不同烧鸡的鲜美滋味并不是由单一氨基酸和游离核苷酸决定的,鲜味、甜味和苦味氨基酸间的平衡以及与核苷酸的协同作用,导致我国四大烧鸡菜肴...     

四大名醋的游离氨基酸组成成分分析

目的检测四大名醋中的游离氨基酸,探讨各游离氨基酸对食醋滋味的贡献度,为食醋的质量控制及滋味品质的提高提供基础。方法先用磺基水杨酸溶液对食醋样品进行前处理,再利用30+氨基酸自动分析仪确定游离氨基酸含量。通过计算味道强度值(TAV)确定各游离氨基酸对食醋滋味的贡献率。结果保宁醋氨基酸含量最多为3438.55 mg/100 mL,红曲醋3年陈酿中氨基酸含量最少为737.55 mg/100 mL。保宁醋、镇江香醋、山西老陈醋中对滋味有贡献的氨基酸个数依次为11、8、5。不同酿造年份(3年、5年、8年)的红曲醋中对滋味有贡献的氨基酸个数依次为3、4、4。结论利用氨基酸自动分析仪可确定食醋中游离氨基酸的含量,而味道强度值的引入可计算各游离氨基酸对食醋滋味的贡献率。     

Direct determination of free tryptophan contents in soy sauces and its application as an index of soy sauce adulteration

A simple and rapid HPLC method using UV detector for determination of tryptophan (Trp) contents in pure fermented soy sauces, acid-HVP, and commercial soy sauces was developed. The method requires only simple sample pretreatment. The limit of detection (LOD) is estimated at 1 mg/L (signal-to-noise ratio of 3), and the recovery yields ranged from 92% to 108%. The analysis showed that Trp in all of the analysed acid-HVP samples was not detected and there was obvious detection of Trp (ranged from 136.4 to 261.8 mg/L) in all of the analysed fermented soy sauce samples. The observations suggest that Trp is a practical index of pure fermented soy sauce. The absence of Trp contents or lower level of Trp contents than that in pure fermented soy sauces suggests the soy sauces are not pure fermented soy sauces or presence of soy sauce adulteration. Simultaneous determination of levulinic acid (LV) in samples may be a good help in making assessment of soy sauce adulteration with acid-HVP.     

Determination of the Free Amino Acid,Organic Acid,and Nucleotide in Commercial Vinegars

The selected taste‐active compounds in several kinds of commercial vinegar including amino acids, organic acids, and nucleotides were determined by High Performance Liquid Chromatography (HPLC). The results showed that glutamine and alanine, which contribute the umami and sweet taste to the flavor of vinegar, are high in Taste Activity Value (TAV). Acetic acid is the major organic acid in vinegar, making up as much as 91.4% of the total organic acid composition. Nucleotides, which were only detected in 5 brands of commercial vinegar and are both low in TAV, contribute less taste in vinegar. Our research provides a multiple chemical compositional characterization of vinegar and proposes a possibility of classification of different kinds of vinegar.     

甜面酱的鲜味成分分析

采用国标方法分别对7种市售甜面酱样品的水分、粗脂肪、总氮和粗蛋白的含量进行了测定,利用氨基酸自动分析仪、高效液相色谱仪分别对甜面酱中的游离氨基酸及核苷酸含量进行了测定,利用凝胶色谱柱对甜面酱中小分子肽的分子量分布进行了测定,同时分析计算了甜面酱的水解度、平均肽链长度和氨基酸味道强度值,及其对呈味的贡献。研究结果表明:7种市售甜面酱的水分、粗脂肪、总氮和粗蛋白等平均含量分别为51.42%,1.84%,1.284%和7.32%;甜面酱中游离氨基酸总含量为1.55~2.78 g/100 g,含量相对较高的为脯氨酸、谷氨酸、亮氨酸、天门冬氨酸,其中谷氨酸的味道强度值(TAV值)最高(7.00~25.67),对鲜味具有重要的贡献;甜面酱中的核苷酸主要为次黄嘌呤(3.19~4.87 mg/100 g),但其TAV值均小于0.5,对甜面酱的滋味没有直接影响;甜面酱中小分子肽的含量为0.55~3.31 g/100 g,平均肽链长度为2~4,分子量主要分布于221~445 u之间,且对鲜味具有一定的贡献。     

Determination of levulinic acid in soy sauce by liquid chromatography with mass spectrometric detection

A novel method using liquid chromatography coupled with mass spectrometry (LC–MS) was developed for the determination of levulinic acid (LV) in soy sauces to identify the addition of acid hydrolyzed vegetable protein (acid-HVP). One hundred percentage naturally brewed soy sauce (NBS) and enzymatic hydrolyzed vegetable protein (enzymatic HVP) did not contain LV (<0.01 mg/mL). There was apparent detection of LV in acid-HVP and blended soy sauce with acid-HVP (2.98–21.66 mg/mL). Gas chromatography (GC) and high performance liquid chromatography (HPLC) at 430 nm methods were also investigated. The results by GC gave similar data to those by LC–MS. In enzymatic HVP, LV was detected by HPLC at 430 nm, but it was confirmed that the detected component was not in fact LV by mass spectrometric identification of the isolated peak compound. We found that LV is under the detection limit in enzymatic HVP. This study showed that LV is below the detection limit in NBS and enzymatic HVP and is apparently detected in acid-HVP and blended soy sauces with acid-HVP. These results indicate that LV is a practical index of blend with acid-HVP and also corresponds with the JAS (Japanese Agricultural Standard) or CNS (Chinese National Standard) criteria in which the presence of LV in soy sauces indicates adulteration with acid-HVP. The LC–MS method is analytically optimal for the precise determination of LV, because peak misidentification may be practically eliminated.     

Determination and quantification of the kokumi peptide, γ-glutamyl-valyl-glycine,in commercial soy sauces

Recent studies have demonstrated that kokumi substances, such as glutathione, are perceived through the calcium-sensing receptor (CaSR), and screening by CaSR assay and sensory evaluation has shown that γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly) is a potent kokumi peptide. In this study, the contents of γ-Glu-Val-Gly in six commercial brands of dark-coloured soy sauces, two brands of light-coloured soy sauce, and one brand of white soy sauce, were investigated by high performance liquid chromatography–tandem mass spectrometry (LC/MS/MS), followed by derivatization with 6-aminoquinoyl-N-hydroxysuccinimidyl-carbamate (AQC). The analyses indicated that γ-Glu-Val-Gly was present in all investigated soy sauces at concentrations ranging from 0.15 to 0.61 mg/dl, demonstrating that it is widely distributed in soy sauces.     

不同地域特色熏鸡非盐呈味物质比较分析

为探明市售熏鸡的滋味呈味物质差异,对我国不同地域特色熏鸡产品的滋味物质进行综合评价。选取6种具有不同地域特色的代表性品牌熏鸡为研究对象,对其游离氨基酸和核苷酸进行分析,利用滋味活性值和等鲜浓度(equivalent umami concentrations,EUC)值评价滋味物质的呈味作用和鲜味强度,通过电子舌评价不同熏鸡间的滋味轮廓差异。结果表明:6种不同地域特色熏鸡的游离氨基酸、核苷酸含量及味觉特征存在显著差异(P<0.05);谷氨酸和5’-肌苷酸(5’-inosinic acid,5’-IMP)是熏鸡中主要的鲜味物质;6种熏鸡的EUC值在0.56%~16.08%范围内;电子舌结果表明鲜味和丰富性是熏鸡重要的味觉特征,其中,聊城熏鸡的丰富性特征最强,藤桥熏鸡的鲜味特征最强。综上,谷氨酸和5’-IMP是熏鸡中主要的鲜味物质,鲜味是熏鸡最主要的呈味特征,鲜味物质的差异可能与当地饮食文化和消费习惯有关。     

Characterisation of taste-active compositions,umami attributes and aroma compounds in Chinese shrimp

Chinese shrimp is one of the most important aquatic resource in China due to its unique flavour and high nutritional value. In this study, the taste-active components including free amino acids (FAAs), 5'-nucleotides, organic acids, inorganic ions, trimethylamine oxide (TMAO) and betaine were analysed. The synergistic effect between amino acids and 5'-nucleotides was determined by partial least squares (PLS) analysis. The taste activity value (TAV) and equivalent umami concentration (EUC) were calculated to analyse the major taste-active components and umami attributes. Then, the aroma compounds were extracted by simultaneous distillation extraction (SDE), head-space solid-phase microextraction (HS-SPME) and supercritical fluid extraction (SFE) methods, respectively, and identified by gas chromatography-mass spectrometry (GC-MS). Arginine (Arg), glycine (Gly), guanosine 5'-monophosphate (5'-GMP), inosine-5´-monophosphate (5'-IMP), de-nosine-5´-monophosphate (5'-AMP), succinic acid, lactic acid and inorganic ions with TAV higher than 1 contributed greatly to the taste. The umami intensity for 100 g of Chinese shrimp was equivalent to 4.58 g monosodium glutamate (MSG), indicating that Chinese shrimp had relatively high umami taste value. Ninety-seven volatile compounds including esters, alcohols, acids, aldehydes, ketones, heterocycles, aromatics and alkanes were identified. This research might help consumers to understand the flavour compositions and promote the development of flavour products of Chinese shrimp.     

Characteristics of Acid Hydrolysate from Defatted Peanut Flour

We hypothesized that aflatoxin-contaminated defatted peanut flour could be acid hydrolyzed to produce an aflatoxin-free seasoning sauce. Physical and chemical properties and amino acid composition of the flour hydrolyzed at 120°C for 4 hr with 5N HCI and destruction of aflatoxin B, during hydrolysis were investigated. The pH (5.72), specific gravity (1.20), total solids (402 mg mL-¹), and reducing sugar (2.9 mg mL^-1) and total nitrogen (17.5 mg mL-¹) contents of the peanut hydrolysate were similar to those of commercial soy sauces or seasoning sauces made by chemical processes. Glutamic acid, aspartic acid, arginine and glycine were the major amino acids in the hydrolysate and should contribute substantially to enhancing flavor. Aflatoxin B, was totally destroyed during acid hydrolysis at 100 or 120°C.     

2种铁营养强化剂对强化酱油感官影响的比较

该实验分别用乙二胺四乙酸铁钠(NaFeEDTA)和硫酸亚铁(FeSO4)与柠檬酸的混合物对低盐固态发酵酱油(虎王酱油)和高盐稀态发酵酱油(宽牌酱油)进行强化，强化剂量均为5mg铁／15mL酱油。室温静置ld后，对强化后酱油的色泽、香气、味道、体态、金属味等指标进行评价。结果表明，2种不同生产工艺的强化酱油中，NaFeEDTA强化酱油的感官评价得分较高，与空白酱油得分相似，明显高于FeSO4强化酱油，说明NaFeEDTA对2种工艺酱油的感官影响均低于FeSO4。     

Profile of Volatile Compounds in 12 Chinese Soy Sauces Produced by a High‐Salt‐Diluted State Fermentation

There have been limited studies on the flavour compounds in Chinese soy sauces. In order to obtain wider information about the chemical composition of the volatile fractions in 12 brands of Chinese soy sauces produced by high‐salt‐diluted state fermentation (HSDSF) and to compare them, a headspace solid microextraction method coupled to gas chromatography‐mass spectrometry (HS‐SPME‐GC‐MS) method was proposed and developed. A 50/30μm Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS) fibre was used for extraction of volatiles. The adsorption time and temperature of the SPME fibre were optimized separately for various aroma compounds in the soy sauce (50°C and 40 min for alcohols and esters; 40°C and 50 min for ketones, aldehydes and pyrazines; 60°C and 50 min for acids, phenols and furans). From the study, a total of 80 compounds were identified in the 12 samples, of which 34 volatiles were in common. Alcohols and acids were the main volatiles present in the soy sauces. Dominant volatile alcohols were ethanol, 2/3‐methyl butanol and β‐phenylethyl alcohol; and important acids were acetic acid, butanoic acid, and 3‐methylbutanoic acid. Miscellaneous, esters, furans and phenols also made large contributions to the total volatiles of the soy sauces. According to the scatter point plot obtained from principal component analysis, the 12 soy sauces could be classified into four groups.     

酱卤鸭脖的特征风味物质剖面解析

为构建酱卤鸭脖的特征风味指纹图谱,该文利用电子鼻、电子舌、气相色谱-质谱联用技术（Gas Chromatography-Mass Spectrometry,GC-MS）和高效液相色谱技术（High Performance Liquid Chromatography,HPLC）结合气味活性值（Odor Activity Value,OAV）、滋味活性值（Taste Activity Value,TAV）和味精当量（Equivalent Umami Concentration,EUC）,对3款市售酱卤鸭脖（W牌、J牌、H牌）的特征风味进行剖面解析。结果表明,W牌、J牌和H牌中分别鉴定出44、37、32种挥发性风味物质。其中丁香酚、芳樟醇、肉桂酸乙酯、茴香脑等因具有较高OAV和特殊香气被划定为3种鸭脖共有的特征挥发性风味物质,可贡献甜香、果香和脂香。电子鼻结果则表明3种鸭脖在含硫化合物和氮氧化合物上存在差异;谷氨酸、丙氨酸、5,-肌苷酸、5,-鸟苷酸因TAV>1被确定为3种酱卤鸭脖的特征滋味物质,对鲜味和甜味贡献突出。此外,H牌的EUC值（4.41 g MSG/100 g）显著高于其他...