葡萄酒中游离氨基酸的HPLC测定方法

近年来,人民饮食消费水平日益提高,营养保健意识也不断增强,要求饮食能促进身体健康,吃要注意三低一高食品,喝酒要选择三低三丰富的酒种。所谓三丰富中有丰富的氨基酸一项,而好的葡萄酒中就含有丰富的氨基酸,因此如何准确快速测定葡萄酒中的氨基酸就显得十分重要。氨基酸的分析方法很多,仅液相色谱法就有柱前衍生法,柱后衍生法两种。柱后衍生法需用离子交换柱及多种试剂,且分析时间长,费用较高。本实验采用柱前衍生法进行。该法具有快速、准确、费用低、易于操作等优点。1 材料与方法1.1 仪器及材料仪器:日本岛津LC-6A高效液相色谱仪,SP…     

6种葡萄籽中水解氨基酸和游离氨基酸含量测定及比较

以异硫氰酸苯酯为柱前衍生试剂,采用Thermo Acclaim~(TM) 120 C_(18)色谱柱(250mm×4.6mm,5μm),流动相A为pH 6.5的乙酸钠缓冲溶液,流动相B为甲醇—乙腈—水(体积比20:60:20),在流速1.0mL/min,梯度洗脱,柱温30℃,检测波长254nm的条件下,建立了高效液相色谱法测定葡萄籽中水解氨基酸和游离氨基酸的含量。结果表明,在试验浓度范围内,17种氨基酸的R~2均0.999 0;水解氨基酸的加样回收率为92.0%～104.6%,RSD为0.83%～4.07%;游离氨基酸的加样回收率为95.2%～102.4%,RSD为1.06%～3.98%。同时,6种葡萄籽中水解氨基酸的含量为130.46～163.24 mg/g,游离氨基酸的含量为2.04～5.13mg/g;用于酿造白葡萄酒的雷司令、赛美容和贵人香3种葡萄籽中游离氨基酸含量较高,用于酿造红葡萄酒的黑皮诺、蛇龙珠和赤霞珠3种葡萄籽中水解氨基酸含量较高。该方法稳定可靠,可用于葡萄籽中水解氨基酸和游离氨基酸的含量测定。     

黑豆发酵过程的氨基酸分析

通过对黑豆发酵产品的氨基酸分析,阐述了豆豉的自然发酵、纯种发酵和多菌种发酵对氨基酸生成的影响。     

AccQ·Tag柱前衍生反相-高效液相色谱法测定齿果酸模中的氨基酸含量

为研究齿果酸模中氨基酸的种类和含量,探讨其营养特性和食用开发价值。以6-氨基喹啉-N-羟基琥珀酰亚胺基甲酸酯(AQC)为衍生试剂,以磷酸盐缓冲液为流动相A,乙腈溶液为流动相B进行梯度洗脱;在柱温37℃条件下用AccQ·Tag进行柱前衍生,反相-高效液相色谱法用紫外检测器在波长248nm进行测定。结果表明:齿果酸模中含有17种氨基酸,干基总含量为252.35mg/g,有很好的食用开发前景。17种氨基酸线性回归方程的相关系数r在0.9995以上(n=5),测定的平均回收率为97.1%～102.6%,相对标准偏差RSD为0.3%～3.2%(n=3),测定结果令人满意。     

鱼腐乳发酵过程中游离氨基酸含量及抗氧化活性的变化

利用总状毛霉（Mucor racemosus）和红曲霉（Monascus）F1对鱼豆腐进行发酵研制鱼腐乳,对鱼腐乳发酵过程中的游离氨基酸及抗氧化活性的变化规律进行分析。结果表明：在发酵过程中,鲜味氨基酸、必需氨基酸、疏水氨基酸、总氨基酸的含量都呈逐渐升高的趋势,在后熟第28天时分别达到了138.57 mg/100 g、491.68 mg/100 g、340.06 mg/100 g、915.77 mg/100 g。在发酵过程中DPPH自由基清除率和羟自由基清除率也呈逐渐升高的趋势,在后熟第28天时分别达到70.30%和63.11%,分别比发酵开始时提高了53.09%和24.14%。     

高效液相色谱法测定玉米蛋白粉中游离氨基酸含量

建立高效液相色谱法同时测定玉米蛋白粉中17种游离氨基酸含量的方法。样品用盐酸溶液(0.1 mol/L)提取,采用6-氨基喹啉-N-羟基琥珀酰亚胺基-氨基甲酸酯(AQC)为衍生剂衍生。应用Nova-PakTM C_(18)柱,以10 mmol/L醋酸铵缓冲液、乙腈和超纯水为流动相进行梯度洗脱,柱温为37℃,检测波长为248 nm,外标法定量。结果表明,17种游离氨基酸线性关系良好,其中16种游离氨基酸在0.002 5~0.5μmol/mL范围内具有良好的线性关系,胱氨酸浓度在0.006 3~1.25μmol/mL范围内线性关系良好,相关系数在0.999 1~0.999 9之间,回收率为95.10%~105.21%,RSD为1.36%~4.39%。该方法灵敏度高、重现性好、操作简单,可用于检测玉米蛋白粉中游离氨基酸含量。     

酱油中游离氨基酸成分分析

采用高效液相色谱柱前衍生法对酱油中氨基酸的组成进行分析,结果表明市售酱油中氨基酸的组成与酿造酱油中氨基酸组成存在一定的差异,这是因为人为添加了鲜味剂,或者是使用植物蛋白水解液所致。经研究表明通过对酱油中氨基酸组成成分分析可以作为酿造酱油品质评价体系提供新思路。     

AccQ.Tag法测定酱油中游离氨基酸组成

采用高效液相色谱柱前衍生AccQ.Tag法对酱油中氨基酸的组成进行分析,结果表明市售酱油中氨基酸的组成与酿造酱油中氨基酸组成存在一定的差异,这是因为人为添加了鲜味剂,或者是使用植物蛋白水解液所致.经研究表明通过对酱油中氨基酸组成成分分析可以作为酿造酱油品质评价体系提供新思路.     

黑豆发酵过程的氨基酸分析

通过对黑豆发酵产品的氨基酸分析,阐述了豆豉的自然发酵、纯种发酵和多菌种发酵对氨基酸生成的影响。     

永川豆豉发酵过程中总糖和氨基酸变化与滋味的形成

通过采集传统发酵过程中的永川豆豉样本,对其总糖、还原糖、糖化酶活性、总氨基酸、游离氨基酸构成进行测定。结果表明,在成品豆豉游离氨基酸中,鲜味氨基酸占总游离氨基酸的23.98%,鲜味风味突出。豆豉中甜味氨基酸和还原糖共同构成了其回甜的滋味特点。豆豉中短链脂肪酸和乳酸使其呈现一定的酸味,酚类物质和苦味氨基酸呈现一定的苦味。这些最终决定了永川毛霉型豆豉的特有的咸鲜回甘风味特点。     

葡萄酒酿造过程中氨基酸含量变化的研究

应用HPLC对我国4个产区多个品种葡萄酒酿造过程样品中氨基酸含量变化趋势进行了研究,结果表明,L-脯氨酸是所有葡萄汁中氨基酸的主体,也是各样品含量差异最大的氨基酸;红葡萄酒中含脯氨酸、苏氨酸、赖氨酸等20种氨基酸,其中以脯氨酸含量最高,发现不同葡萄品种之间游离氨基酸种类和含量有差别,这与葡萄品种、气候、发酵工艺有关。     

Analysis of free amino acids in green coffee beans

For the determination of free amino acids in green coffee beans, 9-fluorenylmethylchloroformate was applied successfully as the precolumn derivatization agent. The separation of the 27 free amino acids of green coffee as yet identified or quantitatively determined is almost complete. The paper describes in detail the conditions of extraction, derivatization and resolution and presents reproducible data of standard curves and of quantitative results. It has been demonstrated that by applying the extraction procedure described, 99.8% of the free amino acids detectable by this method are extracted. On principle, Arabica and Robusta coffees contain the same main and minor amino acids. It was possible for the first time to determine the free amino acids ornithine, -alanine and pipecolic acid quantitatively in Arabica and Robusta coffees as well as hydroxyproline in Arabica coffees.

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Bestimmung freier Aminosäuren in grünen Kaffeebohnen. I. Bestimmung der Aminosäuren nach Vorsäulen-Derivatisierung mit 9-Fluorenylmethyloxycarbonylchlorid

Zusammenfassung Zur Bestimmung freier Aminosäuren in Rohkaffees wurde 9-Fluorenylmethyloxycarbonylchlorid als Vorsäulenderivatisierungsreagenz erfolgreich eingesetzt. Die Trennung der 27 in Rohkaffee bisher identifizierten bzw. quantitativ bestimmten freien Aminosäuren gelang weitestgehend vollständig. Extraktions-, Derivatisierungs- und Trennbedingungen sind detailliert beschrieben, Eichung sowie Ergebnisse der quantitativen Aminosäurenanalytik wurden statistisch abgesichert. Es konnte gezeigt werden, daß durch Anwendung des beschriebenen Extraktionsverfahrens 99,8% der mittels dieser Methode erfaßbaren freien Aminosäuren aus Rohkaffees extrahiert werden. Arabica- und Robusta-Rohkaffees weisen prinzipiell gleiche Haupt- und Minoraminosäuren auf. Erstmals wurden die freien Aminosäuren Ornithin, -Alanin und Pipecolinsäure in Arabica- und Robusta-Rohkaffees sowie Hydroxyprolin in Arabica-Rohkaffees quantitativ bestimmt.

     

Analysis of free amino acids in green coffee beans

To investigate amino acid changes in green coffee beans in the post-harvest period, amino acid concentrations were determined in green beans and after modelled drying, fermentation and storage. After the drying at alternating temperatures up to maximally 40°C, considerable changes in the concentrations of individual amino acids were identified. At the beginning of the storage period, significant changes in concentration were found to a minor extent. Under the condition of drying, it was mainly the concentration of glutamic acid that changed considerably. There was an increase in all the samples by 500 mg/kg dry matter on average, which corresponds to an increase of about 50% of the original value. In contrast, the concentration of aspartic acid in most of the samples decreased clearly due to drying. For the predominant part of the coffee samples, there was a significant increase in the hydrophobic amino acids Val, Phe, Ile and Leu. Changes of the quantities of other amino acids were non-uniform and only insignificant. Constant drying at 80°C for most of the amino acids brought about only minor concentration changes compared to those values obtained at 40°C. Modelled fermentation had no significant effect on the concentrations of the individual amino acids. After a 4-week storage of dried beans, amino acid concentrations did not change further. It is very possible that different post-harvest treatment parameters may influence the amount of aroma precursor compounds in the coffee beans.     

Changes on free amino acids during the alcoholic fermentation of strawberry and persimmon

Changes in amino acids and ammonium were monitored during the alcoholic fermentation of strawberry and persimmon purees. Fermentations were carried out either by autochthonous or by commercial yeasts. The amino acid content in strawberry and persimmon was lower than that of grapes but enough to successfully perform the alcoholic fermentation, showing a different consumption pattern. Arginine, although is not present in the most strawberry substrates, appears in strawberry wines (2.75–3.36 mg L^?1). Additionally, as opposed to grape wine, an exceptional high consumption of proline was observed during the alcoholic fermentation of strawberry purees. The consumption of amino acids was highly influenced by the substrate and the S. cerevisiae strain used for the fermentation process. These results were confirmed by principal component analysis, which was able to group the samples based on substrate, harvest or yeast strain, considering the amino acids as variables.     

HPLC法测定丙酸菌发酵液中游离氨基酸的含量

建立了一种利用反相高效液相色谱法检测18种氨基酸的方法。以2,4-二硝基氟苯(DNFB)为柱前衍生剂,使用TIANHE Kromasil C18(4.6mm×250mm,5μm)反相色谱柱,采用二元梯度洗脱,流动相A相为0.05mM醋酸钠缓冲液(pH5.3),B相为乙腈-水(v/v=1∶1)。在该条件下,各氨基酸线性回归方程相关系数均大于0.9991,18种氨基酸的加样回收率均在95%103%范围内,该法快速、可靠,并将其应用于丙酸菌发酵液中的氨基酸检测。     

四川麸醋发酵过程中有机酸及游离氨基酸含量变化分析

为了解四川麸醋发酵过程中有机酸及游离氨基酸含量的变化规律,采用高效液相色谱和氨基酸自动分析仪对发酵过程中7种有机酸及17种游离氨基酸含量进行测定。结果表明,四川麸醋发酵过程中含量最高的2种有机酸为乙酸和乳酸,随着发酵的进行,其含量显著增加;草酸、柠檬酸、酒石酸、苹果酸、琥珀酸含量较低,在发酵过程中含量略有变化。游离氨基酸含量随着发酵的进行呈增加趋势,从发酵初期668mg/100g增至1 470 mg/100g,其中天门冬氨酸、丝氨酸、谷氨酸、甘氨酸、丙氨酸、缬氨酸、组氨酸、异亮氨酸、酪氨酸、脯氨酸对四川麸醋风味形成具有较大的贡献。     

发芽对黑大麦游离氨基酸及其他营养成分的影响

黑大麦是一种营养丰富,开发价值较高的谷物,发芽会引起谷物食品中成分的变化。本实验首先研究了黑大麦的发芽工艺条件,在此基础上进一步研究发芽对黑大麦中游离氨基酸、蛋白质、脂肪、淀粉、膳食纤维和维生素B₁、维生素B₂等常规营养成分含量的影响。结果表明:浸泡8 h后,15 ℃温度条件下发芽48 h,黑大麦的发芽率达到最高(62.14%)。与未发芽黑大麦相比,发芽72 h后,黑大麦中游离氨基酸、蛋白质、淀粉、不可溶性膳食纤维、总膳食纤维、维生素B₁、维生素B₂及钙、铁和锰等元素的含量均显著升高(p<0.05),而可溶性膳食纤维含量显著降低(p<0.05)。发芽可使黑大麦营养价值得到显著提升。     

贵州代表性茶树品种茶青萎凋期游离氨基酸动态分析及评价

该研究对福鼎、金观音和黔茶1号3个贵州代表性品种萎凋处理,基于高效液相色谱分析不同萎凋期茶鲜叶中游离氨基酸含量动态变化,结合味道活性值和特殊氨基酸分析,探究不同品种萎凋期游离氨基酸差异,增加对品种适制性的理解.结果表明,萎凋期间游离氨基酸含量总体呈上升趋势;必需氨基酸占比均值黔茶1号最高(33.200％),金观音次之(...     

Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

The aim of the work was to evaluate the profile of free amino acids (FAA) as the possible precursors of biogenic amines (BAs) in different varieties and hybrid lines of Lupinus luteus and Lupinus angustifolius and its changes during fermentation. Lupins have high amounts of FAA, and therefore, significant contents of BAs by the action of bacterial amino acid decarboxylases can be formed. In view of this, the effect of three Pediococcus pentosaceus strains KTU05‐8, KTU05‐9 and KTU05‐10 on BA formation during lupin fermentation was studied. The formation of BAs was monitored during 48‐h fermentation at solid‐state conditions and compared with that in samples after submerged fermentation and in the control nonfermented samples. The lupin variety, fermentation conditions and the Pediococcus strain were found to have the significant effect on the FAA profile and BA contents in fermented lupin; the interaction between analysed factors was F(5.989) = 1755.321 (P < 0.0001) and F(5.660) = 130.736 (P < 0.0001), respectively. A weak correlation was found between amino acid His and histamine (r = 0.3709; P = 0.0005) and between Phe and phenylethylamine (r = 0.3914, P = 0.0002) in lupin samples, but the significant correlations between amino acid Tyr and tyramine and between Lys and cadaverine were not found. By optimising the fermentation technology, it is possible to increase the nutritional value and functionality of lupin.     

红枣白兰地发酵过程中酒醅氨基酸和有机酸的变化分析

利用高效液相色谱法(HPLC)对红枣白兰地酒醅发酵过程中的氨基酸和有机酸含量,及发酵过程中酒度、酸度的动态变化进行了分析研究。研究表明:红枣白兰地发酵酒醅中检测到16种氨基酸和7种有机酸,其中脯氨酸、天冬氨酸、谷氨酸是红枣白兰地发酵的主要氨基酸,发酵过程中平均含量分别为39.749、35.477、11.888 mg/g;乙酸、苹果酸、乳酸是红枣白兰地发酵的主要有机酸,在发酵结束时含量分别为8.189、4.243、3.646 mg/g。发酵过程中,氨基酸和有机酸整体含量呈增长趋势;甜味氨基酸和鲜味氨基酸为总氨基酸含量的45.39%、35.79%,苦味氨基酸含量较低,酒醅中氨基酸是红枣白兰地中风味成分的重要前体物质,并赋予红枣白兰地柔和的风味;比例协调的有机酸有利于增强酒的醇厚口感。