慕萨莱思葡萄酒酿造过程中的氨基酸组成及含量分析

为探究慕萨莱思葡萄酒酿造过程中氨基酸的变化,以慕萨莱思葡萄酒酿造过程中的葡萄原汁、浓缩汁及成品酒为研究对象,采用氨基酸自动分析仪对3种样品中的氨基酸组成及含量进行分析。结果表明,慕萨莱思葡萄酒中含脯氨酸、苏氨酸、赖氨酸等19种氨基酸;且葡萄原汁、浓缩汁和成品酒中的氨基酸组成及含量不同,其中脯氨酸含量差异大,在成品酒中的含量为609.04 mg/L,占氨基酸总量的95.37%。同时在慕萨莱思葡萄酒酿造的各个阶段中均检出γ-氨基丁酸。     

新疆慕萨莱思葡萄酒的加糖酿制及其酒质检验

为提升慕萨莱思葡萄酒葡萄汁的发酵糖度,改善酒的风味品质。试验以木纳格鲜葡萄为原料,在其葡萄汁中添加蔗糖,检测其高温浓缩时间,酿制葡萄酒中的酒精度,澄清度、总酸、8种金属元素以及酒的口感风味。结果表明:加糖酿制可缩短葡萄汁高温浓缩时间(糖度达22.0°Brix提前约1.5 h),可明显提高慕萨莱思葡萄酒的酒精度(由13.60°上升至14.83°)、澄清度(由48.22%上升至60.62%)、总酸及挥发酸含量(由70.88 mg/L上升至79.06 mg/L),均达极显著差异(p0.01);而对慕萨莱思的镁(Mg)、铁(Fe)、铜(Cu)、锌(Zn)、钙(Ca)、锰(Mn)、钾(K)和钠(Na)金属元素含量均未造成显著影响(p0.05)。结合感官评定加糖酿制可减轻熬煮浓缩产生的焦糖味和苦涩味,突出果香和醇香味,能有效改善慕萨莱思葡萄酒的品质。     

慕萨莱思降糖、降酸优良酵母菌的筛选

酸度和甜度是影响慕萨莱思葡萄酒的重要指标,慕萨莱思糖酸含量过高会导致酒体不协调,影响其感官品质。酿酒酵母是慕萨莱思发酵过程中的重要微生物,具有一定的降糖降酸能力,本实验对50株降糖特性菌和50株降酸特性菌进行相关实验,筛选获得T-Y128-2和F2-P90-3两株降糖、降酸效果优良的酿酒酵母,经降糖降酸处理后,其糖度和酸度比原酒低。     

新疆慕萨莱思自然发酵过程中酵母菌表型多样性及优势菌分析

目的：研究新疆慕萨莱思自然发酵过程中酵母菌种群表型多样性与其优势菌,探讨慕萨莱思传统工艺对其主要菌群结构的影响。方法：来自于新疆阿瓦提一古作坊的慕萨莱思酿制原料、原料处理液及发酵液(自然发酵过程中)共19份样品被用于酵母菌分离,分离株利用WL培养基培养归类,筛选代表株,对代表株进行形态观察、生理生化特征检测与类平均连算法聚类分析,探讨新疆慕萨莱思自然发酵过程中酵母菌表型多样性及优势菌群。结果：分离得到217株酵母菌,13种WL培养类型,8个表观群。13株代表菌株经初步鉴定为7个属,疑似为13个种,表明慕萨莱思酵母菌具有丰富的多样性。Hanseniaspora spp.为葡萄果皮、果汁及皮渣中的优势菌,S.cerevisiae为慕萨莱思自然发酵过程中起发者及唯一一种优势菌,非酿酒酵母偶尔在发酵液中发现。结论：慕萨莱思酿制过程中,葡萄原料原有的酵母菌经熬煮工序几乎被全部杀死,自然发酵中唯一优势菌S.cerevisiae可能来自酿制场所和设备,并具有较高适应能力。     

慕萨莱思中呋喃酮、5-甲基糠醛和3-甲硫基丙醇的香气阈值及二元协同作用

采用3点选配法确定慕萨莱思重要香气物质5-甲基糠醛（5-methylfurfural,5-MF）、呋喃酮（furanone,DMHF）和3-甲硫基丙醇（3-methylthiopropanol,3-MTP）阈值,并运用S型曲线和σ-τ图分析其二元互作关系,以期为慕萨莱思产品风味控制提供参考。5-MF、DMHF、3-MTP在乙醇体积分数12%模拟葡萄酒中阈值分别为190.000、45.000μg/L和382.000μg/L,在乙醇体积分数12%的慕萨莱思脱香液（7.4～7.9°Brix）中阈值分别为97.580、798.950μg/L和196.533μg/L。经研究发现糖度7.4～7.9°Brix和糖度6.4～7.9°Brix慕萨莱思脱香液（12%乙醇）对3种香气阈值的影响较小,8%、10%、12%、14%乙醇体积分数慕萨莱思脱香液（糖度7.4～7.9°Brix）中3种香气的阈值无明显差异。运用S型曲线和σ-τ图分析在12%乙醇的模拟葡萄酒和12%乙醇的慕萨莱思脱香液（糖度7.4～7.9°Brix）中3种香气的二元混合溶液均呈加成作用。     

浓缩方式对慕萨莱思品质及香气成分的影响

研究4种处理方式慕萨莱思的品质及香气成分的差异,并对其进行QDA统计分析。结果表明:冷浓缩处理组的慕萨莱思中总糖、还原糖、可溶性固形物、pH、澄清度及生物活性指标均显著高于热浓缩慕萨莱思组;4种酒样中酯类物质种类最多,高达65种,为主要呈香物质。冷浓缩慕萨莱思中酯类物质相对含量最高,占总挥发性物质相对含量的48.77%,热浓缩慕萨莱思中酯类物质相对含量略低于冷浓慕萨莱思,为36.95%。QDA统计结果表明:冷浓缩慕萨莱思色泽鲜亮均一、口感柔滑、酸甜适口,具有明显的花果香味,且余香、余味时间长,其感官评价最高,风味最佳。     

液质联用技术在慕萨莱思葡萄酒非挥发性成分检测中的应用

探究不同酿造时期的慕萨莱思、自酿葡萄酒以及进口葡萄酒的物质种类及含量的区别。采用液质联用技术(liquid chromatography-mass speetromety,LC-MS)分析不同酿造时期的慕萨莱思葡萄酒以及慕萨莱思与进口葡萄酒、自酿葡萄酒中的成分及相对含量的差别。分析得出,慕萨莱思葡萄酒主要成分为儿茶素、没食子酸、酒石酸、对羟基苯甲酸、阿魏酸、肉桂酸、表儿茶素等几十余种成分。其中的一些功能性成分,如没食子酸、儿茶素等,都高于其他葡萄酒,但酒石酸、苹果酸含量较低,进而发现在慕萨莱思葡萄酒的酿造过程中大部分物质的含量均呈增加的趋势。     

不同成熟度烤烟烘烤过程中游离氨基酸及转氨酶活性变化

为明确不同成熟度烤烟烘烤过程中游离氨基酸组分转化规律,以烤烟品种K326为材料,对烟叶游离氨基酸组分含量及转氨酶活性进行了动态变化分析。结果表明,烟叶烘烤过程中,以谷氨酸等10种氨基酸含量和氨基酸总量变幅较大;不同成熟度烟叶中谷氨酸、丙氨酸、苯丙氨酸、缬氨酸和天冬氨酸含量变化差异主要集中在变黄后期和定色前期,此时,适熟和过熟烟叶在烘烤中转氨酶活性较高;与尚熟烟叶相比,适熟和过熟烟叶丝氨酸、组氨酸酸、精氨酸和赖氨酸含量从烘烤定色期开始,呈现下降的变化,表明烟叶成熟度对游离氨基酸转化为美拉德产物有一定影响。由此,适当提高烟叶成熟度,有助于烟叶游离氨基酸互相转化和美拉德反应产物的生成。     

慕萨莱思葡萄酒中13种常见金属元素及硒含量分析

采用火焰原子吸收光谱法、石墨炉原子吸收光谱法和原子荧光光度法测定阿瓦提慕萨莱思成品酒、红提葡萄原汁、实验室自酿慕萨莱思及酒泥中镁(Mg)、铁(Fe)、铜(Cu)、锰(Mn)、锌(Zn)、钙(Ca)、铅(Pb)、镉(Cd)、镍(Ni)、铬(Cr)、钴(Co)、钾(K)、钠(Na)和硒(Se)14种元素含量。结果表明,慕萨莱思葡萄酒中富含Na、K、Fe、Mg、Ca和Se,其Pb、Cd和Cr等重金属元素均符合国家标准限量,但阿瓦提慕萨莱思葡萄酒中Fe含量显著高于实验室自酿慕萨莱思(P0.01),为12.13~13.35 mg/L,已超出我国葡萄酒国家标准(≤8 mg/L),但未超出新疆地方标准的限量(≤15 mg/L)。此外,酒泥中富含绝大多数金属元素和Se。由此,实验室自酿慕萨莱思的酿制工艺可有效降低Fe含量。     

高温灭菌过程中三种鲜食玉米汁游离糖与氨基酸含量变化的比较

为明确鲜食玉米汁在高温灭菌过程中滋味成分的变化特点,采用HPLC对甜玉米、糯玉米和常规玉米汁在灭菌过程中蔗糖、果糖、葡萄糖和19种游离氨基酸的含量变化进行了测定和分析。结果显示,甜玉米汁中蔗糖含量最高,为11.94～18.09 mg/mL,含量最低的为糯玉米汁0.12～0.34 mg/mL。在灭菌过程中,常规玉米和糯玉米汁中的果糖和葡萄糖含量均呈下降趋势,而甜玉米汁中三种糖随时间延长均表现为先上升后下降。甜味氨基酸和鲜味氨基酸为三种玉米汁的主要氨基酸,为总游离氨基酸的68.77%～80.20%。19种氨基酸在灭菌过程中含量变化经主成分分析得到相关性热图和主成分图谱,结果显示甜玉米汁和糯玉米汁中的氨基酸变化相似,均有6种氨基酸随灭菌时间延长含量上升,呈显著相关关系,而常规玉米汁中氨基酸变化与二者差别较大。结果为不同的鲜食玉米汁加工中品质调控提供参考。     

The Free Amino Acids of Israel Orange Juice

SUMMARY— Twenty-two Israel orange juice samples were analyzed chromatographically, and 16 free amino acids were identified with seven different solvent systems. Aspartic acid, glutamic acid, lysine, alanine, and proline were identified with all 7 solvent systems; asparagine with 6; serine with 5; arginine, valine and leucine with 4; γ-amino-butyric acid with 3; glycine, methionine and phenylalanine with 2; and threo-nine and tyrosine with 1. The presence of isoleucine in Israel orange juice appears doubtful.
A quantitative estimation of the free amino acids indicates that amounts of aspartic acid, serine, and alanine are high compared with California orange juice, but glutamic acid and lysine are low.     

Effects of nitrogen,phosphorus and potassium on amino acid composition and on relationships between nitrogen and amino acids in wheat and oat grain

During two seasons, pot experiments in which increasing applications of nitrogen, phosphorus and potassium were given to wheat and oats produced grain with widely varying N contents. The total amino acid composition of the grain was mainly dependent on N content of grain. Phosphorus and potassium affected the amino acid composition of wheat and oat grain only indirectly through their effects on nitrogen concentration. In wheat increasing grain N% was accompanied by a decrease in the amount (as g per 16 g N) of lysine, threonine, methionine, cystine and an increase in glutamic acid, proline, phenylalanine, and serine contents. Lysine, methionine, and cystine in oats decreased with increasing grain N content, but arginine, aspartic acid, glutamic acid and phenylalanine increased. Changes were less pronounced with oats than with wheat, and concentrations of most essential amino acids were higher in oats. When expressed as % dry matter all amino acids increased with increasing N concentration. Linear regression equations were calculated and significant correlations were found in both crops between concentrations of most amino acids and N content in grain. Some correlations between amino acids in the grain are also given. Correlations between amino acids and nitrogen within a variety were similar despite widely differing yields.     

Study of agricultural by-products. Extractability and amino acid composition of grape (Vitis vinifera) skin proteins from cv palomino

Extractability in various solvents of grape skin proteins from cv Palomino, the most abundant and characteristic grape in the sherry zone, was studied. The greatest extractability was obtained in NaOH solutions. Amino acid analysis of the various protein extracts showed that the most abundant amino acid was glutamic acid and the limiting ones were tryptophan and the sulphur-containing amino acids, methionine and cystine.     

Nutritional studies on agadagidi

The analysis showed a gradual fall of the sugar content as fermentation period increased. Ascorbic acid content decreased while nitrogen and crude protein increased during fermentation. The predominant amino acids are leucine, lysine, valine, asparagine and glutamic acid, methionine, phenylalanine.     

荔枝酒酿造过程中氨基酸的变化

利用高效液相色谱法(HPLC)对不同发酵温度的荔枝酒酿造过程中氨基酸含量的动态变化进行了分析研究。结果表明,荔枝汁和荔枝酒中均含有丙氨酸、苏氨酸、缬氨酸、谷氨酸、丝氨酸等14种氨基酸,其中,丙氨酸是荔枝汁和荔枝酒中的主体氨基酸,含量分别达1 139.682 mg/L、341.049～412.161 mg/L。不同发酵温度的荔枝酒酿造动态过程中,其游离氨基酸的种类和含量变化较大,且变化趋势各异。不同贮藏方式对荔枝酒中氨基酸含量和种类影响也不同。通过比较,发酵温度12℃优于15℃,发酵温度为15℃的荔枝酒中氨基酸含量在贮藏过程中变化幅度较大,不稳定,且影响风味的氨基酸较多。     

Effect of processing on the amino acid content of New Zealand spinach (Tetragonia tetragonioides Pall. Kuntze)

The aim of this work was to evaluate the effect of processing on the amino acid content and protein quality of New Zealand spinach (Tetragonia tetragonioides Pall. Kuntze). In this research, fresh and cooked New Zealand spinach as well as two frozen products prepared for consumption, one obtained using the traditional method (blanching–freezing–storage–cooking) and the other a convenience food product obtained using a modified process (cooking–freezing–storage–defrosting and heating in a microwave oven), were analysed. Glutamic acid was the dominant amino acid in fresh New Zealand spinach, and the limiting amino acids were cystine and methionine. Technological and culinary processing caused a significant increase in amino acid content in 100 g of edible portion, with the exception of methionine and cystine in frozen products prepared for eating. Changes in amino acid content expressed in g/16 g of N (which corresponded to 100 g tissue protein) were not significant, with the exception of the lower glutamic acid content in the frozen product obtained using traditional processing method.     

不同处理方法对草菇呈味物质释放的影响

以草菇子实体为研究对象,以可溶性糖及糖醇、有机酸、5’-核苷酸、游离氨基酸组成和含量、分子质量分布为指标,研究常压蒸煮、高压蒸煮和酶解3?种处理方法对草菇呈味物质释放的影响,结果表明：常压蒸煮制备液可溶性糖及糖醇的总量显著降低,高压蒸煮制备液可溶性糖及糖醇的总量和原液基本相同,而酶解作用显著地提高了样品中可溶性糖的含量;和原液相比,常压蒸煮和高压蒸煮提取后有机酸总量显著增加,而复合酶解制备液有机酸总量显著降低;3?种处理方法作用后的游离氨基酸总量都有所增加,以高压蒸煮增加最显著,同时高压蒸煮制备液的鲜味氨基酸、甜味氨基酸以及苦味氨基酸的含量均显著增加;常压蒸煮和高压蒸煮制备后,大于3?000?Da组分的含量有所减少,高压蒸煮制备液中小于3?000?Da的组分含量最多,是制备呈味肽的重要来源。因此,不同处理方法对草菇呈味物质的释放有着明显差异,可以根据所需要的呈味物质采用不同的处理方法。     

Grape,apple and pineapple juice characterisation and detection of mixtures

Several multivariate statistical methods (principal component, cluster, stepwise discriminant and multiple linear regression analysis) were applied to analytical data obtained by conventional methods and to analytical data for free amino acids, in an attempt to distinguish between grape, apple and pineapple juice. Analysis for methionine, proline, asparagine, arginine and glutamic acid made it possible to differentiate among the 34 samples of grape, apple and pineapple juices studied. Multiple linear regression analysis of computer-simulated mixtures of grape and apple juices made it possible to detect the proportion of each fruit within the blend.     

不同棚膜颜色对赤霞珠葡萄果实氨基酸含量的影响

葡萄中的氨基酸含量是影响葡萄和葡萄酒香气品质的重要因素。试验以陕西泾阳的赤霞珠葡萄为试材，研究了不同颜色的避雨棚膜（白色、蓝色和紫色）对葡萄成熟时氨基酸含量的影响。结果表明，连续两年，蓝色和白色棚膜显著提高了葡萄中的谷氨酸、丝氨酸和天冬氨酸含量（P＜0.05）；蓝色棚膜显著提高了葡萄中精氨酸、甘氨酸和丙氨酸等大部分氨基酸的含量（P＜0.05）。综合考虑，蓝色棚膜是提升赤霞珠葡萄氨基酸含量的最佳棚膜。     

广东河源客家黄酒氨基酸分析

为分析广东客家黄酒关键工艺中的炙酒、贮藏、原料等对客家黄酒氨基酸的组成、含量及呈味特性的影响,采用日立氨基酸自动分析仪分析检测客家黄酒中的氨基酸含量,通过计算氨基酸分值、味道强度值(DoT)等确定各氨基酸对客家黄酒的影响。结果表明,客家娘酒中总氨基酸含量在2658.99mg/L- 5420.632mg/L之间,黑豆娘酒氨基酸含量及总量最高,商品板栗娘酒氨基酸含量最低,客家黄酒中最主要的氨基酸是谷氨酸和天冬氨酸,两者合计占氨基酸总量的20%以上,而胱氨酸、蛋氨酸和苯丙氨酸含量最低,是限制性氨基酸。板栗娘酒氨基酸含量低于传统的糯米娘酒,商品板栗娘酒总氨基酸含量仅为糯米娘酒总氨基酸的49%,必需氨基酸仅为64.69%,脯氨酸和苯丙氨酸含量为糯米娘酒的80%,其余氨基酸仅仅达到50%左右。黑豆娘酒比糯米娘酒总氨基酸含量提高42.6%,必需氨基酸提高23.2%,其中胱氨酸提高1倍,脯氨酸提高92.5%,谷氨酸提高80.7%,甘氨酸和丙氨酸提高40%以上,苏氨酸、丝氨酸、异亮氨酸提高30%以上,天冬氨酸、亮氨酸、酪氨酸提高20%以上。炙酒、贮藏过程能降低氨基酸含量,炙酒后氨基酸总量降低20.3%,炙酒后每一种氨基酸含量都明显降低,其中降低最明显的是蛋氨酸和苯丙氨酸,降低氨基酸含量可达50%,苏氨酸、甘氨酸、胱氨酸、赖氨酸、精氨酸在炙酒过程中降低1/3以上,而亮氨酸、异亮氨酸、组氨酸在炙酒过程中氨基酸降低20%以上;贮藏1年以后氨基酸总量降低12.4%,必需氨基酸降低10.9%,组氨酸和精氨酸降低20%以上,除蛋氨酸和苯丙氨酸以外,其余氨基酸均降低10%以上。计算不同酒样的氨基酸的味道强度即剂量比域因子DoT的排序为Glu ＞ Asp ＞ His ＞ Ala ＞ Lys ＞ Tyr ＞ Ile ＞ Gly,只有谷氨酸(Glu)的DoT 值大于1,说明黄酒中决定口味的氨基酸主要是谷氨酸。本文提出味道指数(Taste Index,TI)作为总体风味的评价指标,其定义为优味氨基酸的味道强度之和与劣味氨基酸的味道强度之和的比值,如果TI > 1,说明风味良好,如果TI<1,则劣味氨基酸占优势,味道不佳。本试验中黄酒的TI指数排序为：商品黑豆娘酒 ＞ 绍兴古越龙山花雕酒 ＞ 商品板栗糯米酒 ＞ 贮藏1年的板栗糯米原酒 ＞ 炙酒后的原酒 ＞ 商品普通糯米酒 ＞ 炙酒前原酒 ＞ 1 。对酒样的氨基酸评价表明,AAS和CS评分排序为炙酒前原酒 > 黑豆商品娘酒> 普通商品糯米酒 > 炙酒后原酒 > 贮藏1年的原酒 > 古越龙山花雕酒 > 商品板栗糯米酒,说明炙酒前酒样和黑豆酒样氨基酸的营养价值较好。