贺兰山东麓酿酒葡萄中有机酸含量分析

分析了宁夏贺兰山东麓不同酿酒红、白葡萄中8种有机酸含量。结果表明:红、白酿酒葡萄中以苹果酸和酒石酸的含量较高,柠檬酸次之,乳酸、丙酸、草酸和抗坏血酸均很低,琥珀酸未检出;酿酒白葡萄中有机酸总量平均值高于酿酒红葡萄。红葡萄中酒石酸和柠檬酸的含量高于白葡萄,苹果酸含量低于白葡萄,其余各有机酸含量不存在显著性差异。不同酿酒葡萄间有机酸含量差别大;红葡萄中以赤霞珠的总有机酸、酒石酸和苹果酸的含量最高;白葡萄中以贵人香和威代尔中酒石酸和苹果酸含量最高。     

新疆产区酿酒葡萄果实中有机酸的比较分析

以新疆4个小产区赤霞珠葡萄果实及天山北麓产区4种红色酿酒葡萄果实(品丽珠、西拉、小味尔多、马瑟兰)为原料,研究了不同产区、品种间有机酸含量的差异。采用反相高效液相色谱法(RP-HPLC),对赤霞珠果实生长周期4种有机酸(草酸、酒石酸、苹果酸、柠檬酸)变化情况进行分析。结果表明,随着葡萄成熟度增加,赤霞珠果实中有机酸总含量呈现下降趋势,草酸和柠檬酸含量较低,变化不明显;新疆4小产区的赤霞珠葡萄果实中有机酸总含量在3.97~7.96mg/g范围内且存在明显差异(p<0.05),产于天山北麓五家渠产地的赤霞珠有机酸总含量最高达7.96 mg/g,其中草酸、酒石酸、苹果酸分别为0.55 mg/g、4.66 mg/g、2.47 mg/g,产于伊犁河谷67团产地的赤霞珠有机酸总含量最低3.97 mg/g;通过对同一产地不同酿酒葡萄果实有机酸物质进行主成分分析,发现西拉、马瑟兰的酒石酸相对含量较高,赤霞珠的草酸和柠檬酸相对含量较高,品丽珠、小味尔多的苹果酸相对含量比较高。试验表明赤霞珠的有机酸含量在不同产区存在一定差异,同时不同品种在同产地的有机酸积累特性也各不相同,以期为新疆产区酿造中"糖高酸低"的研究提出一些思路。     

几个酿酒葡萄品种及品系的有机酸分析

本研究利用反相高效液相色谱技术,分析同一地区几个酿酒葡萄品种(赤霞珠、美乐和品丽珠等)及其品系的果实中4种有机酸(酒石酸、苹果酸、柠檬酸和草酸)的含量.结果表明:同一品种不同品系间果实有机酸含量存在显著差异;不同定植地点的赤霞珠果实有机酸含量也存在一定差异;不同品种的酿酒葡萄其有机酸含量也有所不同;而有机酸含量差异主要与苹果酸和酒石酸合成代谢中碳的流向改变有关.这些结果为品种及品系的选择及酿造工艺与产品类型的制定提供依据.     

前处理对‘澳洲青苹’苹果果实中有机酸组成与含量的影响

将‘澳洲青苹’样品去除果皮、果心,采用液相色谱法,研究破碎处理方式、浸提条件、测定前样品贮藏条件对其果肉组织有机酸组成与含量的影响。结果表明:人工研磨与机械匀浆都是样品破碎处理的有效手段,其选择要视实验目的、要求及具体实施情况而定。浸提温度与振荡时间对提取效果没有显著影响,以在常温(25℃)条件下超声波振荡提取15 min为宜。样品前处理后最好立即检测分析,如不能立即进行,则以将破碎后经离心处理的样品保存在常温、光照条件下做短期贮藏为好。‘澳洲青苹’果实中含有草酸、奎尼酸、苹果酸、莽草酸和柠檬酸5种有机酸,含量顺序为苹果酸奎尼酸柠檬酸草酸莽草酸,苹果酸是最为主要的有机酸,同一果实中不同有机酸与不同果实中相同有机酸含量相差悬殊,实验时要注意试材的选取。     

液相色谱法测定葡萄中有机酸的条件优化及其变化规律

应用高效液相色谱法测定广西特色两收葡萄不同成熟期有机酸的含量变化。采用Ultimate?AQ-C18(3μm,4.6 mm×200 mm)色谱柱,以1%甲醇-99%0.01 mol/L磷酸氢二铵缓冲溶液(pH=2.6)作为流动相,柱温30℃,检测波长210 nm,流速0.3 mL/min,可以有效分离草酸、酒石酸、苹果酸、柠檬酸。该方法有机酸回收率为88.1%~104.6%,上机检出限(S/N=3)为1.0~5.0ng。结果表明,该方法能够快速测定葡萄中的有机酸,检测成本低,具有较高的准确度和精确度;葡萄中主要有机酸是酒石酸和苹果酸,草酸和柠檬酸含量很低,在葡萄成熟过程中苹果酸和酒石酸含量逐渐降低,苹果酸含量变化明显,酒石酸较苹果酸稳定。     

山葡萄酒发酵过程中营养成分变化的研究

以山葡萄"北国蓝"果实为试材,分析山葡萄酒发酵过程中各成分的变化及差异显著性。结果表明,在山葡萄酒酿造过程中,醪液中总糖含量持续下降并趋于稳定,可滴定酸含量持续下降;总糖含量在发酵前期差异极显著,后发酵阶段无差异,可滴定酸差异显著性则与之相反;总酚、单宁含量均呈先升高后降低的趋势,总酚、单宁在整个发酵过程存在差异,但差异不显著。有机酸总量在葡萄酒发酵过程中持续降低,降低了55.67%。酒石酸与苹果酸含量明显降低,分别降低了59.53%和62.50%;柠檬酸含量低于2.00 g/L,并无明显变化;乳酸、琥珀酸和乙酸均持续升高,草酸明显降低,这四种有机酸含量均低于0.30 g/L。有机酸总量、酒石酸和苹果酸均在发酵各时期差异极显著,乳酸差异显著,乙酸、草酸差异不显著,柠檬酸、琥珀酸无差异。     

山葡萄有机酸降解菌的筛选、分离及鉴定

从山葡萄（Vitis amurensis Rupr）生长的土壤中分离出8株可降解果实中有机酸的菌株,通过比较降解率,筛选出1株可降解酒石酸、苹果酸、柠檬酸的菌株,命名为S4。对菌株S4进行形态学及26s rDNA分析,鉴定其为草酸青霉（Penicillium oxalicum）。并对S4进行有机酸降解性和耐受性试验。结果为：降酸菌株的酒石酸降解率为（71.90±0.27）%,苹果酸降解率为（86.33±0.53）%,柠檬酸降解率为（72.77±0.46）%。菌株S4酒精耐受性大于体积分数12%、SO2耐受性大于质量浓度500 mg/L,致死温度为60℃～65℃,20 min～30 min。从山葡萄生长土壤中筛选出的草酸青霉具有良好的降酸效果。     

不同产地酿酒葡萄“赤霞珠”果实中有机酸差异性研究

采用反相高效液相色谱法(RP-HPLC),对云南迪庆德钦、河北怀来沙城和山东烟台莱山三地的成熟期酿酒葡萄"赤霞珠"果实中6种主要有机酸的含量进行差异性分析。结果表明,不同产地的酿酒葡萄果肉和果皮中有机酸总量存在明显差异(p0.05)。三产地酿酒葡萄果肉中有机酸含量以云南迪庆德钦11.434 mg/g·FW为最高,而酿酒葡萄果皮中有机酸含量最高的是山东烟台莱山19.081 mg/g·FW。6种主要有机酸在不同产地酿酒葡萄果肉和果皮中含量均不同,其中酒石酸与L-苹果酸共占葡萄果肉和果皮中有机酸总量的86.5%和77.0%以上,共同构成了酿酒葡萄果肉和果皮中最主要的有机酸。另外,不同产地的酿酒葡萄果皮中酒石酸、L-苹果酸、乳酸、柠檬酸和琥珀酸的含量均高于果肉。除山东烟台莱山,其它两产地酿酒葡萄果肉中草酸含量高于果皮。总之,酿酒葡萄"赤霞珠"果实中有机酸的分布存在组织特异性,并且其含量与产地的气候密切相关。     

反相高效液相色谱法测定葡萄中的有机酸

本研究建立了反相高效液相色谱检测葡萄果实有机酸的方法,并评价该方法的准确性和灵敏度。结果显示,用酸性水溶液提取果实有机酸,当应用色谱柱为KromasilC18,流动相为3%CH3OH-0.01mol/LKH2PO4(pH2.8)缓冲液,流速为0.8mL/min,柱温为25℃,检测波长为210nm时,在8min内可将提取液中的酒石酸、苹果酸、柠檬酸和草酸有效分离。此方法的平均回收率90%,定量相对标准偏差均在5%以内,最低检测限在0.067～1.12g/L,表明此法具有快速、灵敏、可靠的特点,能够满足果实样品4种有机酸同时检测的要求。运用该方法,分析了赤霞珠和霞多丽果实发育过程中有机酸含量的变化,发现红、白两品种间有机酸变化趋势相似,即草酸和酒石酸含量逐渐下降,而苹果酸在转色前逐渐积累,而后迅速下降;柠檬酸含量变化不明显。     

不同地区不同成熟度青梅有机酸的测定及相关性分析

目的：对四川达州青梅有机酸含量进行测定并分析其相关性,为产品深加工提供基础数据。方法：采用高效液相色谱法测定成熟度不同的青梅中有机酸含量,并对草酸、酒石酸、苹果酸、抗坏血酸、L-乳酸、乙酸、柠檬酸、丁二酸、齐墩果酸、熊果酸进行相关性分析。结果：同一地区,景市镇全熟黄果中柠檬酸、苹果酸均高于七成熟绿果,百节镇和渡市镇七成熟绿果中的柠檬酸均高于全熟黄果,而苹果酸反之。相关性分析表明,柠檬酸与熊果酸、L-乳酸、乙酸、齐墩果酸存在显著变化,与苹果酸无显著变化。结论：四川达州不同地区青梅中有机酸含量最高的是柠檬酸（19.546%）,其次是苹果酸（4.013%）,较其他产区青梅的高。     

碳酸钙降酸对山葡萄酒有机酸及感官品质的影响

利用CaCO3对山葡萄酒进行降酸,研究不同CaCO3添加量对山葡萄酒总酸含量、有机酸含量和有机酸质量分数变化及对感官品质的影响。结果表明,随CaCO3添加量的增加（8～12 g/L）,山葡萄酒总酸含量和有机酸含量逐渐降低,苹果酸和酒石酸质量分数逐渐降低,琥珀酸、草酸、乳酸和乙酸质量分数逐渐增加,柠檬酸质量分数先增加后降低。 添加10 g/L CaCO3的山葡萄酒降酸效果最佳,总酸含量为9.13 g/L,苹果酸、酒石酸、柠檬酸、琥珀酸、草酸、乳酸和乙酸含量分别为5.59 g/L、0.16 g/L、1.45 g/L、1.20 g/L、0.09 g/L、 0.31 g/L和0.11 g/L,相应的质量分数分别为62.87%、1.79%、16.36%、13.51%、0.96%、3.28%和1.24%。 降酸后的山葡萄酒酸感平衡,入口柔和;酒体丰满、圆润;感官品质得分最高为（91.6±2.4）分。     

葡萄酒酿造过程中有机酸变化规律研究

采用离子色谱法分析了葡萄酒中9种有机酸含量。通过对赤霞珠葡萄酒发酵过程中主要有机酸变化分析,研究其从葡萄汁到原酒的酿造过程中有机酸含量变化规律和量变的幅度。结果表明,葡萄酒中有机酸主要有酒石酸、苹果酸、乳酸、柠檬酸和琥珀酸,葡萄汁经发酵产生了乳酸、乙酸和琥珀酸。酿造过程中酒石酸、苹果酸、抗坏血酸和柠檬酸含量一直呈下降趋势;草酸和琥珀酸含量先增高后减少,乳酸含量一直呈上升趋势。乙酸是葡萄酒酒精发酵的主要副产物,含量为0.2～0.3 g/L。     

The organic acid profile in wheat cultivar grains

Organic acids, pH and total acidity were determined in the grains of nineteen wheat cultivars. Six organic acids, such as glutamic, oxalic, malic, tartaric, shikimic and fumaric acids, were separated and identified in all wheat samples applying HPLC coupled to diode array detector. Glutamic acid was the major organic acid followed by tartaric and malic acids. A low oxalic acid/calcium ratio was observed in the wheat samples analysed. The wheat samples belonging to Triticum turgidum had a higher (P < 0.05) mean tartaric acid and pH values than the wheat samples from the Triticum aestivum. Some correlations between the analysed parameters were observed, emphasising the correlation between the malic and fumaric acids. Stepwise discriminant analysis was applied on the parameters analysed, allowing to differentiate the wheat samples according to the species.     

中国野生葡萄果实基本品质、酚类物质含量及其抗氧化活性分析

中国野生葡萄资源丰富,但对其利用有限;为揭示不同种野生葡萄的品质差异及进一步利用奠定理论基础,本研究对中国野生葡萄的10个种(46个株系)和不同对照品种(4份材料)的基本品质、酚类物质含量及其抗氧化活性指标进行评价。结果表明:1)除刺葡萄外,中国野生葡萄的单果质量小于‘赤霞珠’;中国野生葡萄的皮果比高于‘赤霞珠’。2)中国野生葡萄和对照之间糖的组成相似,果糖与葡萄糖所占的比例没有差异,总糖含量显著低于‘赤霞珠’和‘户太8号’;除刺葡萄外,中国野生葡萄的总酸含量显著高于对照‘赤霞珠’和‘户太8号’,中国野生葡萄的酒石酸/苹果酸的比值低于‘赤霞珠’,说明中国野生葡萄属于高苹果酸型;河岸葡萄和圆叶葡萄的糖酸含量与中国野生葡萄的糖酸含量较接近;‘赤霞珠’和‘户太8号’属于高糖低酸型,中国野生葡萄属于低糖高酸型。3)中国野生葡萄的抗氧化活性和酚类物质的含量变异较大,大部分的野生葡萄与‘赤霞珠’的酚类物质含量和抗氧化活相近,但中国野生葡萄的花色苷含量高于对照的花色苷含量。综上所述,中国野生葡萄中的燕山葡萄、蘡薁葡萄和刺葡萄的品质较好,其与‘赤霞珠’和‘户太8号’的糖酸组分、酚类物质含量及抗氧化活性接近。     

桑椹酒发酵过程中有机酸含量变化

利用高效液相色谱法测定桑椹酒发酵过程中七种有机酸的变化,结果显示:桑椹原果汁中琥珀酸含量最高,柠檬酸次之;发酵过程中酒石酸、苹果酸、柠檬酸、琥珀酸、草酸、抗坏血酸含量变化均先呈上升趋势,达到最大值后呈下降趋势,而乳酸含量则一直上升;发酵结束后检测到酒石酸、苹果酸、柠檬酸、琥珀酸、草酸、抗坏血酸、乳酸含量分别为1.822、2.54、2.44、0.76、0.772、0.0756、0.0846g/L。     

葡萄生长成熟过程中有机酸变化的研究

将 2 0 0 3年份 ,沙城、蓟县、汉沽、昌黎四个葡萄产地 ,不同葡萄品种 ,生长过程中各种有机酸的变化进行高效液相色谱法测定比较 ,结果葡萄在成熟过程中各种有机酸含量的变化为 :柠檬酸在葡萄中的含量很小 ,小于 0 .4g/L ,且在葡萄成熟过程中含量变化不大。葡萄中的酒石酸和L -苹果酸含量在葡萄成熟过程中逐渐降低 ,其中L -苹果酸降低的趋势比酒石酸要大     

First steps towards the development of a non-destructive technique for the quality control of wine grapes during on-vine ripening and on arrival at the winery

NIR spectroscopy was used as a non-destructive technique for the assessment of changes in certain internal quality properties of wine grapes (Vitis vinifera L.) during on-vine ripening and at harvest. A total of 108 different wine grape samples were used to construct calibration models based on reference data and NIR spectral data, obtained using a commercially-available diode-array spectrophotometer (380-1700 nm). The feasibility of testing bunches of intact grapes was investigated and compared with more traditional methods of presentation, such as berries or must. Predictive models were constructed to quantify changes in soluble solid content (SSC, °Brix), reducing-sugar content (g/l), pH-value, titrable acidity (g/l tartaric acid), tartaric acid (g/l) and malic acid (g/l), these being the major parameters used to chart ripening. NIRS technology provided good precision for the bunch analysis mode assayed for SSC (r² = 0.89; SECV = 1.41 °Brix), for reducing-sugar content (r² = 0.87; SECV = 17.13 g/l) and for pH-value (r² = 0.69; SECV = 0.19). Models developed for testing other fruit acidity parameters yielded results sufficient to provide a screening tool to distinguish between low and high acidity values in intact grapes. Significantly, the results obtained with bunch presentation were similar to those obtained with berries and must, thus justifying further implementation of NIRS technology for the non-destructive analysis of quality properties both during on-vine ripening and on arrival at the winery. This method allows musts to be processed separately depending on initial grape quality, assessed with a single spectrum measurement and in a matter of seconds.     

Sugar and acid concentrations in 98 grape cultivars analyzed by principal component analysis

A total of 98 grape cultivars were studied for content and composition of organic acids and sugars in grape juice during two consecutive years. Glucose and fructose were the predominant sugars in grape berries and ranged from 45.86 to 122.89 mg mL^?1, and 47.64 to 131.04 mg mL^?1, respectively, in two years. Sucrose was present at trace amounts in most cultivars, but two cultivars of hybrids between Vitis labrusca and V. vinifera contained large amounts of sucrose. Tartaric acid content in berries, varying from 1.57 to 9.09 and 1.54 to 9.05 mg mL^?1, respectively, in two years, was significantly higher than malic acid, which ranged from 0.38 to 6.05 and 0.36 to 7.06 mg mL^?1, respectively, in two years. Moreover, significantly higher total soluble sugars and fructose and lower total acids and malic acid were found in cultivars from hybrids between V. labrusca and V. vinifera than those in V. vinifera cultivars, and wine grapes had higher total sugars and acids than table grapes from V. vinifera. Principal component analysis (PCA) indicated that genotypic correlations among sugar and acid contents were stable and the first three PCs accounted for about 82% of total variance in both years. PC1 was highly connected with glucose and fructose contents, and sucrose was an important contributor to the variance for PC2, as well as for PC3. PC2 and PC3 were highly connected also with organic acids, but the contributor to variance differed from one year to the next. Tartaric acid was the main contributor to variance in 2003, and malic acid was important in 2004 for PC2 and PC3. In a scatter plot of the score values of all genotypes projected to the PC1 and PC2 plane, three groups of cultivars tend to cluster based on their genetic background or purpose of use. The cultivars of hybrid V. labrusca and V. vinifera were represented by high sugars, especially sucrose, and low acids. Among the cultivars of V. vinifera, wine grapes were found in general to have more sugars and acids than table grapes. The composition of sugars was stable in grape berries between the two years, while acids were sensitive to climate changes. Finally, the different responses of malic and tartaric acids to climate change is discussed. Copyright © 2006 Society of Chemical Industry