荧光光度法测定花生红衣提取物中白藜芦醇含量

建立了一种利用荧光分光光度计检测花生红衣提取物中白藜芦醇的新方法,探讨了白藜芦醇荧光光谱检测的最佳条件,其激发波长和发射波长分别是324.06 nm和400.00 nm。白藜芦醇产生的荧光强度与浓度在0~1.68×10-5mol/L的范围内具有良好的线性关系,检出限为8.14×10-10mol/L。     

纤维素酶法提取花生红衣中的白藜芦醇

目的:研究纤维素酶解法提取花生红衣中白藜芦醇的工艺条件.方法:在单因素试验基础上,采用L9(34)正交试验法对花生红衣白藜芦醇的酶法提取工艺进行优选.以白藜芦醇的得率为参考指标,考察酶用量、酶解温度、酶解时间、酶解pH值和乙醇浓度对花生红表白藜芦醇得率的影响.结果:最佳工艺条件为:纤维素酶与花生红衣粗粉的配比为1:500,酶解温度50℃,酶解pH 5.0,酶解时间90 min,提取溶剂乙醇的体积分数为60%.在此条件下白藜芦醇的得率为1.25%.与传统醇提工艺相比,其提取率提高了4.43倍.结论:该工艺是纤维素酶法提取花生红衣白藜芦醇的最佳工艺.     

碱法提取花生红衣中白藜芦醇的研究

研究了碱法从花生红衣中提取白藜芦醇的工艺.对Ph,温度,提取时间和提取次数四个因素分别进行了单因素和正交实验,从而得到最佳的提取工艺条件,即:Ph10.0,温度为40℃,提取时间2h,提取次数4次.实验结果表明,花生红衣中白藜芦醇的得率可达0.196%.     

碱法提取花生红衣中白藜芦醇的研究

研究了碱法从花生红衣中提取白藜芦醇的工艺。对pH,温度,提取时间和提取次数四个因素分别进行了单因素和正交实验,从而得到最佳的提取工艺条件,即:pH10.0,温度为40℃,提取时间2h,提取次数4次。实验结果表明,花生红衣中白藜芦醇的得率可达0.196%。      

花生红衣中白藜芦醇、原花色素提取工艺的研究

对超声波辅助提取花生红衣中白藜芦醇、原花色素的工艺进行了研究。从5种常用试剂中选择出乙醇作为提取剂,并在单因素实验的基础上,通过正交实验优化了白藜芦醇、原花色素的提取条件:料液比1:6,温度70℃,乙醇浓度60%,提取时间20min,pH3,提取次数1次;在最佳工艺条件下,白藜芦醇、原花色素的提取得率分别为0.036%、4.96%。     

超声波辅助酶法提取花生红衣中白藜芦醇的工艺优化

为提高花生油提取副产物花生红衣的利用价值,以乙醇体积分数、料液比、超声时间、超声温度、酶的种类为考察因素,白藜芦醇提取量为指标,通过单因素实验对超声波辅助酶法提取花生红衣中白藜芦醇工艺进行优化。结果表明,在酶解pH 5. 0、酶添加量2%下,得到的最佳工艺条件为:乙醇体积分数80%,料液比1∶25,超声时间30 min,超声温度50℃,采用半纤维素酶提取。在最佳工艺条件下,白藜芦醇提取量为(0. 854±0. 025) mg/100 g。     

超声辅助低共熔溶剂提取花生红衣中白藜芦醇的研究

采用低共熔溶剂,以超声辅助提取花生红衣中的白藜芦醇。通过对低共熔溶剂的筛选,氯化胆碱/乙二醇(摩尔比1∶2)具有较好的提取效果。在氯化胆碱/乙二醇为提取溶剂、加水量(以体积比计)为40%、超声温度为60℃、超声时间为60 min、料液比为1∶15(g/mL)的条件下,白藜芦醇的提取量为(5.16±0.07)μg/g。     

花生红衣中自藜芦醇、原花色素提取工艺的研究

对超声波辅助提取花生红衣中白藜芦醇、原花色素的工艺进行了研究。从5种常用试剂中选择出乙醇作为提取剂，并在单因素实验的基础上，通过正交实验优化了白藜芦醇、原花色素的提取条件：料液比1：6，温度70℃，乙醇浓度60％，提取时间20min，pH3，提取次数1次；在最佳工艺条件下，白藜芦醇、原花色素的提取得率分别为0．036％、4．96％。     

从花生红衣皮中提取红衣粉的研究

本文介绍了花生红衣皮的主要营养成分，化学成分及止血功效，机理。研究了从花生红衣皮中提取红衣粉的工艺方法及红衣粉在食品中的应用。     

花生红衣中多酚的研究进展

多酚作为一种生物活性成分,对它的分离提取、结构和功能的研究由来已久。文中对花生红农多酚的测定方法、提取、分离纯化,以及抗氧化和抑菌活性等做了论述。     

葡萄原料对干红葡萄酒品质及白藜芦醇含量的影响

以宁夏贺兰山东麓、天津蓟县产区、山东蓬莱产区的赤霞珠和梅鹿辄葡萄酿制的干红葡萄酒为试验材料,研究了不同葡萄品种、不同产区、不同年份对干红葡萄酒中白黎芦醇含量的影响。结果表明:在宁夏贺兰山和天津蓟县2个产区,采用同种生产工艺,梅鹿辄干红葡萄酒的白藜芦醇含量高于赤霞珠干红葡萄酒。白黎芦醇总量受年份、产地气候因素的影响较大,对于赤霞珠干红葡萄酒,西部贺兰山产区白黎芦醇的含量明显高于东部蓟县和蓬莱产区。     

A review of the content of the putative chemopreventive phytoalexin resveratrol in red wine

Resveratrol, a naturally occurring compound of various fruits such as grapes, is thought to possess chemopreventive properties. The levels of resveratrol in grapes and grape products including wine, varies from region to region and from one year to another. This paper reviews the resveratrol content in red wine based on relevant published data. Red wine contains an average of 1.9 ± 1.7 mg trans-resveratrol/l (8.2 ± 7.5 μM), ranging from non-detectable levels to 14.3 mg/l (62.7 μM) trans-resveratrol. In general, wines made from grapes of the Pinot Noir and St. Laurent varieties showed the highest level of trans-resveratrol. No region can be said to produce wines with significantly higher level of trans-resveratrol than all other regions. Levels of cis-resveratrol follow the same trend as trans-resveratrol. The average level of trans-resveratrol-glucoside (trans-piceid) in a red wine may be as much as 29.2 mg/l (128.1 μM), i.e., three times that of trans-resveratrol.     

Influence of winemaking techniques on the resveratrol content, total phenolic content and antioxidant potential of red wines

In this paper, the influence of winemaking techniques and cultivars on the resveratrol content, total phenolic content and antioxidant potential of red wines was studied. Wines were made from the cultivars Merlot, Cabernet Sauvignon, Pinot Noir and Prokupac. Applied winemaking technologies included thermovinification and separation of must from pomace. The analysis of trans- and cis-resveratrol in wines was performed by HPLC, while the total phenolic content and antioxidant potential was determined by spectrophotometric methods. The total resveratrol content in analysed samples ranged from 0.35 to 4.85 mg/l; Merlot wines had the highest average resveratrol content, while the lowest was found for native cultivar Prokupac. Although the resveratrol content depended on grape variety, correlation between the winemaking technology applied and the resveratrol level in wines was not observed. The total phenolic content (TPC) varied from 544.4 to 1410.4 mg/l expressed as gallic acid equivalents, and the antioxidant potential, assayed by DPPH in terms of SC₅₀ (mean scavenging concentration), ranged from 0.58 to 2.91 μl/ml. Obtained results showed that thermovinificated wine samples had higher amount of phenolic compounds. Significant negative correlation was observed (p < 0.05) between the total phenolic content and SC₅₀, but there was no significant correlation (p > 0.05) between the resveratrol content and SC₅₀ or TPC. This study could contribute to the establishment of optimal conditions for producing red wines which contain more beneficial phenolic compounds.     

用新鲜红苋菜提取天然苋菜红色素的工艺研究

用新鲜苋菜为原料,蒸馏水作提取溶剂,对提取苋菜红色素的工艺进行研究。实验结果表明,提取苋菜红色素的工艺条件是:提取时间60min;提取温度50℃;料液比180mL蒸馏水/g苋菜;提取次数为2次。此提取工艺具有生产成本低,操作简单安全,适合于工业化生产。     

饮料中新红检验方法的研究

目的：按国家标准GB/T5009.35-2003食品中合成着色剂的测定第一法给定的方法测定时,新红与周围物质无法分开,因此对饮料中新红的检验方法进行研究。方法：在复杂饮料基质中添加新红标准物质,通过吸附、洗涤、浓缩等步骤制备测试液,采用高效液相紫外检测器检测目标化合物。结果：通过改变流动相比例并采用308nm波长测定,获得了良好的检测结果。     

Influence of skin maceration time on the proanthocyanidin content of red wines

This paper studies the influence of different maceration times (5, 10 and 20?days) during the elaboration of Monastrell, Syrah and Cabernet Sauvignon wines on the proanthocyanidin composition and sensory characteristics of the resulting wines. Significant differences were found between wines elaborated with different maceration times. The different maceration times affected the qualitative and quantitative proanthocyanidin composition of the resulting wines, the total proanthocyanidin content increasing with the maceration time. The percentage of skin-derived proanthocyanidins was always higher than that of seed-derived proanthocyanidins for all the maceration time assayed, although the contribution of seed proanthocyanidins to wine composition increased for the longest maceration time. However, the study also shows that differences exist between wines elaborated with the same maceration time but with different varieties, indicating the importance of two factors, the initial concentration of grape phenolic compounds and their extractability, on the final concentration of wine proanthocyanidins. In this way, the wines obtained from Syrah had the highest proanthocyanidin content compared with the corresponding wines from Cabernet Sauvignon or Monastrell, even though Syrah grapes presented the lowest proanthocyanidin content in skins and similar seed proanthocyanidin content to Cabernet and Monastrell grapes.     

Preliminary study of resveratrol content in Aragón red and rosé wines

A survey of resveratrol content in wines of the four Aragón designations of origin (Borja, Cariñena, Calatayud and Somontano) was carried out. Concentrations of trans- and cis-resveratrol isomers of 98 commercial wines of the four designations of origin, from several vintages, were analyzed by means of reverse-phase high-performance liquid chromatography. Concentration of trans-resveratrol ranged from 0.32 to 4.44 mg/l in red wines and from 0.12 to 2.80 mg/l in rosé wines. cis-Resveratrol levels ranged from 0.20 to 5.84 mg/l in red wines and from 0.02 to 3.17 mg/l in rosé wines. The grape variety influenced resveratrol contents in wines from the different regions. The highest trans/cis ratios were found in Somontano (4.50) and Calatayud wines (2.90), both of the Tempranillo variety. However, a discriminant analysis applied to the concentrations did not show significant differences between young red wines nor between rosé wines of the four designations of origin.     

食品中双乙酸钠含量测定方法的研究

双乙酸钠(SDA)是一种新型的多功能绿色食品添加剂.主要用作粮食、食品、饲料的防腐剂、防霉剂、保鲜剂、调味剂、pH调节剂、品质改良剂、肉制品的保存剂,也是复合型防霉剂的主要配料.论述了食品中双乙酸钠含量的定性鉴别以及运用高效液相色谱进行定量分析的方法.     

红葡萄酒澄清工艺中白藜芦醇的变化

采用RP-HPLC方法,测定红葡萄酒澄清处理前后白藜芦醇四种异构体的含量变化,发现:1)澄清处理后红葡萄酒中白藜芦醇总量减少了15.7%;2)下胶和硅藻土过滤主要引起水溶性较强白藜芦醇糖苷含量的减少,损失率达到25.9%;3)速冷处理对红葡萄酒中白藜芦醇的保留率达到100%.