葡萄穗轴中白藜芦醇、原花色素提取工艺的研究

利用正交实验对葡萄穗轴中白藜芦醇、原花色素的提取条件,即乙醇浓度、固液比、提取时间、提取温度进行了优化.结果表明,60%的乙醇溶液为提取剂,固液比为1:20,在80℃下提取2h为最佳提取条件,通过溶剂萃取进行分离,用紫外分光光度法和香草醛.盐酸法分别测定其含量.在最佳提取条件下,白藜芦醇的提取率为0.083%,原花色素的提取率为0.516%.     

A Food-Grade Method for Enhancing the Levels of Low Molecular Weight Proanthocyanidins with Potentially High Intestinal Bioavailability

Proanthocyanidins (PACs) are a group of bioactive molecules found in a variety of plants and foods. Their bioavailability depends on their molecular size, with monomers and dimers being more bioavailable than those that have a higher polymerization degree. This study aimed to develop a method to convert high-molecular-weight PACs to low-molecular-weight ones in a grape seed extract (GSE) from Vitis vinifera L. Therefore, GSE was subjected to alkaline treatment (ATGSE), and its difference in chemical composition, compared to GSE, was evaluated using a molecular networking (MN) approach based on results obtained from HPLC-ESI HRMS/MS characterization analysis. The network analysis mainly noted the PAC cluster with about 142 PAC compounds identified. In particular, the obtained results showed a higher content of monomeric and dimeric PACs in ATGSE compared to GSE, with 58% and 49% monomers and 31% and 24% dimers, respectively. Conversely, trimeric (9%), polymeric (4%), and galloylated PACs (14%) were more abundant in GSE than in ATGSE (6%, 1%, and 4%, respectively). Moreover, in vitro antioxidant and anti-inflammatory activities were investigated, showing the high beneficial potential of both extracts. In conclusion, ATGSE could represent an innovative natural matrix rich in bioavailable and bioaccessible PACs for nutraceutical applications with potential beneficial properties.     

响应面法优化超声波提取鸡蛋枣原花青素工艺

本文采用单因素实验和响应面分析法对鸡蛋枣中原花青素进行提取工艺优化。在单因素实验的基础上,根据中心组合（BOX-Behnken）实验设计,采用四因素三水平对各个因素进行研究与分析,结果表明:鸡蛋枣中原花青素的最佳提取工艺为超声时间16 min、超声功率为618 W、超声温度为65℃、料液比为1∶21,在此工艺下的鸡蛋枣原花青素得率1.82%。证实超声波提取鸡蛋枣中原花青素的工艺是可行的。体外抗氧化实验表明:鸡蛋枣原花青素对DPPH自由基、羟基自由基的清除具有显著效果,同时还原力显著,且不输于V_C。      

闪式提取法提取落叶松树皮中原花青素的研究

利用闪式提取法提取落叶松树皮中的原花青素。研究了乙醇体积分数、料液比、提取时间和提取温度对落叶松树皮中原花青素提取得率的影响。在单因素实验的基础上,运用正交实验对结果进行优化。结果表明,闪式提取法提取落叶松树皮中原花青素的优化条件为:乙醇体积分数为60%,料液比1∶25(g/mL),提取时间为4min,提取温度40℃。在此条件下进行验证实验,原花青素得率达11.42%。该方法操作简单、速度快、得率高,适用于落叶松树皮中原花青素的提取。      

红皮云杉原花青素的配合性质及配合物的抗氧化活性研究

研究了二次纯化后的红皮云杉球果原花青素与金属离子（Fe2+、Zn2+）螯合、与蛋白质大分子（牛血清蛋白）络合反应的条件。考察了原花青素浓度、温度和pH对配合反应的影响,优化了反应条件,并进一步通过体外抗氧化实验考察了配合体的性质。结果表明,优化后原花青素与Fe2+、Zn2+螯合率分别为89.12%±1.06%、88.31%±0.87%,与牛血清蛋白络合率为91.78%±1.25%。原花青素经过配合后其生物活性有一定的增强,且不同配合物的生物活性增强程度不同,但均具有较强的ABTS+·、DPPH·的清除能力和还原力,其浓度在一定范围内与清除能力呈量效关系。      

沙棘籽原花色素对卵磷脂脂质体氧化的抑制和促进作用

分别采用2,2’-盐酸脒基丙烷（AAPH）和Cu^2＋引发的卵磷脂脂质体氧化模型体系,以共轭二烯氢过氧化物为指标,通过监测氧化的动力学过程,研究了沙棘籽原花色素对氧化的抑制和促进作用。结果表明：沙棘籽原花色素显著抑制AAPH诱导的卵磷脂脂质体氧化,抑制效果强于葡萄籽原花青素,抑制作用与清除水溶性过氧自由基和脂过氧化物自由基有关;低浓度沙棘籽原花色素促进Cu^2＋催化的卵磷脂脂质体氧化,高浓度则抑制Cu^2＋催化的卵磷脂脂质体氧化。     

均匀设计优化超临界CO2提取含原花青素的葡萄籽油

以原花青素的提取率和葡萄籽的出油率为考察指标,利用均匀设计法对超临界CO2萃取时间、萃取压力、萃取温度进行了优化,得到最佳工艺条件为:萃取压力15 MPa,萃取时间3 h,萃取温度50 ℃;在最佳条件下葡萄籽出油率为(10.92±0.25)%,原花青素提取率为(23.4±7.2)mg/100 g.在加入无水乙醇夹带剂的前提下,利用超临界CO2萃取葡萄籽油,可以使油中含有原花青素,提高葡萄籽油的品质.     

莲房原花青素体外抗肿瘤作用研究

目的:研究莲房原花青素(LSPC)的相对分子量分布及体外抗肿瘤作用。方法:用ESI-MS分析LSPC,MTT法检测人肺癌LETP-2、胃腺癌SGC-7901、黑色素瘤A3753种细胞增殖,采用平板集落实验测定3种癌细胞集落形成。结果:LSPC的分子量范围为290.1～1154.3,是以二聚体为主的低聚原花青素;一定浓度的LSPC对3种瘤细胞均有抑制作用,当LSPC浓度为100μg/mL作用72h时对3种瘤细胞生长抑制率分别为62.6%、49.8%、77.0%;集落形成抑制率分别为77.0%、43.2%、95.3%。结论:LSPC体外对LETP-2、SGC-7901、A3753种瘤细胞有显著的抑制作用。     

Evolution of the localisation and composition of phenolics in grape skin between veraison and maturity in relation to water availability and some climatic conditions

BACKGROUND: Several studies have investigated the composition of phenolics in grape skin during grape maturation under various conditions of light exposure, water stress, nitrogen supply and mineral nutrition, but their localisation during berry development is not well known. In this study the composition and localisation of proanthocyanidins were monitored for three years on four plots known to induce a distinctive behaviour of the vine (Cabernet Franc). The composition of phenolics was determined by spectrophotometry; also, in one year, proanthocyanidins were determined by high‐performance liquid chromatography. Further information was obtained histochemically by means of toluidine blue O staining and image analysis. RESULTS: The results indicated that clear differences in phenolic quantification existed between the biochemical and histochemical approaches; the proportion of cells without phenolics was not linked with the quantity determined by the analytical methods used. The histochemical method showed the evolution of the localisation and typology of cells with and without phenolics during ripening. The number of cells without any phenolic compounds appeared to be very dependent on the mesoclimatic conditions and only slightly dependent on the site water status. CONCLUSION: Clear differences in phenolic quantification existed between the biochemical and histochemical approaches; the proportion of cells with phenolics was not linked with the quantity determined by biochemistry. The histochemical method showed an evolution of the localisation and typology of cells with and without phenolics in which mesoclimatic conditions were the most influential factor. Finally, the study showed some advantages of the histochemical approach: it gives information about the anatomy of the tissue as well as the nature and distribution of some of the large macromolecules and allows reconstruction of the three‐dimensional plant structure. Copyright © 2011 Society of Chemical Industry     

In vitro gastrointestinal digestion of polyphenols from different molasses (pekmez) and leather (pestil) varieties

In this study, to evaluate the in vitro bioaccessibility of eight different pekmez and pestil samples, total phenolics, flavonoids, proanthocyanidins, anthocyanins and antioxidant capacity were determined at different phases of simulated gastrointestinal (GI) digestion. For the analysis of antioxidant activity, four different methods were used including 2,2‐azinobis(3‐ethylbenzothiazoline)‐6‐sulfonic acid, 1,1‐diphenyl‐2‐picrylhydrazil, ferric reducing antioxidant power and cupric ion reducing antioxidant capacity. The results revealed that the dialysed fraction (IN) represented 12–50%, 3–17% and 3–72% of the total phenolics, flavonoids and proanthocyanidins, respectively. Moreover, total antioxidant capacity of IN fraction was 2–57% of the initial values obtained for pekmez and pestil samples. To identify the influence of simulated in vitro GI digestion on total anthocyanins, only black mulberry molasses (pekmez) and plum leather (pestil) were analysed and according to the results no anthocyanins were detected in the IN fraction for both samples. The present study presented a detailed insight of bioaccessibility of polyphenols in various pekmez and pestil samples.