酰基稳态化花色苷的制备及其热降解特性和抗氧化活性

食品级的肉桂酸甲酯为酰基供体,运用减压酶法,催化其与矢车菊素-3-O-葡萄糖苷（C3G）发生酰化反应,具有绿色安全、高效且酰化产物单一等优点。对酰化产物进行分离,并进行热稳定性和抗氧化性等性质的测定。结果表明：酰化转化率为80%;利用半制备高效液相色谱仪对酰化后的产物进行分离纯化,纯化后的酰化C3G纯度达98.3%;经质谱分析可知,酰化后产物为矢车菊素-3-(6-肉桂酰)-葡萄糖苷（C3(6C)G）。酰基化修饰使花色苷的脂溶性、热稳定性得到了明显改善。采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除、2,2-氨基-二(3-乙基-苯并噻唑啉-6-磺酸)（2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid,ABTS）阳离子自由基清除、铁离子还原/抗氧化能力法（ferric reducing and antioxidant power,FRAP）、羟自由基清除体外实验测定不同浓度下C3G、C3(6C)G和VC的抗氧化能力。与相同浓度的VC相比,除了在ABTS阳离子自由基清...     

甲基丙烯酸酐改性胶原蛋白的研究

用甲基丙烯酸酐改性胶原蛋白,采用单因素和正交试验研究所得的胶原蛋白乙烯基化改性条件为：温度50℃,反应时间2h,甲基丙烯酸酐的用量为1．5mL。通过核磁（^1H-NMR）和红外光谱（FT-IR）对乙烯基化改性前后的胶原蛋白进行表征,证明胶原蛋白被成功改性并在其分子链上引入C—C双键。并对3种不同相对分子质量的胶原蛋白G1、G2和G3进行乙烯基化改性,发现小分子质量的胶原蛋白改性得到的乙烯基胶原蛋白的取代度较大。     

酶催化蔗糖八乙酸酯与油酸乙酯转酯化反应的研究

在有机溶剂中,以脂肪酶Novo435为催化剂,蔗糖八乙酸 酯与油酸乙酯通过转酯化反应合成了同时含有油酸酰基 和乙酸酰基的混合型蔗糖酯,当蔗糖八乙酸酯与油酸乙酯 的物质的量之比为1:1时,油酸乙酯的转化率达95％。正 交实验给出该转酯化反应的最适条件是:以叔戊醇为反应 介质,反应温度为40℃,脂肪酶用量为5000U／1mmol蔗 糖酯,分子筛用量为500mg/1mmol蔗糖酯。     

酶催化蔗糖八乙酸酯与油酸乙酯转酯化反应的研究

在有机溶剂中,以脂肪酶Novo435为催化剂,蔗糖八乙酸 酯与油酸乙酯通过转酯化反应合成了同时含有油酸酰基 和乙酸酰基的混合型蔗糖酯,当蔗糖八乙酸酯与油酸乙酯 的物质的量之比为1:1时,油酸乙酯的转化率达95％。正 交实验给出该转酯化反应的最适条件是:以叔戊醇为反应 介质,反应温度为40℃,脂肪酶用量为5000U／1mmol蔗 糖酯,分子筛用量为500mg/1mmol蔗糖酯。      

花青素苷的酰基化结构修饰及织物染色

为了改善花青素苷织物染色的K/S值、色牢度和抗氧化等性能，用丁二酸对花青素苷进行酰基化改性，利用红外光谱和紫外可见光谱对改性前后花青素苷进行分析，对改性前后花青素苷染色织物的各项性能进行比较。结果表明：酰基化花青素苷染色棉织物的K/S值明显高于花青素苷染色棉织物，酰基化对染色羊毛织物K/S值的影响不明显。花青素苷的酰基化可提高染色织物的各项色牢度。（酰基化）花青素苷均能提高染色织物的DPPH自由基清除率和UPF值，且酰基化染色织物的提高程度更大。     

果蔬汁饮料中花色苷与维生素C相互作用研究进展

花色苷是果汁饮料中主要的呈色物质,然而,其稳定性差,特别是在抗坏血酸（Vitamin C,V_C）存在下极易降解褪色,严重影响果汁饮料的品质。为探究V_C存在下花色苷的稳定性,本文以矢车菊-3-O-葡萄糖苷（Cyanidin-3-O-glucoside,C3G）-V_C模拟体系为对象,研究贮存过程中明胶对C3G稳定性的影响,并通过荧光光谱、分子对接等手段对明胶与V_C及明胶与C3G之间的相互作用进行研究并揭示相关机理,同时,也考察了在无V_C的模拟体系中明胶对C3G稳定性的影响。结果表明,共存V_C下明胶能显著提高C3G的稳定性,当体系中明胶质量浓度为0.5 g/L时,C3G的半衰期由121 h延长至191 h,而无V_C存在下明胶不能提高C3G的稳定性。荧光分析表明,C3G和V_C均对明胶有较强的荧光猝灭作用,猝灭机制都为静态猝灭,且C3G与明胶的结合常数远大于V_C与明胶的结合常数（10⁵ vs 10⁴）,这表明三者共存时明胶将优先与C3G结合。另外,分子对接也证实了C3G与明胶的结合能力强于V_C与明胶的结合能力,且两者与明胶的作用力都主要是通过氢键及疏水作用。因此,推测明胶与V_C竞争结合C3G形成复合物,降低了V_C对C3G的可及性,从而提高了C3G稳定性。     

硒化壳聚糖的制备及理化性质的研究

运用乌氏粘度计、常规溶剂和WZZ-1自动指示旋光仪等方法对硒化壳聚糖的理化性质进行测定,结果表明:硒化壳聚糖的特性粘度为96;脱乙酰度为29.43%;硒化壳聚糖在水中可溶,而且溶解度随温度升高而增加,但在有机溶剂中基本不溶;硒化壳聚糖在25℃时的旋光度为-14。通过紫外光谱、红外光谱的测定分析,确定亚硒酸根连接在壳聚糖分子中C2位的氨基上和C6位的羟基上。     

硒化壳聚糖的制备及理化性质的研究

运用乌氏粘度计、常规溶剂和WZZ-1自动指示旋光仪等方法对硒化壳聚糖的理化性质进行测定,结果表明:硒化壳聚糖的特性粘度为96;脱乙酰度为29.43%;硒化壳聚糖在水中可溶,而且溶解度随温度升高而增加,但在有机溶剂中基本不溶;硒化壳聚糖在25℃时的旋光度为-14。通过紫外光谱、红外光谱的测定分析,确定亚硒酸根连接在壳聚糖分子中C2位的氨基上和C6位的羟基上。      

蓝莓花青素的酰化及其抗氧化性评价

以三乙酰没食子酰氯作为酰基化剂,对蓝莓花青素提取物进行酰基化反应,制得酰基化蓝莓花青素产物没食子酸酰化花青素(GAA)。薄层色谱追踪反应进程、毛细管法测定熔点保证酰化剂合成纯度。对原花青素提取物、酰化中间产物和酰化花青素进行了红外光谱扫描,对比三者谱图,证实了酰基化实验的成功,并利用HPLC测定了酰化度。分别通过DPPH法、邻苯三酚自氧化法、卵磷脂脂质体法测定了酰化花色苷对于清除自由基、清除超氧阴离子和抑制脂质体过氧化的能力,酰化花色苷对于以上3实验的IC50分别为26.8、17.5、171.7μg/mL;相比较,原蓝莓花青素为39.8、27.0、219.7μg/mL;抗坏血酸为45.1、51.2、1084.8μg/mL。实验表明没食子酸酰化花青素方法切实可行,产物没食子酸酰化花青素的抗氧化性得到提升。     

蓝莓花青素的酰化及其抗氧化性评价

以三乙酰没食子酰氯作为酰基化剂,对蓝莓花青素提取物进行酰基化反应,制得酰基化蓝莓花青素产物没食子酸酰化花青素(GAA)。薄层色谱追踪反应进程、毛细管法测定熔点保证酰化剂合成纯度。对原花青素提取物、酰化中间产物和酰化花青素进行了红外光谱扫描,对比三者谱图,证实了酰基化实验的成功,并利用HPLC测定了酰化度。分别通过DPPH法、邻苯三酚自氧化法、卵磷脂脂质体法测定了酰化花色苷对于清除自由基、清除超氧阴离子和抑制脂质体过氧化的能力,酰化花色苷对于以上3实验的IC50分别为26.8、17.5、171.7μg/mL;相比较,原蓝莓花青素为39.8、27.0、219.7μg/mL;抗坏血酸为45.1、51.2、1084.8μg/mL。实验表明没食子酸酰化花青素方法切实可行,产物没食子酸酰化花青素的抗氧化性得到提升。      

杨梅中主要花色苷的组成与结构

采用V(甲醇)∶V(甲酸)=19∶1溶液提取杨梅中的花色苷,并用阳离子交换树脂初步纯化得到杨梅花色苷提取物,然后以水-正丁醇-甲基叔丁基醚(TBME)-乙腈-三氟乙酸(TFA)(体积比5∶2∶1.5∶1∶0.001)为溶剂系统,用高速逆流色谱对杨梅花色苷进行分离。再由C18柱色谱纯化后,得到2种主要的花色苷单体Ⅰ和Ⅱ。经ESI-MS和NMR鉴定为矢车菊色素-3-β-吡喃型葡萄糖苷(Ⅰ)和飞燕草色素-3-葡萄糖苷(Ⅱ)。另外,文中对3个杨梅品种的花色苷组成进行了分析,结果表明,矢车菊色素-3-β-吡喃型葡萄糖苷是杨梅花色苷的主要组成成分,占花色苷总量的90%以上。     

蔓越莓花色苷的组成鉴定及抗氧化能力

对蔓越莓花色苷的组成进行鉴定,并对其抗氧化能力进行测定。采用pH示差法测定花色苷提取量,超高压辅助提取蔓越莓花色苷含量为（75.49±0.43）mg/100?g,常规溶剂提取蔓越莓花色苷含量为（67.31±1.08）mg/100?g,蔓越莓中总花色苷含量为（79.52±0.50）mg/100?g;选择AB-8大孔树脂对蔓越莓花色苷粗提物进行纯化,冻干粉中花色苷含量从（46.10±0.92）mg/g提高到（309.26±2.37）mg/g。通过测定1,1-二苯基-2-三硝基苯肼自由基清除率、2,2’-联氮基-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐自由基清除能力和总抗氧化能力,比较蔓越莓花色苷与VC的抗氧化能力。结果表明：同质量浓度条件下,蔓越莓花色苷的抗氧化能力强于VC。通过高效液相色谱-质谱联用技术在蔓越莓中鉴定出7?种花色苷：芍药素-3,5-二己糖苷、矢车菊素-3-半乳糖苷、矢车菊素-3-葡萄糖苷、矢车菊素-3-阿拉伯糖苷、芍药素-3-半乳糖苷、芍药素-3-葡萄糖苷、芍药素-3-阿拉伯糖苷,其中芍药素-3,5-二己糖苷首次在蔓越莓中被鉴定出。     

Purification of Anthocyanins from Extracts of Red Raspberry Using Macroporous Resin

The performances and separation characteristics of nine widely used macroporous resins for the enrichment and purification of anthocyanins from red raspberries extracts were investigated. AB-8 resin offered the maximum adsorption and desorption behavior for anthocyanins among the resins tested, and its adsorption behavior was fitted to the Langmuir and Freundlich isotherms at different temperatures. In order to optimize the operating process, the dynamic adsorption and desorption experiments were carried out on an AB-8 resin-packed column. The optimum parameters for adsorption were sample solution anthocyanins concentration 0.2912 mg/mL, processing volume 3.5 BV, flow rate 0.5 mL/min; optimum parameters for desorption were elution solvent ethanol–water (60:40, v/v) 2.5 BV and flow rate 1.0 mL/min. After one run treatment with AB-8 resin, the anthocyanins purity increased 19.1-fold with a recovery yield of 98.84%. Two kinds of anthocyanins were obtained by further processing with a Sephadex LH-20 column, which were identified as cyanidin-3-glucoside and cyanidin-3-sophoroside using high-performance liquid chromatography–mass spectrometry, and the purity was 95.52 and 94.76%, respectively. The separation process developed via column chromatography in this study provided a potential approach for scale-up purification of anthocyanins from red raspberries or other similar berries.     

利用中压制备液相色谱从桑葚中快速制备矢车菊素-3-葡萄糖苷单体

单体花色苷的快速大量制备长久以来是花色苷产业化中的难题,而中压制备液相色谱在产业应用中有着很大的开发空间。选取花色苷组分较单一的桑葚为实验原料,经提取分离总花色苷后使用填装有反相C18填料的耐压玻璃柱作为中压制备液相色谱柱,纯化制备矢车菊素-3-葡萄糖苷单体。结果显示：3 个色谱分离峰中目的峰（峰2）经高效液相色谱和质谱确证为由矢车菊素-3-葡萄糖苷（cyanidin-3-glucoside,C3G）和矢车菊素-3-芸香糖苷（cyanidin-3-rutinoside,C3R）组成,采用峰面积归一化法计算得到C3G纯度为73.56%;通过对峰2采用切割方式进行收集,C3G纯度达到98%以上,单次收集到C3G单体溶液650?mL。中压制备液相色谱法单次上样量大、步骤简洁、成本低廉,可为矢车菊素-3-葡萄糖苷单体的规模化生产提供一定的参考。     

基于液相色谱-质谱联用技术定性定量分析黑豆种皮中可溶型和结合型花青素

以超声波辅助有机溶剂提取法获得黑豆种皮可溶型花青素提取物,再进一步对不含可溶型花青素的黑豆种皮残渣使用酸水解和碱水解以及酸碱/碱酸轮提水解,获得黑豆种皮结合型花青素提取物。采用超高效液相色谱-电喷雾-四极杆飞行时间质谱联用仪分析鉴定各黑豆种皮提取物中所含有的共17 种花青素成分,包括11 种花青素糖苷类：飞燕草素-3-O-葡萄糖苷、飞燕草素-3-O-半乳糖苷、矮牵牛花素-3-O-葡萄糖苷、矮牵牛花素-3-O-半乳糖苷、天竺葵素-3-O-芸香糖苷、矢车菊素-3-O-葡萄糖苷、矢车菊素-3-O-半乳糖苷、天竺葵素-3-O-己糖苷、芍药花素-3-O-己糖苷、天竺葵素-3-O-(6”-丙二酰葡萄糖苷)和芹菜定-3-O-(6”-丙二酰葡萄糖苷);6 种花青素苷元：飞燕草素、矢车菊素、矮牵牛花素、天竺葵素、芹菜定和芍药花素。采用高效液相色谱-电喷雾-三重四极杆质谱联用仪精确定量各类黑豆种皮提取物中的花青素含量,结果表明,酸性结合型花青素提取物中结合型花青素的总含量最高。此外,在黑豆种皮的可溶型花青素提取物中,花青素主要以花青素糖苷类形式存在,苷元含量相对极少;而在结合型花青素提取物中,则主要以花青素苷元为主,糖苷类化合物相对少见。     

Storage Changes in Anthocyanin Content of Red Raspberry Juice Concentrate

Anthocyanins from red raspberry juice concentrates were extracted with acidified ethanol and methanol and separated by high performance liquid chromatography. Six anthocyanin peaks were identified as cyanidin-3-sophoroside (cy-3-sop), cyanidin-3-glucorutinoside (cy-3-glru), cyanidin-3-glucoside (cy-3-gl), cyanidin-3-rutinoside (cy-3-ru), pelargonidin-3-sophoroside (pg-3-sop), and pelargonidin-3-glu-corutinoside (pg-3-glru). Relative proportions of individual anthocyanins were determined by comparing peak areas. The proportions of cy-3-sop, cy-3-glru and cy-3-gl in particular changed greatly on storage for 3 mo at + 20°C. Minor changes occurred when the raspberry juice concentrate was stored at ?20°C.     

Analytical characterization and the impact of ageing on anthocyanin composition and degradation in juices from five sour cherry cultivars

Five different sour cherry cultivars were processed to sour cherry juices in order to analyze their composition and the impact of storage on anthocyanin composition. Regarding primary juice parameters all cultivars showed high dry masses (13.8–17.2° Brix) and sugar free extracts (59.4–74.3 g/L). Anthocyanins were identified as cyanidin-3-(2^G-glucosylrutinoside), cyanidin-3-(2^G-xylosylrutinoside), cyanidin-3-sophoroside, cyanidin-3-glucoside, cyanidin-3-rutinoside, and peonidin-3-rutinoside. Besides the original anthocyanins, 5-carboxypyrano-anthocyanins occurred as new reaction products during storage. HPLC-MSⁿ experiments revealed, that a further ageing pigment was probably resulting from the reaction of an original anthocyanin with acetaldehyde. A significant decline of the original anthocyanin concentrations could be observed (70–75%) during 6 months of storage at 20 °C. Degradation kinetics of anthocyanins were calculated taking the reaction rate as first order. Colourless polyphenol concentrations and antioxidant capacities (TEAC) of the juices were not affected during storage.     

Identification of anthocyanins isolated from black rice (Oryza sativa L.) and their degradation kinetics

Black rice is rich in anthocyanins-plant pigments. The aim of this work was to identify anthocyanins in black rice using high-performance liquid chromatography (HPLC)-electrospray ionization — mass spectrometry with diode array detection. Four different anthocyanins (cyanidin-3-glucoside, peonidin-3-glucoside, cyanidin-3,5-diglucoside, cyanidin-3-rutinoside) were identified in black rice. Thermal stability of the four anthocyanins in black rice extract was studied at selected temperatures (80 °C, 90 °C and 100 °C) in the range of pH 1.0–pH 6.0. The results indicated that the thermal degradation of anthocyanins followed the first-order reaction kinetics. The temperature-dependent degradation was adequately modeled on the Arrhenius equation. The calculated values of activation energies (Ea), t_1/2 and k were different for the four anthocyanins. The degradation rate of monomeric anthocyanin increased with increasing heating temperature and pH values. Especially, as heating temperature increasing to 100 °C and pH value to 5.0.     

红莓果中花青素的提取工艺研究

以HCl-乙醇为溶剂,研究了红莓果中花青素的最佳提取工艺。在单因素试验中,选择了单次提取和2次提取,分别测定了不同提取级数下各因素(物料比、提取时间、提取温度)的最佳水平值。同时,以果实中花色苷的绝对含量作为提取效率的评价标准,提高了单纯采用吸光度值测定法作为评定指标的精确性与可靠性。通过响应面试验确定了最佳的提取工艺参数为:浓度为1.5 mol/L的HCl和体积分数95%的乙醇(体积比15∶85)为溶剂,提取料液比为5 g∶1 mL,提取时间为53 min,提取温度为71℃,提取2次。依此工艺,红莓花青素的提取得率为36.39 mg/100 g(鲜果)。