Stability of black carrot anthocyanins in various fruit juices and nectars

Fruit juices (apple, grape, orange, grapefruit, tangerine and lemon) and nectars (apricot, peach and pineapple) were coloured with black carrot juice concentrate and stability of black carrot anthocyanins in these matrices was studied during heating at 70–90 °C and storage at 4–37 °C. Anthocyanin degradation, in all coloured juices and nectars, followed first-order reaction kinetics. During heating, black carrot anthocyanins in apple and grape juices showed higher stability than those in citrus juices at 70 and 80 °C. High stability was also obtained for the anthocyanins in peach and apricot nectars at these temperatures. Black carrot anthocyanins were the least stable in orange juice during both heating and storage. During storage, degradation of anthocyanins was very fast at 37 °C, especially in pineapple nectar. Refrigerated storage (4 °C) markedly increased the stability in all samples. Activation energies for the degradation of black carrot anthocyanins in coloured juices and nectars ranged from 42.1 to 75.8 kJ mol⁻¹ at 70–90 °C and 65.9–94.7 kJ mol⁻¹ at 4–37 °C.     

Effects of temperature,solid content and pH on the stability of black carrot anthocyanins

Anthocyanin stability of black carrots was studied at various solid contents (11, 30, 45 and 64° Brix) and pHs (4.3 and 6.0) during both heating, at 70–90 °C, and storage at 4–37 °C. Monomeric anthocyanin degradation fitted a first-order reaction model. Degradation of monomeric anthocyanins increased with increasing solid content during heating, while it decreased during storage. For example, at pH 4.3, half-life periods for anthocyanins at 30, 45 and 64° Brix were, respectively, 8.4, 6.9 and 5.2 h during heating at 80 °C and 18.7, 30.8 and 35.9 weeks during storage at 20 °C. At 30–64° Brix, increasing pH from 4.3 to 6.0 enhanced the degradation of anthocyanins during heating. The effect of pH on thermal stability of anthocyanins was also studied at six different pHs (2.5–7.0) in citrate-phosphate buffer solutions and significant decrease in anthocyanin stability was observed at pHs above 5.0. Higher activation energies (E_a) were obtained during heating than during storage with increasing solid contents. At 30–64° Brix, E_a values ranged from 68.8 to 95.1 kJ mol⁻¹ during heating and from 62.1 to 86.2 kJ mol⁻¹ during storage. Q₁₀ values at 20–37 °C were as high as 3.1 at 45° Brix and 3.6 at 64° Brix.     

黑树莓花色苷分离、纯化与抗氧化活性

采用AB-8大孔树脂和硅胶柱层析技术纯化并分离黑树莓花色苷,分别通过DPPH自由基、ABTS自由基和羟自由基清除试验评价花色苷组分的抗氧化活性。结果表明:经过大孔树脂纯化后的花色苷的纯度从17.18%提高到85.21%,得率为0.60%;硅胶柱层析参数为洗脱液配比为正丁醇∶乙酸∶水的体积比为4∶2∶0.5,流速为0.5 mL/min,树莓花色苷粗品与硅胶的质量比为1∶550;得到黑树莓花色苷产物组分分别为BRA1和BRA2,纯度分别为94.53%和92.14%。组分BRA1的抗氧化活性优于组分BRA2,两者均呈现出良好的抗氧化活性。     

黑糯玉米芯花色苷提取工艺优化及抗氧化活性研究

以黑糯玉米芯为实验对象,以花色苷提取液的吸光值作为提取效果指标,采用响应面法优化了黑糯玉米芯中花色苷的提取工艺条件。在单因素实验的基础上,采用响应面分析法中的Box-Behnken模式进行三因素三水平的实验设计,结果表明:当乙醇浓度62%,液料比24∶1（m L/g）,提取温度47℃,提取时间为120 min,p H为2时,黑糯玉米芯花色苷提取效果最好;在该条件下,采用p H示差法测得到黑糯玉米芯中花色苷含量为57.29 mg/g。通过高效液相色谱-二极管阵列-电喷雾-串联质谱法鉴定了黑糯玉米芯中花色苷的组成,主要为三种花色苷:矢车菊素-3-葡萄糖苷、天葵色素-3-葡萄糖苷、芍药色素-3-葡萄糖苷。抗氧化活性实验表明:黑糯玉米芯花色苷提取物具有一定的清除DPPH自由基和ABTS自由基的能力,同时也显示了较强的还原能力和铁还原力。      

Clarification and pasteurisation effects on monomeric anthocyanins and percent polymeric colour of black carrot (Daucus carota L.) juice

Black carrots (BCs) are a rich source of stable anthocyanins (ACNs). The purpose of this study was to evaluate the effects of clarification and pasteurisation on ACNs of black carrot juice (BCJ). Monomeric ACNs, ACN profile and percent polymeric colour were determined during processing of BCJ. While depectinisation and bentonite treatments resulted in 7% and 20% increases in monomeric ACN content of BCJ, respectively, gelatine–kieselsol treatment and pasteurisation resulted in 10% and 3–16% reduction. Percent polymeric colour decreased after clarification, but substantially increased in samples subjected to heat. ACNs of BCJ samples were identified by HPLC–MS. Unclarified BCJ contained cyanidin-3-galactoside-xyloside-glucoside-ferulic acid as the major ACN, followed by cyanidin-3-galactoside-xyloside-glucoside-coumaric acid, and cyanidin-3-galactoside-xyloside-glucoside. After depectinisation, two more ACNs (cyanidin-3-galactoside-xyloside and cyanidin-3-galactoside-xyloside-glucoside-sinapic acid) were also identified. These results indicated that depectinisation and bentonite treatment had positive effect on the colour of BCJ, while gelatin–kieselsol treatment and pasteurisation had negative effect.     

黑胡萝卜色素酸水提取工艺条件的研究

以黑胡萝卜为原料,采用酸水提取的方法,通过单因素及正交实验研究诸多因素对黑胡萝卜色素提取效率的影响.结果表明,各因素对黑胡萝卜色素提取效果的影响程度依次为浸提液酸度＞浸提温度＞料液配比＞浸提时间.确定了酸水提取黑胡萝卜色素的最佳工艺条件为浸提液酸度pH=1、浸提温度70℃、料液比1 ∶ 6、浸泡时间1.5h、浸提级数1.     

黑胡萝卜色素酸水提取工艺条件的研究

以黑胡萝卜为原料,采用酸水提取的方法,通过单因素及正交实验研究诸多因素对黑胡萝卜色素提取效率的影响.结果表明,各因素对黑胡萝卜色素提取效果的影响程度依次为浸提液酸度＞浸提温度＞料液配比＞浸提时间.确定了酸水提取黑胡萝卜色素的最佳工艺条件为浸提液酸度pH=1、浸提温度70℃、料液比1∶6、浸泡时间1.5h、浸提级数1.     

四种黑米花色苷抗氧化活性的构效关系

锦葵素、天竺葵-3,5-二葡萄糖苷、矢车菊素-3-葡萄糖苷和矢车菊素-3,5-二葡萄糖苷具有很高的抗氧化活性,是黑米抗氧化作用的主要成分.4种分子中B-4'-OH是强活性基,B-3'-OH、A-5、7-OH是增效基,因具有增效基数目和位置不同抗氧化活性表现出了一定的差异.     

Hepatoprotective and antioxidant activity of anthocyanins in black rice bran on carbon tetrachloride-induced liver injury in mice

The benefits of anthocyanin-rich black rice bran extract (ARBE) on the liver of carbon tetrachloride (CCl₄)-intoxicated mice was investigated. Based on the in vivo experiment, the effect of cyanidin-3-glucoside (Cy-3-G) and peonidin-3-glucoside (Pn-3-G), the predominant anthocyanins in ARBE, on CCl₄ insulted hepatocytes L-02 was further evaluated. Mice treated with ARBE for 7 weeks by oral administration showed reduced aminotransferase activities in serum, accompanied by enhanced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, while tiobarbituric acid reactive substances (TBARS), and 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels were significantly decreased compared to CCl₄-intoxicated model group. Histopathological observation showed ARBE administration alleviated the pathological changes in livers of CCl₄-intoxicated mice. Similarly, preincubation of L-02 cells with Cy-3-G or Pn-3-G significantly alleviated CCl₄-induced injury dose-dependently, exhibited higher cell viability, decreased aminotransferase activity and enhanced cellular antioxidant status. Furthermore, Cy-3-G showed much stronger hepatoprotective activity than Pn-3-G at the same concentration. HPLC analysis showed that Cy-3-G accounted for more than 88% of total anthocyanins in ARBE. These results indicate that ARBE is significantly beneficial to liver health, and that Cy-3-G is the predominant anthocyanin in ARBE exerting this effect. The antioxidant activity of anthocyanins is an important mechanism by which ARBE exerts hepatic health benefit.     

黑豆种皮色素的测定和提取

研 究 了 直 接 测 定 法 、pH 差 示 法 和 单 pH 测 定 法 测 定 黑 大 豆 皮 提 取 液 中 色 素 总 含 量 时 的 影 响 因 素 、 线 性 范 围 及 适 用 性 。 对 比 后 认 为 ,单 pH 测 定 法 是 三 种 方 法 中 最 适 宜 用 来 测 定 黑 大 豆 皮 提 取 液 中 色 素 总 含 量 的 方 法 。 然 后 以 色 素 总 含 量 为 指 标 , 以 单 pH 测 定 法 为 色 素 总 含 量 测 定 方 法 , 采 用 响 应 面 分 析 法 对 黑 豆 皮 中 色 素 的 提 取 进 行 了 优 化 ,在 豆 皮 粒 度 为 60目 ,料 液 比 为 1∶30,提 取 时 间 为 2h 的 固 定 条 件 下 , 得 到 的 优 化 条 件 为 : 提 取 剂 为 pH 0.5的 60%乙 醇 溶液 ,提 取温 度为 80℃。     

Effect of genuine non-anthocyanin phenolics and chlorogenic acid on color and stability of black carrot (Daucus carota ssp. sativus var. atrorubens Alef.) anthocyanins

This work aimed at studying the color intensity and stability of black carrot anthocyanins as influenced by intermolecular co-pigmentation. For this purpose, purified anthocyanin solutions were supplemented with purified genuine black carrot phenolics, chlorogenic acid, and an aqueous phenolic-rich green coffee bean extract at various anthocyanin:co-pigment ratios (1:0–1:162; pH 3.6). The hyperchromic co-pigmentation effect depended on the concentration of added co-pigments, resulting in an absorbance increase of up to 22% at the absorption maximum. Anthocyanin stability during heating (90 °C, 5 h) was barely improved unless the concentrations of co-pigments exceeded those of their natural source. When adding co-pigments at ratios above 1:9.4, anthocyanin heat stability was significantly improved. As acylated anthocyanins were most stable, breeders might aim at increasing their content in the future, while breeding for high levels of colorless polyphenols may be unreachable. Nevertheless, we provided proof-of-concept for the successful color enhancement by the addition of a phenolic-rich green coffee bean extract, being useful for food-grade applications.     

黑豆皮花色苷的降血糖作用及其机理的研究

目的:观察黑豆皮花色苷(Black Soybean Anthocyanins,BSA)的降血糖效果,并对其机理进行初步研究。方法:对不同组的正常小鼠和利用四氧嘧啶造模的实验性糖尿病小鼠分别进行相应浓度的黑豆皮花色苷腹腔注射,并测定血糖、超氧化物歧化酶(SOD)、丙二醛(MDA)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-PX)以及胰岛素含量。结果:黑豆皮花色苷可以降低糖尿病小鼠的血糖和血清中MDA与CAT的含量,提高血清中SOD和GSH-PX的含量,同时提高了血清中胰岛素的含量。结论:黑豆皮花色苷具有降低糖尿病小鼠高血糖的作用,而它的作用机理可能是通过促进胰岛素分泌和清除自由基及抗脂质过氧化过程实现的。     

黑米花色苷的分离纯化及其抗氧化性的研究

对黑米花色苷进行分离纯化并研究不同部分的抗氧化活性。首先采用溶剂萃取的方法将黑米花色苷粗提取物依极性大小分成石油醚可溶部位、乙酸乙酯可溶部位、正丁醇可溶部位和水可溶部位,并对各部位清除2,2-二苯基-1-苦味肼基自由基（DPPH·）和羟基自由基（·OH）的活性进行了分析,确定了抗氧化能力最强的组分是水可溶部分。其次用大孔树脂柱层析的方法对水可溶部位进行了细分,得到C1、C2、C3、C4、C5五个组分,并对各组分清除DPPH·和·OH的活性进行了分析,确定了各组分抗氧化能力从大到小依次为:C2>C3>C4>C1>C5。研究发现,黑米花色苷水可溶部位中20%⁴0%乙醇洗脱的部分（C2、C3）具有更强的抗氧化活性。      

黑米花色苷的分离纯化及其抗氧化性的研究

对黑米花色苷进行分离纯化并研究不同部分的抗氧化活性。首先采用溶剂萃取的方法将黑米花色苷粗提取物依极性大小分成石油醚可溶部位、乙酸乙酯可溶部位、正丁醇可溶部位和水可溶部位,并对各部位清除2,2-二苯基-1-苦味肼基自由基(DPPH·)和羟基自由基(·OH)的活性进行了分析,确定了抗氧化能力最强的组分是水可溶部分。其次用大孔树脂柱层析的方法对水可溶部位进行了细分,得到C1、C2、C3、C4、C5五个组分,并对各组分清除DPPH·和·OH的活性进行了分析,确定了各组分抗氧化能力从大到小依次为:C2C3C4C1C5。研究发现,黑米花色苷水可溶部位中20%~40%乙醇洗脱的部分(C2、C3)具有更强的抗氧化活性。     

黑米花青素微胶囊制备的工艺研究

目的以黑米花青素为主要原料,开发一种能够顺利到达肠道并在肠道内缓慢释放以发挥花青素益生元功效的微胶囊。方法采用锐孔法,以包埋率为指标,分别以壁芯比、针头孔径、海藻酸钠及CaCl_2浓度为因素,采用单因素试验,确定微胶囊的制备条件;在此基础上,采用四因素三水平L_9(3~4)正交试验,优化了该微胶囊的最佳制备工艺;最后,通过微胶囊在胃和肠模拟液中的释放试验,验证该微胶囊的缓释功能。结果微胶囊的最佳制备工艺:壁芯比3:1、针头孔径0.45 mm、海藻酸钠2.0%、CaCl_2 2.0%;该微胶囊可以在人胃模拟液中保持4.0 h以上,在人肠模拟液中缓慢释放。结论采用锐孔法制备的花青素微胶囊能够顺利到达肠道缓慢释放,发挥其益生元功效。     

笃斯越橘花色苷抗氧化活性研究

目的:研究笃斯越橘花色苷的体外抗氧化活性、作用于肿瘤细胞后细胞内抗氧化酶的活性以及氧化产物的含量。方法:采用分光光度法、水杨酸比色法、邻苯三酚自氧化法、硫代硫酸钠滴定法、铁氰化钾还原法测定对DPPH·、·OH、O-2·、H2O2的清除能力以及总还原能力,采用试剂盒测定GSH-PX、CAT、SOD的活性和MDA的含量。结果:笃斯越橘花色苷清除DPPH·的能力略大于VC,清除其他三种自由基的能力和总还原能力都小于VC,并且作用于肿瘤细胞后,细胞内GSH-PX、CAT、SOD的活性都随笃斯越橘花色苷浓度的升高而减少,具有一定的量效关系,而细胞内MDA的含量随笃斯越橘花色苷浓度的升高而增加,呈线性关系。结论:笃斯越橘花色苷的体外抗氧化活性较强,并对肿瘤细胞内抗氧化酶的活性和氧化产物的含量具有一定影响。      

黑米花青素体内抗氧化研究

本文研究了黑米花青素对小白鼠的抗氧化及免疫调节作用。以生理盐水为载体,维生素C作为阳性对照,分别采用高、中、低三种剂量的黑米花青素粗提物及其纯化物,灌胃喂养小白鼠30d后,测定小白鼠的脾和胸腺指数,血清、肝脏、心脏和肾脏中总抗氧化力（T-AOC）、超氧化物歧化酶（SOD）和谷胱甘肽过氧化酶（GSH-Px）的活力,丙二醛（MDA）和羟自由基含量。研究结果表明:该花青素能增加小白鼠的脾和胸腺指数,显著提高其体内T-AOC水平和SOD、GSH-Px的活性,降低MDA和羟自由基的含量。因此,黑米花青素具有提高小白鼠的体内抗氧化及免疫调节作用。