蓝莓叶多酚与蓝莓果渣多酚提取物抗氧化活性研究

通过7种方法比较了蓝莓叶多酚（Blueberry leaves polyphenols,BBLP）提取物、蓝莓果渣多酚（Blueberry pomace polyphenols,BBPP）提取物以及对照品Rutin的抗氧化活性。在ABTS⁺清除能力、还原力、亚硝酸盐清除能力、FRAP值、ORAC值方面,BBLP与BBPP均高于Rutin或者与其相当。而三种样品DPPH·清除能力顺序为BBLP>Rutin>BBPP,·OH清除能力顺序为Rutin>BBLP>BBPP。除亚硝酸盐清除能力和ORAC值与BBPP相当、·OH清除能力弱于BBPP外,BBLP在其余4种方法中表现出的抗氧化活性均强于BBPP。结果表明,BBLP与BBPP具有较强的抗氧化作用,可用于开发天然抗氧化剂。      

黑加仑果渣提取物抗氧化活性研究

以黑加仑果汁加工后的果渣为原料,通过微波-超声辅助提取法提取果渣中多糖及水、醇萃取物;采用体外抗氧化体系研究果渣提取物超氧自由基、羟基自由基、DPPH自由基的清除能力,采用红外对多糖进行表征。结果表明:多糖为α-吡喃糖;多糖、醇提取物浓度在0.8 mg/mL时DPPH自由基、羟基自由基清除率达到90%以上,水提取物达到80%以上;其多糖超氧自由基清除率达到60%以上;水、醇提取物超氧自由基在50%以上。所以,提取物具有显著抗氧化活性,具有好的开发前景。     

蓝莓叶不同溶剂提取物抗氧化活性研究

研究蓝莓叶不同溶剂提取物中总酚和黄酮的含量以及抗氧化活性。分别用水、甲醇、乙醇、乙酸乙酯、氯仿、石油醚等不同极性溶剂提取蓝莓叶中的活性物质,采用Folin-Cioeaile法、三氯化铝显色法分别测定不同提取物中总酚和黄酮的含量;应用1,1-二苯基-2-三硝基苯肼（DPPH）自由基和2,2-联氮基双（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）自由基清除体系及β-胡萝卜素-亚油酸体系评价其抗氧化活性,考察活性物质含量与抗氧化活性的关系。结果表明,蓝莓叶提取物的抗氧化活性随提取溶剂极性的减小而减小。水提取物具有较强的抗氧化活性,其清除DPPH·和ABTS+·的EC50分别为（12.78±0.10）、（6.35±0.03）μg/mL,抑制β-胡萝卜素淬灭IC50值为（25.33±0.02）μg/mL。含量测定显示水提物中总酚含量最高,为（264.67±0.29）mg/g,而甲醇提取物中黄酮含量最高,为（68.94±0.08）mg/g,相关性分析表明,不同溶剂提取物抗氧化能力差别较大,总酚和黄酮含量与抗氧化能力具有相关性,提示水可作为蓝莓叶抗氧化活性物质提取的优选溶剂,而总酚和黄酮含量可作为蓝莓叶抗氧化提取物的质量评价指标。      

蓝莓叶多酚提取物对3种细菌的抑菌活性

以金黄色葡萄球菌、铜绿假单胞菌和大肠杆菌为试验菌,采用涂布法确定蓝莓叶多酚的抑菌浓度及牛津杯法明确蓝莓叶多酚p H值对抑菌活性的影响。通过测定蓝莓叶多酚与3种试验菌作用前后的生长曲线、菌液的电导率值、260 nm处的吸光值和观察细胞形态变化,初步阐明蓝莓叶多酚对3种试验菌的抑菌机理。结果表明,蓝莓叶多酚对金黄色葡萄球菌、铜绿假单胞菌、大肠杆菌都有较强的抑菌活性,最低抑菌浓度分别为0.062 5%、0.062 5%和0.125%,在p H7.0~8.0抑菌性较强。经蓝莓叶多酚处理后,3种试验菌生长缓慢,菌液电导率值、260 nm处的吸光值均增大;蓝莓叶多酚作用于菌体细胞后,菌体细胞出现断裂,细胞壁凹陷等现象,表明蓝莓叶多酚可使细胞膜通透性增加,破坏细胞膜完整性,使细胞内容物外泄。     

蓝莓果渣花色苷提取工艺优化及抗氧化活性比较研究

以蓝莓干果渣为原料,酸化乙醇为溶剂,应用超声辅助法提取花色苷,利用pH示差法测定花色苷含量,通过单因素实验和响应面试验优化得出蓝莓干果渣花色苷提取工艺条件,比较相同干重的蓝莓干果渣、湿果渣采用超声辅助提取和无超声辅助工艺得到的提取液的总多酚、花色苷含量及抗氧化活性。结果表明,蓝莓干果渣最佳提取工艺为液料比(31:1)mL/g,乙醇浓度63%,pH2.6,超声功率500 W,提取时间20 min,在此条件下蓝莓果渣提取液中花色苷含量为498.84 mg/100 g。相同原料,超声辅助提取工艺提取液较无超声辅助提取工艺提取液的总多酚和花色苷含量多;相同工艺条件下,相同干重的湿果渣总多酚和花色苷含量较干果渣低,但却拥有更高的抗氧化活性。     

黑果枸杞多酚体外抗氧化活性研究

采用FRAP值、·OH清除力、DPPH自由基清除力、还原力和总抗氧化能力（TEAC）5个体外抗氧化指标对26个不同产地的黑果枸杞多酚进行抗氧化活性评价。结果表明,产地间样本抗氧化活性差异较大;抗氧化模型不同,其抗氧化活性存在差异;综合分析,样本来自宁夏回族自治区贺兰县12-01、宁夏回族自治区银川市掌政、青海省格尔木市乌图美仁乡、新疆维吾尔自治区阜康市甘河子镇、新疆维吾尔自治区喀什市、甘肃省民勤县中渠可作为较好的开发功能性食品的资源。      

蓝莓叶多酚减压提取工艺优化

采用减压提取蓝莓叶多酚,在单因素基础上采用正交实验对pH、提取时间、料液比、粒度进行优化,得到最佳提取条件为:真空度-0.07MPa,乙醇浓度60%,pH3.5,提取时间60min,料液比1∶50,物料粒度80～100目,在此条件下多酚提取率为81.47%,多酚纯度为45.32%,其中多酚纯度比常压提取高6.57%。采用ORAC法、TEAC法、DPPH法、亚硝酸盐法对蓝莓叶多酚抗氧化能力进行评价,结果表明:蓝莓叶多酚有很强的抗氧化能力,减压提取的蓝莓叶多酚比常压提取的蓝莓叶多酚具有更强的抗氧化能力。     

红枣果汁果渣与果酒果渣中色素抗氧化活性的比较

为比较红枣果汁果渣与果酒果渣中色素抗氧化活性的差异,以红枣果汁及果酒果渣为原料,碱法提取红枣色素,运用比色法测定红枣果汁果渣、果酒果渣色素中抗氧化活性成分含量,测定DPPH·、ABTS⁺·、·OH、O₂^-·清除能力和还原力,比较红枣果汁果渣与果酒果渣色素的抗氧化活性,采用SPSS软件分析抗氧化活性成分含量与抗氧化活性之间的相关性。结果表明:红枣果汁果渣与果酒果渣色素抗氧化活性成分含量间存在显著差异(P<0.05),且随着发酵时间延长,色素抗氧化活性成分含量逐渐降低;红枣果汁果渣与果酒果渣色素清除DPPH·、ABTS⁺·、·OH、O₂^-·能力和还原力差异显著(P<0.05),随着发酵时间延长,色素抗氧化活性逐渐降低;相关性研究显示,果汁果渣色素抗氧化活性成分含量与抗氧化活性相关性较强,果酒果渣色素总黄酮含量与抗氧化活性相关性相对较弱,表明红枣果汁果渣色素抗氧化活性显著高于果酒果渣(P<0.05)。     

超声辅助酶解法优化油橄榄果渣多酚提取工艺及其抗氧化活性研究

通过单因素试验和响应面法优化超声辅助酶解法提取油橄榄果渣多酚的工艺,同时用Fe³⁺还原能力(FRAP)法评价多酚的抗氧化能力。结果表明：最优的提取工艺为双酶(纤维素酶和果胶酶质量比1∶1)添加量1.5%(以油橄榄果渣质量计)、超声时间30 min、溶剂pH 3.5、提取温度50℃,在此条件下油橄榄果渣多酚得率为1.798%±0.078%。当油橄榄果渣多酚质量浓度为10 mg/mL时,FRAP值为5.42μg/mL。     

木瓜叶多酚的提取及抗氧化活性研究

以提取木瓜叶多酚并研究其抗氧化活性为目的。利用乙醇提取木瓜叶多酚,采用DPPH法、水杨酸法检测其对DPPH.和.OH的清除作用。结果表明,最佳提取条件为提取温度70℃、乙醇体积分数70%、提取时间2.5 h、料液比1∶15(m/V)。在该条件下木瓜叶多酚得率最高,达到18 mg/g。木瓜叶多酚清除DPPH.和.OH的半抑制质量浓度(EC50)分别为67μg/mL和0.44 mg/mL。结论为木瓜叶中含有丰富的多酚,并且其具有较强的抗氧化活性。     

Comparison of the Volatile Constituents from Rabbiteye Blueberries (Vaccinium ashei) During Ripening

GLC-MS analyses of steam distillates prepared from Delite, Tifblue, and Woodard cultivars of rabbiteye blueberries at three stages of maturity showed qualitative and quantitative differences in their organic constituents. Fifty-one compounds, consisting of aldehydes, ketones, alcohols, aromatic hydrocarbons, terpenes, esters, and three methyl substituted indanones (the latter tentative) were identified and compared. Most compounds with molecular weights of 100 - 200 amu appeared to increase with maturity and indicate potential use as indices of quality. Terpenes, C6 unsaturated aldehydes, and unsaturated alcohols were the predominant types of compounds identified in the distillates. Synthetic mixtures of lina- 1001, trans-2-hexenal, trans-2-hexenol, cis-3-hexen-1-ol and geraniol possessed typical fruity aromas reminiscent of fresh blueberry odorflavor as determined by informal sensory evaluations.     

Antioxidant capacities vary substantially among cultivars of rabbiteye blueberry (Vaccinium ashei Reade)

Fruits from forty‐two blueberry cultivars, including thirty‐six rabbiteye (Vaccinium ashei Reade), three V. ashei hybrid derivatives and three northern highbush (V. corymbosum L.) standards, were evaluated for their antioxidant activities against peroxyl free radicals (ROO˙), hydroxyl radicals (OH˙), hydrogen peroxide (H₂O₂), superoxide radicals () and singlet oxygen (¹O₂) radicals. The differences in scavenging capacities for these radicals among forty‐two selected blueberry cultivars were significant. Oxygen radical absorbance capacity values ranged from 33.8 to 118.7 μmol Trolox equivalents (TE) g fresh wt^?1, 196.1 to 518.8 μmol TE g dry wt^?1 and 7.1 to 22.2 μmol cm^?2‐surface area. Extracts from fruit of pure rabbiteye had higher levels of scavenging capacities of oxygen species , ¹O₂ and H₂O₂ compared to V. ashei hybrid derivatives and northern highbush blueberry standards. The rabbiteye cultivars ‘Early May’ and ‘Centurion’ had the highest scavenging capacity for the reactive oxygen species, not only for ROO˙ and ˙OH, but also for , ¹O₂ and a strong oxidant, H₂O_2. In contrast, ‘Pink Lemonade’ (pink‐fruited) had the lowest ability to inhibit free radical activity of ROO˙,˙OH, ¹O_2, and H₂O_2.‘Snowflake’ had the lowest scavenging capacity for . Blueberry cultivars with high antioxidant activity and radical scavenging capacity have potential to improve human health and can possibly be used as parents for future blueberry breeding programs to develop new blueberry cultivars with higher antioxidant activity.     

新疆野生苹果(Malus sieversii)的总多酚、总黄酮提取物的抗氧化活性研究

以采集于新疆不同地区的20个野生苹果品种为研究对象,福林酚法测总多酚,分光光度计法测定总黄酮,DPPH、ABTS、还原能力法测定总抗氧化能力,相关系数法分析各个指标之间的相关性。结果显示,不同品种的野生苹果的总多酚、总黄酮及抗氧化活性之间具有显著差异,其中,HDM-23的总多酚含量最高（4714.33μmol没食子酸/100g鲜果）,XY-31的总黄酮含量最高（2452.84mg芦丁/100g鲜果）。总多酚、总黄酮及抗氧化活性之间呈极显著（p<0.01）正相关,表明总多酚与总黄酮是野生苹果抗氧化活性的主要贡献物质。      

Vacuum-Belt Drying of Rabbiteye Blueberry (Vaccinium ashei) Slurries: Influence of Drying Conditions on Physical and Quality Properties of Blueberry Powder

Continuous vacuum-belt drying was studied as a means to produce high-quality powders from blueberry slurries, with limited degradation of anthocyanins. Drying was performed at three different temperatures (80, 95, 110 °C) and the resulting dried material (a _w?～?0.2) ground into powders. Drying times ranged from 70 min at 80 °C to 50 min at 110 °C. Maltodextrin (MD) was used as a drying agent at three levels (0.3, 0.45, and 0.6 kg/kg dry blueberry solid). Powders were purple, with no signs of browning, and similar in appearance to those produced by freeze-drying. Increasing MD level and drying temperature decreased the hygroscopicity of the powders. Moisture isotherms showed type 3 behavior and were well-fit with the Guggenheim–Anderson–de Boer equation. Higher levels of MD improved flowability of the powders, with >93 % of the powders with MD flowing from the test fixture after 30 s, compared to only 62.1 % emerging for powders without MD. Powders dried at 80 °C were slightly darker (L*?=?25.73–28.4) than those produced 110 °C (L*?=?27.10–28.53), presumably due to less degradation of anthocyanins. Total monomeric anthocyanins (TMA) for MD dried at 80 °C (13.1 mg C3G/g) were not different than for freeze-dried blueberries. Higher drying temperatures caused some loss of TMA. Higher levels of MD result in lower TMA by increasing the amount of dry matter in the powders. Vacuum-belt drying at 80 °C with 0.3 kg MD/kg dry solids produced non-sticky powders with anthocyanin content similar to freeze-dried powders.     

蓝莓皮渣花色苷粗提物的抗氧化性

从蓝莓加工废弃物-皮渣中提取花色苷粗提物,研究花色苷粗提物清除超氧阴离子自由基、DPPH自由基、羟自由基和抗脂质氧化、还原力等活性。结果表明:蓝莓皮渣花色苷粗提物对超氧阴离子自由基、DPPH自由基、羟自由基的清除率和还原能力随着添加浓度的增大而升高。花色苷粗提物的羟自由基抑制率在同等浓度下与标准抗氧化剂VC相近、对脂质的抗氧化作用比标准抗氧化剂BHT和VC表现出更好的活性,但花色苷粗提物显著低于同浓度VC对DPPH自由基的清除率。通过与VC、刺梨多糖的协同作用分析发现,VC对蓝莓皮渣花色苷粗提物具有更好的协同作用。因此,蓝莓皮渣花色苷粗提物具有一定的还原能力、较强的抗脂质过氧化能力,并对自由基具有较强的清除效果,为贵州省蓝莓皮渣的综合开发及新型食品添加剂的研制及进一步推广应用提供了依据。     

蓝莓叶中抗氧化物质提取工艺研究

主要以对DPPH自由基的清除能力为抗氧化指标,研究蓝莓叶中抗氧化物质的提取工艺。探究了pH、提取温度、料液比、提取时间等因素对蓝莓叶中抗氧化物质提取的影响。在单因素和正交实验中,确定了各因素影响蓝莓叶中抗氧化物质提取的主次顺序为：料液比〉提取温度〉酸碱度〉提取时间,并得到了最佳提取工艺条件：料液比为1：14（g：mL）,提取温度为100℃,酸碱度为pH2.0,提取时间为60min。最佳工艺条件下,蓝莓叶提取物中抗氧化活性为159.88mg/g·FW。     

竹叶黄酮的抗氧化活性研究

为了有效利用竹叶中黄酮类物质,研究采用不同的方法(DPPH法、邻苯三酚自氧化法(325nm)和Fenton法)评价了竹叶黄酮的抗氧化活性,以Vc和茶多酚为阳性对照品。结果表明:竹叶黄酮清除超氧负离子自由基和DPPH自由基的能力比茶多酚强,其EC50相应为11.7μg/mL和18.3μg/mL,分别是Vc的约1.2倍和3.4倍;竹叶黄酮在清除羟自由基效果与茶多酚相当,EC50为0.58mg/mL,比Vc效果好。因此竹叶黄酮具有很强的抗氧化能力,值得深入研究其生理功能及开发利用价值。