甜橙油抗氧化活性研究

[目的]研究甜橙油的抗氧化活性。[方法]分别采用DPPH自由基清除法和普鲁士蓝法测定甜橙油的抗氧化活性。[结果]甜橙油的质量浓度小于192.5 mg/ml时,甜橙油对DPPH自由基的清除率呈剂量效应增加;当其质量浓度超过192.5 mg/ml时,甜橙油对DP-PH自由基的清除率基本维持不变。在27.5～192.5 mg/ml的浓度范围内,DPPH自由基清除率与甜橙油浓度呈现良好的量效关系：y=0.3192x＋28.9（R2=0.987 1）。DPPH自由基清除试验中,以518 nm为检测波长,反应平稳时间为60 minI,C50值为（66.10±0.39）mg/ml。在27.5～137.5 mg/ml范围内甜橙油的还原能力呈线性增高趋势,其线性拟合方程为y=0.004 1x＋0.121 1（R2=0.989 9）,证实甜橙油具有较强的还原性,是比较好的电子供应者。[结论]甜橙油具有较强的还原能力,其还原力与质量浓度在27.5～137.5 mg/ml范围内存在极显著的量效关系。     

Changes in phytochemical, antimicrobial and free radical scavenging activities of the Peruvian pepper tree (Schinus molle L.) as influenced by fruit maturation

The effect of stage of maturity on total lipids, fatty acids, yields and essential oil composition and their antimicrobial and free radical scavenging activities of the Schinus molle fruits was investigated. The content of total lipids varied from 2.87 to 5.35% (w/w, dw) and were rich in unsaturated fatty acids particularly linoleic acid. As maturation progress, the essential oil yield dropped from 5.18% to 1.15%. Monoterpene hydrocarbons with α-phellandrene (35.15-40.38%), limonene + β-phellandrene (21.47-36.62%), β-myrcene (7.61-24.96%) and α-pinene (1.92-2.58%) were found to be the main components. At the same time, the essential oils were evaluated for their antimicrobial and free radical scavenging activities. They were found to be active against Bacillus subtilis, Bacillus cereus, Salmonella typhymurium and Escherichia coli but they do not inhibit the growth of Candida albicans. Conversely, they showed very weak activity against the DPPH radical. In both assay, the oil derived from the intermediate stage was reported as more efficient.     

苹果醋清除DPPH自由基活性成分的研究

以苹果、酵母菌和醋酸菌为试验材料,采用不同的发酵工艺,对4种苹果醋样品进行抗氧化活性成分分析和DPPH自由基清除率的测定,研究其主要活性成分含量与DPPH自由基清除率之间的相关性.结果表明:苹果醋具有较高的抗氧化活性成分和较强的抗氧化能力,其中固态发酵苹果醋中总酚、总黄酮含量分别达到2.14、2.19 mg/mL;当加...     

高丛蓝莓品种花青素含量与抗氧化能力比较

对高丛蓝莓6个品种的果实花青素含量测定发现,花青素平均含量为4．62mgg,其中,品种爱国者花青素含量最高,蓝丰最低。对清除DPPH自由基能力、总抗氧化能力和总还原能力的评价表明,花青素含量较高的蓝莓品种抗氧化能力较强,但在一定浓度范围内,蓝莓花青素含量与抗氧化活性间无显著相关性。综合评价表明,品种埃利奥克表现出较强的DPPH自由基清除能力和总还原能力,有较好的抗氧化效果。     

管花肉苁蓉粗多糖提取方法及其清除二苯代苦味酰基自由基的效果

为探索管花肉苁蓉活性成分多糖的最佳提取方法,初步评价其抗氧化活性,分别采用超声-微波协同萃取、微波、水浴及超声波4种不同方法提取管花肉苁蓉中的粗多糖,并对其清除DPPH自由基的效果进行了初步研究.结果表明,超声-微波协同提取效果最佳,其次是微波、水浴和超声波.管花肉苁蓉粗多糖的最佳提取条件为:提取温度95℃,提取时间1...     

Preparation and evaluation of antioxidant capacity of Jackfruit (Artocarpus heterophyllus Lam.) wine and its protective role against radiation induced DNA damage

Jackfruit is an underutilized edible fruit in the tropics and subtropics. The aim of this study was to produce wine from jackfruit pulp and to evaluate the total phenolic and flavonoid contents and antioxidant properties of the wine. The ability of scavenging free radicals was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant assay (FRAP), N, N-dimethyl-p-phenylendiamine (DMPD) and nitric oxide (NO) scavenging assays. Experimental results indicated that jackfruit wine was effective in DPPH radical scavenging (69.44 ± 0.34%), FRAP (0.358 optical density value, O.D.), DMPD (78.45 ± 0.05%) and NO (62.46 ± 0.45%) capacity. By the analysis of the high performance liquid chromatography coupled to diode array detector (HPLC-DAD), two phenolic compounds namely gallic acid and protocatechuic acid were identified. The jackfruit wine was also able to protect H₂O₂ + UV radiation and γ-radiation (100 Gy) induced DNA damage in pBR322 plasmid DNA. The antioxidant and DNA damage protecting properties of jackfruit wine confirmed health benefits when consumed and could become a valuable source of antioxidant rich neutraceuticals. Additionally, the wine could be a commercially valuable by-product for the jackfruit growers.     

神秘果果皮的抗氧化性

[目的]研究神秘果果皮总酚含量与抗氧化性的关系。[方法]综合各种数据,选分别取60%乙醇和0.1%HCl为最佳浸泡溶剂和酸度条件,采用2×3因素均匀设计法,时间为0.5～5.0h,温度为30～50℃,研究神秘果的总酚与还原力和DPPH清除率之间的关系。[结果]在不同温度与时间条件下,干燥果皮的总酚含量与其抗氧化性相关性不大。基于均匀设计的提取花青素工艺筛选试验表明,在用60%乙醇和0.1%HCl的提取条件下,温度对神秘果果皮的抗氧化性有促进作用,其抗氧化性随温度升高而增大,且1.0h为提取花青素的最佳提取时间。[结论]该研究为进一步探究神秘果果皮的抗氧化性提供参考。     

桑枝皮醇提物的抗氧化和对α-糖苷酶活性的抑制作用

α-糖苷酶活性抑制剂是一种治疗糖尿病的口服药物。以醇水溶液为萃取溶剂,从桑树枝条的皮中获得一种具有抑制α-糖苷酶活性的桑枝皮醇提物。桑枝皮醇提物的体外生物活性试验显示其对1,1-二苯基苦基苯肼自由基具有良好的清除作用,抑制中值(IC50)为100μg/mL;对酪氨酸酶、麦芽糖酶和蔗糖酶的活性均具有很强的抑制作用,IC50值分别为0.44 mg/mL、6.5μg/mL和0.25μg/mL。对桑枝皮醇提物的酶动力学分析显示其属于底物竞争性的α-糖苷酶抑制剂。研究结果初步表明,桑枝皮醇提物不仅具有一定的抗氧化作用,而且可作为一种新型的α-糖苷酶抑制剂用于糖尿病的血糖控制。     

不同提取方法对双叉犀金龟蛋白质提取率 及体外抗氧化活性的影响

双叉犀金龟（Allomyrina dichotoma）蛋白质含量丰富，是一种重要的资源昆虫。采用碱提法、酸提法、盐提法和醇提法分别提取双叉犀金龟幼虫蛋白质，并以DPPH自由基清除活性、ABTS自由基清除活性和总还原力为指标，测定4种方法所提取的蛋白质的抗氧化活性。结果显示：碱提法蛋白质提取率显著最高，蛋白质浓度与抗氧化活性之间呈现良好的正相关关系，但不同种类蛋白质的抗氧化能力有所不同；其中盐溶蛋白的DPPH自由基清除活性及总还原力最强，IC₅₀和A₇₀₀为1时的浓度分别0.360 4 和4.780 5 mg·mL^-1；酸溶蛋白的ABTS自由基清除活性最强，IC₅₀为4.439 0 mg·mL^-1。综合来看，提取方法不同时，双叉犀金龟蛋白质具有一定的ABTS自由基清除活性、较高的DPPH自由基清除活性和总还原力，可为后续进一步向食品、医药等方向开发利用提供理论参考。     

云南十三种野生菌粗多糖含量和抗氧化活性的研究

以云南十三种野生菌为试材,比较其粗多糖含量,同时通过测定总还原能力和DPPH自由基清除率,并计算AC_(0.5)和IC_(50),比较不同野生菌粗多糖的总还原能力、清除DPPH自由基能力。结果表明:(1)点柄粘盖牛肝菌的粗多糖含量最高,为9.16 g/100 g,干巴革菌粗多糖含量最低,为2.22 g/100 g;(2)粗多糖浓度与还原能力、清除DPPH自由基能力都有较好的线性关系;干巴革菌粗多糖在低浓度下即有较好的还原能力及清除DPPH自由基能力;桃红牛肝菌粗多糖的还原能力、块鳞灰鹅膏菌粗多糖清除DPPH自由基能力也有较好的效果,与供试的其他野生菌样品差异显著。研究结果说明,干巴革菌、点柄粘盖牛肝菌、桃红牛肝菌、块鳞灰鹅膏菌中粗多糖抗氧化活性高,在保健功能方面有潜在的开发应用价值。