黑桑椹的营养成分和抗氧化作用的研究

本文分析了山西地产黑桑椹的13种微量无素和VC、VE、β-胡萝卜素、黄酮等多种营养成分,并观察了其对大鼠机体脂质过氧化作用和果蝇寿命的影响。用10%桑椹鲜果或原汁饲喂大鼠8w,可显著降低大鼠血浆和肝脏组织中脂质过氧化产物丙二醛(MAD)含量及肝脏中脂褐素含量(p<0.05～0.01),增加超氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活性(p<0.05～0.01)。黑桑椹能显著延长果蝇寿命(p<0.05～0.01)。     

马尾藻岩藻聚糖硫酸酯对高脂血症小鼠抗脂质过氧化的作用

本文研究了中、低分子量岩藻聚糖(MMWF1、MMWF2、LMWF1、LMWF2)四个不同组分马尾藻岩藻聚糖硫酸酯(SF)对高胆固醇血症小鼠脂质过氧化指标的影响。建立高脂血症小鼠模型。测定血清和肝脏中的脂质过氧化指标,包括丙二醛(MDA)含量、总超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、过氧化物酶(POD)活性、谷胱甘肽过氧化物酶(GSH-PX)活性。实验表明:四组SF都能提高血清和肝脏中CAT、GSH-PX、SOD、POD活性;都能使血清和肝脏中MDA含量降低,其中高剂量组达到极显著水平(p0.01),都能提高脂质代谢紊乱小鼠机体的抗氧化能力,恢复机体内氧化系统平衡,降低脂质过氧化的产生,保持机体内脂质代谢相关酶的活力,改善并恢复脂质正常代谢。四组SF抗脂质过氧化能力依次为:MMWF2MMWF1LMWF2LMWF1,MMWF抗氧化能力比LMWF强,相似组分间硫酸根含量越高的抗氧化能力越强。     

氧化·疾病·抗氧化(四十八)

<正>11.3.2.2谷胱甘肽过氧化物酶活力测定谷胱甘肽过氧化物酶(GSH-Px)是动物体内一种重要抗氧化酶,能消除自由基,抑制自由基反应进程;是抑制体内自由基所致膜脂质过氧化重要组分,其活力强弱可判断所进食抗氧化物质活性强度。除本方法外,也可采用简便"GSH-Px活力测定试剂盒"(南京建成生物工程公司生产)。     

珊瑚状猴头菌多糖抗氧化作用研究

目的:探讨珊瑚状猴头菌多糖的抗氧化作用。方法:体外抗氧化活性以测定其总还原力,对DPPH自由基、O2-·、·OH的清除率,抑制体外脂质过氧化能力为指标;体内抗氧化试验:将48只昆明小鼠,雌、雄各半,随机分为对照组、低剂量组【100 mg/(kg·d)】、中剂量组【200 mg/(kg·d)】、高剂量组【400 mg/(kg·d)】4个组。灌胃30d后,采样,测定小鼠血清、心脏、肝脏、肾脏组织中总抗氧化能力、超氧化物歧化酶、谷胱甘肽过氧化物酶、过氧化氢酶活力及丙二醛含量。结果:随着珊瑚状猴头菌多糖质量浓度的增加,其抗氧化能力增强;当其质量浓度达到2 mg/m L时,还原力吸光度为0.482,对DPPH自由基、O2-·和·OH的清除率分别为80.10%,91.72%和94.33%,脂质过氧化物抑制率为68.71%;可提高心脏、肝脏、肾脏等组织及血清中T-AOC、SOD、GSH-Px和过氧化氢酶活力,降低MDA含量,在高剂量时差异达极显著水平(P0.01)。结论:珊瑚状猴头菌多糖具有抗氧化作用。     

迷迭香酸对火腿肠的抗氧化作用

将纯化后的迷迭香酸添加到火腿肠中,与异VC钠相比较,考察其抗氧化效果,发现添加量为0.01%迷迭香酸火腿肠的过氧化值和TBA值都比较低,对火腿肠的脂质过氧化起到很好的减缓作用。并且发现异VC钠对迷迭香酸有一定的增效作用。     

不同处理条件对花生抗氧化肽抗氧化活性的影响

以花生蛋白粉为原料,采用Viscozyme L预水解,Alcalase水解法制备花生抗氧化肽。通过7种不同的处理条件(加热、食品添加剂、防腐剂、金属离子、杀菌、调pH值、低温)对花生抗氧化肽的4种体外抗氧化指标(清除DPPH自由基、还原力、铁离子螯合力、抗脂质体过氧化能力)进行研究。结果显示：加热处理和添加食品防腐剂有利于提高抗氧化肽的抗氧化活性;添加酒石酸、柠檬酸对抗氧化活性有较大影响,而添加氯化钠和蔗糖后对抗氧化活性影响小;添加铜离子对抗氧化活性影响较大;各种杀菌工艺有利于清除DPPH自由基、还原力、铁离子螯合力,但却降低脂质过氧化抑制率;碱性pH值条件有利于提高抗氧化肽的还原力、铁离子螯合力和脂质过氧化抑制力,酸性pH值条件不利于铁离子螯合力和脂质过氧化抑制力;低温处理降低抗氧化肽抗氧化活性。     

壳聚糖姜精油复合保鲜剂对甜椒贮藏品质的影响

为探究有效延长甜椒货架期的方法,以壳聚糖姜精油复合保鲜剂对甜椒涂膜,在8℃下贮藏35 d,分析其贮藏期间的失重率、过氧化物酶活性、叶绿素、VC等营养特性及理化指标的变化。结果表明,体积分数为0. 1%的姜精油壳聚糖复合保鲜剂对于甜椒的保鲜效果最佳,降低了样品贮藏期的失重率,诱导植物体内防御酶POD的产生,减少了VC的损失,保持了叶绿素的含量,抑制了细菌的繁殖。并且,贮藏期间涂膜处理后的甜椒样品电导率和丙二醛含量均有所增加,但仍远低于对照组。该结论为壳聚糖复合涂膜的应用提供了方向,为今后甜椒保鲜提供理论参考。     

鲢鱼鱼鳞胶原蛋白肽抗氧化作用研究

研究鲢鱼鱼鳞胶原蛋白肽-SCSCP-的抗氧化活性. 依次采用截留分子量为5, 3, 1ku的超滤膜对鲢鱼鱼鳞胶原蛋白肽进行分离分级,通过6种体外抗氧化指标评价各超滤组分抗氧化活性的强弱,分子量小于1ku的SCSCP-IV体外抗氧化活性最强-P＜005- ;氨基酸组成分析表明,SCSCP-IV中总疏水性氨基酸和精氨酸含量均较高,推测可能与其较高的抗氧化活性有关;建立高脂动物模型,考察SCSCP-IV在大鼠体内的抗氧化作用,结果显示SCSCP-IV能显著提高大鼠血清中抗氧化酶超氧化物歧化酶与谷胱甘肽过氧化物酶活力以及降低丙二醛含量-P＜0 05- ,表明SCSCP-IV在大鼠体内具有较好的抗氧化作用;结果表明SCSCP在体外和体内均具有良好的抗氧化活性.     

玫瑰多酚-壳聚糖纳米粒的制备及其抗氧化、降血糖活性研究

该研究采用离子交联法将玫瑰多酚包埋在壳聚糖中制备成玫瑰多酚-壳聚糖纳米粒,以包封率为评价指标,单因素试验得到最佳制备工艺条件为壳聚糖与三聚磷酸钠质量比为2∶1,乙酸体积分数为0.5%,玫瑰多酚添加量为3 mg/g,包封率为94.85%,比优化前提高了4.43%,此时玫瑰多酚负载率为21.26%。稳定性实验表明,光照和空气条件下,在壳聚糖纳米粒中的玫瑰多酚比游离玫瑰多酚更稳定。小鼠灌胃实验表明,玫瑰多酚-壳聚糖纳米粒可以减缓小鼠体重下降,降低空腹血糖值,提高口服葡萄糖耐量;提高小鼠体内超氧化物歧化酶、谷胱甘肽过氧化物酶活性,降低丙二醛含量。结果说明玫瑰多酚-壳聚糖纳米粒具有较好的抗氧化和降血糖活性。制备的玫瑰多酚-壳聚糖纳米粒不仅能够增强玫瑰多酚的生物利用率和稳定性,还可以提高其应用价值,在食品、药品、化妆品等行业领域具有广泛的应用前景。     

桑葚多糖调节血糖代谢及体外抗氧化效果研究

研究桑葚多糖（mulberry polysaccharides,MBPs）对糖尿病大鼠的降糖效果及体内外抗氧化活性。在体外化学条件下,测定MBPs清除·OH和O2－·能力;采用链脲佐菌素诱导建立糖尿病大鼠模型,糖尿病大鼠分别灌胃150、300、450 mg/（kg·d）剂量的MBPs。结果表明：MBPs清除·OH和O2－·的EC50分别为0.17、0.54 mg/mL;MBPs能显著改善糖尿病大鼠血糖水平、血脂指标（甘油三酯、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇）、脂质过氧化水平（丙二醛）和血清抗氧化状态（谷胱甘肽过氧化物酶、超氧化物歧化酶及总抗氧化能力）;MBPs具有降血糖作用。     

Nanoencapsulation of synergistic combinations of acai berry concentrate to improve antioxidant stability

The objectives of this study were to increase the antioxidant activity of acai berry concentrate (Acai) by combining it with various antioxidants to exploit synergistic effects and improve antioxidant stability by nanoencapsulation. Ascorbic acid and trolox were identified as synergistic antioxidants for Acai. The optimal mixing ratio of ascorbic acid (74.64 μg/mL) and trolox (47.88 μg/mL) for synergistic activity in both oxygen radical absorbance capacity (ORAC) and DPPH assays was 1.56:1. A mixture of Acai, ascorbic acid, and trolox at the optimum ratio was nanoencapsulated using chitosan and gum arabic. Nanoparticles exhibited homogenous dispersion with a 230 to 260 nm particle size. During storage, nanoparticles exhibited better antioxidant stability than non-nanoencapsulated antioxidants. These results suggest that mixing Acai with ascorbic acid and trolox or nanoencapsulating this mixture with chitosan and gum arabic are both effective techniques for improving antioxidant activities.     

甘蔗皮花色苷的提取及抗氧化能力研究

目的:对甘蔗皮花色苷的抗氧化活性进行研究。方法:采用4种体外实验模型对甘蔗皮花色苷清除有机自由基(DPPH·)、羟基自由基(·OH)、超阴氧离子自由基(O2-·)能力和抗脂质过氧化能力进行了实验研究,并与抗坏血酸进行比较。结果:甘蔗皮花色苷具有抗脂质过氧化能力,清除有机自由基、羟基自由基、超阴氧离子自由基能力。甘蔗皮花色苷抗脂质过氧化能力强于抗坏血酸;在清除超阴氧离子自由基能力方面不如抗坏血酸;在清除有机自由基、羟基自由基能力方面,低浓度时二者接近,高浓度时花色苷略强于抗坏血酸。结论:甘蔗皮花色苷作为具有抗氧化功能的天然色素,其应用前景广阔。     

Antioxidant and tyrosinase inhibitory activities of a novel chitosan–phloroglucinol conjugate

A novel chitosan–phloroglucinol conjugate was developed by conjugating phloroglucinol onto a chitosan backbone. The chitosan–phloroglucinol conjugate was characterised by ¹H nuclear magnetic resonance (NMR), and the NMR spectra confirmed the conjugation. Antioxidant and tyrosinase inhibitory activities of the chitosan–phloroglucinol conjugate were investigated. The chitosan–phloroglucinol conjugate showed strong 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), hydrogen peroxide and ABTS⁺ radical scavenging activities as well as reducing power compared with those of the unmodified chitosan (P < 0.05). The formation of malondiadehyde (MDA) as an indicator of lipid peroxidation in a linoleic acid emulsion was 30.56 μM in the absence of the chitosan–phloroglucinol conjugate after 4 days incubation, whereas MDA was 4.14 μM in the presence of the chitosan–phloroglucinol conjugate (P < 0.05). The activity was higher than that of ascorbic acid, which is currently used as a food preservative. Moreover, the chitosan–phloroglucinol conjugate inhibited 56.30% tyrosinase activity, which is responsible for browning of foods, and acted as non‐competitive inhibitor. Taken together, the chitosan–phloroglucinol conjugate may have potential for application in functional foods and/or as a food preservative.     

抗坏血酸与壳聚糖处理对鲜切香芋贮藏效果的研究

以湖南香芋头为试材,研究不同浓度抗坏血酸与壳聚糖处理对鲜切香芋的贮藏效果及生理生化变化的影响。结果表明,在15℃贮藏温度下,与对照相比,0、1.0、5.0、10.0g/L 抗坏血酸(VC)分别与15.0g/L 壳聚糖配合处理较好地保持了鲜切香芋的外观和营养,减少鲜切香芋的失重率和褐变度,并抑制多酚氧化酶(PPO)、过氧化物酶(POD)和淀粉酶的活性。其中,5.0g/L 抗坏血酸与壳聚糖配合处理的保鲜效果最明显。     

Modification of chitosan using hydrogen peroxide and ascorbic acid and its physicochemical properties including water solubility,oil entrapment and in vitro lipase activity

Chitosan was modified using H₂O₂ and ascorbic acid with different incubation temperatures (4–40 °C). The properties of modified chitosan, including its oil entrapment ability, water solubility and the lipase-resistant activities, using in vitro intestine model system were determined. Nuclear magnetic resonance analysis showed that ascorbic acid was bound to modified chitosan. All of the modified chitosan from 4 to 40 °C demonstrated improved water solubility (even in pH 7) compared to non-modified chitosan, which was only soluble at pH 4. Modified chitosan from 4 °C exhibited 27.40% of oil entrapment ability which was approximately four times higher than 6.87% of non-modified chitosan. Modified chitosan from 4 and 40 °C had increased resistance against lipase activity compared to other biopolymers, including beeswax, carnauba wax and non-modified chitosan. Modified chitosan could be used as a new food ingredient due to their high water solubility, oil-entrapping ability and resisting lipase activity.     

野玫瑰色素对油脂的抗氧化作用

以猪油和菜籽油作为底物,采用烘箱贮藏法测定油脂的POv值,研究野玫瑰天然色素时油脂的抗氧化活性,结果表明,野玫瑰色素具有一定的抗油脂氧化能力,当色素的添加量分别为猪油和菜籽油质量的0.03%和0.02%时.效果最好,而且柠檬酸与抗坏血酸对色素的抗氧化性有协同增效作用,抗坏血酸的协同作用更好.     

复合防腐剂对鲜奶品质变化的影响

研究在4℃冷藏条件下鲜奶品质的变化以及通过添加乳酸链球菌素、壳聚糖、抗坏血酸3 种复合天然防腐剂对鲜奶品质的影响,实验结果表明：与新鲜牛乳相比,空白组在4℃保存3d 后,菌落总数和新鲜度明显变化,添加复合防腐剂的实验组与空白组相比保鲜效果明显,在鲜乳中添加200mg/kg Nisin、0.15% 壳聚糖、0.2g/kg 抗坏血酸保藏效果最佳。可见乳酸链球菌素、壳聚糖、抗坏血酸的共同使用对抑制乳中细菌的生长繁殖和防腐保鲜具有重要的作用。     

板栗壳天然色素对油脂抗氧化作用的研究

以猪油和花生油作为底物,采用烘箱贮藏法测定油脂的 POV值,研究板栗壳天然色素对油脂的抗氧化活性,结 果表明,板栗壳色素具有一定的抗油脂氧化能力,当色素 的添加量分别为猪油和花生油质量的0.03％和0.01％时, 效果最好,而且柠檬酸与抗坏血酸对色素的抗氧化性有 协同增效作用,柠檬酸的协同作用更好,同时添加质量分 数0.005％的柠檬酸和0.03％与0.01％的色素,对猪油和花 生油的抗氧化效果可与0.02％的BHT媲美。     

壳聚糖涂膜包装对鲜切莴苣保鲜效果的研究

以壳聚糖为成膜剂,4%的柠檬酸为溶剂配制成壳聚糖成膜液,再加入硬脂酸为增塑剂,同时加入抗坏血酸等添加剂,用浸渍的方法在鲜切莴苣表面形成壳聚糖膜,然后使其在0～4℃环境下保存5天,通过测定莴苣的硬度、多酚氧化酶(PPO)活性、过氧化物酶(POD)的活性、褐变强度(BD)、叶绿素的含量等指标进行保鲜效果分析。研究表明:用2%壳聚糖涂膜对鲜切莴苣具有良好的保鲜效果。     

The anti-inflammatory effect of lycopene complements the antioxidant action of ascorbic acid and α-tocopherol

Tomato foods contain bioactive compounds, such as lycopene, ascorbic acid and α-tocopherol, which are assumed to show synergistic effects. The aim of the study was to investigate this presumed synergy. The effect on lipid peroxidation and inflammation was assessed. Lipid peroxidation was effectively inhibited by combinations of the compounds compared to the single compounds. Synergy between the combination of ascorbic acid and α-tocopherol was confirmed. Lycopene on its own effectively reduced inflammation by inhibiting the release of TNF-α and stimulating IL-10 production. The combination of lycopene, ascorbic acid and α-tocopherol tended to display a synergistic interaction on IL-10 production. Our observations highlight that lycopene mitigates inflammation, whereas ascorbic acid and α-tocopherol efficiently protect against lipid peroxidation. Both activities are complementary since they diminish the process of inflammation differently on different levels. In relation to health, this is an added value of fruit and vegetables such as tomato products that contain complementary bio-active compounds.