菜籽多酚在猪油中的抗氧化作用

将猪油在60±2℃下贮藏,在高温下煎炸,测定猪油的过氧化值,对猪油进行感官评定,研究菜籽多酚对猪油在贮藏与煎炸过程中的抗氧化作用。结果表明:菜籽多酚在猪油贮藏与煎炸过程中均具有抗氧化作用。菜籽多酚在猪油60℃贮藏中的最佳添加量为0.05%,在温度低于250℃下煎炸时的最佳添加量为0.01%。菜籽多酚与柠檬酸在猪油抗氧化中具有协同增效作用,0.1%菜籽多酚与2%柠檬酸联合应用的效果优于BHA、HAT、PG,可以取代合成抗氧化剂。      

蜂胶提取物对菜籽油抗氧化性的研究

蜂胶富含黄酮,具有较好的抗氧化功能。采用微波辅助提取技术对蜂胶中的抗氧化物质进行了优化提取,研究了提取物在菜籽油中的抗氧化性能,并对其有效的抗氧化成分进行了分析和初步研究。研究结果表明,蜂胶提取物具有较好的抗氧化作用,其抗氧化性优于茶多酚,与VC相近。     

Antioxidant activity of ginger extract in sunflower oil

The antioxidant activity of dichloromethane extract from ginger was evaluated during 6 months of storage of refined sunflower oil at 25 and 45 °C. Free fatty acid (FFA) content, peroxide value (POV) and iodine value (IV) were used as criteria to assess ginger extract as an antioxidant. After 6 months of storage at 45 °C, sunflower oil containing 1600 and 2400 ppm ginger extract showed lower FFA contents (0.083 and 0.080%) and POVs (24.5 and 24.0 meq kg^?1) than the control sample (FFA contents 0.380%, POV 198.0 meq kg^?1). Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) showed FFA contents of 0.089 and 0.072% and POVs of 26.5 and 24.7 meq kg^?1 respectively after 6 months of storage at 45 °C. Similarly, after 6 months of storage at 45 °C, IVs of sunflower oil containing 1600 and 2400 ppm ginger extract were 80 and 92 respectively, higher than that of the control sample (53). However, IVs of sunflower oil treated with 200 ppm BHA and BHT were 94 and 96 respectively after 6 months of storage at 45 °C. These results illustrate that ginger extract at various concentrations exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT). Ginger extract also showed good thermal stability and exhibited 85.2% inhibition of peroxidation of linoleic acid when heated at 185 °C for 120 min. Therefore the use of ginger extract in foods is recommended as a natural antioxidant to suppress lipid oxidation. © 2003 Society of Chemical Industry     

Antioxidant activity of sage extracts in rapeseed oil irradiated with UV‐rays

The antioxidant activities of sage acetone oleoresin and its methanol‐water fractions were tested in rapeseed oil at 0.1% concentrations and 80°C temperature after irradiation with UV‐rays (exposition 0.5 h). It was determined that even little doses of UV irradiation induce oxidation process in rapeseed oil samples both with additives and without them. The antioxidant activity of a synthetic antioxidant BHT was much lower than that of the sage fractions at 80°C and forced air oven conditions. This finding proves the advantage of sage extracts in comparison with BHT at high temperatures. It was also found that methanol‐water fraction separated from acetone oleoresin had the highest antioxidant activity in terms of the formation of primary and secondary oxidation products. Oil sample with this additive had the highest protection factor (PF = 4.53) when the oil was not irradiated with UV rays. The data obtained showed that all sage extracts had very strong antioxidant activity (PF > 3).     

Antioxidant activity of sage extracts in rapeseed oil irradiated with UV-rays

The antioxidant activities of sage acetone oleoresin and its methanol-water fractions were tested in rapeseed oil at 0.1% concentrations and 80 degrees C temperature after irradiation with UV-rays (exposition 0.5 h). It was determined that even little doses of UV irradiation induce oxidation process in rapeseed oil samples both with additives and without them. The antioxidant activity of a synthetic antioxidant BHT was much lower than that of the sage fractions at 80 degrees C and forced air oven conditions. This finding proves the advantage of sage extracts in comparison with BHT at high temperatures. It was also found that methanol-water fraction separated from acetone oleoresin had the highest antioxidant activity in terms of the formation of primary and secondary oxidation products. Oil sample with this additive had the highest protection factor (PF = 4.53) when the oil was not irradiated with UV rays. The data obtained showed that all sage extracts had very strong antioxidant activity (PF > 3).     

杨梅叶原花色素对猪油抗氧化作用的研究

以过氧化值(POV)、酸价(AV)、丙二醛含量为指标,采用Schaal烘箱法研究了杨梅叶原花色素对猪油的抗氧化作用,并用食品氧化稳定性测定仪测定氧化诱导期(IP)。结果表明:杨梅叶原花色素对猪油过氧化值、酸价、丙二醛含量的升高具有显著的抑制作用(p<0.05),能抑制猪油的氧化。当杨梅叶原花色素添加量为0.1%时,其对猪油氧化的抑制作用强于BHT,但比TBHQ稍弱,表明杨梅叶原花色素对猪油具有良好的抗氧化效果,能有效延缓猪油的氧化程度。在第14 d时,相比空白组,杨梅叶原花色素添加量为0.1%的处理组对猪油过氧化值、酸价、丙二醛含量的抑制率分别为76%、69%、94%。此外,随着杨梅叶原花色素添加量的增加,猪油的氧化诱导期增加,杨梅叶原花色素添加量达到0.1%时其氧化诱导期和抗氧化系数介于BHT和TBHQ之间,且与BHT无显著性差异(p>0.05),说明杨梅叶原花色素对猪油具有抗氧化作用。      

猪油和单甘酯含量对菜籽油凝胶油性质的影响研究

考察了将猪油与菜籽油按一定比例混合,并以单甘酯为凝胶剂形成的混合凝胶油的性质,探讨猪油和菜籽油质量比及单甘酯含量对混合凝胶油性质的影响,以制备出低饱和脂肪酸、能够更好地部分替代猪油的菜籽油混合凝胶油。测定了混合凝胶油的流变性质、质构性质、固体脂肪含量以及热力学性质。结果表明,当猪油和菜籽油质量比为5∶5,加入8%的单甘酯时,混合凝胶油与菜籽油凝胶油相比凝胶性质更好,在常温下固体脂肪含量更接近猪油。     

菜籽肽抗氧化活性的研究

用分光光度法测定大鼠红细胞溶血程度,用丙二醛(MDA)试剂盒测定MDA。结果显示,通过腹膜注射菜籽肽,可以使小鼠血清中MDA含量显著减少。高剂量组[100 mg/(kg.d)]与对照组相比,MDA的降低达到极显著水平(P<0.01)。离体实验结果显示,菜籽肽粗品及各级分对体外温育和H2O2诱导的小鼠肝组织匀浆MDA生成有较强的抑制作用,其中粗品RSP-R和级分RSP-1的作用最好,且有量效关系,而对Fe2 诱导的MDA生成的抑制作用稍差。另外,RSP-R还可抑制大鼠红细胞氧化溶血程度。以上结果表明,菜籽肽在体内外均具有明显的抗氧化作用。     

芥末有效成分对猪油的抗氧化性研究

主要研究了芥末有效成分的耐热性、抗氧化作用、最适添加剂量以及柠檬酸在抗氧化中的增效作用.结果表明,芥末有效成分具有较好的耐热性和抗氧化作用,在猪油中添加0.6g/kg的情况下,抗氧化效果最佳,柠檬酸具有明显的增效作用.     

菜籽油低共熔溶剂萃取物抗氧化活性研究

以菜籽油为材料,DPPH自由基清除活性为指标,比较了氯化胆碱-尿素、氯化胆碱-甘油、氯化胆碱-乙酰丙酸3种低共熔溶剂(DES)和80%甲醇萃取物的抗氧化活性,筛选出最优的低共熔萃取剂,并分析了其与80%甲醇萃取物的抗氧化成分差异。研究表明：氯化胆碱-乙酰丙酸低共熔溶剂菜籽油萃取物的抗氧化活性显著高于80%甲醇萃取物,而氯化胆碱-尿素和氯化胆碱-甘油低共熔溶剂萃取物的抗氧化活性低于80%甲醇。通过总酚含量测定、薄层层析-DPPH显色、HPLC等方法,比较了氯化胆碱-乙酰丙酸低共熔溶剂和80%甲醇萃取物成分的差别,氯化胆碱-乙酰丙酸低共熔溶剂萃取物的总酚含量是80%甲醇的143.27%,抗氧化物质的种类和数量也比80%甲醇萃取物有显著的提升。因此氯化胆碱-乙酰丙酸低共熔溶剂可用于植物油脂抗氧化成分萃取和分析。     

五味子挥发油抗氧化性研究

通过对不同部位和不同方法提取的五味子挥发油抗氧化性研究,进一步探索五味子挥发油的药用价值。以水蒸气蒸馏法和超声波辅助萃取法提取五味子挥发油,Vc和VE作为阳性对照品,采用DPPH法测定不同质量浓度挥发油的抗氧化性,以EC50为指标,比较不同方法和部位提取的挥发油抗氧化性。抗氧化性以EC50比较,由强到弱依次为:Vc(34.1140μg/mL)>超声波提取五味子藤茎挥发油(0.7319mg/mL)>超声波提取五味子种子挥发油(0.9983mg/mL)>VE(5.2049mg/mL)>水蒸气蒸馏法提取五味子种子挥发油(7.7334mg/mL)>水蒸气蒸馏法提取五味子藤茎挥发油(10.2814mg/mL)。不同部位,不同提取方法所得的五味子挥发油均具有一定程度的抗氧化活性。     

Antioxidant and antilisterial activity of olive oil,cocoa and rosemary extract polyphenols

Antibacterial and antioxidant activity of polyphenols from olive oil, cocoa, and rosemary extract was tested. Antimicrobial activity against Listeria strains was assessed using broth dilution and time-kill curve methods. The 2,2-diphenyl-2-picrylhydracyl hydrate (DPPH) radical scavenging method, Folin–Ciocalteu method, and high performance liquid chromatography (HPLC) were used for phenolics identification and determination of antioxidants level. Antibacterial and antioxidant activity of main pure phenolic compounds, such as hydroxytyrosol in olive oil, epicatechin in cocoa and carnosic acid in rosemary was each compared with their extracts.     

Antioxidant activity of microwave-assisted extract of longan (Dimocarpus Longan Lour.) peel

The longan (Dimocarpus Longan Lour.) peel was extracted with 95% ethanol employing microwave-assisted extraction and Soxhlet extraction method, the total phenolic content of microwave-assisted extract of Langan peel (MEL) and Soxhlet extract of Langan peel (SEL) reached 96.78 mg/g and 90.35 mg/g dry weight, respectively, expressed as pyrocatechol equivalents, which were quantified using Folin–Ciocalteu reagent. Subsequently, antioxidant properties of two extracts were investigated employing various established systems in vitro including 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, hydroxyl radical scavenging assay using a new resonance scattering (RS) method, reducing power and total antioxidant capacity. MEL and SEL showed excellent antioxidant in all test systems compared to synthetic antioxidant 2,6-di-ter-butyl-4-methylphenol (BHT) and the antioxidant activities of MEL were all superior to those of SEL. Furthermore, the suitability of MEL and SEL as substitute of BHT were determined in peanut oil, and the decrease of lipid oxidation were monitored using thiobarbituric acid-reactive substances (TBARS) assay. MEL and SEL treatment significantly (P < 0.05) reduced lipid oxidation in peanut oil compared to the control. No significant differences (P=0.05)$P=0.05)$ in lipid oxidation were detected between MEL, SEL and BHT samples of peanut oil.     

Antioxidant activity of ethanolic extract of Cortex fraxini and use in peanut oil

Cortex fraxini was extracted with 95% ethanol to obtain a crude antioxidant extract. The antioxidant activity was evaluated using the linoleic acid peroxidation method and the free radical scavenging assays, namely 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals. Cortex fraxini extract (CFE) showed high inhibition of peroxidation of linoleic acid when compared with butylated hydroxytoluene (BHT). CFE also exhibited excellent scavenging activity on DPPH and hydroxyl radicals. Total antioxidant activity was measured by the reduction of Mo(VI) to Mo(V) by the extract, and subsequent formation of a green phosphate/Mo(V) complex at acid pH. CFE had significant total antioxidant activity and the effects were increased with increasing reaction time. The total phenolic content of the sample, analyzed by using Folin–Ciocalteu’s reagent, was 91.33 mg/g dry weight expressed as pyrocatechol equivalents. Then the suitability of CFE as an antioxidant was determined in peanut oil, and the decrease of lipid oxidation was monitored using thiobarbituric acid-reactive substances (TBARS) assay. CFE treatment significantly (P < 0.05) reduced lipid oxidation in peanut oil compared to the control. No significant differences (P = 0.05) in lipid oxidation were detected between CFE antioxidant and BHT antioxidant samples.     

负载二氢槲皮素的甘油解猪油微乳液体外抗氧化性及消化性

为解决含甘油解猪油的食品在贮藏过程中易被氧化的问题,向甘油解猪油中加入二氢槲皮素,制备负载二氢槲皮素的甘油解猪油微乳液,通过体外模型测定该微乳液的还原力以及对DPPH、ABTS和羟自由基的清除能力,探讨含二氢槲皮素甘油解猪油微乳液的体外抗氧化性,同时通过体外模拟胃肠消化测定其消化性。结果表明：该微乳液具有一定的还原力及DPPH、ABTS、羟自由基的清除能力,且还原力及自由基清除能力均随着二氢槲皮素负载量的增加而升高,相关性显著;该微乳液经胃消化2 h后二氢槲皮素的保留率为79.25%,说明该微乳液能有效保护二氢槲皮素实现靶向性肠道输送,在肠道消化2 h后,微乳液的游离脂肪酸释放率达到73.85%,二氢槲皮素生物利用率达33.3%。综上,负载二氢槲皮素的甘油解猪油微乳液在食品工业中有较大的应用潜力。     

迷迭香酸对猪油的抗氧化效果

比较了迷迭香酸、柠檬酸、VE、TBHQ几种抗氧化剂对猪油的抗氧化效果。结果表明,0.01%迷迭香酸与0.01%TBHQ对猪油的抗氧化效果最好,二者具有相似的抗氧化能力,可对猪油的酸败起到延缓作用;TBHQ对迷迭香酸具有一定的协同抗氧化作用。     

Antioxidant activity of sesame cake extract

Sesame cake was extracted with methanol to obtain a crude antioxidant extract. The qualitative and quantitative analysis of antioxidants/lignans present in the extract was carried out by reverse phase high performance liquid chromatography (HPLC) using a C₁₈ column. In this study, sesame cake was also subjected to successive extractions with solvents of differing polarity to get a purified antioxidant extract with higher antioxidant content and better activity. The antioxidant activity was evaluated using the β-carotene bleaching method, linoleic acid peroxidation method and free radical scavenging assay, using 2,2-diphenyl-1-picryl hydrazyl radical (DPPH). Results showed that crude extract was effective at 100 and 200 ppm levels and comparable with butylated hydroxy toluene (BHT) at 200 ppm, whereas purified extract showed comparable or better activities at 5, 10, 50, 100 and 200 ppm levels.     

Antioxidant activity of flaxseed oil

Effective concentration of antioxidants and its reactivity toward peroxil radicals (constant k7) have been measured by the chemiluminescence technique for flaxseed oil. Effective concentration of antioxidants is shown to depend on the technology of producing flaxseed oil; period of seed storage before use; and storing duration of flaxseed oil also. Minor component content of flaxseed oil, which may be the members of antioxidant pool, has been quantitatively estimated.     

Physical and sensory characteristics of pork sausages from enzymatically modified blends of lard and rapeseed oil during storage

Physical and sensory characteristic of pork sausages produced from enzymatic interesterified blends of lard and rapeseed oil during storage were evaluated. All three enzymatic interesterified blends (IE90, IE70 and IE50) had ratios of unsaturated to saturated fatty acids within the range of 1.47–2.84 which is favourable for cardiovascular disease risk reduction. Blends of IE90 and IE70 were found to have suitable solid fat content, melting and crystallization profile suitable for sausages production. Sausages were produced from blends of IE90 and IE70 with different muscle types (musculus longissimus dorsi and musculus sternomandibularis) and processing conditions such as cooling rates and final processing temperature. Cooling rate was found to have no significant (P > 0.05) effect on hardness of the sausages throughout storage. Both musculus longissimus dorsi and high final processing temperature of 20 °C increased the hardness of the sausages during storage. In terms of fat particle size distribution, it was found that sausages IE70 had significantly (P < 0.05) lower amount of small fat particles (<4 μm) and higher amount of big fat particles (4–500 μm). This is in agreement with the findings on softer texture of sausages IE70. All the sausages produced from interesterified blends of lard and rapeseed oil had no apparent fat excretion and were rated as having acceptable sensory attributes as compared to reference sausage which was produced from pure lard.     

吕梁红枣提取物的抗氧化性研究

以浸提法用80％vol乙醇提取吕梁红枣中的非酶类抗氧化物质,从总酚含量、DPPH自由基清除能力、还原能力以及清除羟基自由基能力4方面对其抗氧化活性进行检测,评价吕梁红枣提取物的体外抗氧化作用。红枣非酶类抗氧化物质溶液浓度设置为：1．34mg／mL、2．69mg／mL、5．38mg／mL、10．75mg／mL、21．5mg／mL。结果表明：红枣乙醇提取物总酚含量为3．22mg／g;DPPH自由基清除能力随提取物质量浓度增大清除自由基能力增强,且高于BHT;还原能力也是随提取物质量浓度增大而增强,明显高于BHT;清除羟基自由基能力随提取物质量浓度增人清除自由基能力呈明显的增强趋势,范围从15．25％增强至62．74％。