三种不同方法提取葵花油的性质比较

本文旨在研究不同提取方法(水酶法;溶剂法;冷榨法)对葵花油的脂肪酸组成、理化性质、酚类物质、生育酚含量、抗氧化活性和氧化稳定性的影响。采用了清除DPPH自由基、抑制β-胡萝卜素-亚油酸乳化体系褪色实验和清除ABTS+·阳离子方法评价葵花油的抗氧化活性,并通过等温DSC测定了三种葵花油的氧化稳定性。结果表明:提取方法对葵花油脂肪酸组成的影响不显著(p0.05)。与溶剂法和水酶法相比,冷榨法葵花油表现出较优质的产品特性。溶剂法葵花油的总酚含量(TPC,0.29 mg/g)、邻苯二酚含量(ODC,0.45 mmol/kg)和总生育酚含量(TTC,1090.81 mg/kg)最高,并且具有最强的DPPH自由基(IC_(50),3.54 mg/m L)、ABTS+·阳离子清除能力(TEAC,652.33μmol/L)以及最强的抑制β-胡萝卜素褪色能力(C%,45.93%)。不同提取方法对葵花油的氧化稳定性影响显著(p0.05),氧化稳定性依次为:溶剂法水酶法冷榨法。     

氧化油脂日粮中添加RRR-α-生育酚琥珀酸酯对鸡肉品质的影响

探讨RRR-α-生育酚琥珀酸酯(TOS)对饲喂氧化油脂日粮鸡肉品质的影响,选用600只1 d AA肉鸡,随机分为10个处理,每处理6个重复,采用2×5因子设计,即2种油脂类型(新鲜和氧化油脂)和5种α-生育酚的处理,30 mg/kg all-rac-α-生育酚醋酸酯(TOA1)、30 mg/kgRRR-α-生育酚醋酸酯(TOA2)及15、30、60 mg/kgRRR-α-生育酚琥珀酸酯(TOS1、TOS2和TOS3),试验期42 d。结果表明:(1)氧化油脂日粮增加了机体脂质过氧化反应,胸腿肌肉色变差,滴水损失增加,MDA含量升高,SOD活性下降(P0.05);(2)不同的油脂日粮处理中,TOS3组均能降低胸肌48 h滴水损失和烹饪损失(P0.05),腿肌亮度、红色度及滴水损失在TOS2或TOS3组得到改善(P0.05);TOS2和TOS3组胸腿肌MDA含量降低(P0.05或P0.01),胸肌TOS3组SOD活性提高(P0.05);与TOS1相比,TOS2和TOS3组血清及肝脏中α-生育酚含量提高(P0.05)。日粮中油脂氧化导致鸡肉品质降低,添加TOS可通过增加机体α-生育酚含量,提高机体抗氧化能力,改善肌肉品质。     

不同方法提取胡麻油性质的对比研究

采用Schaal烘箱法对不同方法提取的胡麻油的氧化性质进行了对比研究。试验结果表明:由3种方法提取的胡麻油的自氧化试验可知,过氧化值变化由大到小为冷榨胡麻油、超临界CO2提油、溶剂提油。碘值变化从大到小的顺序为超临界提油、冷榨胡麻油、溶剂提油;酸值变化从大到小的顺序为超临界提油、溶剂提油、冷榨胡麻油;黏度变化从大到小的是超临界提油、冷榨胡麻油、溶剂提油。3种胡麻油中特征值变化最大的是超临界CO2提取的胡麻油。     

制油工艺对油茶籽油生物活性成分含量和抗氧化活性的影响北大核心CSCD

为了了解不同制油工艺对油茶籽油生物活性成分含量和抗氧化活性的影响,以油茶果为原料,采取鲜榨法、浸提法、新水法、冷榨法和热榨法5种制油工艺分别制取油茶籽油,研究对比了5种制油工艺的提油率,所制取的油茶籽油的脂肪酸组成、生物活性成分(生育酚、角鲨烯及多酚)含量及其对DPPH自由基和ABTS自由基的清除能力。结果表明,5种制油工艺的提油率均在73%以上,其中浸提法((96.45±3.02)%)最高,冷榨法((73.72±2.76)%)最低,鲜榨法((82.36±2.24)%)、新水法((81.91±3.21)%)和热榨法((80.34±2.09)%)没有显著差异;5种工艺所制取的油茶籽油具有相似的脂肪酸组成;在α-生育酚和总生育酚含量方面,新水法制取的油茶籽油含量最高(α-生育酚含量(263.77±1.58)mg/kg,总生育酚含量(280.55±1.64)mg/kg),鲜榨法、冷榨法和热榨法制取的油茶籽油中总生育酚含量接近,在233~244 mg/kg之间,浸提法制取的油茶籽油中总生育酚含量只有(17.10±0.76)mg/kg;在角鲨烯和多酚含量方面,鲜榨法制取的油茶籽油明显高于其他工艺的,分别为(350.56±7.60)mg/kg和(45.04±4.50)mg/kg,新水法制取的油茶籽油角鲨烯含量最低,为(249.99±3.73)mg/kg,浸提法制取的油茶籽油多酚含量最低,为(7.06±0.03)mg/kg;在清除DPPH自由基和ABTS自由基方面,鲜榨法制取的油茶籽油的清除能力最强,浸提法的最弱。     

制油工艺对花生油品质的影响

以花生仁为原料,对比研究了冷榨法(60℃)、热榨法(150℃)和水酶法3种制油工艺对花生油色泽、酸价、过氧化值、氧化稳定指数、脂肪酸组成、微量活性成分(生育酚、多酚及角鲨烯)、DPPH和ABTS自由基清除能力的影响。结果表明:水酶法制得的花生油色泽(Y19. 5R1)最浅,酸价(KOH)((0. 66±0. 05) mg/g)最高,过氧化值((2. 05±0. 00) mmol/kg)最低,氧化稳定指数((3. 95±0. 11) h)最高,油酸含量最高((50. 73±0. 43)%);热榨花生油中α-生育酚、总生育酚和多酚含量最高,分别为(124. 57±0. 03) mg/kg、(206. 61±3. 24) mg/kg、(44. 27±2. 60)mgGAE/kg;冷榨花生油中角鲨烯含量最高,为(477. 20±10. 31) mg/kg;热榨花生油清除DPPH自由基和ABTS自由基能力最强,抗氧化性最好。     

电化学分析法测定植物油中的VE

利用循环伏安技术研究了α-生育酚在玻碳电极上的伏安性质,其循环伏安图表明,在0.2～0.8V扫描电位范围内,在0.576V处出现一个良好的氧化峰,无还原峰出现,表明α-生育酚的电极反应是一个非可逆过程,是一个由扩散控制的电极反应过程.基于α-生育酚的电化学氧化机理,研究了α-生育酚的电化学分析法.利用微分脉冲伏安技术,研究确定了α-生育酚的最优分析条件:1,2二氯乙烷与乙醇(1:3)组成混合溶剂,支持电解质LiClO4的浓度为0.05mol/L,pH值为3.0,电位扫描速度为10mV/s,脉冲幅度为50mV:在5～350μmol/L范围内,α-生育酚的氧化峰电流与其浓度表现为线性关系,Ip=0.2872 0.01852×Cα-T,(相关系数r=0.9997),检测灵敏度为1.852×10-8AL/mol,最低检测为1.5μmol/L(S/N=3),每个样品分析所需时间80s.同时研究了植物油中常用合成抗氧化剂对α-生育酚的电化学法分析可能存在的影响与干扰,最后通过电化学分析法与HPLC法分析同一油样中VE的含量并进行对比,结果表明该法所测得的VE的含量与HPLC法测得的的α-、β-、γ-、δ-生育酚的总和一致,可用于植物油中VE的定量分析,无需任何油样预处理程序,操作简单,分析快捷、准确.     

葵花籽油脂肪酸与α-生育酚对其稳定性的影响

以4个品种葵花籽油为研究对象,采用Schaal烘箱法连续加热12 d,通过GC-MS测定葵花籽油中脂肪酸含量,并用高效液相色谱法分析α-生育酚含量。结果显示:加速氧化中各品种脂肪酸与α-生育酚含量都存在差异,其中‘白杂6号’与‘油葵6号’中棕榈酸、硬脂酸、油酸、山嵛酸的净增量与亚油酸、亚麻酸的净减量均显著低于‘内杂3号’与‘T012244’,‘油葵6号’含有的α-生育酚含量显著高于各品种。经分析α-生育酚含量对其氧化稳定性的影响高于不饱和脂肪酸的含量,表明‘油葵6号’氧化稳定性较强,其原因在于α-生育酚含量较高。     

不同产地南瓜籽油组成及氧化稳定性的差异

以我国8 个不同产地南瓜籽为原料,压榨制备南瓜籽油,对比分析不同南瓜籽油的组成和氧化稳定性。结果表明,南瓜籽油主要含有棕榈酸、硬脂酸、油酸、亚油酸4 种脂肪酸,不饱和脂肪酸含量占80.565%～84.964%,总酚含量为167.21～204.50 mg/kg,总甾醇含量为1 204.38～1 604.51 mg/kg,α-生育酚含量为25.7～58.7 mg/kg,γ-生育酚含量为1 839.8～2 728.3 mg/kg,δ-生育酚含量为248.8～518.7 mg/kg。Pearson双变量相关性分析表明,总酚与极性组分自由基清除能力有显著相关性（P＜0.05）,α-生育酚等油脂伴随物也发挥了一定的抗氧化作用。主成分分析和聚类分析的结果显示：不同产地的南瓜籽油功能性成分相似,由于含量差别显示出具有显著差异的2 个集群,甘肃省白银市产的南瓜籽油综合评分最高。本研究对南瓜籽资源的开发利用具有一定的指导意义。     

制油工艺对三叶木通籽油活性成分及抗氧化活性的影响

目的:比较不同制油工艺对三叶木通籽油活性成分及氧化活性的影响。方法:以三叶木通籽为原料,采用冷榨法、热榨法、超临界CO₂萃取法和浸提法4种油脂制取工艺分别制备三叶木通籽油,分析其脂肪酸组成、活性成分(类胡萝卜素、生育酚、多酚、黄酮)含量,以及其清除DPPH自由基的能力。结果:4种工艺制得的三叶木通籽油脂肪酸组成相近,其中棕榈酸含量在20.62%～21.42%,硬脂酸含量在2.68%～3.08%,油酸含量在47.03%～47.37%,亚油酸含量在27.75%～28.07%,其他脂肪酸含量则均未超过0.5%;在活性成分含量方面,冷榨法制取的三叶木通籽油总生育酚、黄酮和多酚含量均最高,分别达到了349.05,103.37,51.78 mg/kg,而浸提法制取的三叶木通籽油总生育酚、黄酮和多酚含量则显著低于其他3种提取方法,仅220.24,57.73,23.45 mg/kg;在DPPH自由基清除能力方面,冷榨法三叶木通籽油的清除效果最佳、浸提法最差。结论:三叶木通籽油富含油酸和亚油酸,且具有清除DPPH自由基能力。     

不同制油工艺对亚麻籽油品质及抗氧化活性的影响

为比较不同工艺制取的亚麻籽油品质及抗氧化活性,分别以索氏提取法、冷榨法和热榨法制取亚麻籽油,测定亚麻籽油得率、基本理化指标、生育酚含量、脂肪酸组成、挥发性成分及抗氧化活性。结果表明：索氏提取法亚麻籽油得率最高,为52.77%,热榨法亚麻籽油得率显著高于冷榨法;冷榨亚麻籽油色泽、脂肪酸组成较佳,α-亚麻酸含量高达54.49%;索氏提取亚麻籽油总生育酚含量最高,为450.79 mg/kg,冷榨和热榨亚麻籽油的总生育酚含量相当;索氏提取和冷、热榨亚麻籽油挥发性成分分别为21、17种和34种,5种为共有成分,其中(E,E)-2,4-庚二烯醛是冷、热榨亚麻籽油的特征风味物质;冷榨亚麻籽油具有较强的ABTS⁺自由基清除能力,而热榨亚麻籽油具有较强的DPPH自由基清除能力,二者铁还原力相当,索氏提取亚麻籽油具有较强的铁还原力。综上,不同制油工艺对亚麻籽油的品质及抗氧化活性具有一定的影响。     

氧化引起肉及肉制品品质劣变的机理及影响因素

肉及肉制品在加工和贮藏过程中品质会下降,如嫩度降低、褪色、形成腐败味道等,而肉品质的降低与肉中含有的主要成分肌红蛋白、肌原纤维蛋白和脂肪的氧化有关,本文主要讨论三者氧化变化以及关联性,并探讨在加工贮藏过程中可能引起氧化的因素,为生产高质量的肉制品提供一定参考。     

肉制品中脂肪氧化与蛋白质氧化及相互影响

近年来,食品中脂肪氧化与蛋白质氧化之间的联系在国内外引起了广泛关注。肉制品中脂肪及蛋白质的氧化能产生特征风味,但更多的是引起风味的劣化和颜色的褪变,且脂肪氧化和蛋白氧化之间是相互关联的,彼此相互促进。针对由脂肪氧化和蛋白质氧化影响肉制品品质的问题,就脂肪氧化与蛋白质氧化机理、肉制品中脂肪与蛋白质氧化的相互影响关系及控制措施进行综述。     

苹果酒中模拟体系下非酶氧化与酶促氧化对聚合度影响的研究

以苹果酒中单酚含量较多的4种酚（儿茶素、表儿茶素、绿原酸和咖啡酸）为研究对象。在模拟苹果酒pH体系环境下,对其在非酶氧化和酶促氧化下聚合度的变化进行了研究。结果表明,在非酶氧化过程中,以儿茶素和表儿茶素的聚合反应为主,而在酶促氧化过程中。则是以绿原酸和咖啡酸的聚合反应为主。     

Fenton氧化和生物法结合深度处理硫化黑印染废水

采用Fenton氧化和生物氧化结合的方法,研究硫化黑印染废水的COD去除率和处理成本。探讨了Fenton氧化的条件包括氧化时间、m(H2O2)∶m(COD)、n(H2O2)∶n(Fe2+)以及Acinetobacter sp.DS-9生物氧化法二级串联处理系统的脱硫和COD去除效果。结果表明,最佳条件为:pH=3,m(H2O2)∶m(COD)=1∶2,n(H2O2)∶n(Fe2+)=10∶1,反应90 min后,按5%的接种量接入高效硫氧化菌株Acinetobacter sp.DS-9。废水脱硫效率提高了34.5%,COD去除率提高了74%。     

烤肉中脂类氧化及抗氧化研究

肉类食品中脂类的氧化会产生许多不利的影响,如使食品风味发生变化以及产生有害人体健康的物质等。本文综述了烤肉中脂类的氧化,分析了影响脂类氧化的因素,并总结了抗氧化的方法。     

牛油氧化工艺影响因素研究

以制备风味牛油基料为目的,分别从氧化反应控制参数(通气量、温度、时间、反应方式)、维生素E的添加及反应原料方面考察了可能影响牛油控制氧化反应的因素。研究结果表明,原料来源、氧化体系和氧化温度参数是影响牛油氧化反应的重要因素,原料差异性对氧化产物感官指标影响较大。     

Comparison of lipid and protein oxidation,total iron content and fatty acid profile of conventional and organic pork

The aim of the research was to compare differences in lipid and protein oxidation, total iron content and fatty acid profile in pork loin obtained from organic and conventionally reared pigs. The samples of organic meat were taken from breeding certified by the polish certifying body according to the Council Regulation (EC) no 834/2007 on organic production and labelling of organic products. The meat samples were examined at the following times post‐mortem: 2, 4, 7 days. Measurements of lipid oxidation showed that the organic meat samples were characterised by lower TBARS values during whole storage period (0.78–0.81 mg kg^?1) compared with those of conventional system production (0.95–0.99 mg kg^?1). Results of protein oxidation measurements of the organic meat sample were significantly lower (0.43 nmol mg^?1 protein) at the beginning of experiment than those for the conventional meat sample (0.66 nmol mg^?1 protein). It was also indicated that the production system had no effect on iron content and myoglobin oxidation during storage. In conclusion, obtained results pointed out that the organic pig meat was characterised by higher lipid stability during the whole storage time compared with meat from conventional production system.     

Protein and Lipid Oxidative Stresses During Cheese Manufacture

ABSTRACT: The amounts of protein-bound carbonyls (PC), malondialdehyde, (MDA) and the tocopherolquinone/ tocopherol ratio (TQ) were used as markers to evaluate the oxidative damage during manufacture. Their concentrations were determined in 11 Italian cheese varieties produced with different curd heat treatments. A positive correlation between heat intensity and oxidative damage was found ( p < 0.05). No correlation was seen between ripening time and oxidation extent in differently ripened Grana Padano cheese. Positive correlation between heating and TQ and PC levels was found ( p < 0.001 and 0.05, respectively) in Grana Padano cheese produced with milk pasteurized at 58, 68, or 72 °C. Pasteurization ad curdling steps, during mozzarella cheesemaking, highly contributed to TQ yield.     

Oxidative stability of pork meat lipids as related to high-oleic sunflower oil and vitamin E diet supplementation and storage conditions

The aim of this research work was to evaluate the oxidative stability of pork meat lipids as related to dietary supplementation with high-oleic sunflower oil (HOSO) and/or α-tocopheryl acetate (VE), as well as the influence of storage conditions. Four different diets (control; HOSO; VE; HOSO+VE), were fed to swines until slaughtering. Meat slices were packed in vessels with transparent shrink film and exposed to white fluorescent light for 3 days at 8 °C. HOSO supplementation increased oleic acid content of pork meat. The highest levels of peroxide value (PV) and cholesterol oxidation products (COPs) were detected in the control group, whereas HOSO-enriched diets displayed the highest thiobarbituric reactive substance (TBARs) content. After storage under light exposure, pork meat slices exhibited a decrease of PV, which resulted in an increasing trend of TBARs and COPs. Feeding enrichment with both HOSO and vitamin E can be, therefore, used as an appropriate supplementation strategy to produce pork meat with a suitable oxidative stability.     

Fluorescence spectroscopy as a novel approach for the assessment of myofibrillar protein oxidation in oil-in-water emulsions

The oxidation of oil-in-water emulsions (37 °C/10 days) containing increasing levels of myofibrillar proteins (MP) (0.5%, 1% and 2% on the basis of lipid content) was investigated. Protein oxidation was assessed by measuring the loss of natural tryptophan fluorescence and the increase in fluorescent protein oxidation products (FP) using fluorescence spectroscopy. Lipid oxidation was simultaneously analysed by measuring the increase of conjugated dienes (CD) and hexanal. The oxidative degradation of tryptophan residues occurred as an early event in MP oxidation whereas FP formed later as secondary protein oxidation products. The shift of the tryptophan maximum fluorescence emission wavelength during oxidation provided information about the location of oxidising tryptophan residues. Emulsions with higher concentrations of MP displayed higher tryptophan fluorescence and yielded a higher amount of FP. MP acted as inhibitors of lipid oxidation because emulsions with higher MP contents contained lower levels of CD and hexanal. Significant negative correlations were found between tryptophan fluorescence and CD, reflecting the timely interaction between primary lipid oxidation products and protein oxidation. Both spectrophotometric techniques were useful although the loss of tryptophan fluorescence is more reliable since it is a specific measurement which is not affected by the presence of other fluorescent protein oxidation products.