脱脂椰肉中多酚化合物抗氧化性的研究

从脱脂椰肉中提取多酚化合物,然后研究该多酚化合物对脂质过氧化的抑制作用,DPPH自由基的清除作用,羟基自由基的清除作用,Fe2+的络合能力以及Fe3+的还原能力,并以BHT、没食子酸,VE做为对照。结果表明脱脂椰肉中多酚类物质(DCP)对Fe2+具有很强的络合能力,对DPPH.和.OH有较强的清除能力,DCP也具有一定的还原能力,但其抑制脂质体过氧化作用的能力较弱。这说明脱脂椰肉中多酚有显著的抗氧化性。     

椰花醋的抗氧化活性

以没食子酸为对照.研究椰花醋对DPPH自由基和羟基自由基的清除能力、Fe2+的络合能力以及Fe3+的还原能力.结果表明,椰花醋具有显著的抗氧化性,对DPPH自由基清除作用和Fe3+的还原能力均低于没食子酸:而对羟基自由基的清除作用和Fe2+的络合能力则高于没食子酸.     

槟榔红色素的抗氧化活性

测定槟榔红色素(areca red pigment,AP)对 DPPH·和·OH的清除能力、对脂质体过氧化的抑制能力、对Fe2+的络合能力,并测定其还原能力.结果表明:槟榔色素对DPPH·、·OH的清除能力较强:对脂质体过氧化的抑制能力很强,抑制率高达79.84%;与VE、没食子酸(gallic acid,GA)、BHT相比,槟榔色素的还原力、对Fe2+的络合能力较弱.说明槟榔红色素是较好的抗氧化剂.     

千层金叶片醇提物抗氧化活性的研究

为了探究千层金叶片醇提物的抗氧化活性,本文研究了千层金叶片醇提物及其不同极性部位的抗氧化活性和总多酚含量。研究结果表明：千层金叶片醇提物正丁醇相的总多酚含量最高,为(453.75±0.75) mg/g;75%甲醇粗提物及其正丁醇相对ABTS ⁺自由基的清除能力较抗坏血酸（VC）强;各组分还原力强弱顺序为VC>正丁醇相>75%甲醇粗提物>水相>乙酸乙酯相>BHT>石油醚相;正丁醇相和乙酸乙酯相对DPPH自由基的清除能力较醇提物和水相强,石油醚相最弱;千层金叶片醇提物及其不同极性部位清除ABTS ⁺自由基清除能力、DPPH自由基清除能力及还原力均与其总多酚含量呈正相关。除石油醚相外,千层金叶片醇提物及其不同极性部位均有较强的抗氧化活性,可作为一种良好天然抗氧化剂的物质来源。     

椰肉中醇溶蛋白抗氧化活性

从脂质过氧化的抑制作用、对DPPH自由基(DPPH.)的清除作用、羟基自由基(·0H)的清除作用、Fe2+的络合能力等几个方面研究椰子醇溶蛋白的抗氧化活性,并以BHT、没食子酸,VE做为对照.结果表明,椰子醇溶蛋白对Fe2+具有很强的络合能力.对DPPH·有较强的清除能力,同时具有一定的清除·OH能力和还原能力,但其抑制脂质体过氧化作用的能力较弱.这表明椰子醇溶蛋白有较好的抗氧化活性,但其溶解性限制了其在脂溶性食品中的应用.     

吲哚丁酸的体外抗氧化活性研究

研究吲哚丁酸的体外抗氧化活性,包括DPPH自由基、羟基自由基和过氧化氢的清除能力,以及金属螯合活性和还原力。结果表明,吲哚丁酸具有显著的抗氧化活性,且与吲哚乙酸相当,其对DPPH自由基和羟自由基清除作用、螯合力、还原能力均高于萘乙酸和2,4-二氯苯氧乙酸,而对Fe2+的络合能力与没食子酸无显著差异。     

鹅掌柴提取物的抗氧化活性

从清除超氧阴离子自由基(O-2)、还原力、清除DPPH自由基、清除羟基自由基(·OH)等方面,研究鹅掌柴提取物的抗氧化活性.结果表明:鹅掌柴提取物对DPPH自由基和羟基自由基的清除能力较强,清除率分别为78.57%和74.99%,对脂质体过氧化的的抑制率为21.41%;与VE、VC、BHT相比,鹅掌柴提取物的还原能力和对Fe2+的络合能力也较强;但对超氧阴离子自由基的清除能力较弱.因此.鹅掌柴提取物是一种抗氧化功效较强的活性物质,具有很好的保健功能.     

苦丁茶提取物多酚含量与抗氧化活性的测定

首先用不同的有机溶剂分部萃取苦丁茶(Ilex kudincha C.J.Tseng)热水提取物(粗提物),得到氯仿萃取物、乙酸乙酯萃取物、正丁醇萃取物及萃取剩余物,然后采用Folin-Ciocalteu比色法测定粗提物和各萃取物的多酚含量,同时应用DPPH法、TEAC法和FRAP法分别测定粗提物和各萃取物的自由基清除能力和还原Fe3+能力。结果表明,苦丁茶提取物具有较高的多酚含量和较强的抗氧化能力;DPPH法和FRAP法测定各提取物抗氧化能力的结果为乙酸乙酯萃取物>正丁醇萃取物>粗提物>萃取剩余物>氯仿萃取物,TEAC法测定结果为乙酸乙酯萃取物>正丁醇萃取物>粗提物>氯仿萃取物>萃取剩余物;多酚含量与抗氧化能力之间、所用抗氧化测定方法之间均存在较好的相关性。     

火麻籽油中酚类化合物的检测及抗氧化活性研究

本文建立了采用高效液相色谱法同时检测火麻籽油中10种酚类物质的方法,10种单体酚检出限为0.05～0.12μg/mL,线性相关系数为0.9970～0.9998,回收率为85%～108%。检测了8份不同产地火麻籽油的总酚、总黄酮含量及体外抗氧化活性指标（DPPH、FRAP、ABTS+·）。总酚含量为1.20～17.35mg对香豆酸/100g,总黄酮含量为7.61～51.72mg柚皮苷/100g。DPPH清除能力为9.03～19.71mmol TE/100g,FRAP还原能力为13.12～30.09mmol TE/100g,ABTS+•清除能力为29.40～358.37mmol TE/100g。相关性分析表明,总酚含量与DPPH、ABTS+•清除能力和FRAP还原能力呈显著正相关;总黄酮含量与DPPH清除能力、FRAP的还原能力呈显著正相关。     

云南普洱茶不同溶剂提取物抗氧化活性研究

以芦丁与Vc为对照,测定云南普洱茶不同溶剂提取物清除DPPH自由基、羟自由基、超氧阴离子自由基、亚硝酸盐的能力及其还原力.结果表明:普洱茶不同溶剂提取物的抗氧化活性与其浓度成正相关,对DPPH自由基、羟自由基与超氧阴离子有较强的清除作用,对亚硝酸盐的清除作用不明显,具有一定的还原力.其中,乙醇沉析物、正丁醇提取物、乙醇提取物、乙醇溶解物对DPPH.自由基清除效果较好,相同浓度下优于芦丁;水提取物、乙醇沉析物及乙酸乙酯提取物对羟自由基清除效果较好,但效果不如Vc;乙酸乙酯提取物对超氧阴离子自由基和亚硝酸盐的清除作用较好,还原力也很强.     

棕榈油制备生物柴油的研究

以精制棕榈油、无水乙醇为原料,NaOH为催化剂,制备得到一种新型生物柴油。采用正交试验研究了反应物配比、催化剂用量、温度、反应时间等因素对产物产率的影响,得出了最佳合成条件,并运用气相色谱质谱技术分析了产物的结构和组成,结果表明,该生物柴油符合GB/T 20828-2007《柴油机燃料调和用生物柴油》,接近美国和德国的生物柴油标准,基本符合GB 252-2000《轻柴油》。可以替代柴油在柴油发动机中使用,满足普通柴油机的要求。     

Quality attributes and storage stability of locally and mechanically extracted crude palm oils in selected communities in Rivers and Bayelsa States,Nigeria

The effect of different extraction methods on the qualityof crude palm oil processed using traditional (local) and mechanical methods in selected areas of Rivers and BayelsaStates and their storage stability were investigated.Certain quality determining parameters such as free fatty acids (FFA), peroxide value (PV), saponification value (SV),moisture, impurities and volatile matter (MIV) content weredetermined prior to and after storage for three months. The free fatty acids (FFA) ranged from 7 to 19 percent, peroxidevalue (PV) ranged from 3 mEq/kg to 6 mEq/kg and moisture, impurity and volatile matter (MIV) ranged from 0.21 to 0.64 percent for locally extracted crude palm oil samples and mechanically extracted crude palm oil samples. There was no significant difference (p > 0.05) in the FFA of samples A and E before and after storage for 3 months. Also two of thelocally extracted crude samples (A and E) stored better whileone of the samples (D) showed a high level of deteriorationas shown in its high levels of FFA, PV and IV values. SamplesA and E resulted in a better quality of oil in terms of FFA (av. 7.25%) and PV (av. 4.5 meg/kg) when compared to the mechanically extracted one (sample C) with FFA (10.0%) and PV (5.78 mEq/kg). However, all the locally and mechanically extracted crude palm oil samples could not meet the industrial and international standard quality for crude palm with FFA (2–5%) and PV (2–3.5 mEq/kg). Among the three different storage containers used under different storage conditions, plastic containers (PC) resulted in a better storage stability of the crude palm oils in terms of FFA, SV, and IV than transparent bottles stored on shelves (TBS) and amber-coloredbottles stored on the bare floor (BPF).     

Reactivity of red palm oil and cyanide ion: Implications for the cyanogen content of palm oil-treated gari

Red palm oil was tested for the reactivity of its components with CN^-, and alkaline picrate as the color developing reagent. Palm oil components have a low-level absorbance at 490 nm which is reduced significantly (p0.01) after reaction with CN^-. Hydrolysis of palm oil components, and reaction of the hydrolysis products with CN^- significantly increased the absorbance at 490 nm. In contrast, after reaction of palm oil with alkaline picrate, the absorbance at 490 nm is very high; this is reduced significantly by reaction with CN^-, hydrolysis with 0.2 M NaOH , and reaction of the hydrolysis products with CN^- before treatment with alkaline picrate. The results indicate that palm oil component(s) sequester CN^- into a complex which may not be correctly estimated during cyanide quantification, resulting in the absence, or low levels of cyanide in palm oil-fried gari as earlier reported.     

Comparison of palm and mixtures of refined palm and soybean oils on serum lipids and fecal fat and fatty acid excretions of adult humans

The effects of palm (P) and mixtures of palmand soybean (PS), palmolein and soybean (POS),palmstearin and soybean (PSS) oils on serum lipids andfecal fat and fatty acid excretions of humans werestudied. Each oil was the dominant fat in dietsconsumed by ten normolipidemic live-in individuals.Test diets were assigned by randomization. All fourdiets had a similar influence on total cholesterol (TC),low density lipoprotein (LDL), high densitylipoprotein (HDL), very low density lipoprotein(VLDL), triglycerides (TG) and phospholipids (PL). Fecalfat excretion was higher (1.81, 1.80 g/d) with PS andPSS and lower (1.78, 1.42 g/d) with P and POS diets.Excretions of palmitic (C16: 0), oleic (C18: 1), andlinoleic (C18: 2) acids were similar for all diets.Excretions of stearic acid (C18: 0) were higher whenfeeding POS and PSS, and lower with feeding P and PS;the changes were statistically significant atp < 0.05. More linolenic acid (C18: 3) was excretedwhen P was fed compared to the feeding of PS, POS, andPSS. Changes in linolenic acid excretion between P andPOS were statistically significant at p < 0.05. It wasconcluded that there were no significant differencesin serum lipid concentrations due to feeding palm orany of the refined palm and soybean oil mixtures.However, a significant difference was found in C18: 0excretions with feeding POS and PSS compared to whenP and PS were fed. Similarly, significant C18: 3excretion was found with feeding P compared to whenPOS was fed.     

Influence of palm oil ( Elaesis guineensis) on health

In recent times there has been a growing research interest in palm oil, one of the major edible plant oils in the tropical countries, because of the link between dietary fats and coronary heart disease. Obtained from a tropical plant, Elaesis guineensis, it has a polyunsaturated fatty acid/saturated fatty acid ratio close to unity and a high amount of antioxidant vitamin A precursors and vitamin E. Palm oil is consumed in the fresh state and/or at various levels of oxidation. Feeding experiments in various animal species and humans have highlighted the beneficial role of fresh palm oil to health. These benefits include reduction in the risk of arterial thrombosis and atherosclerosis, inhibition of cholesterol biosynthesis and platelet aggregation, and reduction in blood pressure. However, a considerable amount of the commonly used palm oil is in the oxidized state which possesses potential dangers to the physiological and biochemical functions of the body. Oxidation is as a result of processing the oil for various culinary purposes. Studies have revealed that relative to fresh palm oil, oxidized palm oil induces an adverse plasma lipid profile, free fatty acids, phospholipids and cerebrosides. Additionally, oxidized palm oil induces reproductive toxicity and organotoxicity particularly of the kidneys, lungs, liver and heart. Available evidence suggests that at least part of the oxidized oil impact on health reflects generation of toxicants due to oxidation. The reduction of the dietary level of oxidized oil and/or the level of oxidation may reduce the health risk associated with consumption of oxidized fats.     

Microemulsion-based palm kernel oil extraction using mixed surfactant solutions

This study introduces a novel technique using surfactant microemulsion-based oil seed extraction. To achieve this objective, microemulsion formation with palm kernel oil was studied first. Then, the selected microemulsion system was used for palm kernel extraction. The results showed that the mixed surfactant of 3 wt% Comperlan KD and either 0.1 wt% Alfoterra145-5PO or 145-8PO provided an ultralow interfacial tension with the palm kernel oil (0.0197 and 0.0359 mN/m, respectively). By using those two aqueous surfactant systems for palm kernel oil extraction, the extraction efficiency was 93.99 and 94.13% at the optimum crushed kernel size between 0.212 and 0.425 mm, using 1 g seed load to 10 ml of solution and 30 min of contact time. The extracted oil quality was evaluated for water content, fatty acids composition and surfactant partitioning into oil phase. The results showed that the quality of the oil obtained using the surfactant microemulsion-based technique is of similar or better quality than when extracted by hexane solvent.     

棕榈油的螺旋压榨提取及其性质研究

采用自制的螺旋压榨机,分别对油棕果穗和果实进行提油,并对所得棕榈油的理化性质进行了检测。结果表明:先将果穗经过杀酵、脱果得到果实,再把果实捣碎、加热后榨取,有利于提高出油率;棕榈油的酸价、熔点、碘值、皂化价等符合国标要求,铜、铁、水分及挥发物、不溶性杂质和不皂化物等的含量很少,满足国家标准;这说明自制的棕油提取设备及其配套操作条件是可行的,这对将来棕油小型提取设备和技术的研发具有一定的意义。     

Synthesis of a base-stock for electrical insulating fluid based on palm kernel oil

This report presents a method for synthesizing base-stock for green industrial product from a vegetable oil with a high composition of unsaturated fatty acids. Epoxy methyl ester of palm kernel oil was synthesized from laboratory purified palm kernel oil using a two-step reaction and the products were used as a base-stock for green electrical insulation fluid. Epoxidized palm kernel oil was first prepared through epoxidation reaction involving purified palm kernel oil, acetic acid and hydrogen peroxide in the presence of amberlite as catalyst which lasted for 4 h. It was then followed by transesterification reaction involving the epoxidized product and methanol in the presence of sodium hydroxide as catalyst to synthesize the corresponding epoxy methyl ester. The thermal and electrical breakdown properties of the epoxy methyl ester demonstrated significantly improved properties for its use as raw material for bio-based industrial products such as electrical insulation fluids.     

棕榈植物芽苗移栽试验

通过芽苗移栽和小苗移栽常规方法的对比试验表明：不同发芽类型的棕榈品种,芽苗移栽的成活率均比常规小苗移栽成活率高;特别适宜远距无鞘型和远距带鞘型棕榈品种的播种繁殖。     

Palm oil: Biochemical,physiological, nutritional,hematological and toxicological aspects: A review

The link between dietary fats and cardiovascular diseases has necessitateda growing research interest in palm oil, the second largest consumedvegetable oil in the world. Palm oil, obtained from a tropical plant, Elaeis guineensis contains 50% saturated fatty acids, yet it does notpromote atherosclerosis and arterial thrombosis. The saturated fatty acidto unsaturated fatty acid ratio of palm oil is close to unity and it containsa high amount of the antioxidants, -carotene, and vitamin E. Although palm oil-based diets induce a higher blood cholesterol level thando corn, soybean, safflower seed, and sunflower oils, the consumption ofpalm oil causes the endogenous cholesterol level to drop. Thisphenomenon seems to arise from the presence of the tocotrienols and thepeculiar isomeric position of its fatty acids.The benefits of palm oil to health include reduction in risk of arterialthrombosis and atherosclerosis, inhibition of endogenous cholesterolbiosynthesis, platelet aggregation, and reduction in blood pressure. Palm oilhas been used in the fresh state and/or at various levels of oxidation.Oxidation is a result of processing the oil for various culinary purposes.However, a considerable amount of the commonly used palm oil is in theoxidized state, which poses potential dangers to the biochemical andphysiological functions of the body. Unlike fresh palm oil, oxidized palm oilinduces an adverse lipid profile, reproductive toxicity and toxicity of thekidney, lung, liver, and heart. This may be as a result of the generation oftoxicants brought on by oxidation. In contrast to oxidized palm oil, red orrefined palm oil at moderate levels in the diet of experimental animalspromotes efficient utilization of nutrients, favorable body weight gains,induction of hepatic drug metabolizing enzymes, adequatehemoglobinization of red cells and improvement of immune function. However, high palm oil levels in the diet induce toxicity to the liver asshown by loss of cellular radial architecture and cell size reductions whichare corroborated by alanine transaminase to aspartate transaminase ratioswhich are higher than unity.The consumption of moderate amounts of palm oil and reduction in thelevel of oxidation may reduce the health risk believed to be associated withthe consumption of palm oil. Red palm oil, by virtue of its-carotene content, may protect against vitamin A deficiency andcertain forms of cancer.