沙生植物长柄扁桃种子油营养成分分析

探讨以长柄扁桃为原料开发新型食用植物油的可能性。采用国家标准对内蒙古产长柄扁桃仁压榨油进行了常见理化指标、营养成分、卫生指标分析及急性毒性试验研究。长柄扁桃种子油理化性能良好,是一种营养丰富的植物油源;总砷、铅、及黄曲霉毒素B_1含量符合食用植物油卫生标准;急性毒性实验结果初步判定其安全性。长柄扁桃油可开发为新型高品质食用油。     

The in vitro antioxidant activity of lotus germ oil from supercritical fluid carbon dioxide extraction

The in vitro antioxidant activity of lotus germ oil extracted by supercritical fluid extraction (SFE) has been investigated. The distinctly high total phenolic compounds content and tocopherol content in lotus germ oil composition were found to be 9.06 ± 0.11% and 485.1 ± 50 mg/100 g, respectively. The lotus germ oil exhibited a dose-dependent inhibitory effect on the hydroxyl free radical and superoxide anion free radical. However, the scavenging effects on the superoxide anion free radical were deceased when the extract concentration was greater than 70 mg/mL. Lotus germ oil showed substantial antioxidant activity in the mice liver and kidney tissues homogenates in a dose-dependent manner. The auto-haemolysis of mice red blood cells was also blocked by lotus germ oil in a dose-dependent manner. Lotus germ oil showed a higher antioxidant activity in the lard system. The high content of phenolic compounds and tocopherol in the lotus germ oil could partially account for the antioxidant activity. These results suggest the lotus germ oil can be used as healthcare oil to develop.     

Comparative evaluation of four free radical scavengers for the inhibition of individual glycidyl ester formation in rice bran oil determined by UPLC-MS/MS

This research investigated the effect of carnosic acid (CA), tert-butyl hydroquinone (TBHQ), sesamol (SL) and L-ascorbyl palmitate (AP) on the inhibition of glycidyl esters (GEs) and oxidation parameter changes in rice bran oil (RBO) during heat processing. The electron spin resonance (ESR) analysis showed that the free radical scavenging ability of them was ranked as CA > TBHQ > SL > AP. With the addition of CA, TBHQ, SL and AP (0.6 g kg⁻¹), the GEs content was reduced significantly from 987.98 ± 8.45 to 283.87 ± 4.78, 303.21 ± 4.38, 440.52 ± 3.82 and 500.55 ± 2.99 μg kg⁻¹, respectively. All four free radical scavengers had the highest inhibitory effect on C18:2-GE, followed by C18:1-GE and C16:0-GE. Moreover, the free radical scavengers were also effective to inhibit oil oxidation. Overall, the natural-free radical scavenger may be a promising candidate to mitigate GE formation and oil oxidation due to its effectiveness and safety.     

Addition of enzymes complex during olive oil extraction improves oil recovery and bioactivity of Western Australian Frantoio olive oil

Olive oil consumption has increased as many studies revealed the health benefits of regular consumption of olive oil. There is a need to find effective oil extraction techniques capable of increasing oil recovery without compromising its quality. This study investigated the impact of adding enzymes complex Viscozymes during olive oil extraction on oil recovery, total phenolic compounds, antiradical activity and the standard quality parameters. It was found that at a concentration of 0.30 g mL^?1, Viscozymes could significantly improve the oil recovery from 49 to 69% (P < 0.001) when compared to the Control sample. The concentration of total phenolic compounds was also significantly improved from 110 to 266 mg kg^?1 oil (P < 0.01) and the antiradical activity increased from 31 to 48% inhibition of 2,2‐diphenyl‐1‐picrylhydrazil radical (P < 0.001). Addition of Viscozymes therefore represents an effective extraction technique that increases oil recovery without compromising the concentration of total phenolic compounds and antiradical activity.     

Using <Superscript>1</Superscript>H and <Superscript>13</Superscript>C NMR techniques and artificial neural networks to detect the adulteration of olive oil with hazelnut oil

The lack of any official analytical method to detect the adulteration of olive oil with a low percentage of hazelnut oil is explained by the similarities in the chemical compositions of both kinds of oils. To counter this problem, an artificial neural network based on ¹H-NMR and ¹³C-NMR data has been developed to detect olive oil adulteration, and the results from this ANN are presented here. A training set consisting of hazelnut oils, pure olive oils, and olive oils blended with 2–20% hazelnut oils was used to design and train a multilayer perceptron with 100% correct classifications. This mathematical model was also validated using an external validation set of blend samples (3–15%) and genuine samples. The detection limit of the model was around 8%.     

柠檬籽油营养评价与急性毒性试验

为了探讨以柠檬籽为原料开发特种油脂的可能性,对压榨柠檬籽油进行了特征活性成分、脂肪酸组成、常用理化指标分析以及急性毒性试验。结果显示,柠檬籽油富含多种活性成分、脂肪酸配比理想,是一种营养丰富的植物油源;急性毒性试验结果初步判定了其安全性。     

Performance of two immobilized lipases for interesterification between canola oil and fully-hydrogenated canola oil under supercritical carbon dioxide

The performance and stability of Lipozyme RM IM and TL IM for the interesterification between canola oil and fully-hydrogenated canola oil (FHCO) in the presence of SCCO₂ were studied using a high pressure batch stirred reactor at 65 °C/17.5 MPa. The influence of exposure time (4, 8, and 12 h) in SCCO₂ and pressurization/depressurization cycles of up to 12 times on the enzyme's resultant activity were studied. There was no significant difference (p > 0.05) in the performance of the two enzymes over reaction time, reaching a constant degree of interesterification of about 23% after 2 h. Although FE-SEM images illustrated some morphological changes on the surface of the enzymes after 4 cycles of 7 h each, similar degrees of interesterification were achieved after each cycle. However, the amount of reaction intermediates decreased by 50–60% in the product obtained by using SCCO₂-treated enzymes after 12 pressurization/depressurization cycles compared to untreated enzymes, while there were no significant changes in the conformational and morphological structure of the treated enzymes based on FTIR and FE-SEM analysis. Findings enhance our understanding of enzymatic conversions of lipids under high pressure CO₂, targeting production of base-stock for zero-trans margarines.     

车前子中黄酮提取物对油脂的抗氧化活性研究

以车前子为原料超声强化乙醇提取黄酮,通过单因素和正交试验获得最佳工艺条件,研究了黄酮提取物对油脂的抗氧化性能及对羟基自由基的清除能力并与常用的抗氧化剂VC和柠檬酸比较。结果表明,在30%乙醇、料液比1∶40、超声温度60℃、超声强化处理60 min的最佳工艺条件时,车前子中黄酮的提取率为2.8%,该提取物对羟基自由基的清除作用随浓度增大而增强,对油脂有较强的抗氧化活性,抗氧化能力接近VC与柠檬酸,当油脂在烘箱放置时间延长使氧化程度加深时,黄酮对动物油的保护作用愈加显著,所以车前子黄酮提取物更宜于作为动物油的天然抗氧化剂添加于油脂及含油食品中。     

Coriander (<Emphasis Type="Italic">Coriandrum sativum</Emphasis> L.) seed oil improves plasma lipid profile in rats fed a diet containing cholesterol

Coriander (Coriandrum sativum L.) seed oil (COR) is a promising oil with high levels of bioactive compounds. Very little information, however, is available on the effect of administration of COR on different aspects of plasma lipid profile in experimental animals. In view of the important implications, the effect of administration of COR and oil blend [a mixture of soybean oil, coriander oil and sunflower oil (4:2:4, w/w/w; Blend)] on the profile of plasma lipids was investigated in 24 male albino rats placed on a cholesterol-rich (1%) basal diet as compared to rats on a cholesterol-free basal diet. Coriander seed oil and Blend were analyzed for composition of fatty acid, sterol and tocopherol. The levels of bioactive compounds (sterols and tocopherols) were higher in COR than in the Blend. In addition, the antiradical potential of COR and Blend was measured and the results showed that COR had stronger radical scavenging activity than Blend. In the biological experiment, rats were divided into four diet groups. The negative control group (control) consumed the basal diet (BD) only, which contained wheat starch, casein and cellulose, as well as mineral and vitamin mixtures. To the BD were added 1 g/100 g cholesterol (Chol/group), or both (Chol/COR group) and (Chol/Blend group). The groups did not differ before the experiment, which lasted 60 days. Plasma total lipids (TL), triacylglycerols (TAG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) were measured at day 15, 30, 45 and 60 during the experiment period. Generally, COR and Blend-supplemented diets decreased the levels of TL, TC, TAG and LDL-C in plasma. In addition, significant increase in the levels of HDL-C was observed for Chol/COR and Chol/Blend groups. The results demonstrated that COR, and to a relatively lesser degree Blend, have hypocholesterolemic properties in rats fed a cholesterol-rich diet.     

葡萄籽油毒性评价的研究

目的检测葡萄籽油的生物安全性。方法对葡萄籽油样品进行小鼠急性毒性试验和小鼠遗传毒性试验。结果小鼠急性和遗传毒性测试均为阴性。对大鼠喂养30天的试验表明，在试验期内个试验组动物生长发育良好，动物体重、食物利用率、血常规、血生化、脏器系数等各项指标均在正常值范围内，与对照组之间差异无显著性（P〉0．05）。病理组织学检查无异常。结论表明该物质对大鼠各项观察指标未产生明显毒性作用。     

Development of a rapid method for the determination of frying oil quality based on capillary penetration

A novel rapid method and apparatus for the determination of frying oil quality based on capillary penetration is presented. The method measures the rate (or time vs. distance) of penetration of the oil in a substrate. Several porous media made of different materials (glass, cellulose, polyethylene) having different pore sizes were examined as potential substrates. A polyethylene substrate was selected as the most appropriate. This substrate was used for measurements with olive and sunflower oil at different levels of degradation (at 170 °C for up to 32 h). The fresh and degraded oil polymer and polar compounds were measured using HPSEC. The results of the method were linearly related to the oil degradation time (R² = 0.95) and the concentration of polymer (R² = 0.95) and polar (R² = 0.91) compounds. The results of this work suggest that the capillary penetration method is a promising novel method that merits further investigation and development.     

The in vitro and in vivo antioxidant properties of seabuckthorn (Hippophae rhamnoides L.) seed oil

The antioxidant capacity of seabuckthorn (Hippophae rhamnoides L.) seed oil was investigated with a number of established in vitro assays and in an in vivo study of carbon tetrachloride (CCl₄)-induced oxidative stress in mice. The results showed that DPPH radical scavenging activity, ferrous ion chelating activity, reducing power and inhibition of lipid peroxidation activity all increased with increasing concentrations of seabuckthorn seed oil. Moreover, the EC₅₀ values of seabuckthorn seed oil from the hydrogen peroxide, superoxide radical, hydroxyl radical scavenging assays were 2.63, 2.16 and 0.77 mg/ml, respectively. In the in vivo study, seabuckthorn seed oil inhibited the toxicity of CCl₄, as seen from the significantly increased activities of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. The GSH content in the liver was also increased, whereas hepatic malondialdehyde was reduced. Taken together, these results clearly indicate that seabuckthorn seed oil has significant potential as a natural antioxidant agent.     

Temperature-dependence of rate of oxidation of rapeseed oil encapsulated in a glassy food matrix

Oxidation of stripped rapeseed oil, encapsulated in a carbohydrate/protein glassy matrix, initiated by a lipophilic free radical initiator (or not initiated) and monitored as peroxide value and conjugated dienes for 45 days, developed differently depending on storage temperature. At low temperature (5 °C), the encapsulated oil and bulk oil, as reference, showed little oxidation which, moreover, could be accounted for by the oxygen dissolved in the oil. At intermediate temperatures (25 and 45 °C), oxidation exceeded the level corresponding to dissolved oxygen and became dependent on oxygen transport through the matrix. At high temperature (60 °C), a rapid, linear increase in peroxide concentration was followed by an autocatalytic phase with a rapid increase in peroxides, subsequently reaching a steady-state concentration. The oxidation of the encapsulated oil was found to have a lower energy of activation (around 60 kJ/mol) than the bulk oil (around 80 kJ/mol), resulting in a protection of the encapsulated oil at higher temperatures. However, the temperature-dependence of the zeroth order rate constants for initial peroxide formation in the encapsulated oil showed a shift from a rate determining reaction at low temperature with a high energy of activation to a reaction at higher temperature with a smaller energy of activation, especially for the encapsulated oil without initiator added. At low temperature, lipid oxidation seems rate-determining while, at higher temperature, oxygen permeation through the matrix with a lower energy of activation becomes rate-determining. The glassy matrix yields only partly protection against lipid oxidation as it allows permeation of oxygen and other small molecules, as further confirmed by the effect of a hydrophilic radical initiator, incorporated in the matrix, on peroxide value of the encapsulated oil.     

The detection of the presence of hazelnut oil in olive oil by free and esterified sterols

Genuine olive and hazelnut oils from diverse geographical origins, as single varieties and blends, were mixed at different percentages and analysed by the method based on the quantification of free and esterified sterols. Two formulas based on three sterols (Campesterol, Δ⁷-stigmastenol and Δ⁷-avenasterol) together with empirical decision rules were able to detect the presence of hazelnut oil in olive oil when the percentage of the former was more than 6–8%, although this figure was much lower in the most of the adulterations. Results of univariate and multivariate statistical procedures based on the analysis of 116 samples are presented in support of the method efficiency.     

Phenolic and antioxidant potential of olive oil mill wastes

Olive oil mill waste was subjected to conventional liquid solvent extraction and supercritical fluid extraction using different solvents and carbon dioxide, respectively. The optimum solvent extraction conditions of phenols were 180 min using ethanol, at a solvent to sample ratio 5:1 v/w, and at pH 2. Solvent and SFE extracts were tested for their antioxidant activity by the DPPH radical scavenging method and by determination of peroxide value on virgin olive oil and sunflower oil. The ethanol extract exhibited the highest antiradical activity, and no correlation was found between antiradical activity and phenol content. The SFE extract exerted good antioxidant capacity although its phenolic yield was not quite high. Moreover, the ethanol extract appeared to be a stronger antioxidant than BHT, ascorbyl palmitate and vitamin E by the Rancimat method on sunflower oil. HPLC analysis of the extracts showed that the predominant phenolic compound was hydroxytyrosol. Various phenolic acids and flavonoids were also identified.     

Effects of residual phospholipids on surface properties of a soft-refined sunflower oil: Application to stabilization of sauce-types’ emulsions

Vinegar sauces’ type emulsions were prepared from water–alcohol mixture (90:10) and three different sunflower oil samples (Reference oil, SUN1 and SUN3) at 20 wt% with sunflower lecithin as O/W emulsifier. Besides the addition of lecithins at 0–2 wt%, the oil composition varied based on the minor components present in each oil due to the different crushing and refining process. Reference oil sample was nutrient-free while SUN oil contained nutrient component sterols, tocopherols, phosphorus and phenols. Interfacial tension of the different systems was monitored using an automated tensiometer. The vinegar sauces’ type oil-in-water emulsions were prepared by a two-step homogenization procedure (10,000 rpm for 10 min, followed by a passage through an homogenizer at 400 bar pressure), the lipid droplets’ stability against aggregation/coalescence was monitored using integrated light scattering (particle size distribution) and multiple light scattering (creaming) measurements for two-month storage at 4 °C. In the absence of added lecithins, SUN oil sample containing phospholipids presented lower interfacial tension values than the Reference oil. Equilibrium values obtained are ∼4.4 mN m⁻¹ for SUN3, ∼10.5 mN m⁻¹ for SUN1, instead of 13.7 mN m⁻¹ for Reference sample. Addition of phospholipids (lecithin) to the Reference sample led to a similar trend of adsorption kinetics observed in the SUN sample (nutrient rich oil). SUN3 showed the best ability to form elastic film and Reference oil showed lowest ability, which could be attributed to concentration and the composition of phospholipids.     

洋葱油的抗氧化活性研究

探讨洋葱油对羟基自由基、超氧阴离子自由基、过氧化氢的清除作用以及对羟基自由基引发DNA损伤的抑制作用,并与天然抗氧化剂Vc作比较。结果显示洋葱油对羟基自由基的清除作用及对羟基自由基引发DNA损伤的抑制作用效果明显,与Vc相当。对超氧阴离子自由基、过氧化氢的也有一定的清除作用,效果稍差于Vc。研究表明,洋葱油具有很好的抗氧化作用。     

核桃油贮藏过程抗氧化能力的研究

以核桃油为试验原料,研究了核桃油在氧化过程中的抗氧化活性的变化。结果表明:未曾氧化的核桃油抗氧化活性较好,核桃油对DPPH·自由基的抑制率随着核桃油样品浓度的增加而不断增强,147.0 mg/m L质量浓度的核桃油清除DPPH·自由基能力为50%;340.83 mg/m L质量浓度的核桃油清除羟基自由基的能力为50%;1.0 mg/m L质量浓度的核桃油对超氧阴离子自由基的平均清除率与1.0 mg/m L质量浓度的Vc相当。而经氧化后的核桃油清除DPPH·自由基和·OH自由基的能力明显降低,相同浓度不同氧化时间的核桃油样品对超氧阴离子自由基的清除能力,随着氧化时间的增长而逐渐下降,但氧化时间越短核桃油对O2-·的抑制率越好,当氧化时间为30天时,核桃油对O2-·的平均抑制率从55.53%降到15.43%。总之,未曾氧化的核桃油的抗氧化物活性较好,随着氧化时间的增加核桃油对以上三种自由基的清除能力逐渐降低。