Possibility of improving the quality characteristics of olive‐pomace oil and enhancing its differentiation from refined olive‐pomace oil

An investigation was carried out to evaluate the oxidative and hydrolytic degradation of 37 olive‐pomace oils marketed in southern Italy and to compare the results with those obtained from 10 deodorised olive‐pomace oils representative of large stocks of oil obtained after the final step of refining. One aim of the research was to ascertain the quality characteristics of commercial olive‐pomace oils; another was to verify whether the legally prescribed addition of virgin olive oil to refined pomace oil, so that the final product may be classified commercially as olive‐pomace oil, was actually sufficient to justify upgrading. The analytical methods used were silica gel column chromatography and high‐performance size exclusion chromatography. The data obtained showed that the final retail olive‐pomace oils had a lower degree of oxidative degradation than the refined oils, as indicated by the lower values obtained when summing the proportions of triglyceride oligopolymers and oxidised triglycerides. Conversely, hydrolytic degradation, which was evaluated by determining diglycerides, proved to be the same in the two categories of oil. The proportions of virgin olive oil added are small, as indicated by the statistically indistinguishable values of triglyceride oligopolymers and free fatty acids obtained. The possibility of setting a limit to the amount of triglyceride oligopolymers present in the commercial category of olive‐pomace oil has been considered. This limit would ensure standardisation of the level of oxidation and, consequently, of the quality of marketed oils and would enhance differentiation between olive‐pomace oil and refined olive‐pomace oil. © 2000 Society of Chemical Industry     

Determination of the country of origin of pistachio nuts by DSC and HPLC

The laboratories of the U.S. Customs Service frequently encounter the major analytical problem of determining the country of origin of imported commodities. This is particularly challenging with natural products. This paper will describe the process for one such commodity —pistachio nuts. Two approaches were taken, high performance liquid chromatography (HPLC) and Differential Scanning Calorimetry (DSC). It was found that the results of these two techniques were complimentary and confirmatory. The HPLC data was obtained on the petroleum ether soluble fraction of the pistachio nuts while the DSC runs evaluated both this fraction and the whole nut. The HPLC results were further investigated by collecting fractions from the eluting peaks, derivatizing them to form the methyl ester of the fatty acids, and profiling by gas chromatography to confirm the triglycerides originally present. The U.S. Customs Service is currently using DSC area ratios to screen imported pistachio nuts for country of origin.     

燕麦对高胆固醇血症男性中老年人血脂水平的影响

目的:观察食用燕麦对城市患高胆固醇血症男性中、老年人空腹血脂水平的影响.方法:参考《中国成人血脂异常防治指南》中的判断标准,将65名患高胆固醇血症男性中、老年人随机分为2组,分别为燕麦组(33人),每人每日给予100 g即冲即食燕麦片;对照组(32人),每人每日给予100 g普通挂面,试验周期6周.研究开始前和6周时对两组受试者进行基本健康状况问卷调查、人体测量、血生化检测以及膳食调查.结果:燕麦组和对照组的能量、蛋白质、脂肪、碳水化合物摄入量无显著差异,但燕麦组膳食纤维摄入量明显增加,增幅显著大于对照组,P＜0.05.6周结束时,燕麦组血清总胆固醇(T℃)、低密度脂蛋白胆固醇(LDL-C)、载脂蛋白B(apoB)水平显著降低(P＜0.05);血清TC、LDL-C平均降低幅度分别为7.0％和7.5％.对照组血清胆固醇、脂蛋白及载脂蛋白水平在试验期间未见显著变化.结论:对于我国城市中患高胆固醇血症的男性中、老年人,每日食用一定量的燕麦作为膳食中的粮谷类食物,可有效降低血清TC、LDL-C和apoB水平,减少心脑血管疾病发生的危险.     

甾醇类化合物降低高胆固醇HepG2细胞内胆固醇的作用机制

通过建立HepG2高胆固醇细胞模型,测定细胞总胆固醇、甘油三酯及其胆固醇调控相关蛋白水平,探讨甾醇类化合物的降胆固醇活性及其作用机制。结果表明：4种甾醇类化合物可以降低HepG2细胞内的甘油三酯和总胆固醇水平,改善高胆固醇细胞模型脂质水平的增加和代谢紊乱,其可能机制是下调尼曼-匹克C1型类似蛋白1、胆固醇酰基转移酶2、羟甲基戊二酸单酰辅酶A合成酶和固醇调节元件结合蛋白的表达,上调ATP结合盒转运体G5/8的表达,降低胆固醇的吸收与生物合成,减少胆固醇酯化,促进胆固醇向肠道的排泄。结论：甾醇类化合物通过影响胆固醇吸收以及代谢相关蛋白的表达来改善高胆固醇细胞模型的脂质水平。     

冷榨茶叶籽油甘三酯的组成分析

本文采用气相色谱法测定了茶叶籽油的脂肪酸组成,得出茶叶籽油中不饱和脂肪酸含量在80%以上,主要是以油酸的形式存在,含量为59.84%;采用胰脂酶水解法测定茶叶籽油的Sn-2位脂肪酸分布,并根据1,3-随机-2-随机分布学说计算出茶叶籽油甘三酯组成, 得出主要甘三酯是OOO、OOL、POO、PLO、LLO等,其中三不饱和脂肪酸甘油酯含量在53.5%以上,而三饱和脂肪酸甘油酯含量仅为0.05%左右;由高效液相色谱测定得出茶叶籽油中的维生素E含量为0.18 mg/g;Rancimat仪测定茶叶籽油氧化稳定时间在110 ℃时为6.02 h。茶叶籽油具有很好的食用营养价值和储藏稳定性。     

Regressional models that describe oil absolute viscosity

Equations that describe the temperature dependence (298–338°K) of absolute viscosity (μ) of 21 oils and oil-liquid fat mixtures were obtained based on two different approaches. Fitting each particular viscosity profile to a quadratic extension of the Andrade equation provided the best predictive models (R²>0.96). However, the coefficients associated with temperature effect did not have a physical-chemical meaning. In contrast, the multiple variable regressional approach fitted, in just one equation, the μ of all 21 oil systems (R²≈0.93). This equation included terms associated with structural parameters of acylglycerides, namely the degree of unsaturation (i.e., iodine value) and chainlength (i.e., saponification value) of the fatty acids. The models described effects of thecis double bonds and fatty acid chainlength on the acylglycerides’ interactions that determine both the μ of the system and its capability to crystallize. Therefore, multiple variable regressional analysis might be an excellent tool to better understand the quantitative structure-functional property relationships in lipids systems.     

Aberrations in Lipid Expression and Metabolism in Psoriasis

Psoriasis (PSO) is a common skin disease that affects about 1%–3% of the general population. It is a great medical, social and economic burden since PSO is associated with many comorbidities, of which the most common are cardiometabolic disorders. Psoriatic patients suffer more frequently from obesity, dyslipidemia, atherosclerosis, and nonalcoholic fatty liver disease. Research shows that lipid expression and metabolism disorders are present more often in such patients. This review focuses on a variety of aberrations in lipids in the skin, blood, and adipose tissue in psoriatic patients and their multifactorial impact on the pathogenesis of psoriasis.     

One-pot solvent-free transformation of natural triglycerides to ester and amide derivatives over CaO@KC nanostructured catalysts

In the present report, the fatty acid alkyl esters and fatty acid amides were synthesized from natural triglycerides by highly selective solvent-free one-step methods using 3.5-CaO@KC-400 nanocrystals as a heterogeneous catalyst. A modified wetness chemical impregnation method was used to prepared potassium carbonate-doped CaO, ZnO, and MgO nanocrystals. The prepared 3.5-CaO@KC-400 nanocrystals were found as the most efficient heterogeneous catalyst (5%, w/w) for amidation (6:1 M ratio of diethanolamine/oil, 110°C) and transesterification (12:1 M ratio of methanol/oil, 65°C) of waste cooking oil and took 30 minutes for the completion of both the reactions. The 3.5-CaO@KC-400 nanocrystals were found to be efficient at room temperature also and reused for 10 reaction cycles for both reactions. The pseudo-first-order kinetic model was applied and the first-order rate constant was calculated as 0.15 minute⁻¹ and 0.103 minute⁻¹ for the amidation and transesterification reactions of waste cooking oil, respectively.     

线性回归在糖尿病诊断中的应用

将数据挖掘技术应用到糖尿病的诊断之中,运用线性回归算法,对糖尿病患者体检的历史记录进行数据处理,分析糖化血红蛋白和甘油三酯与糖尿病之间的关系,以发现其中的医学诊断规则和模式,辅助医生进行疾病的诊断.根据数据挖掘的结果分析糖尿病患者的数据,得出结论：糖化血红蛋白和甘油三酯在人体内的含量越高,患糖尿病的概率就越大.     

Enzyme‐based approaches for pitch control in thermomechanical pulping of softwood and pitch removal in process water

BACKGROUND: In the pulp and paper manufacturing process, pitch colloidal particles have a tendency to agglomerate and deposit on pulp fibres and equipments. They reduce the efficiency of the washer, increase the dirt count and bleach chemical consumption, reduce pulp brightness thus leading to paper defects. Triglycerides are considered to be the most problematic compounds during the manufacturing of mechanical and acidic sulfite pulps from various softwood species. RESULTS: Using enzyme‐based approaches, a pitch control method was developed for use with thermomechanical pulping of softwood and for pitch removal from process water. Results showed that with combination of a novel biodegradable surfactant and a lipase resin acids, sterols and triglyceride groups were reduced by 48%, 32% and 78%, respectively, compared with untreated samples. Using laccase treatment of the process water the fatty and resin acids were reduced by 42% and the lignans by 60%. CONCLUSION: By combining the proposed pulp treatment with laccase decontamination of the process water, this new method offers an efficient alternative to control the various pitch‐associated problems. Copyright © 2008 Society of Chemical Industry