茶油精炼副产物皂脚制备生物柴油的研究

以茶油精炼副产物皂脚和甲醇为原料,NaOH为催化剂,经酯交换合成生物柴油,研究了工艺条件对皂脚合成生物柴油收率的影响。结果表明,适宜的工艺条件为:醇油摩尔比为5∶1,反应时间为30 min,反应温度为30℃,催化剂NaOH用量为油重的0.7%,反应收率为98.0%。     

Synthesis of structured triglycerides from peanut oil with immobilized lipase

Structured triglycerides (ST) that contain medium- and long-chain fatty acids were synthesized by lipase-catalyzed interesterification between tricaprylin and peanut oil. To select appropriate enzymes, we investigated nine commercial lipase preparations for their ability to hydrolyze pure triglycerides as well as natural oils. Three microbial lipases from Rhizomucor miehei (RML), Candida sp. (CSL), and Chromobacterium viscosum (CVL) gave good results, and immobilized preparations were used in the interesterification. RML gave the highest yields of ST (73%, 40°C), although its hydrolytic activity toward triolein was low. As the temperature was raised to 50°C, the yield of ST increased to 79%. After 120 h reaction time, remaining activities were high for CSL (71%), moderate for CVL (48%), and low for RML (20%). Parts of this paper were presented as a poster at the Biochemical Engineering Conference IX, May 1995, Davos, Switzerland.     

HPLC analysis of phenolic antioxidants,tocopherols and triglycerides

Triglycerides, together with nine synthetic phenolic antioxidants most commonly used to prevent oxidation of edible oils and fats, as well as the natural antioxidants tocopherols andα-tocopherol acetate, were separated by high performance liquid chromatography by means of a reversed phase C₁₈-column and gradient elution with water/acetonitrile/methanol/isopropanol. Besides dilution of the oil with isopropanol/hexane, no further example preparation was required. UV detection was applied. The synthetic antioxidants propyldodecylgallate, octyldodecylgallate, dodecylgallate, 3-tert-butyl-4-hydroxyanisol,tert-butylhydroquinone, 3,5-di-terf-butyl-4-hydroxytoluene, 2,6-di-tert-butyl-4-hydroxymethyl-phenol, 2,4,5-trihydroxybutyrophenone and nordihydro-quaiaretic acid, as well asα- andδ-tocopherol andα-tocopherol acetate were base-line separated;β- andγ-tocopherol, however, eluted together. The triglycerides, detected at λ = 215 nm, were separated according to then-partition number. The absorption at λ = 215 nm revealed saturated and unsaturated triglycerides. The absorption at λ = 280 nm indicated triglycerides with conjugated unsaturation, relating information about refining and heat treatment of the oil. Oxidized unsaturated triglycerides showed absorption at γ = 230 nm. Triglycerides of ricinoleic acid, a hydroxymonoun-saturated acid, gave identical UV spectra. The simultaneous detection of antioxidants and triglycerides may be used to study inhibition effects by antioxidants in oils. To whom correspondence should be addressed.     

油茶籽油不皂化物的提取与抗氧化性研究

以油茶籽油为原料,通过皂化-己烷萃取法提取其不皂化物。通过气相色谱-质谱联用技术(GC-MS)对油茶籽油不皂化物的组成进行了分析,并通过1,1-二苯基-2-三硝基苯肼(DPPH)法、三价铁离子还原力(FRAP)法以及细胞抗氧化(CAA)法对其抗氧化性能进行了测定,并与α-生育酚进行了比较。结果表明,通过皂化-己烷萃取法得到的油茶籽油不皂化物主要含有烃类、三萜醇以及植物甾醇;油茶籽油不皂化物的DPPH自由基清除率可达到95%,EC50为1.9 g/L;油茶籽油不皂化物具有一定的Fe3+还原能力,在质量浓度为5 g/L时,FRAP值可达170;油茶籽油不皂化物能够进入细胞并对2,2'-偶氮(2-甲基丙基脒)二盐酸盐(ABAP)诱导的细胞内活性氧水平升高具有抑制作用,质量浓度为100 mg/L时CAA值可达36.6。     

Hydrogenation of soybean oil triglycerides: Effect of pressure on selectivity

Soybean oil contains five triglycerides that account for over 70% of the total. These include LLL, LLO, LLP, LOO, and LOP and their isomers (where L=linoleic, O=oleic, P=palmitic). High-performance liquid chromatographic analysis of samples taken during a typical hydrogenation run in which the iodine value (IV) was reduced from 130 to about 70 showed that the linoleate-containing triglycerides were reduced at a much faster rate than the linolenate-containing triglycerides. Results clearly show that hydrogenation proceeds through definite pathways rather than by random saturation of fatty acids within the triglyceride molecules. Pressure has a significant effect on the course of hydrogenation. At higher pressures (500 psi), the reaction is truly nonselective, since di-and trisaturated glycerides are formed at about 70 IV, whereas at 50 psi, the reaction becomes selective. At higher pressures, fat functionality and solid fat result primarily from di-and trisaturated fatt acid triglycerides as well as trans fatty acid triglycerides. At lower pressures, functionality results from trans acid triglyceride formation. Although the reactivity of linoleate containing triglycerides followed the pattern 6 double bonds>5 double bonds>4 double bonds, other factors may be important. For example, LLP is reactive and undergoes hydrogenation, while LLS remains unchanged. Triolein, which constitutes less than 3% of the total triglyceride in natural soybean oil, is a significant product of hydrogenation, which suggests that LLL and LLO are reduced directly while adsorbed on the catalyst surface. Presented in part at the A.E. Bailey Award Dinner, Peoria, IL, Feb. 23, 1999.     

Effect of drying method and wall material composition on the characteristics of camellia seed oil microcapsule powder

Camellia seed oil (CSO) is one of the richest sources of oleic acid (75–80%) and it is considered to provide beneficial health effects to humans. However, its susceptibility to oxidative degradation prevents its widespread use in the food industry. This study was aimed to improve the stability of camellia seed oil by microencapsulation. CSO was microencapsulated using whey protein concentrate (WPC) and maltodextrin (MD) or starch sodium octenylsuccinate (SSOS) as wall materials. The produced oil-in-water emulsion was subsequently dehydrated to produce microcapsule powder using spray and freeze drying techniques, respectively. Various characteristics of oil-in-water emulsion and final microcapsule powder including particle size distribution, encapsulation efficiency, morphology, rheological properties of reconstituted emulsions, in vitro digestion behavior and oxidative stability were determined to investigate the effect of wall material composition and drying method on these microcapsule powder characteristics. The spray-dried powder had significantly higher bulk density and smoother surface compared to freeze-dried powder while the freeze-dried CSO microcapsule powder with WPC/SSOS as wall material had the highest encapsulation efficiency and the lowest surface oil. The subsequent in vitro digestion test suggested the microencapsulated CSO could be successfully controlled-released in the simulated gastric (10.28–13.03%) and the subsequent intestinal fluid (72.89–89.61%). Oxidative stability of camellia seed oil was significantly improved by microencapsulation. The freeze dried CSO microcapsule powder in WPC/SSOS wall material exhibited highest encapsulation efficiency (95.17%) and best oxidative stability (peroxide value and p-anisidine values of 3.57 meq/kg oil and 3.01, respectively, during the 45 days storage at 25°C.     

餐饮油烟催化净化技术的研究进展

油烟污染控制是近年来人们关注的重点,介绍油烟的形成过程以及油烟的成分分析,表明油烟主要成分是脂肪酸、烷烃和烯烃等,其次是醛类、酯类、醇类及多环芳烃等。探讨当前油烟净化处理的多种方式,着重对催化转化法的研究现状进行阐述。     

驱油方式对采出液破乳效果的影响

通过室内模拟试验评价了驱油方式对采出液化学破乳效果的影响.水驱、聚合物驱和三元复合驱采出液化学破乳效果之间存在明显差异,聚合物驱和三元复合驱采出液的热化学脱水效果好于水驱采出液,三元复合驱采出液破乳后的水相残余乳化油量大于水驱和聚合物驱采出液;三元复合驱工业化应用后,如果直接沿用已建水驱和聚合物驱采出液游离水脱除装置处理三元复合驱采出液,那么将使游离水脱除器放水的含油量大幅度上升,所以必须研制适应三元复合驱采出液,特别是弱碱体系三元复合驱采出液的高效破乳剂.     

Method for analysis of TAG formed by reaction of fish oil with hydrogenated soybean oil

An HPLC method was developed for analysis of the TAG formed during interesterification of a fish oil rich in DHA residues and of a fully hydrogenated soybean oil. TAG species were separated using a three-phase (acetone/acetonitrile/chloroform) solvent system. Peak identities were assigned on the basis of a multiple linear regression analysis by using factors such as carbon number, number of double bonds, and number of PUFA in the molecule as predictors for TAG retention time. Good agreement between experimental and predicted retention times was observed when the effect of the PUFA was separated in the regression model from that of the monounsaturated FA. In addition, the new method permits one to determine tristearin at concentrations up to 3 mg/mL without encountering the problem of partial retention of this TAG in the column that was observed when chloroform is not incorporated in the mobile phase.     

近年我国油气管道防腐技术的应用

本文综述了我国近几年石油、天然气管道防腐技术的应用情况.根据新近的文献报道,从管道腐蚀产生的机理、原因及我国近年油气管道防腐技术应用的现状等方面系统总结论述了管道防腐新技术的应用情况.着重讨论了国内外油气管道防腐技术应用历史沿革与发展趋势、近年我国油气管道防腐技术的应用以及油气管道防腐技术应用中应注意的问题等方面的内容.     

Determination of iodine value of palm oil based on triglyceride composition

The triglyceride (TG) composition of palm oil is normally determined by high-performance liquid chromatography (HPLC). The HPLC chromatograms indicated a good separation of most of the TG components in the oil. The TG can be classified based on either the TG groups, i.e., triunsaturated, monosaturated, disaturated, or trisaturated, or the number of double bonds, i.e., zero, one, two, three, or four double bonds. The more unsaturated the fatty acid, the greater the iodine value (IV). Therefore, it is hypothesized that the IV of an oil can be determined based upon the TG composition of the oil. Based on the TG groups, stepwise regression analysis showed that the areas of the disaturated, trisaturated, and triunsaturated TG peaks could predict the IV with a coefficient of determination (R ²) of 0.990. The regression based on the number of double bonds yielded a good regression equation with R ²=0.992. The important variables were the peak area of the fatty acids that contained zero, one, two, and three double bonds. This study concludes that the TG composition can be used to predict the IV of palm oil. The best prediction model is obtained by using the number of double bonds in the TG as the independent variable.     

Comparability and reliability of different techniques for the determination of phenolic compounds in virgin olive oil

Phenolic compounds represent a unique and functional part of the polar fraction of virgin olive oils. Many different approaches for the analysis of these compounds have been published, which has led to ambiguous results that are difficult to compare. In order to explain the controversial data reported in the literature, extraction techniques (solid‐phase extraction, SPE, and liquid‐liquid extraction, LLE), methods of analysis (HPLC and colorimetric assay) and quantification methods have been re‐investigated with genuine olive oil phenols. The optimized LLE system led to high recovery of the nine major olive oil phenolics (93%) and, in addition, was at least as good as the SPE technique in view of costs, solvent and sample consumption, and analysis time. SPE was shown to be problematic because of the selectivity towards the individual phenolics, particularly the aglycone‐type ones. The proposed LLE/HPLC method was compared with the traditional colorimetric assay (Folin‐Ciocalteu method) by analyzing 23 samples of virgin olive oils. A strong correlation between both methods has been found, suggesting that the colorimetric assay is reasonably valid for a rough prediction of the total phenolic content. In the literature, the level of phenolics is expressed in several different units (reference compound equivalents in case of colorimetric measurements and ppm in HPLC measurements). As these units can differ in orders of magnitude, it is necessary to convert the data to a common base before comparing or combining them.     

供氢剂辅助重油热改质技术研究进展

重油高黏度和高密度的特点给重油开采、集输和加工带来极大不便,一般都要先对其进行降黏处理。供氢热裂化是在传统减黏裂化基础上加入供氢剂,以改善减黏裂化加工深度不大、装置易生焦、产品安定性差等问题的一种高效重油改质降黏技术。文章首先介绍了重油管输技术基本类型,然后从供氢剂的供氢机理、供氢剂加入的作用、供氢剂的基本类型、供氢剂可供氢量的计算方法和供氢剂的运用等方面进行了综述。对于供氢剂的选择需要根据工艺条件和供氢剂性质等方面综合分析。指出在不生焦的前提下,尽可能提高改质苛刻度可有效提升重油改质效果,而影响生焦和抑制结焦的关键在于来自供氢剂的活泼氢能否及时封闭沥青质自由基。     

Combinatorial chemistry methods for coating development: VI. Correlation of high throughput screening methods with conventional measurement techniques

Combinatorial chemistry has proven to be a valuable tool for the development of new compounds. In the pharmaceutical industry, where combinatorial chemistry began, the approach has been instrumental in the high-speed development of new drugs. Due to the overwhelming success of the combinatorial methodology in the pharmaceutical industry, it has been recently applied to materials development. We have recently developed a combinatorial factory capable of preparing and evaluating on the order of 100 organic clear coatings in a day.

One of the most challenging aspects of the creation of the combinatorial factory was the development of the high throughput screening (HTS) methods for the primary coating properties of interest such as optical clarity, abrasion resistance, adhesion, and weatherability. For each property, an entirely new method was developed that allowed for rapid measurement of these properties on very small samples. This paper describes various aspects of the development of these novel measurement systems including the correlation of the HTS methods with conventional, industry standard measurement methods.     

Rapid methods for predicting the appearance of turbidity in sunflower oil and their comparison with cold tests

Two rapid turbidimetric methods have been applied to determine the content of wax in refined and refined-bleached sunflowerseed oils in the range of 0 to 120 ppm. Synthetic wax-oil mixtures were prepared to construct calibration plots. Turbidimetric results were compared with visual evaluation of these mixtures as well as of the industrial oils by an expert panel, during 2 wk, under cold-test (0°C) and tempering (15°C) conditions. Based on the standard AOCS cold-test, the visual turbidity threshold of these Argentine oils was under 40 ppm, a value significantly lower than that found in European cultivars. Also, while both types of industrial oils passed the cold-test, the refined oil developed cloudiness after tempering for 14 d, whereas the refined-bleached oil remained transparent. Because the calibration plots showed that the turbidity difference values, given by these fast methods, corresponded to wax contents that caused visible turbidity but fell into the nonsensitive region of the instrument, a simple standard addition technique was used to extend their sensitivity to these low wax contents. With this improvement, oils that contained more than 40 ppm of wax by fast turbidimetry, which can be expected to develop cloudiness on storage in the winter season, can be promptly identified, thus allowing any desired corrective action.     

Fabrication of hollow and porous polystyrene fibrous membranes by electrospinning combined with freeze-drying for oil removal from water

A novel method was proposed to fabricate hollow and surface porous polystyrene (PS) fibrous membranes for the removal of oil from water. Spinning solutions were prepared by using camphene and tetraethoxysilane (TEOS) as pore-forming agents, and hollow PS fibers with 100–400 nm pores on the surface were fabricated by electrospinning and freeze-drying. The distribution and volatilization of camphene and TEOS, as well as the drying behavior of solvents in high relative humidity, were important factors in forming the porous structure of PS fibers. The specific surface area of obtained PS fibrous membranes was twice that of conventional electrospun PS fibrous membranes and displayed superhydrophobic properties. Moreover, the large adsorption storage space was formed due to the hollow structure and porous surface of PS fibers. The maximum oil adsorption capacity of the porous PS fibrous membrane was 105.4 g g⁻¹, and was larger than that of the conventional PS fibrous membrane after repeated five times, thus making it a promising tool for oil spill cleanups. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47262.     

HPLC法测定樟脑丸中萘含量及与GC法的比较

用HPLC法测定樟脑丸中萘的含量,并与GC法进行了比较。结果表明,HPLC法所消耗的样品量最少仅为GC法的1/100~1/10;限于所取样品中萘的含量的条件,HPLC法测定下限为8.541×10-2μg。