Separation of Triacylglycerol Species from Interesterified Oils by High-Performance Liquid Chromatography

Using a 1,3-regioselective lipase as a catalyst, soybean oil and olive oil were interesterified with the short-chain triacylglycerol tributyrin (1,2,3-tributyrylglycerol) to produce mixtures of structured triacylglycerols (SL-TAG). The SL-TAG were purified by column chromatography and analyzed by both normal-phase (silica column; NP_SIL) and reversed-phase [octadecyl silane (ODS) column] high-performance liquid chromatography (HPLC). Individual SL-TAG molecular species were detected by evaporative light-scattering detection, and characterized by mass spectrometry. NP_SIL HPLC successfully separated the newly synthesized SL-TAG into two groups of TAG: one composed of one butyryl group and two long-chain fatty acyl groups (from soybean or olive oil); the second was composed of two butyryl groups and one long-chain fatty acyl group. The SL-TAG species were further analyzed by reversed-phase HPLC which gave a more detailed separation of the TAG species present in the two SL-TAG.     

STD工控机电气成套装置的应用与升级

总结了用STD总线工业控制计算机(以下简称为STD工控机)构成的电气自动化成套装置在研制、开发及现场实际商业运行期所积累的经验,并根据市场预测以及目前工控机发展动态,结合微机继电保护的开发,提出了电气自动化成套装置设计的最佳解决方案.     

Critical Ratios for structural analysis of triacylglycerols using mass spectrometry

Recent developments have finally allowed fragment behaviors using APCI‐MS to be elucidated after twenty years of literature reports. Critical Ratios have been defined that correspond to various aspects of triacylglycerol (TAG) analysis, from overall degree of unsaturation to localization of fatty acids on the glycerol backbone (regioisomers), to grouping of unsaturated fatty acids. The same ratios also constitute a compact library of TAG mass spectra.     

Supercritical CO2 oil extraction from Chinese star anise seed and simultaneous compositional analysis using HPLC by fluorescence detection and online atmospheric CI‐MS identification

BACKGROUND: Supercritical CO₂ was utilised to extract Chinese star anise seed oil (CSASO), and a three‐level Box–Behnken factorial design from response surface methodology was applied to optimise the extraction conditions, including pressure, temperature and amount of modifier (ethanol). The compositional analysis of fatty acids in CSASO was performed by HPLC with fluorescence detection using 2‐(11H‐benzo[a]carbazol‐11‐yl)‐ethyl‐4‐methylbenzenesulfonate (BCETS) as labelling reagent. Identification was carried out by online atmospheric chemical ionisation–mass spectrometry. RESULTS: The optimum extraction conditions were as follows: extraction pressure, 27.72 MPa, extraction temperature, 46.22 °C, and amount of modifier, 8.58 vol.%. The experimental result showed that the maximum extraction yield was 25.31 ± 0.22% (w/w) under the conditions proposed. The compositional analysis indicated that CSASO mainly contained C18:2, C18:1, C18:3, C20:4, C16, C18 and C20 fatty acids. CONCLUSION: In this study, a fast, simple and high‐efficiency supercritical technique for extracting oil from Chinese star anise seed was developed. Simultaneous determination of fatty acids in CSASO using BCETS as the labelling reagent with HPLC fluorescence detection and online mass spectroscopy identification has been successfully achieved. Copyright © 2010 Society of Chemical Industry     

Volatile profile of Stilton cheeses: Differences between zones within a cheese and dairies

Penicillium roqueforti grows and sporulates during the ripening period of blue cheeses and it is responsible for the typical blue cheese flavour formation. However, the sporulation (blue veins) is taking place in a fraction of the total mass and the cheese matrix is highly heterogeneous. The aroma profiles regarding the three different sections of Stilton cheese, blue veins outer crust and white core, were studied using solvent extraction GC–MS, a headspace GC–MS technique (SPME GC–MS) and direct headspace analysis (APCI–MS). Cheeses from different dairies were analysed, allowing the question of how similar are different batches of cheese from different dairies.     

Rapid Analysis of Volatile Release from Powders using Dynamic Vapor Sorption Atmospheric Pressure Chemical Ionization Mass Spectrometry

ABSTRACT: It is hypothesized that a dynamic vapor sorption instrument coupled with an atmospheric pressure chemical ionization mass spectrometer (APCI-MS) may be useful for rapid analysis of volatile release from dry food materials. Preliminary data from a related system (Vapor Generator Instrument-APCI-MS) was used to monitor release of volatiles from spray-dried food polymers as a function of relative humidity at 40 °C. The system demonstrated differences in volatile release as a function of volatile compound, relative humidity, and food polymer. Comparison of these data with data collected using traditional shelf life study methodologies, and concerns for the ability of the method to accurately reflect time-dependent changes are discussed.     

Effects of Ethanol,Carbonation and Hop Acids on Volatile Delivery in a Model Beer System

A model beer was created to investigate the effects of ethanol, carbonation and hop acids on volatile release (ethyl acetate, isoamyl alcohol and phenethyl alcohol) using both headspace analysis and in‐nose measurement during consumption. None of the factors were found to impact on equilibrium headspace partitioning, however headspace sampling after short term decanting revealed minor and compound specific effects of each of the components. When measured in‐vivo, hop acids had no significant effect on volatile delivery; however ethanol significantly increased the delivery of volatiles during consumption. This increase was sustained throughout the release profile. Carbonation was found to increase the release of ethyl acetate and isoamyl alcohol during the first release peak after swallowing, but had no significant effect on phenethyl alcohol. Furthermore, ethyl acetate was increased by carbonation in the second peak after swallowing, but this effect was not found to be persistent in subsequent peaks. These results indicate a trend between the compound's air‐water partition coefficient and the effects of carbonation in‐vivo. The effects of ethanol and carbonation seemed to be independent and therefore an additive effect is possible. This study highlights the difference between data collected by headspace and in‐vivo means.     

Naturally-occurring folates in foods: Method development and analysis using liquid chromatography–tandem mass spectrometry (LC–MS/MS)

An accurate method for detecting and quantifying both synthetic (folic acid) and naturally-occurring folates in foods is described. A system capable of analysing the five most commonly occurring folates (pteroylglutamic acid, 5-methyltetrahydrofolate, tetrahydrofolate, 10-formylfolate and 5-formyltetrahydrofolate) in 20 min using liquid chromatography–tandem mass spectrometry (LC–MS/MS) was developed. Quantification of folates was performed using ¹³C labelled internal standards. This paper outlines the development of a comparatively fast LC–MS/MS method, method validation using commercially available folate standards and establishment of the method’s suitability for quantification using selected reaction monitoring (SRM) mass spectrometry. The application of the system was verified by analysing several certified reference materials and comparing results with certified values as determined by microbiological assay. LC–MS/MS promises to be an ideal tool for the quantitative analysis of folates in food.     

IEC104规约应用协议控制信息测试内容及方法研究

为规范化电力系统中广泛使用的IEC104规约应用协议控制信息(APCI)测试内容及方法,简化测试流程,提高测试效率,介绍了IEC104规约APCI测试的内容,包括基本APCI测试、启/停数据传输测试、“测试过程”测试、防止报文丢失与报文重复传送的测试、K/W参数测试、超时时间参数测试,并针对各部分测试内容进行了详细的研究和阐述,分别提供了具体的测试方法和步骤,在测试方法和步骤中提供了独特的思路和见解.应用结果表明,该方法对IEC104规约APCI测试具有参考价值,对使用类似机制规约的测试亦具有一定的参考价值.