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Propolis has attracted commercial interest as a good source of flavonoids and terpenes. This study applied a two-step sequential extraction process, consisting of a super/subcritical extraction step and an ultrasound-assisted ethanol extraction (UAEE) step to raw propolis. The yields of propolis extracts and the extraction rates of flavonoids and terpenes have been used to evaluate the different extraction methods. The results have indicated that the yields of propolis extracts, total flavonoids, and eight characteristic flavonoids from subcritical fluid extraction (SFE) were much higher than the yields from supercritical CO2 extraction (SC-CO2), especially when the subcritical mixed-fluids extraction (SMFE) and subcritical subsection extraction (SSE) techniques were used. However, the extraction rate of terpenes from subcritical propane extraction (SPE) was obviously higher than the rates obtained with the other techniques. Furthermore, compared with the ethanol extracts of the super/subcritical raffinates, there is still a considerable amount of flavonoids in SPE raffinates (at 114.48 mg/g raffinate). SMFE and SSE can achieve efficient extraction of flavonoids, but synchronous extraction of terpenes and flavonoids can be achieved via two-step sequential extraction with SPE and UAEE. These findings provide a solid theoretical foundation for the effective extraction of propolis. [ABSTRACT FROM AUTHOR]

Effects of subcritical solvents (propane, dimethyl ether (DME), and their 1:1 mixed solvents) and extraction temperatures (30 to 60 °C) on oat lipids and phospholipid extraction are investigated using the Patricelli kinetic model and thermodynamic analysis. The mass‐transfer coefficient (k1) of the washing stage is approximately ten times higher than the diffusion stage under different solvents and temperature conditions. Compared with the subcritical propane and mixed solvents, the maximum equilibrium yield of oat lipids and phospholipids are obtained using subcritical DME. With increased extraction temperature from 30 to 60 °C, the equilibrium yield of phospholipids increases, whereas the equilibrium yield of lipids increases to 5.30% at 40 °C and then decreases. The enthalpy and entropy changes for phospholipid extraction are higher than those for lipid extraction. The Gibbs free energy for phospholipid extraction rapidly decreases with increased extraction temperature. A loose endosperm of oat grain is observed, and the concentration of lipids in the bran layer is higher than in the endosperm. In conclusion, kinetic and thermodynamic analyses statistically prove that DME is more effective than propane and mixes solvents for extracting lipids and phospholipids from oat flakes, and that phospholipid extraction strongly depends on temperature. Practical Application: The removal of lipids and phospholipids benefits oat‐product processing and storage. However, traditional industrial n‐hexane extraction usually requires a high‐temperature process for solute–solvent separation, which may result in low quality of the meal. Subcritical‐fluid extraction is a rising technology for lipid and phospholipid extraction. The yields of lipids and phospholipids using subcritical dimethyl ether (DME) is higher than those propane and its mixed solvents. The temperature dependence of phospholipid extraction is more active than that of lipid extraction. Thus, use of subcritical DME is a promising lipid‐extraction technique to obtain solvent-free oat oil and high‐quality defatted oat flour with potential application in the oat‐processing industry. [ABSTRACT FROM AUTHOR]

Areca nut ( Areca catechu L.) is commonly consumed as a chewing food in the Asian region. However, the investigations into the components of areca nut are limited. In this study, we have developed an approach that combines mass spectrometry with feature-based molecular network to explore the chemical characteristics of the areca nut. In comparison to the conventional method, this technique demonstrates a superior capability in annotating unknown compounds present in areca nut. We annotated a total of 52 compounds, including one potential previously unreported alkaloid, one carbohydrate, and one phenol and confirmed the presence of 7 of them by comparing with commercial standards. The validated method was used to evaluate chemical features of areca nut at different growth stages, annotating 25 compounds as potential biomarkers for distinguishing areca nut growth stages. Therefore, this approach offers a rapid and accurate method for the component analysis of areca nut.

Background: Traditional survey methods may cause refusals to respond or untruthful replies when encounter the sensitive questions. The Randomized Response Technique (RRT) is designed to decrease social desirability bias and obtain reliable estimates. This study aimed to apply these new methods on the sensitive questions survey., Methods: Simmons model was applied in the survey of issues relevant to commercial sex among men who have sex with men (MSM) in Beijing, China. Stratified two-stage sampling and stratified random sampling were applied., Results: During July to December 2010 in Beijing, the commercial sex proportion among MSM was 0.051(95% CI: 0.017, 0.085), its estimated variance was 3.01×10(-4). The last male condom use rate during commercial sex was 0.778(95% CI: 0.746, 0.810), its estimated variance was 2.6×10(-4)., Conclusion: We have introduced new approaches for the sensitive question survey among MSM. The new approaches are proved to be reliable and valid.

A method was established for the determination of 6 zearalenonic compounds (alpha-zearalanol, beta-zearalanol, alpha-zearalenol, beta-zearalenol, zearalanone and zearalenone) in grain and its products based on solid-phase extraction coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The samples was extracted by 84% (v/v) acetonitrile-water solution and further purified by an ENVI-Carb graphite carbon black (GCB) cartridge, which was eluted by 6 mL dichloromethane-methanol (7:3, v/v) solution. The target compounds were assayed by UPLC-MS/MS. The chromatographic separation was performed on an ACQUITY UPLC BEH C18 column with gradient elution using acetonitrile and water as mobile phases. The mass spectrometric acquisitions were carried out by means of multiple reaction monitoring (MRM) in electrospray negative ionization mode. The good linearities (R2 > 0.99) were achieved for the 6 compounds over the range of 0.1-50 microg/L based on the internal standard calibration of a-zearalenol-d4. The detection limits of the method were 0.1-0.2 microg/kg. The mean recoveries of the 6 target compounds (spiked at three concentration levels) ranged from 79.9% to 104.0%, with the relative standard deviations (RSDs) no more than 10%. It has been applied in the analysis of grain and related products taken from Beijing. As a result, zearalenone presented a highest detectable frequency, with a concentration range of 0.42-220.7 microg/kg. In addition, alpha-zearalenol and beta-zearalenol were also detected in this survey. This proposed method is simple, sensitive, reproducible, and complied with the regulations for the determination of trace contaminants residues in food matrices.