Esters of 2- and 3-monochloropropane-1,2-diol (MCPD) are significative contaminants of processed edible oils used as foods or food ingredients. The aim of this study was to develop and validate a new method by GC-MS f...Esters of 2- and 3-monochloropropane-1,2-diol (MCPD) are significative contaminants of processed edible oils used as foods or food ingredients. The aim of this study was to develop and validate a new method by GC-MS for the simultaneous quantification of 2 and 3-MCPD esters in infant milk powder and edible vegetable oils. The developed protocol included fat fraction in infant milk powder and edible vegetable oils samples was extracted and treated with sodium methylate-methanol to cleave the ester bonds of the 2- and 3-MCPD esters, moreover, standard samples of deuterium isotope-labeled 2- and 3-MCPD palmitic acid double esters and stearic acid double esters were used as the internal standards. Furthermore, this method was validated when it was applied to food products, concrete manifestation in its good accuracy (the recovery of MCPD esters ranged from 86% to 114%), high sensitivity (the LOD of 3-MCPD and 2-MCPD esters were 0.025 and 0.020 mg/kg, LOQ were 0.075, 0.060 mg/kg, respectively) and satisfactory repeatability (RSD below 6.8%) for all analytes. In the 150 commercial edible vegetable oils and infant formula milk powder samples, we obtained a preliminary profile of MCPD ester contamination.展开更多
In this study, the electrorheological （ER） behavior of suspensions prepared from d50 = 2.4 lam talc powder, dispersed in insulating silicone oil （SO） medium was investigated. Sedimentation stabilities of suspensio...In this study, the electrorheological （ER） behavior of suspensions prepared from d50 = 2.4 lam talc powder, dispersed in insulating silicone oil （SO） medium was investigated. Sedimentation stabilities of suspensions （c = 5 wt%） prepared using these talc powder powders were determined to be 78 days. The ER activity of all the suspensions was observed to increase with increasing electric field strength, concentration and decreasing shear rate. The shear stress of talc powder suspensions increased linearly with increasing concentrations of the particles and with the applied electric field strength. Electric field viscosity of all the suspensions decreased sharply with increasing shear rate and showed a typical shear thinning non-Newtonian visco-elastic behavior. Effects of frequency on the ER activity of talc powder/SO system were also investigated.展开更多
Dried leaves of <i><span style="font-family:Verdana;">Eucalyptus</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span st...Dried leaves of <i><span style="font-family:Verdana;">Eucalyptus</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> were finely grinded and fractionated</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> by sieving into four granulometric classes (<100 μm, 100 - 200 μm, 200 - 355 μm and >355 μm). The obtained powder fractions were used for essential oil (EO) extraction by hydrodistillation and their phytochemical profile and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant activities were evaluated. The mother powder (unsieved powder) was used for comparison. Particle size exerted a significant influence (</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05) on the phytochemical composition and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant prop</span><span><span style="font-family:Verdana;">erties of the EOs. Comparatively, the mother powder had the highest contents of </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-pinene (55.6%), camphene (3.4%) and limonene (3.7%), while 1,8-cineole (26.6% and 22.4%), </span></span><span style="font-family:Verdana;">exo-fenchol (5.6% and 3.5%), </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-campholenol (4.2% and 3.4%), L-trans-pinocarveol (5.5% and 2.7%), L-borneol (12.6% and 6.8%) and </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-terpineol (16.4% and 7.6%) are the main compounds of EOs from the <100 μm and 100 - 200 μm fractions, respectively. The antioxidant activities of the EOs revealed higher radical-scavenging activities DPPH (90.62% and 70.46%) and ABTS (89.59% and 73.31%) for finer fractions (<100 μm and 100 - 200 μm, respectively). The best reducing power (36.15% and 34.27%) were also found in these finer powder fractions which improved by more than 2 times the value of mother powder (reducing power of 17.01%). These results suggest that grinding followed by sieve fractionation concentrates the majority of antioxidant phytochemicals in the EOs of the finer powder fractions of </span><i><span style="font-family:Verdana;">E.</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> leaves. Finer powders could be used as functional ingredients in food formulations for the management of chronic diseases.</span></span>展开更多
目的梳理中药炮制学中制霜法的定义以及英文翻译词,探讨其概念范围和英文翻译词的准确性。方法汇总分析包括中药炮制学教材在内的权威文献中制霜法的概念定义,及其英文翻译词。结果关于制霜法的定义、概念范围及英文翻译在不同文献中存...目的梳理中药炮制学中制霜法的定义以及英文翻译词,探讨其概念范围和英文翻译词的准确性。方法汇总分析包括中药炮制学教材在内的权威文献中制霜法的概念定义,及其英文翻译词。结果关于制霜法的定义、概念范围及英文翻译在不同文献中存在较大差异,易造成偏颇和混淆。结论制霜法应包括传统的去油制霜、渗析制霜、升华制霜、煎煮制霜4种,难以用单一英文词汇对应“制霜法”一词,根据中文“霜”字的含义和制霜法的中药炮制品性状,可将制霜法翻译为method of making frostlike powder。展开更多
文摘Esters of 2- and 3-monochloropropane-1,2-diol (MCPD) are significative contaminants of processed edible oils used as foods or food ingredients. The aim of this study was to develop and validate a new method by GC-MS for the simultaneous quantification of 2 and 3-MCPD esters in infant milk powder and edible vegetable oils. The developed protocol included fat fraction in infant milk powder and edible vegetable oils samples was extracted and treated with sodium methylate-methanol to cleave the ester bonds of the 2- and 3-MCPD esters, moreover, standard samples of deuterium isotope-labeled 2- and 3-MCPD palmitic acid double esters and stearic acid double esters were used as the internal standards. Furthermore, this method was validated when it was applied to food products, concrete manifestation in its good accuracy (the recovery of MCPD esters ranged from 86% to 114%), high sensitivity (the LOD of 3-MCPD and 2-MCPD esters were 0.025 and 0.020 mg/kg, LOQ were 0.075, 0.060 mg/kg, respectively) and satisfactory repeatability (RSD below 6.8%) for all analytes. In the 150 commercial edible vegetable oils and infant formula milk powder samples, we obtained a preliminary profile of MCPD ester contamination.
基金This work was supported by the Omya Mining Co of Istanbul and Harran University.
文摘In this study, the electrorheological （ER） behavior of suspensions prepared from d50 = 2.4 lam talc powder, dispersed in insulating silicone oil （SO） medium was investigated. Sedimentation stabilities of suspensions （c = 5 wt%） prepared using these talc powder powders were determined to be 78 days. The ER activity of all the suspensions was observed to increase with increasing electric field strength, concentration and decreasing shear rate. The shear stress of talc powder suspensions increased linearly with increasing concentrations of the particles and with the applied electric field strength. Electric field viscosity of all the suspensions decreased sharply with increasing shear rate and showed a typical shear thinning non-Newtonian visco-elastic behavior. Effects of frequency on the ER activity of talc powder/SO system were also investigated.
文摘Dried leaves of <i><span style="font-family:Verdana;">Eucalyptus</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> were finely grinded and fractionated</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> by sieving into four granulometric classes (<100 μm, 100 - 200 μm, 200 - 355 μm and >355 μm). The obtained powder fractions were used for essential oil (EO) extraction by hydrodistillation and their phytochemical profile and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant activities were evaluated. The mother powder (unsieved powder) was used for comparison. Particle size exerted a significant influence (</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05) on the phytochemical composition and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant prop</span><span><span style="font-family:Verdana;">erties of the EOs. Comparatively, the mother powder had the highest contents of </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-pinene (55.6%), camphene (3.4%) and limonene (3.7%), while 1,8-cineole (26.6% and 22.4%), </span></span><span style="font-family:Verdana;">exo-fenchol (5.6% and 3.5%), </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-campholenol (4.2% and 3.4%), L-trans-pinocarveol (5.5% and 2.7%), L-borneol (12.6% and 6.8%) and </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-terpineol (16.4% and 7.6%) are the main compounds of EOs from the <100 μm and 100 - 200 μm fractions, respectively. The antioxidant activities of the EOs revealed higher radical-scavenging activities DPPH (90.62% and 70.46%) and ABTS (89.59% and 73.31%) for finer fractions (<100 μm and 100 - 200 μm, respectively). The best reducing power (36.15% and 34.27%) were also found in these finer powder fractions which improved by more than 2 times the value of mother powder (reducing power of 17.01%). These results suggest that grinding followed by sieve fractionation concentrates the majority of antioxidant phytochemicals in the EOs of the finer powder fractions of </span><i><span style="font-family:Verdana;">E.</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> leaves. Finer powders could be used as functional ingredients in food formulations for the management of chronic diseases.</span></span>
基金supported by grants from the National Key Research and Development Program on the Modernization of Traditional Chinese Medicine (2022YFC3502104 to R.L.and R.S.)the recipient of a Research Career Scientist Award from the Department of Veterans Affairs (IK6BX004477)。
文摘目的梳理中药炮制学中制霜法的定义以及英文翻译词,探讨其概念范围和英文翻译词的准确性。方法汇总分析包括中药炮制学教材在内的权威文献中制霜法的概念定义,及其英文翻译词。结果关于制霜法的定义、概念范围及英文翻译在不同文献中存在较大差异,易造成偏颇和混淆。结论制霜法应包括传统的去油制霜、渗析制霜、升华制霜、煎煮制霜4种,难以用单一英文词汇对应“制霜法”一词,根据中文“霜”字的含义和制霜法的中药炮制品性状,可将制霜法翻译为method of making frostlike powder。
