The kinetic mechanism for the preparation of silymarin from milk thistle seeds was studied during the microwave-assisted extraction （MAE） process. The results showed that the transfer rate of silymarin from milk thi...The kinetic mechanism for the preparation of silymarin from milk thistle seeds was studied during the microwave-assisted extraction （MAE） process. The results showed that the transfer rate of silymarin from milk thistle seeds increased with the microwave output power and temperature during MAE processing. The apparent extraction rate constant k （s-1） was 1.2028×10-2 , 1.2248×10-2 , and 1.2485×10-2 , and diffusion coefficient D （m2·s-1 ） was 4.21×10-10, 4.29×10-10 , and 4.37×10-10 at the microwave temperatures of 383, 393, and 403 K, respectively, in the silymarin MAE process. With the help of scanning electron microscopy （SEM）, the microstructures of the samples extracted by MAE were observed. The results revealed that the increased efficiency and rate of MAE of silymarin could be attributed mainly to the subsequent cell change resulting from superheating effects during MAE.展开更多
In this work,xanthophylls were extracted from Marigold using supercritical CO_(2).A response surface experimental design was used to optimize operating conditions for extraction pressure(22-30 MPa),extraction temperat...In this work,xanthophylls were extracted from Marigold using supercritical CO_(2).A response surface experimental design was used to optimize operating conditions for extraction pressure(22-30 MPa),extraction temperature(50-60℃),CO_(2) flow rate(9-15 kg/h).The maximum concentration of xanthophyll in extracts was determined to be 35.8%by high performance liquid chromatography(HPLC),and optimum xanthophylls extraction was obtained at 55℃,26 MPa and 12 kg/h.The optimization results demonstrated that for xanthophylls extraction,all variables(temperature,pressure and CO_(2) flow rate)were to be the influential variables,with the statistical significant effect p-value was smaller than 0.05.展开更多
Tertiary amines dissolved in diluents are attractive extractants for recovery of carboxylic acids from dilute aqueous solutions. Quantitative Fourier transform infrared (FTIR) analysis of organic solutions containin...Tertiary amines dissolved in diluents are attractive extractants for recovery of carboxylic acids from dilute aqueous solutions. Quantitative Fourier transform infrared (FTIR) analysis of organic solutions containing various concentrations of trioctylamine (TOA), n octanol, and propionic acid was carried out, and liquid liquid equilibrium was investigated using TOA in n octanol as the solvent. The fraction of ion pair association between TOA and propionic acid in the organic phase was quantitatively determined by FTIR. The apparent reactive extraction equilibrium constant, K 11 , was calculated using the quantitative FTIR spectrum and the equilibrium data. The results show that the fraction of ion pair association depends on diluent concentration, complex dissolution for propionic acid, and association between TOA and propionic acid. The K 11 based on quantitative FTIR has the same loading trend as that from the equilibrium data.展开更多
基金Supported by the National Natural Science Foundation of China(31071579)the Key Program of the Natural Science Foundation of Heilongjiang Province of China(ZD201013)the Key Project of Education Department of Heilongjiang Province of China(125212003)
文摘The kinetic mechanism for the preparation of silymarin from milk thistle seeds was studied during the microwave-assisted extraction （MAE） process. The results showed that the transfer rate of silymarin from milk thistle seeds increased with the microwave output power and temperature during MAE processing. The apparent extraction rate constant k （s-1） was 1.2028×10-2 , 1.2248×10-2 , and 1.2485×10-2 , and diffusion coefficient D （m2·s-1 ） was 4.21×10-10, 4.29×10-10 , and 4.37×10-10 at the microwave temperatures of 383, 393, and 403 K, respectively, in the silymarin MAE process. With the help of scanning electron microscopy （SEM）, the microstructures of the samples extracted by MAE were observed. The results revealed that the increased efficiency and rate of MAE of silymarin could be attributed mainly to the subsequent cell change resulting from superheating effects during MAE.
基金supported by Shandong Provincial Education Department Plan for Scientific and Technology Development(J08LF05)。
文摘In this work,xanthophylls were extracted from Marigold using supercritical CO_(2).A response surface experimental design was used to optimize operating conditions for extraction pressure(22-30 MPa),extraction temperature(50-60℃),CO_(2) flow rate(9-15 kg/h).The maximum concentration of xanthophyll in extracts was determined to be 35.8%by high performance liquid chromatography(HPLC),and optimum xanthophylls extraction was obtained at 55℃,26 MPa and 12 kg/h.The optimization results demonstrated that for xanthophylls extraction,all variables(temperature,pressure and CO_(2) flow rate)were to be the influential variables,with the statistical significant effect p-value was smaller than 0.05.
基金the National Natural Science Foundationof China(No. 2 9836 130 )
文摘Tertiary amines dissolved in diluents are attractive extractants for recovery of carboxylic acids from dilute aqueous solutions. Quantitative Fourier transform infrared (FTIR) analysis of organic solutions containing various concentrations of trioctylamine (TOA), n octanol, and propionic acid was carried out, and liquid liquid equilibrium was investigated using TOA in n octanol as the solvent. The fraction of ion pair association between TOA and propionic acid in the organic phase was quantitatively determined by FTIR. The apparent reactive extraction equilibrium constant, K 11 , was calculated using the quantitative FTIR spectrum and the equilibrium data. The results show that the fraction of ion pair association depends on diluent concentration, complex dissolution for propionic acid, and association between TOA and propionic acid. The K 11 based on quantitative FTIR has the same loading trend as that from the equilibrium data.
