method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the ...method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane （volume ratio of 2 ： 1）, the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.展开更多
[Objective] This study aimed to investigate the optimal condition for extrac- tion of ellagic acid from pomegranate peels. [Method] With ellagic acid yield as an indicator, ultrasound extraction method was adopted to ...[Objective] This study aimed to investigate the optimal condition for extrac- tion of ellagic acid from pomegranate peels. [Method] With ellagic acid yield as an indicator, ultrasound extraction method was adopted to extract the ellagic acid from pomegranate peels, and the concentration of ellagic acid was measured by using ul- traviolet spectrophotometry; L9（34） orthogonal experiment was designed with four fac- tors at three levels, to investigate the effect of extraction temperature, extraction du- ration, solid-liquid ratio and ultrasound power on extraction rate of ellagic acid. [Re- sult] The optimal extraction condition for ellagic acid is extraction temperature of 30 ~C, solid-liquid ratio of 1：200, extraction duration of 20 min, and ultrasound power of 50 W. The relationship between primary and secondary factors affecting experimental indicators was solid-liquid ratio 〉 extraction duration 〉 ultrasound power 〉 extraction temperature. [Conclusion] Solid-liquid ratio has the maximum effect on extraction rate of ellagic acid. The ellagic acid extraction technology identified in this study is rea- sonable and feasible.展开更多
Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid-liquid extraction model has been established to analyze and discuss on multi-stage centrifuga...Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid-liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of4-nitrobenzene glycine （PGL） enantiomers. The influence of phase ratio, extractant concentra- tion, and PFff concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PFff concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeo （equal enantiomeric excess） can reach to 99%展开更多
基金Supported by the Fundamental Research Funds for the Central Universities （FRF-AS-10-001B） and the National Natural Science Foundation of China （11071013）.
文摘method of extracting astaxanthin from Phaffia rhodozyma with various solvents after acid washing was investigated. The extraction efficiency was distinctly increased after acid washing of P. rhodozyma cells. When the concentration of HCl was 0.4 mol.L^-1, the highest extraction efficiency of astaxanthin was achieved which was about three times higher than the control. Acetone or benzene as single polar or non-polar solvent was the most ef- fective solvent in our research. With a combination of isopropanol and n-hexane （volume ratio of 2 ： 1）, the maxi- mal extraction efficiency was achieved, approximately 60% higher than that obtained with a single solvent. The liquid-solid ratio and the extracting time were also optimized. Under the optimum extraction conditions, the extraction yield of astaxanthin exceeded 98%.
基金Supported by College-level Special Fund of Sichuan Agricultural University(06070904)~~
文摘[Objective] This study aimed to investigate the optimal condition for extrac- tion of ellagic acid from pomegranate peels. [Method] With ellagic acid yield as an indicator, ultrasound extraction method was adopted to extract the ellagic acid from pomegranate peels, and the concentration of ellagic acid was measured by using ul- traviolet spectrophotometry; L9（34） orthogonal experiment was designed with four fac- tors at three levels, to investigate the effect of extraction temperature, extraction du- ration, solid-liquid ratio and ultrasound power on extraction rate of ellagic acid. [Re- sult] The optimal extraction condition for ellagic acid is extraction temperature of 30 ~C, solid-liquid ratio of 1：200, extraction duration of 20 min, and ultrasound power of 50 W. The relationship between primary and secondary factors affecting experimental indicators was solid-liquid ratio 〉 extraction duration 〉 ultrasound power 〉 extraction temperature. [Conclusion] Solid-liquid ratio has the maximum effect on extraction rate of ellagic acid. The ellagic acid extraction technology identified in this study is rea- sonable and feasible.
基金Supported by the National Natural Science Foundation of China(21176062)the Natural Science Foundation of Hunan Province(12JJ2007)+2 种基金Scientific Research Fund of Hunan Provincial Education Department(12B053)Science and Technology Planning Project of Hunan Province(2012GK3107)Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
文摘Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid-liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of4-nitrobenzene glycine （PGL） enantiomers. The influence of phase ratio, extractant concentra- tion, and PFff concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PFff concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeo （equal enantiomeric excess） can reach to 99%
