Fat and wax (F&W) compounds have to be removed from raw plant materials before pectin and oligosaccharides (OS) can be isolated. In this research, the mixtures of F&W, and polyphenols and sugars were firstly s...Fat and wax (F&W) compounds have to be removed from raw plant materials before pectin and oligosaccharides (OS) can be isolated. In this research, the mixtures of F&W, and polyphenols and sugars were firstly separated from the roots of Eremurus hissaricus (Eremurus h.), and the byproducts of fruit processing, such as apple pomace, sunflower head residues, and grape seeds, etc., using hexane/ethanol or ethyl acetate as leaching reagents at various ratios of liquid to solid. The resultant mixtures were then extracted with an ethanol/water mixture to separate F&W from polyphenols and sugars. It was found that the F&W yield decreased in the sequence of apricot > apple > sunflower head residues > peach > pumpkin with 21.84% in apricot as the highest number. The amount of alcohol-water soluble compounds (AWSC), mainly polyphenols and sugars, decreased in the sequence of peach > sunflower head residues > apricot > pumpkin > apple. No inter-dependence of AWSC and F&W was identified.展开更多
Dimethylsulfoxide(DMSO)extraction is commonly used to study the chemical structures of orig-inal xylan in the plant cell wall,since the DMSO can preserve the original structure of the xylan as much as possible during ...Dimethylsulfoxide(DMSO)extraction is commonly used to study the chemical structures of orig-inal xylan in the plant cell wall,since the DMSO can preserve the original structure of the xylan as much as possible during the extracting process.In addition,the DMSO-extracted xylans have unique properties allowing their potential applications in emulsifying or filming materials.How-ever,the yield of DMSO-extracted xylan is always low and the effects of different DMSO extraction conditions on the chemical compositions of xylan have not been fully studied,which greatly hin-ders its researches and applications.In this study,we have found that extensive delignification before DMSO extraction results in destruction of lignin-carbohydrate complex(LCC),leading to xylan yield and xylose unit content increased by up to 220%and 20%,respectively.Tert-butanol washing of the holocellulose can further increase the DMSO extracted xylan yield by∼10%.The yield of xylan extracted by the DMSO at 80°C for 7 h was obviously higher than that at room temperature for 3 d by 30%-40%.Thermal analysis showed that the xylans extracted at differ-ent conditions had thermal stability without obvious differences.The results indicate that the DMSO-extracted xylan with a high yield,a high purity and a high degree of acetylation can be ex-tracted at a high delignification level,a high reaction temperature and a short reaction time.This study is of great significance for studying xylan structure-property relationships and promoting the applications of DMSO-extracted xylan.展开更多
文摘Fat and wax (F&W) compounds have to be removed from raw plant materials before pectin and oligosaccharides (OS) can be isolated. In this research, the mixtures of F&W, and polyphenols and sugars were firstly separated from the roots of Eremurus hissaricus (Eremurus h.), and the byproducts of fruit processing, such as apple pomace, sunflower head residues, and grape seeds, etc., using hexane/ethanol or ethyl acetate as leaching reagents at various ratios of liquid to solid. The resultant mixtures were then extracted with an ethanol/water mixture to separate F&W from polyphenols and sugars. It was found that the F&W yield decreased in the sequence of apricot > apple > sunflower head residues > peach > pumpkin with 21.84% in apricot as the highest number. The amount of alcohol-water soluble compounds (AWSC), mainly polyphenols and sugars, decreased in the sequence of peach > sunflower head residues > apricot > pumpkin > apple. No inter-dependence of AWSC and F&W was identified.
基金supported by Natural Science Foundation of Guangdong Province(No.2020A1515011021).
文摘Dimethylsulfoxide(DMSO)extraction is commonly used to study the chemical structures of orig-inal xylan in the plant cell wall,since the DMSO can preserve the original structure of the xylan as much as possible during the extracting process.In addition,the DMSO-extracted xylans have unique properties allowing their potential applications in emulsifying or filming materials.How-ever,the yield of DMSO-extracted xylan is always low and the effects of different DMSO extraction conditions on the chemical compositions of xylan have not been fully studied,which greatly hin-ders its researches and applications.In this study,we have found that extensive delignification before DMSO extraction results in destruction of lignin-carbohydrate complex(LCC),leading to xylan yield and xylose unit content increased by up to 220%and 20%,respectively.Tert-butanol washing of the holocellulose can further increase the DMSO extracted xylan yield by∼10%.The yield of xylan extracted by the DMSO at 80°C for 7 h was obviously higher than that at room temperature for 3 d by 30%-40%.Thermal analysis showed that the xylans extracted at differ-ent conditions had thermal stability without obvious differences.The results indicate that the DMSO-extracted xylan with a high yield,a high purity and a high degree of acetylation can be ex-tracted at a high delignification level,a high reaction temperature and a short reaction time.This study is of great significance for studying xylan structure-property relationships and promoting the applications of DMSO-extracted xylan.
