[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid rati...[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid ratio and pH value on the extraction yield of polysaccharide from pumpkin. [Method] The best enzyme ratio and extraction conditions for complex enzymes extraction were determined through orthogonal tests. Scavenging ·OH and O-2 activities of pumpkin polysaccharides were also investigated by salicylic acid and improved self-oxidation of o-pheno methods respectively. [Results] The results showed that the biggest extraction yield of polysaccharide from pumpkin can be got when adding 1% cellulose enzyme,1.5% pectinase,1.0% papain and Na2HPO4-citric acid buffer solution (pH was 4.6),and oscillating for 30 min under water at 40 ℃ with the solid-liquid ratio of 1:30. In addition,pumpkin polysaccharides had a strong activity of eliminating ·OH,but very weak activity to scavenge O-2. [Conclusion] This study provided basic data for research and application of Pumpkin polysaccharide.展开更多
Self-cleaning surfaces have received a great deal of attention recently,both in theoretical studies and commercial applications.The self-cleaning surface of lotus leaf is hydrophobic and rough,showing a micro-and nano...Self-cleaning surfaces have received a great deal of attention recently,both in theoretical studies and commercial applications.The self-cleaning surface of lotus leaf is hydrophobic and rough,showing a micro-and nano-scale morphology.The micro-reliefs of lotus leaf were mimicked using polyvinylidene fluoride(PVDF)film and nano-scale peaks on the top of the micro-reliefs were implemented by the reaction between methyltrichlorosilane and the reactive groups of PVDF film treated by oxygen plasma.A lotus-leaf-like surface of the PVDF film was clearly observed by scanning electronic microscopy(SEM)and atomic force microscope(AFM).Elemental composition analysis by X-ray photoelectron spectroscopy(XPS)revealed that the material of the nanostructure of PVDF film was polymethylsiloxane.The superhydrophobic property of the mimicked self-cleaning surface was validated by the water contact angle and sliding angle on the lotus-leaf-like PVDF film,which were 156.6° and 4°,respectively.In this case,water droplets can easily move across the PVDF film surface,carrying dirt particles away,leaving no contamination.展开更多
基金Supported by the Key Scientific and Technological Project of Henan Province (102102110157)the Scientific Research Found Project of Henan University of Urban Construction (2010JZD008)~~
文摘[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid ratio and pH value on the extraction yield of polysaccharide from pumpkin. [Method] The best enzyme ratio and extraction conditions for complex enzymes extraction were determined through orthogonal tests. Scavenging ·OH and O-2 activities of pumpkin polysaccharides were also investigated by salicylic acid and improved self-oxidation of o-pheno methods respectively. [Results] The results showed that the biggest extraction yield of polysaccharide from pumpkin can be got when adding 1% cellulose enzyme,1.5% pectinase,1.0% papain and Na2HPO4-citric acid buffer solution (pH was 4.6),and oscillating for 30 min under water at 40 ℃ with the solid-liquid ratio of 1:30. In addition,pumpkin polysaccharides had a strong activity of eliminating ·OH,but very weak activity to scavenge O-2. [Conclusion] This study provided basic data for research and application of Pumpkin polysaccharide.
基金Tianjin Municipal Science and Technology Commission,China(No.06YFJZJC14802)
文摘Self-cleaning surfaces have received a great deal of attention recently,both in theoretical studies and commercial applications.The self-cleaning surface of lotus leaf is hydrophobic and rough,showing a micro-and nano-scale morphology.The micro-reliefs of lotus leaf were mimicked using polyvinylidene fluoride(PVDF)film and nano-scale peaks on the top of the micro-reliefs were implemented by the reaction between methyltrichlorosilane and the reactive groups of PVDF film treated by oxygen plasma.A lotus-leaf-like surface of the PVDF film was clearly observed by scanning electronic microscopy(SEM)and atomic force microscope(AFM).Elemental composition analysis by X-ray photoelectron spectroscopy(XPS)revealed that the material of the nanostructure of PVDF film was polymethylsiloxane.The superhydrophobic property of the mimicked self-cleaning surface was validated by the water contact angle and sliding angle on the lotus-leaf-like PVDF film,which were 156.6° and 4°,respectively.In this case,water droplets can easily move across the PVDF film surface,carrying dirt particles away,leaving no contamination.
