Xylooligosaccharides(XOS)are mainly derived from lignocellulosic materials,such as rice husk,corn cobs,straw,wheat bran,wheat straw and other grain by-products.XOS have become one of the functional oligosaccharides of...Xylooligosaccharides(XOS)are mainly derived from lignocellulosic materials,such as rice husk,corn cobs,straw,wheat bran,wheat straw and other grain by-products.XOS have become one of the functional oligosaccharides of great concern at home and abroad due to their beneficial functional properties,such as low calorie,high stability,poor digestibility and high performance in proliferating probiotics.At present,the XOS extraction methods from grain byproducts mainly include autohydrolysis,acidolysis and enzymolysis.Among them,autohydrolysis has high requirements for equipment for achieving higher extraction rate and higher purity of products;and acidolysis can cause environmental pollution due to the usage of harmful reagents.Enzymolysis is the most common method for the production of XOS because of its high convenience,high efficiency and no pollution;and the widely used enzyme is the xylanase from Aspergillus niger.Current researches have showed that XOS can be utilized by probiotics such as Bifidobacteria and Lactobacillus to exert prebiotic effects,such as optimizing intestinal flora,promoting intestinal health,improving intestinal barrier,enhancing immune function,improving antioxidant capacity and so on.However,XOS extracted from the grain byproducts contain a large amount of impurities,which limits their industrial application and makes it dif-ficult to control the product quality.Therefore,XOS refining,separation and purification has become the key to their subsequent industrial application.This paper reviewed the current status of XOS extraction technologies from various grain by-products,and also summarized the prebiotic effect of XOS to provide reference for industrial production of XOS and its wide application in prebiotics market,thereby facilitating utilization and development of grain byproducts.展开更多
In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system o...In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system on the degradation of methyl orange（MO） were explored.The heterostructured Ag/TiO2 nanocomposite was achieved via decorating the Ag quantum dots（QDs） on the commercially available TiO_2catalyst（P25） through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of（200）,（220） and（311）,respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined（6 wt%）.The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.展开更多
A nonthermal plasma processing combined with Cr2O3/TiO2 catalyst was applied to the decomposition of trichloroethylene （TCE）. A dielectric barrier discharge reactor was used as the nonthermal plasma reactor. The eff...A nonthermal plasma processing combined with Cr2O3/TiO2 catalyst was applied to the decomposition of trichloroethylene （TCE）. A dielectric barrier discharge reactor was used as the nonthermal plasma reactor. The effects of the reaction temperature and input power on the decomposition of TCE and the formation of byproducts including HCl, Cl2, CO, NO, NO2 and O3 were examined. With an identical input power, the increase in the reactor temperature lowered the decomposition of TCE. The presence of the catalyst downstream the plasma reactor not only enhanced the decomposition of TCE but also affected the distribution of byproducts significantly. However any synergetic effect as a result of the combination of the nonthermal plasma with the catalyst was not observed, i.e., the TCE decomposition ei^ciency in the plasma- catalyst combined system was almost similar to the sum of those obtained with each process. To improve the decomposition of TCE argon as a plasma-assisting gas was added to the feeding gas and a large enhancement in the TCE decomposition was achieved.展开更多
基金the National Key Research and Development Program(No.2018YFD0401000)National Natural Science Foundation of China(31701636).
文摘Xylooligosaccharides(XOS)are mainly derived from lignocellulosic materials,such as rice husk,corn cobs,straw,wheat bran,wheat straw and other grain by-products.XOS have become one of the functional oligosaccharides of great concern at home and abroad due to their beneficial functional properties,such as low calorie,high stability,poor digestibility and high performance in proliferating probiotics.At present,the XOS extraction methods from grain byproducts mainly include autohydrolysis,acidolysis and enzymolysis.Among them,autohydrolysis has high requirements for equipment for achieving higher extraction rate and higher purity of products;and acidolysis can cause environmental pollution due to the usage of harmful reagents.Enzymolysis is the most common method for the production of XOS because of its high convenience,high efficiency and no pollution;and the widely used enzyme is the xylanase from Aspergillus niger.Current researches have showed that XOS can be utilized by probiotics such as Bifidobacteria and Lactobacillus to exert prebiotic effects,such as optimizing intestinal flora,promoting intestinal health,improving intestinal barrier,enhancing immune function,improving antioxidant capacity and so on.However,XOS extracted from the grain byproducts contain a large amount of impurities,which limits their industrial application and makes it dif-ficult to control the product quality.Therefore,XOS refining,separation and purification has become the key to their subsequent industrial application.This paper reviewed the current status of XOS extraction technologies from various grain by-products,and also summarized the prebiotic effect of XOS to provide reference for industrial production of XOS and its wide application in prebiotics market,thereby facilitating utilization and development of grain byproducts.
基金the support from National Natural Science Foundation of China under Grant No.11175157the Zhejiang Natural Science Foundations of China under No.LY16A050002+1 种基金521 Talent Project of Zhejiang Sci-Tech Universitythe Young Researchers Foundations of Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology
文摘In this paper,the collective effects of combining heterogeneous Ag/TiO2 nanocomposite catalyst with the byproducts（primarily the irradiation and the O3 species） of an atmospheric pressure plasma jet（APPJ） system on the degradation of methyl orange（MO） were explored.The heterostructured Ag/TiO2 nanocomposite was achieved via decorating the Ag quantum dots（QDs） on the commercially available TiO_2catalyst（P25） through a hydrothermal method.The x-ray diffraction analysis of the nanocomposite catalyst showed the diffraction peaks at 44.3°,64.4°,and 77.5°,corresponding to the Ag planes of（200）,（220） and（311）,respectively.The high resolution transmission electron microscope characterization of the nanocomposite catalyst indicated that the Ag QDs with an average diameter of 5 nm were homogeneously distributed on the P25 surface.The experimental results on the MO photodegradation showed that the APPJ irradiation had a marginal effect on the cleavage of the MO molecules.When the Ag/TiO2 nanocomposite catalyst was used,the photodegradation rate of MO increased about 5 times.When both the APPJ byproducts and the Ag/TiO2 nanocomposite catalyst were used,however,over 90% of the MO in the tested solution was cleaved within 15 min,and the energy efficiency was about 0.6 g/k W h.Moreover,an optimal Ag dosage value was determined（6 wt%）.The catalytic results indicated that combining the DBD plasma byproducts with heterogeneous nanocomposite catalysts may be an effect protocol for decreasing the application cost of the DBD system and mitigating the environment pollution by organic dyes in the textile industry.
文摘A nonthermal plasma processing combined with Cr2O3/TiO2 catalyst was applied to the decomposition of trichloroethylene （TCE）. A dielectric barrier discharge reactor was used as the nonthermal plasma reactor. The effects of the reaction temperature and input power on the decomposition of TCE and the formation of byproducts including HCl, Cl2, CO, NO, NO2 and O3 were examined. With an identical input power, the increase in the reactor temperature lowered the decomposition of TCE. The presence of the catalyst downstream the plasma reactor not only enhanced the decomposition of TCE but also affected the distribution of byproducts significantly. However any synergetic effect as a result of the combination of the nonthermal plasma with the catalyst was not observed, i.e., the TCE decomposition ei^ciency in the plasma- catalyst combined system was almost similar to the sum of those obtained with each process. To improve the decomposition of TCE argon as a plasma-assisting gas was added to the feeding gas and a large enhancement in the TCE decomposition was achieved.
