Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent resea...Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.展开更多
Fresh wet noodles(FWN) are popular staple foods due to its unique chewy texture and favorable taste. However,the development of FWN is limited by its short shelf life and high browning rate. It has been found that the...Fresh wet noodles(FWN) are popular staple foods due to its unique chewy texture and favorable taste. However,the development of FWN is limited by its short shelf life and high browning rate. It has been found that the quantity of original microorganisms in wheat flour produced by traditional method is relatively high, which is detrimental to the processing quality and storage stability of FWN. Consequently, it becomes imperative to decrease microorganisms in wheat flour. Microwave treatment has been regarded as a promising method in the food industry due to its potential in inhibiting microbial growth and inactivating enzymes without causing adverse effect on the food quality. This study aims to investigate the effects of microwave treatment of wheat kernels under different powers(1, 2, 3, 4, 5 kW) on the physicochemical properties of wheat flour and the quality of FWN. The results revealed that microwave treatment had a significant effect on microbial inhibition and enzyme inactivation, wherein the total plate count(TPC) and yeast and mold counts(YMC) decreased by 0.87 lg(CFU/g) and 1.13 lg(CFU/g) respectively, and PPO activity decreased from 11.40 U to 6.31 U. The dough quality properties, such as stability, extensibility, and starch viscosity, improved significantly under different microwave conditions. Confocal laser scanning microscopy(CLSM) images indicated that starch and proteins aggregated gradually in treated flour, altering rheological properties of dough. From the results of scanning electron microscopy(SEM), microwave treatment led to the appearance of disrupted structure in the gluten proteins, but the secondary structure of proteins altered slightly. Rheological properties of dough confirmed that the microwave treatment greatly affected processing characteristics of wheat flour products, with significant advantageous consequences on product quality, especially for textural properties of FWN. Furthermore, FWN darkening could be inhibited noticeably after microwave treatment, thereby prolonging its shelf life. Therefore, microwave treatment could thus be an effective, practical technology to produce low-bacterial flour and thereby enhance its product quality.展开更多
Glycerol-assisted instant catapult steam explosion(ICSE)of lignocellulose is an effective pretreatment method for enhancing sugar production compared to glycerol-free ICSE.In this study,glycerol-assisted ICSE of corn ...Glycerol-assisted instant catapult steam explosion(ICSE)of lignocellulose is an effective pretreatment method for enhancing sugar production compared to glycerol-free ICSE.In this study,glycerol-assisted ICSE of corn stover was studied in order to understand the reaction mechanisms and further optimize the process.Results showed that water extraction of corn stover prior to ICSE reduced pseudo-lignin formation.The combination of water extraction and glycerol-assisted ICSE led to the formation of lignin with a lower molecular weight(Mw)of 2851 g/mol than 3521 g/mole of that from the combination of water extraction and glycerol-free ICSE.1H-13C NMR analysis revealed that glycerol likely reacted with lignin carboxylic OHs through esterification while etherification of aliphatic OHs was not observed in ICSE.These lignin analyses indicated that glycerol protected lignin from condensation/repolymerization during glycerol-assisted ICSE.Enzymatic hydrolysis results showed that without water extraction increasing glycerol usage from 0.2 kg/kg stover to 0.4 kg/kg stover improved glucan digestibility to 78%but further increase to 0.5 kg/kg stover reduced glucan digestibility.In addition,at the glycerol usage of 0.2-0.4 kg/kg stover,washing of pretreated stover for removal of glycerol and other biomass-derived compounds did not improve glucan digestibility compared to unwashed ones.Combination of water extraction and glycerol-assisted ICSE led to a high glucan digestibility of 89.7%and a total glucose yield of 25.5 g glucose/100 g stover,which were 30.1%and 7.5 g/100 g stover higher than those derived from glycerol-free ICSE of stover,respectively.Since glycerol is a low-cost carbon source,the resulting enzymatic hydrolysate that contained both glucose and glycerol may be directly used to produce bioproducts by microbial fermentation.展开更多
基金supported by the National Natural Science Foundation of China(21706052,22278114)Natural Science Foundation of Henan Province(242300421575).
文摘Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.
基金supported by the Key Scientific and Technological Research Projects of Henan Province (Grant No. 202102110133)Special Innovation Fund of Henan Agricultural University (Grant No. KJCX2019C04)。
文摘Fresh wet noodles(FWN) are popular staple foods due to its unique chewy texture and favorable taste. However,the development of FWN is limited by its short shelf life and high browning rate. It has been found that the quantity of original microorganisms in wheat flour produced by traditional method is relatively high, which is detrimental to the processing quality and storage stability of FWN. Consequently, it becomes imperative to decrease microorganisms in wheat flour. Microwave treatment has been regarded as a promising method in the food industry due to its potential in inhibiting microbial growth and inactivating enzymes without causing adverse effect on the food quality. This study aims to investigate the effects of microwave treatment of wheat kernels under different powers(1, 2, 3, 4, 5 kW) on the physicochemical properties of wheat flour and the quality of FWN. The results revealed that microwave treatment had a significant effect on microbial inhibition and enzyme inactivation, wherein the total plate count(TPC) and yeast and mold counts(YMC) decreased by 0.87 lg(CFU/g) and 1.13 lg(CFU/g) respectively, and PPO activity decreased from 11.40 U to 6.31 U. The dough quality properties, such as stability, extensibility, and starch viscosity, improved significantly under different microwave conditions. Confocal laser scanning microscopy(CLSM) images indicated that starch and proteins aggregated gradually in treated flour, altering rheological properties of dough. From the results of scanning electron microscopy(SEM), microwave treatment led to the appearance of disrupted structure in the gluten proteins, but the secondary structure of proteins altered slightly. Rheological properties of dough confirmed that the microwave treatment greatly affected processing characteristics of wheat flour products, with significant advantageous consequences on product quality, especially for textural properties of FWN. Furthermore, FWN darkening could be inhibited noticeably after microwave treatment, thereby prolonging its shelf life. Therefore, microwave treatment could thus be an effective, practical technology to produce low-bacterial flour and thereby enhance its product quality.
基金supported by the Henan Provincial Science and Technology Research Project(222102520015)the Science and Technology Innovation Leading Talents of Central Plains,Henan province,China(204200510018).
文摘Glycerol-assisted instant catapult steam explosion(ICSE)of lignocellulose is an effective pretreatment method for enhancing sugar production compared to glycerol-free ICSE.In this study,glycerol-assisted ICSE of corn stover was studied in order to understand the reaction mechanisms and further optimize the process.Results showed that water extraction of corn stover prior to ICSE reduced pseudo-lignin formation.The combination of water extraction and glycerol-assisted ICSE led to the formation of lignin with a lower molecular weight(Mw)of 2851 g/mol than 3521 g/mole of that from the combination of water extraction and glycerol-free ICSE.1H-13C NMR analysis revealed that glycerol likely reacted with lignin carboxylic OHs through esterification while etherification of aliphatic OHs was not observed in ICSE.These lignin analyses indicated that glycerol protected lignin from condensation/repolymerization during glycerol-assisted ICSE.Enzymatic hydrolysis results showed that without water extraction increasing glycerol usage from 0.2 kg/kg stover to 0.4 kg/kg stover improved glucan digestibility to 78%but further increase to 0.5 kg/kg stover reduced glucan digestibility.In addition,at the glycerol usage of 0.2-0.4 kg/kg stover,washing of pretreated stover for removal of glycerol and other biomass-derived compounds did not improve glucan digestibility compared to unwashed ones.Combination of water extraction and glycerol-assisted ICSE led to a high glucan digestibility of 89.7%and a total glucose yield of 25.5 g glucose/100 g stover,which were 30.1%and 7.5 g/100 g stover higher than those derived from glycerol-free ICSE of stover,respectively.Since glycerol is a low-cost carbon source,the resulting enzymatic hydrolysate that contained both glucose and glycerol may be directly used to produce bioproducts by microbial fermentation.
