Microcrystalline cellulose(MCC)is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high crystallinity.When implemented in other polymers,high crystallinit...Microcrystalline cellulose(MCC)is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high crystallinity.When implemented in other polymers,high crystallinity correlates with greater strength and stiffnes,but it can reduce the water-holding capacity.The acid concentration and hydrolysis time will affect the acquisition of crystallinity and water absorption capacity,both of which have significance as properties of hydrogel filler.The study aimed to evaluate the properties and select the MCC generated from varying the proportion of hydrochloric acid(HCl)and the appropriate hydrolysis time as a filler for film hydrogel.MCC was produced by hydrolyzing cellulose of oil palm empty fruit bunches(OPEFB)with the HCl solution at varied concentrations and periods.The results show that the longer hydrolysis times and higher HCl concentrations increase crystallinity and density while lowering yield and water absorption.The extensive acid hydrolysis reduces the amorphous area significantly,allowing the depolymerization to occur and extend the crystalline area.The morphological properties of the MCC,which are smaller but compact,indicate the presence of disintegrating and diminishing structures.A 2.5 N HCl concentration and a 45-min hydrolysis time succeed in sufficient crystallinity as well as maintaining good water absorption capacity.The treatment produced MCC with absorption capacity of 4.03±0.26 g/g,swelling capacity of 5.03±0.26 g/g,loss on drying of 1.44%±0.36,bulk and tapped density of 0.27±0.031 g/cm^(3) and 0.3±0.006 g/cm^(3),respectively,with a crystallinity index of 88.89%±4.76 and a crystallite size of 4.23±0.70 nm.The MCC generated could potentially be utilized as a hydrogel film filler,since a given proportion will be able to maintain the strength of the hydrogel,not readily dissolve but absorb water significantly.展开更多
As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This ...As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs.展开更多
Cellulose nanocrystals (NCC) and cellulose nanofibrils (CNF) were obtained by a single step process, with synergy between 64% sulfuric acid hydrolysis and high shear from ultra-turrax stirring, which is an advantageou...Cellulose nanocrystals (NCC) and cellulose nanofibrils (CNF) were obtained by a single step process, with synergy between 64% sulfuric acid hydrolysis and high shear from ultra-turrax stirring, which is an advantageous process for disintegrating cellulose microcrystalline and also may improve the hydrolysis process. The surface modification on the cellulose was performed by the sol-gel process, in which the sulfate groups from hydrolysis were replaced by nanoparticles of zinc oxide, which led to the increase of up to 54°C Tonset, according to thermogravimetric analysis (TGA) results. The morphology and crystallinity degree were characterized by Helium Ion Microscopy (HIM), atomic force microscopy (AFM) and X-ray diffraction. In addition, the ZnO band was observed in Fourier transform infrared spectroscopy, furthermore, the change in the zeta potential confirmed the cellulose modification. The changes in the values of proton spin-spin relaxation time for the systems showing the confined hydrogen in the rigid domains, confirmed the results observed with the aforementioned techniques, for both cellulose after hydrolysis and ZnO modified cellulose, suggesting that ZnO disrupted crystal formation in cellulose.展开更多
The present work firstly aimed to obtain cellulose from sugarcane bagasse by using alkaline methods in pulping/delignifying and, at bleaching stages, using sodium chlorite, glacial acetic acid, and hydrogen peroxide, ...The present work firstly aimed to obtain cellulose from sugarcane bagasse by using alkaline methods in pulping/delignifying and, at bleaching stages, using sodium chlorite, glacial acetic acid, and hydrogen peroxide, associated to NaOH/KOH. The process was carried out at temperatures varying from 55°C to 110°C, under magnetic stirring in various steps lasting from 2 h to 12 h. The yields of the two cellulose extracted, SCB24-Na-I and SCB24-Na-II, were 37% and 41%, respectively, from samples of ca. 15 g of the bagasse. Secondly, it is to extract nanoparticles from the obtained celluloses via acid hydrolysis (with 77% H2SO4) to lately be tested as reinforcement in biodegradable packagings. Both celluloses and their respective nanoparticles were characterized by several techniques, among them ATR-FTIR, DSC-TGA, XRD, SEM, and TEM. Despite that the yields of cellulose nanoparticles have been low, the preliminary studies of their use in biodegradable films coated on biodegradable pots were promising.展开更多
In this work,a sustainable method to prepare functional cellulose nanocrystals(CNCs)and cellulose nanofibrils(CNFs)using formic acid(FA)(a recoverable organic acid)was established.After FA hydrolysis,the obtained CNCs...In this work,a sustainable method to prepare functional cellulose nanocrystals(CNCs)and cellulose nanofibrils(CNFs)using formic acid(FA)(a recoverable organic acid)was established.After FA hydrolysis,the obtained CNCs could be well dispersed in DMAC.Thus,the CNC products and fibrous cellulosic solid residue(FCSR)in DMAC could be easily separated by a conventional centrifugal process,and the collected FCSR could be further fibrillated to CNFs with relatively low-intensity mechanical fibrillation process.The isolated CNC products showed high crystallinity index(about 75%)and excellent thermal stability(with onset thermal degradation temperature of 325℃).Both the resultant CNCs and CNFs showed better dispersibility in DMSO,DMF and DMAC respectively because of the introduction of ester groups on the surface of the products.The presence of surface ester groups could increase the interface compatibility of nanocelluloses with polymeric matrices and enable their applications in reinforcing polymeric matrix materials(e.g.the composite films like PHVB+CNFs).展开更多
Five new terpenoids,including two vibsane-type diterpenoids(1,2)and three iridoid allosides(3-5),together with eight known ones,were isolated from the leaves and twigs of Viburnum odoratissimum var.sessiliflorum.Their...Five new terpenoids,including two vibsane-type diterpenoids(1,2)and three iridoid allosides(3-5),together with eight known ones,were isolated from the leaves and twigs of Viburnum odoratissimum var.sessiliflorum.Their planar structures and relative configurations were determined by spectroscopic methods,especially 2D NMR techniques.The sugar moieties of the iridoids were confirmed asβ-D-allose by GC analysis after acid hydrolysis and acetylation.The absolute configurations of neovibsanin Q(1)and dehydrovibsanol B(2)were determined by quantum chemical calculation of their theoretical electronic circular dichroism(ECD)spectra and Rh2(OCOCF_(3))_(4)-induced ECD analysis.The anti-inflammatory activities of compounds 1,3,4,and 5 were evaluated using an LPS-induced RA W264.7 cell model.Compounds 3 suppressed the release of NO in a dose-dependent manner,with an IC_(50) value of 55.64μmol·L^(-1).The cytotoxicities of compounds 1-5 on HCT-116 cells were assessed and the results showed that compounds 2 and 3 exhibited moderate inhibitory activities with IC_(50) values of 13.8 and 12.3μmol·L^(-1),respectively.展开更多
Objective:To investigate the hypoglycemic components from the acid hydrolyzates of Panax quinquefolius total saponins,and screen the active compounds by in vitro inhibitory activities toα-glycosidase enzymes and prot...Objective:To investigate the hypoglycemic components from the acid hydrolyzates of Panax quinquefolius total saponins,and screen the active compounds by in vitro inhibitory activities toα-glycosidase enzymes and protein tyrosine phosphatase-1 B(PTP1 B).Methods:The hydrolyzates were chromatographed repeatedly over silica gel column,and the structures of the compounds were determined by means of NMR.The in vitro bioassay was performed through the inhibitory effects onα-glucosidase or/and PTP1 B.Results:Eight compounds were isolated,which identified as 20(S)-panaxadiol(1),(20 S,24 R)-dammarane-20,24-epoxy-3β,6α,12β,25-tetraol(2),20(R)-dammarane-3β,12β,20,25-tetraol(3),20(S)-dammarane-3β,6α,12β,20,25-pentol(4),20(R)-dammarane-3β,12β,20,25-tetrahydroxy-3β-O-β-D-glucopyranoside(5),β-sitosterol(6),oleanolic acid(7)and 20(S)-protopanaxadiol(8).Compound 5 was ginseng triterpenoid isolated from the acid hydrolysates of total saponins from P.quinquefolius for the first time.In this paper,the possible in vitro inhibitory activities were investigated.Compound 5 exhibited significantly inhibitory activity againstα-glucosidase,and the IC50 value[(0.22±0.21)μmol/L]was about 43-fold lower than positive control.For the PTP1 B inhibition assay,compound 5 indicated the strongest inhibitory effect with IC50 of(5.91±0.38)μmol/L,followed by compound 4 with IC50 of(6.21±0.21)μmol/L,which were all showed competitive inhibitory pattern by using a Lineweaver-Burk plot.Conclusion:These results supported the potential application of dammaranes from acid hydrolyzates of P.quinquefolius total saponins can be used as ingredients of ancillary anti-diabetic agent or functional factor.展开更多
Cellulose nanocrystal(CNC)with distinctive shape-morphology,enhanced thermal stability and dispersibility is essential for overcoming the challenges in processing polymer/CNC nanocom-posites through melt compounding a...Cellulose nanocrystal(CNC)with distinctive shape-morphology,enhanced thermal stability and dispersibility is essential for overcoming the challenges in processing polymer/CNC nanocom-posites through melt compounding at elevated temperatures.This study shows a mixed acid hy-drolysis method to produce CNC with improved thermal stability and high productivity.The use of phosphoric acid(H_(3)PO_(4)),as a mild acid,in combination with a strong acid either sulphuric acid(H_(2)SO_(4))or hydrochloric acid(HCl)leads to reduced use of strong acids and low impact on our environment.The influences of acid combination and sequence of addition on the production yield were investigated by retaining the proportion of H_(3)PO_(4)to corrosive acid(H_(2)SO_(4)and HCl)4 to 1,and solid to liquid ratio 1꞉75.This methodology has enabled to isolate CNC with higher thermal stability,dispersibility and productivity in terms of amount acid used 1 g of CNC,as compared with single acid hydrolysis.The CNC produced using the combination of H_(3)PO_(4)and HCl exhibits high thermal stability,dispersibility and rod-like shape morphology with length and width of(424±86)and(22±3)nm,respectively.Moreover,this approach has reduced H_(3)PO_(4)consumption by 54%as compared with single acid hydrolysis method for the production of same amount of CNC.展开更多
In this work,the ethanol production from sweet sorghum residue was studied.Sweet sorghum res-idue was hydrolyzed with phosphoric acid under mild conditions.The liquid hydrolysate was fermented by Pachysolen tannophilu...In this work,the ethanol production from sweet sorghum residue was studied.Sweet sorghum res-idue was hydrolyzed with phosphoric acid under mild conditions.The liquid hydrolysate was fermented by Pachysolen tannophilus,and the hydrolysis residue was fermented by the simultaneous saccharification and fer-mentation(SSF)using Saecharomyces cerevisiae with cel-lulase(60 FPU/g dry materials).Orthogonal experiments were carried out to investigate the effects of main reaction condition factors,such as temperature,acid concentra-tion,time and dry-matter content,on the reducing sugar yield.The results show that the optimal reaction condi-tions should be 120℃,80 g/L,80 min and 10%,respect-ively.Under these conditions,0.3024 g reducing sugar/g dry material was obtained.The liquid hydrolysate was then fermented by P.tannophilus with the highest ethanol concentration of 14.5 g/L.At a water-insoluble solid con-centration of 5%,5.4 g/L ethanol was obtained after 12 h of SSF.The total ethanol yield was 0.147 g/g dry material,which would be beneficial for the application of ethanol production from sweet sorghum residue.展开更多
Tryptophan is one of the nine essential amino acids in humans that can only be obtained through diets and supplements.It is a precursor to many biological processes,such as serotonin,melatonin,kynurenin,and niacin(nic...Tryptophan is one of the nine essential amino acids in humans that can only be obtained through diets and supplements.It is a precursor to many biological processes,such as serotonin,melatonin,kynurenin,and niacin(nicotinamide)vitamin synthesis.The content of tryptophan in foods,such as soybean is an important indicator of nutritional value.Therefore,accurate quantification of tryptophan in soybean is crucial to soybean nutritional improvement.Quantification of soybean protein-bound amino acids first involves acid hydrolysis of total protein to liberate amino acids.However,tryptophan quantification following acid hydrolysis is difficult or impossible due to its reactions with soybean carbohydrates.Therefore,removal of carbohydrates from soy proteins prior to acid hydrolysis is necessary.In this study,we compared four common protein precipitation methods(i.e.,methanol,acetonitrile,acetone,and trichloroacetic acid(TCA)protein precipitation methods)to determine the best method to separate soy proteins from carbohydrates,and concluded that acetone provided the highest recovery of soy proteins.Tryptophan content in the precipitated proteins was determined after acid hydrolysis of the proteins using liquid chromatography-tandem mass spectrometry multiple reaction monitoring(LC-MS/MS-MRM).No significant difference in the tryptophan content was found among proteins precipitated with methanol,acetonitrile,and TCA,suggesting that these precipitated proteins have similar compositions.A slightly lower,but statistically significant tryptophan content was found in the acetonitrile-precipitated proteins,suggesting that these proteins contain slightly higher glycosylated proteins.展开更多
Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective...Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective of this study is to prepare the starch nanoparticles from cassava peel by mineral acid hydrolysis using hydrochloric and sulfuric acids and perform the characterization of starch nanoparticles with Fourier transform infrared (FTIR),X-ray diffraction (XRD) and scanning electron microscope (SEM)It was found that the obtained yield of starch nanoparticles by H2SO4was higher than that by HCl.展开更多
基金the Universitas Gadjah Mada’s financial support for this research.This research was conducted using the Final Project Recognition Grant Universitas Gadjah Mada Indonesia Number of 5075/UN1.P.II/DitLit/PT.01.01/2023.
文摘Microcrystalline cellulose(MCC)is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high crystallinity.When implemented in other polymers,high crystallinity correlates with greater strength and stiffnes,but it can reduce the water-holding capacity.The acid concentration and hydrolysis time will affect the acquisition of crystallinity and water absorption capacity,both of which have significance as properties of hydrogel filler.The study aimed to evaluate the properties and select the MCC generated from varying the proportion of hydrochloric acid(HCl)and the appropriate hydrolysis time as a filler for film hydrogel.MCC was produced by hydrolyzing cellulose of oil palm empty fruit bunches(OPEFB)with the HCl solution at varied concentrations and periods.The results show that the longer hydrolysis times and higher HCl concentrations increase crystallinity and density while lowering yield and water absorption.The extensive acid hydrolysis reduces the amorphous area significantly,allowing the depolymerization to occur and extend the crystalline area.The morphological properties of the MCC,which are smaller but compact,indicate the presence of disintegrating and diminishing structures.A 2.5 N HCl concentration and a 45-min hydrolysis time succeed in sufficient crystallinity as well as maintaining good water absorption capacity.The treatment produced MCC with absorption capacity of 4.03±0.26 g/g,swelling capacity of 5.03±0.26 g/g,loss on drying of 1.44%±0.36,bulk and tapped density of 0.27±0.031 g/cm^(3) and 0.3±0.006 g/cm^(3),respectively,with a crystallinity index of 88.89%±4.76 and a crystallite size of 4.23±0.70 nm.The MCC generated could potentially be utilized as a hydrogel film filler,since a given proportion will be able to maintain the strength of the hydrogel,not readily dissolve but absorb water significantly.
文摘As the world's population exponentially grows,so does the need for the production of food,with cereal production growing annually from an estimated 1.0 billion to 2.5 billion tons within the last few decades.This rapid growth in food production results in an ever increasing amount of agricultural wastes,of which already occupies nearly 50%of the total landfill area.For example,is the billions of dry tons of cellulose-containing spent coffee grounds disposed in landfills annually.This paper seeks to provide a method for isolating cellulose nanocrystals(CNCs)from spent coffee grounds,in order to recycle and utilize the cellulosic waste material which would otherwise have no applications.CNCs have already been shown to have vast applications in the polymer engineering field,mainly utilized for their high strength to weight ratio for reinforcement of polymer-based nanocomposites.A successful method of purifying and hydrolyzing the spent coffee grounds in order to isolate usable CNCs was established.The CNCs were then characterized using current techniques to determine important chemical and physical properties.A few crucial properties determined were aspect ratio of 12±3,crystallinity of 74.2%,surface charge density of(48.4±6.2)mM/kg cellulose,and the ability to successfully reinforce a polymer based nanocomposite.These characteristics compare well to other literature data and common commercial sources of CNCs.
基金financially supported by CAPES code 001 and CNPQ.
文摘Cellulose nanocrystals (NCC) and cellulose nanofibrils (CNF) were obtained by a single step process, with synergy between 64% sulfuric acid hydrolysis and high shear from ultra-turrax stirring, which is an advantageous process for disintegrating cellulose microcrystalline and also may improve the hydrolysis process. The surface modification on the cellulose was performed by the sol-gel process, in which the sulfate groups from hydrolysis were replaced by nanoparticles of zinc oxide, which led to the increase of up to 54°C Tonset, according to thermogravimetric analysis (TGA) results. The morphology and crystallinity degree were characterized by Helium Ion Microscopy (HIM), atomic force microscopy (AFM) and X-ray diffraction. In addition, the ZnO band was observed in Fourier transform infrared spectroscopy, furthermore, the change in the zeta potential confirmed the cellulose modification. The changes in the values of proton spin-spin relaxation time for the systems showing the confined hydrogen in the rigid domains, confirmed the results observed with the aforementioned techniques, for both cellulose after hydrolysis and ZnO modified cellulose, suggesting that ZnO disrupted crystal formation in cellulose.
基金the FINEP/FUNDEP for the awarded grantsthe FAPESP(process#2017/09469-2)for financial support
文摘The present work firstly aimed to obtain cellulose from sugarcane bagasse by using alkaline methods in pulping/delignifying and, at bleaching stages, using sodium chlorite, glacial acetic acid, and hydrogen peroxide, associated to NaOH/KOH. The process was carried out at temperatures varying from 55°C to 110°C, under magnetic stirring in various steps lasting from 2 h to 12 h. The yields of the two cellulose extracted, SCB24-Na-I and SCB24-Na-II, were 37% and 41%, respectively, from samples of ca. 15 g of the bagasse. Secondly, it is to extract nanoparticles from the obtained celluloses via acid hydrolysis (with 77% H2SO4) to lately be tested as reinforcement in biodegradable packagings. Both celluloses and their respective nanoparticles were characterized by several techniques, among them ATR-FTIR, DSC-TGA, XRD, SEM, and TEM. Despite that the yields of cellulose nanoparticles have been low, the preliminary studies of their use in biodegradable films coated on biodegradable pots were promising.
基金supported by the National Natural Science Foundation of China (contract grant numbers:21306261,31470609,and 25106240)Primary Research and Development Plan of Shandong Province (contract grant numbers:2016GGX104003,and 2016CYJS07A02).
文摘In this work,a sustainable method to prepare functional cellulose nanocrystals(CNCs)and cellulose nanofibrils(CNFs)using formic acid(FA)(a recoverable organic acid)was established.After FA hydrolysis,the obtained CNCs could be well dispersed in DMAC.Thus,the CNC products and fibrous cellulosic solid residue(FCSR)in DMAC could be easily separated by a conventional centrifugal process,and the collected FCSR could be further fibrillated to CNFs with relatively low-intensity mechanical fibrillation process.The isolated CNC products showed high crystallinity index(about 75%)and excellent thermal stability(with onset thermal degradation temperature of 325℃).Both the resultant CNCs and CNFs showed better dispersibility in DMSO,DMF and DMAC respectively because of the introduction of ester groups on the surface of the products.The presence of surface ester groups could increase the interface compatibility of nanocelluloses with polymeric matrices and enable their applications in reinforcing polymeric matrix materials(e.g.the composite films like PHVB+CNFs).
基金supported by the National Natural Science Foundation of China(Nos.22077111,22177016,81872756,and 81901678)Department of Education of Guangdong Province(No.2020KZDZX1203)。
文摘Five new terpenoids,including two vibsane-type diterpenoids(1,2)and three iridoid allosides(3-5),together with eight known ones,were isolated from the leaves and twigs of Viburnum odoratissimum var.sessiliflorum.Their planar structures and relative configurations were determined by spectroscopic methods,especially 2D NMR techniques.The sugar moieties of the iridoids were confirmed asβ-D-allose by GC analysis after acid hydrolysis and acetylation.The absolute configurations of neovibsanin Q(1)and dehydrovibsanol B(2)were determined by quantum chemical calculation of their theoretical electronic circular dichroism(ECD)spectra and Rh2(OCOCF_(3))_(4)-induced ECD analysis.The anti-inflammatory activities of compounds 1,3,4,and 5 were evaluated using an LPS-induced RA W264.7 cell model.Compounds 3 suppressed the release of NO in a dose-dependent manner,with an IC_(50) value of 55.64μmol·L^(-1).The cytotoxicities of compounds 1-5 on HCT-116 cells were assessed and the results showed that compounds 2 and 3 exhibited moderate inhibitory activities with IC_(50) values of 13.8 and 12.3μmol·L^(-1),respectively.
基金supported by the National Natural Science Foundation of China(No.81602983)。
文摘Objective:To investigate the hypoglycemic components from the acid hydrolyzates of Panax quinquefolius total saponins,and screen the active compounds by in vitro inhibitory activities toα-glycosidase enzymes and protein tyrosine phosphatase-1 B(PTP1 B).Methods:The hydrolyzates were chromatographed repeatedly over silica gel column,and the structures of the compounds were determined by means of NMR.The in vitro bioassay was performed through the inhibitory effects onα-glucosidase or/and PTP1 B.Results:Eight compounds were isolated,which identified as 20(S)-panaxadiol(1),(20 S,24 R)-dammarane-20,24-epoxy-3β,6α,12β,25-tetraol(2),20(R)-dammarane-3β,12β,20,25-tetraol(3),20(S)-dammarane-3β,6α,12β,20,25-pentol(4),20(R)-dammarane-3β,12β,20,25-tetrahydroxy-3β-O-β-D-glucopyranoside(5),β-sitosterol(6),oleanolic acid(7)and 20(S)-protopanaxadiol(8).Compound 5 was ginseng triterpenoid isolated from the acid hydrolysates of total saponins from P.quinquefolius for the first time.In this paper,the possible in vitro inhibitory activities were investigated.Compound 5 exhibited significantly inhibitory activity againstα-glucosidase,and the IC50 value[(0.22±0.21)μmol/L]was about 43-fold lower than positive control.For the PTP1 B inhibition assay,compound 5 indicated the strongest inhibitory effect with IC50 of(5.91±0.38)μmol/L,followed by compound 4 with IC50 of(6.21±0.21)μmol/L,which were all showed competitive inhibitory pattern by using a Lineweaver-Burk plot.Conclusion:These results supported the potential application of dammaranes from acid hydrolyzates of P.quinquefolius total saponins can be used as ingredients of ancillary anti-diabetic agent or functional factor.
文摘Cellulose nanocrystal(CNC)with distinctive shape-morphology,enhanced thermal stability and dispersibility is essential for overcoming the challenges in processing polymer/CNC nanocom-posites through melt compounding at elevated temperatures.This study shows a mixed acid hy-drolysis method to produce CNC with improved thermal stability and high productivity.The use of phosphoric acid(H_(3)PO_(4)),as a mild acid,in combination with a strong acid either sulphuric acid(H_(2)SO_(4))or hydrochloric acid(HCl)leads to reduced use of strong acids and low impact on our environment.The influences of acid combination and sequence of addition on the production yield were investigated by retaining the proportion of H_(3)PO_(4)to corrosive acid(H_(2)SO_(4)and HCl)4 to 1,and solid to liquid ratio 1꞉75.This methodology has enabled to isolate CNC with higher thermal stability,dispersibility and productivity in terms of amount acid used 1 g of CNC,as compared with single acid hydrolysis.The CNC produced using the combination of H_(3)PO_(4)and HCl exhibits high thermal stability,dispersibility and rod-like shape morphology with length and width of(424±86)and(22±3)nm,respectively.Moreover,this approach has reduced H_(3)PO_(4)consumption by 54%as compared with single acid hydrolysis method for the production of same amount of CNC.
文摘In this work,the ethanol production from sweet sorghum residue was studied.Sweet sorghum res-idue was hydrolyzed with phosphoric acid under mild conditions.The liquid hydrolysate was fermented by Pachysolen tannophilus,and the hydrolysis residue was fermented by the simultaneous saccharification and fer-mentation(SSF)using Saecharomyces cerevisiae with cel-lulase(60 FPU/g dry materials).Orthogonal experiments were carried out to investigate the effects of main reaction condition factors,such as temperature,acid concentra-tion,time and dry-matter content,on the reducing sugar yield.The results show that the optimal reaction condi-tions should be 120℃,80 g/L,80 min and 10%,respect-ively.Under these conditions,0.3024 g reducing sugar/g dry material was obtained.The liquid hydrolysate was then fermented by P.tannophilus with the highest ethanol concentration of 14.5 g/L.At a water-insoluble solid con-centration of 5%,5.4 g/L ethanol was obtained after 12 h of SSF.The total ethanol yield was 0.147 g/g dry material,which would be beneficial for the application of ethanol production from sweet sorghum residue.
基金the National Science Foundation(NSF Molecular and Cellular Biosciences Award 1024976National Science Foundation IOS and Japanese Science and Technology Agency joint Metabolomics for Low Carbon Society Awards 1139489 and 1639618+1 种基金National Science Foundation IOS Awards 1340058 and 1743594)Ritesh Kumar was supported by a grant from the United Soybean Board(USB,award#1920-152-0120-B)to Minviluz G.Stacey,Lloyd W.Sumner and Zhentian Lei.
文摘Tryptophan is one of the nine essential amino acids in humans that can only be obtained through diets and supplements.It is a precursor to many biological processes,such as serotonin,melatonin,kynurenin,and niacin(nicotinamide)vitamin synthesis.The content of tryptophan in foods,such as soybean is an important indicator of nutritional value.Therefore,accurate quantification of tryptophan in soybean is crucial to soybean nutritional improvement.Quantification of soybean protein-bound amino acids first involves acid hydrolysis of total protein to liberate amino acids.However,tryptophan quantification following acid hydrolysis is difficult or impossible due to its reactions with soybean carbohydrates.Therefore,removal of carbohydrates from soy proteins prior to acid hydrolysis is necessary.In this study,we compared four common protein precipitation methods(i.e.,methanol,acetonitrile,acetone,and trichloroacetic acid(TCA)protein precipitation methods)to determine the best method to separate soy proteins from carbohydrates,and concluded that acetone provided the highest recovery of soy proteins.Tryptophan content in the precipitated proteins was determined after acid hydrolysis of the proteins using liquid chromatography-tandem mass spectrometry multiple reaction monitoring(LC-MS/MS-MRM).No significant difference in the tryptophan content was found among proteins precipitated with methanol,acetonitrile,and TCA,suggesting that these precipitated proteins have similar compositions.A slightly lower,but statistically significant tryptophan content was found in the acetonitrile-precipitated proteins,suggesting that these proteins contain slightly higher glycosylated proteins.
文摘Starch nanoparticles are used as a matrix with natural rubber for tire making, alternative adsorbents for wastewater treatment, drug carriers, packaging materials, emulsion stabilizers and fat replacers. The objective of this study is to prepare the starch nanoparticles from cassava peel by mineral acid hydrolysis using hydrochloric and sulfuric acids and perform the characterization of starch nanoparticles with Fourier transform infrared (FTIR),X-ray diffraction (XRD) and scanning electron microscope (SEM)It was found that the obtained yield of starch nanoparticles by H2SO4was higher than that by HCl.
