Enzymatic hydrolysis of silkworm pupa and its allergenicity evaluation by animal model with different immunization routes

Silkworm pupa is a nourishing food with high nutritional value,but its consumption has been greatly limited given its allergenicity.Enzyme hydrolytic technique is recognized as an effective method to reduce the allergenicity of protein.In this study,we aimed to investigate the effect of enzymolysis on the allergenicity of silkworm pupa.Crude silkworm pupa protein was extracted through alkali extraction and acid precipitation,which included 5 proteins with the molecular weights ranging from 34 kDa to 76 kDa,and silkworm pupa were then hydrolyzed by alkaline protease.The allergenicity of silkworm pupa protein and its enzymatic hydrolysates was evaluated by establishing BALB/c mice model,and the mice were immunized via intragastric gavage and intraperitoneal injection,respectively.The results indicated that the intraperitoneal inj ection immunization route induced more by detecting with antibodies,histamine and Th2-related cytokines.Moreover,mice treated with silkworm pupa protein peptide displayed no obvious allergic symptoms,indicating that enzyme hydrolytic technique could significantly reduce the allergenicity of silkworm pupa.

Structural and antioxidative properties of royal jelly protein by partial enzymatic hydrolysis

The objective of this study was to investigate the structural and antioxidative properties of royal jelly protein(RJP)at different degrees of hydrolysis(DH)by partial enzymatic hydrolysis. RJP was hydrolyzed by alcalase for 0 min, 15 min, 1 h, 5 h and 8 h to obtain hydrolysates at DH of 5.34%, 11.65%, 15.19%, 21.38% and 23.91%, respectively. With the increased DH, the RJP hydrolysates showed elevated antioxidative activities. The molecular weight of RJP hydrolysates was significantly decreased but their primary backbone kept unchanged. Analysis of circular dichroism spectra revealed that the enzymolysis reduced the content of α-helix but increased the contents of β-sheet, β-turn and random coil. Meanwhile, the surface hydrophobicity and fluorescence intensity of RJP hydrolysates were decreased and a red shift occurred. As the enzymolysis continued, the surface morphology of RJP was gradually changed from a sheet-like structure into microparticles. Changes in antioxidative activities and structures generally followed a DH-dependent manner, however these changes became insignificant for samples at DH beyond 20%. Taking into consideration of both effectiveness and productivity, the optimum enzymatic duration was determined at 5 h.

Structure, composition and enzymatic hydrolysis of steam-exploded lespedeza stalks

Pretreatment of lespedeza stalks by steam explosion has been studied. The results indicate that steam-exploded pretreatment has strong effects on physical features, morphology, crystallinity, and composition of lespedeza stalks as shown by scanning electron microscopy （SEM）, infrared （IR）, and X-ray diffraction spectrometry methods. After steam explosion, the cellulose and lignin contents of lespedeza stalks varied only slightly, but the hemicellulose content had decreased from 29.34% to 7.48%. The cellulose obtained by steam-exploded pretreatment had a higher degree of crystallinity than that of the raw material. At the explosion condition of 2.25 MPa and 4 min, lignocellulose is easier to hydrolyze by enzyme than the original lignocellulose. The concentration of reduced sugar in the hydrolyzate liquid increased from 71.77 to 162.84 g·L^-1.

Dynamic changes of peptidome and release of polysaccharide in sea cucumber(Apostichopus japonicus) hydrolysates depending on enzymatic hydrolysis approaches

Enzymatic hydrolysis has been widely used to produce bioactive hydrolysates from sea cucumber body wall.Here,inspired by the clarification of Apostichopus japonicus genome,we investigated the enzymatic hydrolysis of sea cucumber body wall by using the omics strategy.Shared proteins,including major yolk proteins,collagens,extracellular matrix glycoproteins and muscle proteins,were released from the body wall by different hydrolysis condition.A portfolio of 216 shared peptides were detected in the peptidome by papain with different hydrolysis time,while 32 shared peptides were detected in the peptidome by differing proteases.Unshared peptides and the relative abundance distribution profiles of shared peptides changed depending on hydrolysis approaches,indicating dynamic changes of peptidome during hydrolysis.Moreover,release of sulfated fucan and fucosylated chondroitin sulfate changed with the hydrolysis condition.The monitoring of dynamic enzymatic hydrolysis process at a molecular scale would contribute to production and quality control of sea cucumber hydrolysates.

Wet Oxidation Pretreatment of Poplar Waste for Enhancing Enzymatic Hydrolysis Efficiency

In this paper, we described the optimization of the wet oxidation pretreatment conditions to enhance enzymatic hydrolysis efficiency, using poplar waste from the stock section of a paper mill as the raw material. We showed that the optimal conditions of the pretreatment for poplar waste were an initial p H value of 10, a temperature of 195℃, a holding time of 15 min, and an oxygen pressure of 1.2 MPa. In this case, the yield of the obtained solid material produced by the process was 51.7% and the reducing sugar yield was 46.8%. The solid part obtained from the pretreatment process was hydrolyzed by cellulase L-10. The optimal enzymatic conditions were a temperature of 49℃, a duration time of 56 h, an enzyme dosage of 38 FPU/g at a p H value of 4.8, and a solid-to-liquor ratio of 1∶50. The resulting cellulose conversion rate reached 96.4% in terms of the pretreated substances. In addition, a chemical composition analysis of the poplar waste and pretreated material indicated that about 92% of the hemicelluloses and 43% of the lignin in the raw material were degraded and dissolved. In addition, the crystallization decreased from 57.5% to 54.8%. An obvious fibrillation of the fiber pretreated by the wet oxidization process was observed by SEM. Moreover, high-performance liquid chromatography(HPLC) results showed a high xylose content and monosaccharide degradation products in the pretreatment solution. In conclusion, the wet oxidation pretreatment process could efficiently degrade or remove the lignin and hemicellulose, as well as reduce the crystallinity of the lignocellulosic material, which resulted in animprovement of the enzymatic ability and an increase in the cellulose conversion rate.

Coupling biomass pretreatment for enzymatic hydrolysis and direct biomass-to-electricity conversion with molybdovanadophosphoric heteropolyacids as anode electron transfer carriers

Owing to their acidity,oxidizing ability and redox reversibility,molybdovanadophosphoric heteropolyacids(H_(n+3)PMo_(12-n)VnO40,abbreviated as PMo_(12-n)Vn) were employed as electron transfer carriers for coupling biomass pretreatment for enzymatic hydrolysis and direct biomass-to-electricity conversion.In this novel coupled process,PMo_(12-n)Vn pretreatment that causes deconstruction of cell wall structure with PMo_(12-n)Vn being simultaneously reduced can be considered as the "charging" process.The reduced PMo_(12-n)Vn are further re-oxidized with release of electrons in a liquid flow fuel cell(LFFC) to generate electricity is the "discharging" process.Several Keggin-type PMo_(12-n)Vn with different degree of vanadium substitution(DSV, namely n) were prepared.Compared to Keggin-type phosphomolybdic acid(PMo_(12)),PMo_(12-n)Vn(n=1-6) showed higher oxidizing ability but poorer redox reversibility.The cellulose enzymatic digestibility of PMo_(12-n)Vn pretreated wheat straw generally decreased with increase in DSV, but xylan enzymatic digestibility generally increased with DSV.PMo_(12) pretreatment of wheat straw at 120℃ obtained the highest enzymatic glucan conversion(EGC) reaching 95%,followed by PMo11V1 pretreatment(85%).Discharging of the reduced heteropolyacids in LFFC showed that vanadium substitution could improve the maximum output power density(Pmax).The highest Pmax was obtained by PMo9 V3(44.7 mW/cm^(2)) when FeCl_(3) was used as a cathode electron carrier,while PMo_(12) achieved the lowest Pmax(27.4 mW/cm^(2)).All the heteropolyacids showed good electrode Faraday efficiency(>95%) and cell discharging efficiency(>93%).The energy efficiency of the coupled process based on the heat values of the products and generated electric energy was in the range of 18%-25% depending on DSV.PMo_(12) and PMo11V1 seem to be the most suitable heteropolyacids to mediate the coupled process.

Alleviation of Drought Stress in Wheat Using Exogenous Ulva prolifera Extract Produced by Enzymatic Hydrolysis

Drought is one of the major abiotic stresses that affect plant growth and reduce agricultural productivity.Use of algal extract as a biostimulant is gaining increased attention from researchers.This study aimed to investigate the potential of Ulva prolifera extract(UE)as a biostimulant when enzymatically extracted under conditions of water deficit.UE treatments(0.02%,0.06%,and 0.1%)significantly improved the shoot length,root length,and dry weight of roots after 120 h of drought stress relative to that in treatment with the negative control.An increase in catalase(CAT)and peroxidase(POD)activity was also observed that resulted in improved antioxidant capacity.Application of 0.1%UE reduced the malondialdehyde(MDA)content by 30.06%compared with that in the negative control.In addition,the soluble sugar and protein content in wheat treated with 0.1%UE was increased by 23.10%and 93.51%,respectively,resulting in adjustment of the osmotic pressure.Results suggest that UE could significantly enhance the drought tolerance of wheat.This study provides a basis for increasing the value of UE as a biostimulant.

Enzymatic Hydrolysis of Sugarcane Biomass and Heat Integration as Enhancers of Ethanol Production

The aim of this study is to assess the possibility of increasing ethanol production by introducing the bagasse hydrolysis process into conventional distilleries.Simulations were performed for mass and energy balances using Aspen Plus?software.It was assumed that sugarcane trash and lignin cake—hydrolysis process residues—are available as supplementary fuel.Several cases were evaluated,including:(a)conventional ethanol distillery,(b)conventional plant combined with a hydrolysis process without heat integration,with different solid contents in the hydrolysis reactor,and(c)conventional plant combined with the hydrolysis process applying heat integration by pinch analysis.The highest ethanol yield was achieved in the case of heat integration and concentration of cellulose hydrolysate by the membrane system with a solid content of 5%in the hydrolysis reactor.This represents an increase of 22%over conventional distilleries currently found in the industry.

Extraction Hydrolysates from Larimichthys Polyactis Swim Bladder Using Enzymatic Hydrolysis

As a kind of biopolymer,hydrolysates of fish swim bladder,safer than those of land mammals,are widely used in food,cosmetics as well as pharmaceutical and biomedical fields for their biocompatibility,biodegradability,and weak antigenicity.To enhance hydrolysate production,in this paper,the papain and alcalase hydrolysis processes of larimichthys polyactis swim bladder were optimized with orthogonal experiments.With 89.5%hydrolysate yield,the optimal processing conditions for alcalase were solid-liquid ratio of 1:30,enzyme concentration of 0.7%,and extraction time of 6 h.As for papain,under the optimal processing conditions:solid-liquid ratio of 1:20,enzyme concentration of 0.5%,and extraction time of 8 h,the hydrolysate yield was 65.1%.To obtain higher hydrolysate yields,the ultrasonic pretreatments were implemented before the optimal enzyme hydrolysis processes.With ultrasonic waves of 100 W for 50 min,the hydrolysate yields were increased 2.1%(alcalase)and 4.5%(papain),respectively.The Fourier Transform Infrared(FTIR)spectroscopic analysis revealed that the hydrolysates extracted by papain exist in triple-helical forms.The Ultra-Violet(UV)absorption spectra indicated that the aromatic amino acids in the hydrolysates had strong absorptions in the wavelength range of 240 nm–300 nm.The results of this research demonstrate that the alcalase hydrolysates have better solubility in water and the solution is more stable under ambient temperature.However,the hydrolysates extracted by papain have a gel property and are insoluble in weak acid at room temperature,which is more suitable for applications in feedstock of biomedical.

Study on Enzymatic Hydrolysis Technology and Antioxidant Activity of Glutinous Rice Glutinous Enzymatic Processes and Antioxidant Activity

[ Objective] This study aimed to investigate enzymatic hydrolysis technology of glutinous rice and the oxidation resistance activity of the enzymatic hydrolysis solution. [ Method ] White glutinous rice was hydrolyzed using four kinds of proteases including neutral protease, alkaline protease, papain and trypsin. Using the scavenging rate of hydroxyl radical （ ·OH） as an indicator and appropriate protease as hydrolytic enzyme, the effects of protein substrate concentration, enzyme dosage, enzymatic hydrolysis temperature and initial pH on the abilities of proteases to scavenge hydroxyl radical from enzymatic hydrolysis solution of glutinous rice were investigated. Based on single-factor test, L9 （34） orthogonal experimental design was adopted, to determine the optimal enzymatic hydrolysis condi- tions leading to the highest oxidation resistance activity of enzymatic hydrolysis solution. [ Result] The optimized process parameters for enzymatic hydrolysis of glu- tinous rice protein with neutral protease were： protein substrate concentration of 2%, enzyme dosage of 24 000 U/g protein （protein meter）, enzymatic hydrolysis temperature of 55 ℃, initial pH of 8.0, and enzymatic hydrolysis duration of 0.5 h; under these conditions, the hydroxyl radical scavenging rate could reach 56. 05% ; protein substrate concentration, enzyme dosage, enzymatic hydrolysis temperature and initial pH had extremely significant effects on the hydroxyl radical scavenging rate. In addition, the activities of antioxidant peptides in glutinous rice hydrolysates were well maintained within a temperature range of 60 - 100℃. [Condusion] The study produced theoretical feasibility reference for the production of functional base powder by spray drying.

High-yield production of porous carbon spheres derived from enzymatic hydrolysis lignin for zinc ion hybrid capacitors

The widespread implementation of supercapacitors is hindered by the limited energy density and the pricey porous carbon electrode materials.The cost of porous carbon is a significant factor in the overall cost of supercapacitors,therefore a high carbon yield could effectively mitigate the production cost of porous carbon.This study proposes a method to produce porous carbon spheres through a spray drying technique combined with a carbonization process,utilizing renewable enzymatic hydrolysis lignin as the carbon source and KOH as the activation agent.The purpose of this study is to examine the relationship between the quantity of activation agent and the development of morphology,pore structure,and specific surface area of the obtained porous carbon materials.We demonstrate that this approach significantly enhances the carbon yield of porous carbon,achieving a yield of 22%in contrast to the conventional carbonization-activation method(9%).The samples acquired through this method were found to contain a substantial amount of mesopores,with an average pore size of 1.59 to 1.85 nm and a mesopore ratio of 25.6%.Additionally,these samples showed high specific surface areas,ranging from 1051 to 1831 m2·g^(−1).Zinc ion hybrid capacitors with lignin-derived porous carbon cathode exhibited a high capacitance of 279 F·g^(−1) at 0.1 A·g^(−1) and an energy density of 99.1 Wh·kg^(−1) when the power density was 80 kW·kg^(−1).This research presents a novel approach for producing porous carbons with high yield through the utilization of a spray drying approach.

Statistically designed enzymatic hydrolysis of an icariin/b-cyclodextrin inclusion complex optimized for production of icaritin

This study focuses on the preparation and enzymic hydrolysis of an icariin/bcyclodextrin inclusion complex to efficiently generate icaritin.The physical characteristics of the inclusion complex were evaluated by differential scanning calorimetry(DSC).Enzymatic hydrolysis was optimized for the conversion of icariin/b-cyclodextrin complex to icaritin by Box–Behnken statistical design.The inclusion complex formulation increased the solubility of icariin approximately 17-fold,from 29.2 to 513.5 mg/mL at 60℃.The optimum conditions were predicted by Box–Behnken statistical design as follows:60℃,pH 7.0,the ratio of enzyme/substrate(1:1.1)and reaction time 7 h.Under the optimal conditions the conversion of icariin was 97.91%and the reaction time was decreased by 68%compared with that without b-CD inclusion.Product analysis by melting point,ESI-MS,UV,IR,1H NMR and 13C NMR confirmed the authenticity of icaritin with a purity of 99.3%and a yield of 473 mg of icaritin from 1.1 g icariin.

Optimizing extrusion pretreatment and big bluestem parameters for enzymatic hydrolysis to produce biofuel using response surface methodology

Biomass has been identified as alternative renewable energy resource to replace 30%transportation fossil fuel through biofuels by 2.025.Big bluestem is a warm season native perennial grass warrants attention and studies revealed its potential as energy feedstock.Extrusion pretreatments employed on big bluestem showed a significant improvement on sugar recovery.The current study was undertaken to understand and optimize pretreatment conditions such as barrel temperature(45-225℃),screw speed(20-200 r/min),moisture content(10%-50%w.b.),and particle size(2-10 mm)for maximum sugar recovery from big bluestem;and to propose a model to predict the glucose,xylose,and combined sugar recovery.Statistical analyses confirmed that all the independent variables included in this study had a strong influence on sugar recovery.A quadratic polynomial model was proposed to predict the glucose,xylose,and combined sugar recoveries from big bluestem,which had high F and R2 values with low p values.The optimum pretreatment conditions such as barrel temperature 180℃,screw speed 150 r/min,moisture content 20%w.b.,and particle size 8 mm resulted in maximum glucose,xylose,and combined sugar recoveries of 71.3%,78.5%,and 56.9%,respectively.Surface area of the optimum pretreated big bluestem increased 68.5%than that of control sample,which is the main cause for increase in sugar recovery.

Optimization of the ultrasonic-microwave assisted enzymatic hydrolysis of freshwater mussel meat

In the present study,the Ultrasonic-Microwave(US-MW)technique was applied for assisting enzymatic hydrolysis of freshwater mussel meat.The operating parameters of enzymatic hydrolysis were investigated and the properties and qualities of the freshwater mussel hydrolysates were also analyzed.The considerable optimum conditions for enzymatic hydrolysis of mussel meat were ratio of liquid to material of 10.36:1,power of 360.52 W,processing time of 6.91 min,enzymolysis time of 4 h.Under these conditions,a degree of hydrolysis(DH)of 48.40% was obtained.The hydrolysates produced under optimum conditions,were characterized in terms of electrophoretic profile,amino acid composition and infrared spectrum analysis.SDS-PAGE profiles of the hydrolysates revealed that several protein bands were cleaved and several light myosin chains(25 kDa and 15 kDa,respectively)and peptides of molecular weight lower than 6.5 kDa were identified.The infrared spectrum absorption peak of amide band A and band III shifted after US-MW pre-treatment,which indicated that the N-H(hydrogen bonding)stretching vibration and triple helix structure of samples were affected.The essential amino acids in hydrolysates with or without US-MW pre-treatment were 36.62 mg/100 g and 33.40 mg/100 g.It was proved that US-MW assisted enzymatic hydrolysis is an effective technology to utilize freshwater mussel meat.

Pretreatment and enzymatic hydrolysis of sunflower hulls for fermentable sugar production

Sunflower is a widely adapted crop and can be grown in every temperature region.In the U.S.,two million acres were cultivated with sunflowers in 2009.During industrial processing,large quantities of hulls are obtained as a waste product from the dehulling process.This study focused on converting the sunflower hulls into fermentable sugars by dilute acid pretreatment and enzymatic hydrolysis.Raw sunflower hulls are composed ofβ-glucan(34%±1.1%),lignin(25%±0.95%),xylan and arabinan(27%±1.56%),extractives(13%±2.5%)and traces of ash.Sunflower hulls were first subjected to pretreatment by varying three independent factors:1)acid concentration(0.5%-2%);2)reaction temperatures(140-160℃);3)reaction time(10-30 min).Slurry samples obtained after pretreatment were separated into liquid and solid fractions.Liquid fractions were analyzed for monomeric and oligomeric sugars and inhibitor products by High Pressure Liquid Chromatography(HPLC).Enzymatic saccharification was then performed on pretreated solid fractions to convert remaining cellulose(β-glucan)into fermentable sugars.The results showed an increase in acid concentration and reaction temperature gave high xylose yield in the liquid fraction.However,an increase in reaction time resulted in degradation of xylose into furfural.A quadratic model for xylose yield was formulated based on the experimental results.The maximum xylose yield predicted by the model was 62%at 158℃for 20 min at 1.75%acid concentration.The maximumβ-glucan digestibility of the enzymatic saccharification was 53.5%at 160℃for 30 min at 2%acid concentration.

Optimization of enzymatic hydrolysis of pigeon pea for cooking quality of dhal

Cooking quality of dehusked splits is influenced by the dehulling method,in particular,by the pre-milling treatments.The effects of four enzymatic hydrolysis parameters,i.e.,enzyme concentration(20-60 mg/100 g dry matter),incubation time(3-15 h),incubation temperature(40-60℃)and tempering water pH(4.0-6.0)on cooking time of pigeon pea dhal were optimized using response surface methodology.Three kinds of enzymes,i.e.,xylanase,pectinase,and cellulas were used in combination for enzymatic pre-treatment.A quadratic model satisfactorily described the dehulling efficiency with high value for the coefficient of determination R^(2)(0.9062).It predicted a minimum cooking time of 21.91 min at enzyme concentration of 37.8 mg/100 g dry matter,incubation time 8.69 min,incubation temperature 48.5℃ and pH 5.49 of tempering water.Cooking time at optimum condition was observed to be 21.50 min and the predicted values of cooking time showed 2.19% deviation from the experimental values.Results of the study revealed that cooking time of enzyme treated dhal could be decreased by 19.77% compared to the oil treated dhal.

Dissolution and enzymatic hydrolysis of casein micelles studied by dynamic light scattering

The effects of temperature,ionic strength,and enzymatic hydrolysis on the average hydrodynamic radius(Rh)of casein micelles in phosphate buffer were studied by using dynamic light scattering.The results showed that the average Rh value of casein micelles decreased irreversibly during the heating,decreased with the increase of ionic strength in lower ionic strength solution(less than 0.05 mol/L),but opposite in higher ionic strength solution(above 0.1 mol/L).The Rh value of casein increased rapidly during the process of enzymatic hydrolysis,and the structural model of casein micelles in the enzymatic hydrolysis process was also proposed,i.e.the casein micelle changed from compact sphere into unfolded and regularly flocky peptides.

Combined enzymatic hydrolysis and herbal extracts fortification to boost in vitro antioxidant activity of edible bird's nest solution

Objective:Edible bird’s nest(EBN)is a popular traditional tonic food in Chinese population for centuries.Malaysia is one of the main EBN suppliers in the world.This study aims to explore the best strategy to boost the antioxidant potential of EBN solution.Methods:In this study,the raw EBN(4%,mass to volume ratio)was initially enzymatic hydrolyzed using papain enzyme to produce EBN hydrolysate(EBNH),then spray-dried into powdered form.Next,4%(mass to volume ratio)of EBNH powder was dissolved in ginger extract(GE),mulberry leaf extract(MLE)and cinnamon twig extract(CTE)to detect the changes of antioxidant activities,respectively.Results:Results obtained suggest that enzymatic hydrolysis significantly reduced the viscosity of 4%EBN solution from(68.12±0.69)m Pa·s to(7.84±0.31)m Pa·s.Besides,the total phenolic content(TPC),total flavonoid content(TFC),total soluble protein,DPPH scavenging activity and ferric reducing antioxidant power(FRAP)were substantially increased following EBN hydrolysis using papain enzyme.In addition,fortification with GE,MLE and CTE had further improved the TPC,TFC,DPPH scavenging activity and FRAP of the EBNH solution.Among the samples,MLE-EBNH solution showed the most superior antioxidant potential at(86.39±1.66)%of DPPH scavenging activity and(19.79±2.96)mmol/L FeSO;of FRAP.Conclusion:This study proved that combined enzymatic hydrolysis and MLE fortification is the best strategy to produce EBN product with prominent in vitro antioxidant potential.This preliminary study provides new insight into the compatibility of EBN with different herbal extracts for future health food production.

Enzymatic Hydrolysis Lignin(EHL)and its applications for value-added products,a quick review

Enzymatic hydrolysis lignin(EHL)has a variety of active groups,which endow it with excellent properties and broad application prospects.Research work on EHL will promote better utilization of lignin resources and sustainable development of ecological environment.This paper briefly reviewed the research progress on EHL structures,properties,modifications and applications.Future research and development on EHL were also discussed.

Optimization and kinetics of glucose production via enzymatic hydrolysis of mixed peels

The optimization and kinetics of glucose production via enzymatic hydrolysis of mixed peels were carried out.The substrate was characterized using proximate analysis and hydrolysis.The process was optimized using response surface methodology while the kinetics of the hydrolysis was studied using Michealis-menten model.The results obtained showed that the mixed peels have high hemicellulose content,hydrolysable carbohydrate and cellulose.The optimum conditions for glucose yield of 79%by enzymatic hydrolysis are temperature of 36℃,time of five days,pH of 4.55 and enzyme dosage of 0.428 g/50 mL.Enzymatic hydrolysis obeyed Michealis-Menten kinetic model with spontaneous and feasible reactions.Therefore,the results have proved that mixed peels(cassava and potato peels)is a good substrate for glucose production and study of other waste peels as feed-stock is recommended.