Optimum Conditions For Enzymatic Hydrolysis Research Articles

Modification of wheat gluten for improvement of binding capacity with keratin in hair.

In this study, enzymatic hydrolysis and cationization with epoxypropyldodecyldimethylammonium chloride of wheat protein, an economic protein complex containing great amount of disulfide bonds, were conducted to improve properties such as solubility and disassociation behaviour for recovery of damaged hair when used in shampoo. The optimal conditions for enzymatic hydrolysis were pH 8.2, 55°C with Alcalase for 60 min. After the selected hydrolysis, the degree of hydrolysis, nitrogen solubility index, foaming capacity index, foam stability index, emulsifying activity index and emulsion stability index of hydrolysate with 58.71% of short-chain peptides (less than 1000 Da) were 8.81%, 39.07%, 225%, 56.67%, 9.62 m2 g−1 and 49.08, respectively. The cationization was followed to raise the isoelectric point of wheat protein hydrolysate from 7.0 to 10.0, which could facilitate the quaternized protein hydrolysate to adhere to the surface of hair at the range of pH 5–6 of hair care products to form more disulfide bonds. The results show that a shampoo with quaternized wheat proteins hydrolysate possesses excellent properties in recovering damaged hair, making the surface of hair smooth and compact.

Interactive effect of enzymes and surfactant on the cellulose digestibility of un-washed and washed dilute ammonia pretreated energy cane bagasse

The interaction effect of cellulase (Cellic® CTec2), xylanase (Cellic® HTec2) and laccase along with a non-ionic surfactant (Tween® 80) on cellulose digestibility of unwashed and washed liquid ammonia pretreated energy cane bagasse was investigated. A polynomial quadratic model was fitted and solved for the optimum value of each variable for the desired response using response surface methodology (RSM). Statistical analysis of the results showed that the interactive effect of all variables with cellulose were significant (p < .05) and resulted in 75.85% and 12.74% improvement in cellulose digestibility of unwashed and washed biomass, respectively. Highest cellulose digestibilities observed were 84.30% and 97.10% for values set within the design range for the unwashed and washed biomass, respectively. Optimum enzymatic hydrolysis conditions for unwashed substrate were 19.39% (mass ratio of glucan) CTec2, 12.04% (mass ratio of glucan) HTec2, a laccase loading on dry biomass of 46.32 IU g−1, and 10.15% (mass ratio of biomass) Tween® 80. Optimum enzymatic hydrolysis conditions for washed substrate were 16.90% (mass ratio of glucan) CTec2, 14.17% (mass ratio of glucan) HTec2 (w/w), a laccase loading on dry biomass of 34.64 IU g−1, and 14.86% (mass ratio of biomass) Tween® 80.

Optimal conditions of enzymatic hydrolysis for producing anti-inflammatory peptides from sandfish (Arctoscopus japonicus) hydrolysate

Optimal conditions of enzymatic hydrolysis for producing anti-inflammatory peptides from sandfish (Arctoscopus japonicus) hydrolysate

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. Keywords: ultrasonic-microwave (US-MW), freshwater mussel meat, enzymatic hydrolysis, degree of hydrolysis (DH) DOI: 10.25165/j.ijabe.20181105.4104 Citation: Zhou Y J, Yi X L, Wang J Y, Yang Q, Wang S J. Optimization of the ultrasonic-microwave assisted enzymatic hydrolysis of freshwater mussel meat. Int J Agric & Biol Eng, 2018; 11(5): 236–242.

Conversion of Lignocellulosic Material Into Fermentable Sugars

Enzymatic hydrolysis process of lignocellulosic biomass materials is difficult because of inherent structural features of biomass, which represents barriers that prevent complete hydrolysis; therefore, pretreatment techniques are necessary to render biomass highly digestible in enzymatic hydrolysis process. In this research, (non?) oxidative short-term lime pretreatment of willow wood was used. A weight of 11.40 g of willow wood was mixed with an excess of calcium hydroxide (0.4 g Ca(OH)2/g raw biomass) and water loading (15 g/g raw biomass). Lime pretreatment was carried out for various periods of time including 1, 2, 3.5, 5 and 6 h, with temperatures at 100, 113, 130, 147 and 1600C, and oxygen pressures as oxidativeagent (6, 9, 13.5, 17.8, 21 bar absolute). The optimization of both pretreatment and enzymatic hydrolysis were depended on the maximum overall yields of glucan and xylan after two processes of lime pretreatment and enzymatic hydrolysis. The optimal conditions of pretreatment were as follow: 1) 1.33 h, 1470C, 17.8 bar absolute, 0.26 g Ca(OH)2/g raw biomass. 2) 1.25 h, 155 0C, 21 bar absolute, 0.26 Ca(OH)2/g raw biomass. Furthermore, the optimal values for low impact factors such as water loading was 15 g/g raw biomass and particle size was less than 3 mm. The optimal conditions of enzymatic hydrolysis were as follow: Cellulase enzymeloading was 0.1 g /g glucan in raw biomass, at substrate concentration of 50 g/L during 72 h of enzymatic hydrolysis The yield of enzymatic hydrolysis under these conditions were as follow: 96.00 g glucan/100 g of glucan in raw biomass, and 65.00 g xylan/100 g xylan in raw biomass.

The potential of agricultural banana waste for bioethanol production

Banana is one of the most important fruit crops around the world. After harvesting, it generates large amounts of lignocellulosic residues that could be used for second generation ethanol production. Optimal operating conditions of saccharification and fermentation processes, of the two main agricultural wastes of banana crop: pseudostem and rachis, for bioethanol production were selected in order attain conditions transferable to industry (optimizing resources and time). Both materials were previously pretreated with acid-catalyzed steam explosion. Full factorial experimental design was used in order to determine enzymatic hydrolysis process conditions to obtain glucose concentrations between 75 and 100 g.L−1. Optimal enzymatic hydrolysis conditions for rachis and pseudostem were 17.6% of solid loading and 16.0 FPU.g−1 glucan of enzyme dosage and 15.1% of solid loading and 14.9 FPU.g−1 glucan of enzyme dosage, respectively. The most suitable configuration to attain the highest volumetric ethanol productivity for rachis was 8 h prehydrolysis followed by a Simultaneous Saccharification and Fermentation (PSSF 8 h). Meanwhile, for pseudostem, higher ethanol production was obtained in Simultaneous Saccharification and Fermentation (SSF) configuration. At optimized conditions, pseudostem reached 112 L.t−1 of ethanol, and rachis 103 L.t−1. These conditions led to achieve ethanol production process at high solid loading, low enzyme dosage, low yeast inoculum, no mineral salts supplementation and maximum ethanol productivities.

Investigating the optimum conditions for minimized 3-chloropropane-1,2-diol esters content and improved sensory attributes during savory beef flavor preparation

In this study, the effects of enzymatic hydrolysis of tallow and addition of sodium chloride (NaCl) were evaluated on the formation of 3-monochloropropane-1,2-diol (3-MCPD) esters and sensory characteristic of beef flavors. The enzymatic hydrolysis condition had significant effects on 3-MCPD mono/di-esters formation during the beef flavor preparation. Considering the safety and sensory characteristics of beef flavors, the optimal enzymatic hydrolysis conditions were selected as: lipase concentration 75U/g tallow, tallow concentration 80% (w/v) and pH 7.0 at 47.5°C for 9.5h. Using the optimal enzymatic hydrolysis conditions, no 3-MCPD monoesters were detected and 3-MCPD-diesters concentration was strongly dependent on NaCl concentration and its addition moment (before or after thermal reaction) at different temperatures. In conclusion, beef flavor was prepared using the optimal hydrolysis conditions and heated at 110°C for 100min, then 10% NaCl was added when the system was cooled to 60°C.

Using an artificial neural network to predict the optimal conditions for enzymatic hydrolysis of apple pomace

The enzymatic degradation of lignocellulosic biomass such as apple pomace is a complex process influenced by a number of hydrolysis conditions. Predicting optimal conditions, including enzyme and substrate concentration, temperature and pH can improve conversion efficiency. In this study, the production of sugar monomers from apple pomace using commercial enzyme preparations, Celluclast 1.5L, Viscozyme L and Novozyme 188 was investigated. A limited number of experiments were carried out and then analysed using an artificial neural network (ANN) to model the enzymatic hydrolysis process. The ANN was used to simulate the enzymatic hydrolysis process for a range of input variables and the optimal conditions were successfully selected as was indicated by the R2 value of 0.99 and a small MSE value. The inputs for the ANN were substrate loading, enzyme loading, temperature, initial pH and a combination of these parameters, while release profiles of glucose and reducing sugars were the outputs. Enzyme loadings of 0.5 and 0.2 mg/g substrate and a substrate loading of 30% were optimal for glucose and reducing sugar release from apple pomace, respectively, resulting in concentrations of 6.5 g/L glucose and 28.9 g/L reducing sugars. Apple pomace hydrolysis can be successfully carried out based on the predicted optimal conditions from the ANN.

Enzymatic hydrolysis of Grass Carp fish skin hydrolysates able to promote the proliferation of Streptococcus thermophilus.

The promotion effect on proliferation of Streptococcus thermophilus by enzymatic hydrolysates of aquatic products was firstly studied. The effect of influencing factors of the hydrolysis on the growth of S. thermophilus was investigated. Grass Carp fish skin was hydrolysed to peptides by enzymatic hydrolysis using protease ProteAX, and for the S. thermophilus growth, the optimal enzymatic hydrolysis conditions were temperature of 60 °C, initial pH of 9.0, enzyme concentration of 10 g kg-1 , hydrolysis time of 80 min, and ratio of material to liquid of 1:2. The Grass Carp fish skin hydrolysate (GCFSH) prepared under the optimum conditions was fractionated to five fragments (GCFSH 1, GCFSH 2, GCFSH 3, GCFSH 4, GCFSH 5) according to molecular weight sizes, in which the fragments GCFSH 4 and GCFSH 5, with molecular weights of less than 1000 Da, significantly promoted the growth of S. thermophilus. The hydrolysis process of Grass Carp fish skin can be simplified, and the peptides with molecular weights below 1000 Da in the hydrolysates are the best nitrogen source for proliferation of S. thermophilus. This work can provide a fundamental theoretical basis for the production of multi-component functional foods, especially in milk drinks or yogurt. © 2017 Society of Chemical Industry.

Improving the hydrolysis efficiency of soy sauce residue using ultrasonic probe-assisted enzymolysis technology

Ultrasonic probe-assisted enzymolysis technology was developed to improve the hydrolysis efficiency of soy sauce residue (SSR). The effects of enzyme type and enzymatic hydrolysis parameters on the hydrolysis degree of SSR were studied firstly to obtain the optimal enzymatic hydrolysis conditions. Then the effects of ultrasound on protease activity and structure of SSR were investigated to elucidate the acting mechanism of ultrasound. Finally, the ultrasonic-assisted enzymatic hydrolysis modes were designed and compared, and the hydrolysates from SSR were characterized to evaluate their further application. The results showed that a hydrolysis degree of 15.53% could be obtained under the optimum enzymolysis conditions: enzyme amount 6000U/g, pH 7.8, temperature 50°C, the ratio of substrate to water phase 1:20, hydrolysis time 4h. Increasing ultrasound treatment time or power could reduce substrate size and consequently enhance the catalytic surface area. Prolonging ultrasound treatment time had a negative influence on enzyme activity, but low ultrasound power was helpful for increasing the enzyme activity. Ultrasound pretreatment of SSR followed by enzymatic hydrolysis increased the hydrolysis degree by 47.6%. When the ultrasound was applied directly to enzymolysis process, the hydrolysis degree of SSR exhibited an increase of 33.0%. The hydrolysates from SSR exhibited good antioxidant activities, and had a potential use as a functional ingredient in food or feed industry.

Extraction and Antioxidant Activity of Soybean Saponins from Lowtemperature Soybean Meal by MTEH

The research aimed at developing an optimal procedure for the extraction of soybean saponins from low- temperature soybean meal with microwave treatment combined with enzymatic hydrolysis (MTEH), and studied the antioxidant activity of soybean saponins. The result showed that the optimal parameters of microwave treatment, determined with the orthogonal array design methods, was the medium fire of microwave power, 1.5 min of microwave time, 80% of ethanol, 1:25 ratio of material to water; the optimal conditions of enzymatic hydrolysis, determined with the response surface experiments, was 50 minutes of hydrolysis time, 51℃ of hydrolysis temperature, 1.5% dosage of cellulase, with which the optimal extraction ratio of the soybean saponins reached 0.916%. The saponins extracted from soybean meal had the ability of antioxidant activity and the effect of scavenging superoxide anion radicals (SAR) and hydrogen peroxide (H 2 O 2 ).

Nutritional Value and Bioactive Properties of Enzymatic Hydrolysates prepared from the Livers of Oncorhynchus keta and Oncorhynchus gorbuscha (Pacific Salmon)

Calculated chemical scores (computed in relation to the FAO/WHO reference protein) for salmon liver protein hydrolysates indicated that all amino acids (other than methionine and threonine) were present in adequate or excess quantities; thus, the raw liver material is a good source of essential amino acids. The hydrophobic amino acids contents in hydrolysates prepared from Oncorhynchus keta and O. gorbuscha were 38.4 and 39.1%, respectively. The proportion of released peptides exceeding 500 kDa was reduced when hydrolysates were treated with the commercial enzyme Alcalase, although proportions in the following MW ranges were elevated: 100-500 kDa and <50 kDa. The optimal conditions for enzymatic hydrolysis were as follows: pH 7.0, <TEX>$50^{\circ}C$</TEX>, and a reaction time of 1 h. Of the different proteases tested, Alcalase was the most efficient for production of salmon liver hydrolysate with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The hydrolysates prepared from salmon liver had a balanced amino acid composition. The liver protein hydrolysates contained low molecular weight peptides, some of which may be bio-active; this bio-active potential should be investigated. Inhibition of the DPPH radical increased with increased degree of hydrolysis (DH), regardless of protease type. DPPH radical scavenging abilities, antithrombotic effects and <TEX>${\alpha}$</TEX>-glucosidase enzyme inhibition effects of O. keta liver hydrolysate increased in a dose-dependent manner. Thus, salmon liver hydrolysate may be useful in functional food applications and as a source of novel products.

An environment friendly and efficient process for xylitol bioconversion from enzymatic corncob hydrolysate by adapted Candida tropicalis

This study reported an environment friendly process for xylitol bioconversion from corncob hemicellulose hydrolysate prepared through xylanolytic enzymes by adapted Candida tropicalis. In order to improve the production of xylanolytic enzymes from Aspergillus terreus, the fermentation medium and growth conditions were optimized. Maximum xylanase (722U/g) and β-xylosidase (196U/g) production were exhibited on wheat bran and corncob (mass ratio of 7:3) medium supplemented with 2% (v/v) NaNO3 and 0.05% (v/v) Tween 80 at pH 6.8, 1:1 (v/w) moisture level, 20% inoculum level and 30°C for 120h of cultivation. For preparation of corncob hemicellulose hydrolysate, the optimum enzymatic hydrolysis conditions contained enzyme dosage (30.6U/g), water addition (19.2mL/g), temperature (48.01°C), pH (5.75). Under these conditions, the sugars of 18.03g/L xylose and 4.87g/L glucose were obtained in 8h. The corncob hemicellulose hydrolysate was used for xylitol fermentation and the maximum xylitol yield of 75.14% was obtained by adapted C. tropicalis after the optimization of fermentation.

Optimization of Hydrolysis Conditions for the Production of Iron-Binding Peptides from Mackerel Processing Byproducts

The aim of this study was focused on optimization of enzymatic hydrolysis conditions for the production of iron-binding peptides from marine mackerel processing byproducts. The marine mackerel processing byproducts protein were hydrolyzed using trypsin, Protamex, Flavourzyme, Alcalase and Neutrase. Alcalase and Protamex proteolytic hydrolysates exhibited the highest iron-binding capacity; however, Alcalase proteolytic hydrolysate had higher degree of hydrolysis than that of Protamex. A four-factor-three-level composition central design experiment in response surface methodology was used to optimize the enzymatic hydrolysis conditions of Alcalase. The optimal enzymatic hydrolysis conditions were temperature of 46.0°C, time of 2.01 h, pH 8.35 and enzyme to substrate 6460 U/mL. The quadratic model predicted well about the actual measured value. The average iron-binding capacity of three verification experiment was 6.62 mg-EDTA/g-protein, which was much closed to model predicted value of 6.69 mg-EDTA/g-protein.

Optimal Conditions of Enzymatic Hydrolysis of Alginic Acid in Brown Algal Carbohydrate

Optimal Conditions of Enzymatic Hydrolysis of Alginic Acid in Brown Algal Carbohydrate

Optimization of enzymatic hydrolysis for preparation of duck flavor precursors

In order to provide the optimally hydrolyzed material for producing duck-flavor essence,proteases were used to hydrolyze the duck protein.The results indicated that the hydrolysis effect of compound flavourzyme and meat enzyme on duck protein were better than that of papain and neutrase.And the effect of using compound flavourzyme and meat enzyme together was better than using the single enzyme alone.The optimal conditions for enzymatic hydrolysis were as follows: hydrolysis temperature,50 ℃;enzyme/substrate ratio,1 500 U/g protein;initial pH,8.0 and compound flavourzyme/meat enzyme ratio,3∶1.Under these conditions,the degree of hydrolysis was about 36% after 3 h of reaction.The hydrolysis liquid with 36% duck protein hydrolyzed could produce the best flavor during the Maillard reaction.

Study on the Preparation Process of Rice Bran Oil by the Ultrasonic Enzymatic Extraction

The influence of oil rate and quality of rice bran oil by enzymatic extraction ultrasonic assisted were studied through designed experiment. The optimum enzymatic hydrolysis conditions were determined by the way of the orthogonal test. The results showed: after lipase enzyme in the rice bran (40 mesh sieve) was killed by the hot steam, the solution compounding material liquid ratio was 1:5 (W/V), 60°C, power and time of ultrasonic treatment were 120 W and 55 min, cellulose 1.2%, protease 0.6% and amylase 0.3%, pH 4.5, temperature 55°C, enzyme hydrolysis 5.5 h, the oil rate would reach to 92.63%.

Effect of β-Cyclodextrin Complexation on Solubility and Enzymatic Conversion of Naringin

In the present paper, the effect of β-cyclodextrin (β-CD) inclusion complexation on the solubility and enzymatic hydrolysis of naringin was investigated. The inclusion complex of naringin/β-CD at the molar ratio of 1:1 was obtained by the dropping method and was characterized by differential scanning calorimetry. The solubility of naringin complexes in water at 37 ± 0.1 °C was 15 times greater than that of free naringin. Snailase-involved hydrolysis conditions were tested for the bioconversion of naringin into naringenin using the univariate experimental design. Naringin can be transformed into naringenin by snailase-involved hydrolysis. The optimum conditions for enzymatic hydrolysis were determined as follows: pH 5.0, temperature 37 °C, ratio of snailase/substrate 0.8, substrate concentration 20 mg·mL−1, and reaction time 12 h. Under the optimum conditions, the transforming rate of naringenin from naringin for inclusion complexes and free naringin was 98.7% and 56.2% respectively, suggesting that β-CD complexation can improve the aqueous solubility and consequently the enzymatic hydrolysis rate of naringin.

Improved enantioselective hydrolysis of racemic ethyl-2,2-dimethylcyclopropanecarboxylate catalyzed by modified Novozyme 435

S-(+)-2,2-dimethylcyclopropanecarboxylic acid (S-(+)-DMCPA) is a key chiral intermediate for the synthesis of Cilastatin. The enzymatic preparation of S-(+)-DMCPA has attracted much attention. In order to improve the activity and stability of Novozyme 435 for enzymatic preparation of S-(+)-DMCPA from 2,2-dimethylcyclopropane carboxylate (DMCPE), the glutaraldehyde modification for Novozyme 435 was investigated and the glutaraldehydemodified Novozyme 435 was used as biocatalyst for the synthesis of S-(+)-DMCPA. The results showed that the modified Novozyme 435 had a better reusing merit than unmodified enzyme. The maximum specific activity was obtained by modification Novozyme 435 with 1.5% glutaraldehyde solution under the conditions of shaking at 200 rpm and 30°C for 45 min. The optimal enzymatic hydrolysis conditions for glutaraldehyde-modified Novozyme 435 were also confirmed. The optimized hydrolytic reaction mixture contained 10 mL potassium phosphate buffer (1.0 mol/L, pH 7.6), 90 mg of DMCPE and 160 mg of glutaraldehyde-modified enzyme, and the reaction was performed at 30oC and 200 rpm for 52 h. The reusing efficiency of modified Novozyme 435 was further evaluated. Under the optimal conditions, the modified enzyme remained 76.0% of its original yield after 10 times reuse, but the optical purity of the product kept intact; whereas the yield of unmodified enzyme reduced to 20.8% of its initial value and the ee value of product decreased a lot to 90.7% after 7 times recycle. These results showed that the modified Novozyme 435 was more cost-effective for the preparation of S-(+)-DMCPA in industrial application.

Optimization of enzymatic hydrolysis of palm kernel cake protein (PKCP) for producing hydrolysates with antiradical capacity

The enzymatic hydrolysis of palm kernel cake protein (PKCP) with trypsin to obtain PKCP hydrolysates (PKCPH) was optimized using response surface methodology (RSM). A central composite design (CCD) was used to study the influence of four independent variables, namely pH, hydrolysis temperature (°C), substrate concentration (w/v) and enzyme/substrate (w/w) ratio on the degree of hydrolysis (DH%). The hydrolysis was carried out using different combinations of four hydrolytic parameters at five levels for 6h. The CCD consisted of 24 experimental points and six replicates of the central points. The data were analyzed using Design-Expert Software. The results showed that all of the variables evaluated significantly influenced the DH% in a second polynomial model, and different combinations of parameters were generated to obtain three different levels of DH (30%, 40% and 50%), namely PKCPH 30, PKCPH 40 and PKCPH 50. The PKCPH with different DH% showed significantly different antiradical properties (p<0.05). The PKCPH 50 preparation had the lowest EC50 value for DPPH radical scavenging capacity (0.14mg/ml). In the ABTS+ radical scavenging capacity and PCL-ACW (photo chemiluminescence-antiradical capacity of water soluble substances) assays, PKCPH 50 showed the highest Trolox equivalent antioxidant capacity value (326.67±5.77μmol TEAC/g) and ascorbic acid equivalent value (11.43±0.03μg AAE/mg) of the preparations tested. Moreover, the protein hydrolysates also exhibited a notable reducing effect in a dose-dependent manner. Optimum conditions for enzymatic hydrolysis of PKCP were established in this study to produce an antiradical agent.