Due to its beneficial health effects,the use of soybean protein has shown a continuous increase,but concerns regarding the allergenicity of soybean antigenic protein have also increased.This study aimed to evaluate th...Due to its beneficial health effects,the use of soybean protein has shown a continuous increase,but concerns regarding the allergenicity of soybean antigenic protein have also increased.This study aimed to evaluate the hydrolytic effects of a non-commercial alkaline protease isolated from the Bacillus subtilis ACCC 01746 on soybeanβ-conglycinin and the allergenicity of its hydrolysates.Alkaline protease of the strain was separated by precipitation method of organic solvents,and theβ-conglycinin was separated by alkali-solution and acid-isolation and purified by use of gel column.Using the degree of hydrolysis(DH)and inhibition rate as evaluation indexes,the enzymatic hydrolysis parameters ofβ-conglycinin was optimized by single factor and L_(9)(3^(4))orthogonal tests,so as to explore the effect of the protease on the hydrolysis degree and the antigenicity ofβ-conglycinin hydrolysates.The results showed that the native enzyme existed as an 18.3 kDa monomer with a 430 U/g maximum activity.The purity ofβ-conglycinin was 84.8%.The single-factor test results showed that DH showed the oppostie trendency with the inhibition rate,and the increase of protein concentration causedmonotone increasing and monotone decreasing of the inhibition rate and the DH,and the optimal protein concentration was 30 mg/mL.The optimization results showed that pH had the largest impacts on both DH and the inhibition rate,followed by enzyme dosage,hydrolysis temperature and hydrolysis time.Under the optimum hydrolysis conditions of protein concentration 30mg/mL,enzymedosage0.7%,hydrolysis time40min,temperature 55°C and pH8.5,the DH reached the highest of 76.28%,and the inhibition rate was the lowest of 27.03%,which was reduced greatly compared with that before optimization.These results suggested that alkaline protease appeared to show a relatively high effeciency in lowering soybean allergenicity,making it possible to produce low-allergenicity soybean protein.展开更多
A new enzyme (alkaline protease 894) obtained from the marine extremophile Flavobacterium yellowsea (YS-80-122) has exhibited strong substrate-binding and catalytic activity, even at low temperature, but the character...A new enzyme (alkaline protease 894) obtained from the marine extremophile Flavobacterium yellowsea (YS-80-122) has exhibited strong substrate-binding and catalytic activity, even at low temperature, but the characteristics of the hydrolysis with this enzyme are still unclear. The pearl oyster Pinctada martensii was used in this study as the raw material to illustrate the kinetic properties of protease 894. After investigating the intrinsic relationship between the degree of hydrolysis and several factors, including initial reaction pH, temperature, substrate concentration, enzyme concentration, and hydrolysis time, the kinetics model was established. This study showed that the optimal conditions for the enzymatic hydrolysis were an initial reaction pH of 5.0, temperature of 30°C, substrate concentration of 10% (w/v), enzyme concentration of 2 500 U/g, and hydrolysis time of 160 min. The kinetic characteristics of the protease for the hydrolysis of P. martensii were obtained. The inactivation constant was found to be 15.16/min, and the average relative error between the derived kinetics model and the actual measurement was only 3.04%, which indicated a high degree of fitness. Therefore, this study provides a basis for the investigation of the concrete kinetic characteristics of the new protease, which has potential applications in the food industry.展开更多
The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five le...The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five levels quadratic rotation perpendicular regressive design. The optimum hydrolysis conditions of hydrolyzing the protein of Silver carp by-products were determined to be concentration of enzyme (E/S) 3.33%, pH 8.54, hydrolyzing temperature 58 ℃, reaction time 90 min, concentration of substrate 8%. Nitrogen recovery was more than 75%.展开更多
Several protein sources can be used to produce bioactive peptides with angiotensin I-converting enzyme (ACE) inhibittory activity. Protein concentrates from ungerminated and germinated lima bean Phaseolus lunatus seed...Several protein sources can be used to produce bioactive peptides with angiotensin I-converting enzyme (ACE) inhibittory activity. Protein concentrates from ungerminated and germinated lima bean Phaseolus lunatus seed flours were hydrolyzed with Alcalase 2.4 L or pepsin-pancreatin sequential hydrolysis, and ACE inhibitory activity measured in the different hydrolysis treatments. Protein hydrolysate production was analyzed with a 23 factorial design with four replicates of the central treatment. Evaluated factors were protein concentrate source (ungerminated seeds, PC1;germinated seeds, PC2), enzyme/substrate ratio E/S (1/50 or 1/10) and hydrolysis time (0.5 or 2.0 h for Alcalase;1 or 3 h for pepsin-pancreatin). Degree of hydrolysis (DH) was high for the Alcalase hydrolysates (24.12% 58.94%), but the pepsin-pancreatin hydrolysates exhibited the highest ACE inhibitory activity (IC50 = 0.250 0.692 mg/mL). Under the tested conditions, the hydrolysates with the highest ACE inhibitory activity were produced with sequential pepsin-pancreatin using either PC1 at 1 h hydrolysis time and a 1/10 E/S ratio or PC2 at 1 h hydrolysis time and a 1/50 E/S ratio. Lima bean protein hydrolysates prepared with Alcalase or pepsin-pancreatin are a potential ingredient in the production of physiologically functional foods with antihypertensive activity.展开更多
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 propert...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.展开更多
The recycling of waste from food processing is an important industrial procedure for obtaining protein sources with high added value.In this study,trout(Onchorynchus mykiss),anchovy(Engraulis encrasicolus),and whiting...The recycling of waste from food processing is an important industrial procedure for obtaining protein sources with high added value.In this study,trout(Onchorynchus mykiss),anchovy(Engraulis encrasicolus),and whiting(Merlangius merlangus)wastes were hydrolyzed.The hydrolyzation procedure was investigated under the optimum predicted conditions defined by time,temperature,and enzyme ratio(E/S)using alkaline protease(pH 8),Protamex(pH 7),and Flavourzyme(pH 7).The hydrolysis conditions that showed the best degree of hydrolysis(DH%)were optimized using response surface methodology(RSM)with the central composite design(CCD)and Box-Behnken design(BBD)models.The effects of three independent variables,temperature(40-60℃),time(1-8 h),and enzyme concentrations(1-2%),were examined for model optimization.It was determined that the DH%varies between 50.92%and 74.30% according to the type of fish waste and enzyme.The highest degree of hydrolysis was observed from trout waste(74.30%)and the lowest degree from whiting waste(50.92%)with Flavourenzyme.From this study,it has been shown that different degrees of hydrolysis and protein recovery can be obtained,depending on fish species,waste composition,enzyme type,and hydrolysis method.展开更多
基金Thanks to Grain&Corn Engineering Technology Research Center,State Administration of Grain(GA2017004)Science and Technology Research Project of Henan(172102110205 and 182102310676)for funding support.
文摘Due to its beneficial health effects,the use of soybean protein has shown a continuous increase,but concerns regarding the allergenicity of soybean antigenic protein have also increased.This study aimed to evaluate the hydrolytic effects of a non-commercial alkaline protease isolated from the Bacillus subtilis ACCC 01746 on soybeanβ-conglycinin and the allergenicity of its hydrolysates.Alkaline protease of the strain was separated by precipitation method of organic solvents,and theβ-conglycinin was separated by alkali-solution and acid-isolation and purified by use of gel column.Using the degree of hydrolysis(DH)and inhibition rate as evaluation indexes,the enzymatic hydrolysis parameters ofβ-conglycinin was optimized by single factor and L_(9)(3^(4))orthogonal tests,so as to explore the effect of the protease on the hydrolysis degree and the antigenicity ofβ-conglycinin hydrolysates.The results showed that the native enzyme existed as an 18.3 kDa monomer with a 430 U/g maximum activity.The purity ofβ-conglycinin was 84.8%.The single-factor test results showed that DH showed the oppostie trendency with the inhibition rate,and the increase of protein concentration causedmonotone increasing and monotone decreasing of the inhibition rate and the DH,and the optimal protein concentration was 30 mg/mL.The optimization results showed that pH had the largest impacts on both DH and the inhibition rate,followed by enzyme dosage,hydrolysis temperature and hydrolysis time.Under the optimum hydrolysis conditions of protein concentration 30mg/mL,enzymedosage0.7%,hydrolysis time40min,temperature 55°C and pH8.5,the DH reached the highest of 76.28%,and the inhibition rate was the lowest of 27.03%,which was reduced greatly compared with that before optimization.These results suggested that alkaline protease appeared to show a relatively high effeciency in lowering soybean allergenicity,making it possible to produce low-allergenicity soybean protein.
基金Supported by the Comprehensive Strategic Cooperation Programs between Guangdong Province and Chinese Academy of Sciences(No.2011A090100008)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-EW-Q214)
文摘A new enzyme (alkaline protease 894) obtained from the marine extremophile Flavobacterium yellowsea (YS-80-122) has exhibited strong substrate-binding and catalytic activity, even at low temperature, but the characteristics of the hydrolysis with this enzyme are still unclear. The pearl oyster Pinctada martensii was used in this study as the raw material to illustrate the kinetic properties of protease 894. After investigating the intrinsic relationship between the degree of hydrolysis and several factors, including initial reaction pH, temperature, substrate concentration, enzyme concentration, and hydrolysis time, the kinetics model was established. This study showed that the optimal conditions for the enzymatic hydrolysis were an initial reaction pH of 5.0, temperature of 30°C, substrate concentration of 10% (w/v), enzyme concentration of 2 500 U/g, and hydrolysis time of 160 min. The kinetic characteristics of the protease for the hydrolysis of P. martensii were obtained. The inactivation constant was found to be 15.16/min, and the average relative error between the derived kinetics model and the actual measurement was only 3.04%, which indicated a high degree of fitness. Therefore, this study provides a basis for the investigation of the concrete kinetic characteristics of the new protease, which has potential applications in the food industry.
基金Heilongjiang Province Science and Technology Key Project
文摘The hydrolysis process for Silver carp by-products was studied. Protein hydrolysate was prepared with proteolytic enzyme, Alcalase. Hydrolysis conditions were optimized by the regression model of three factors five levels quadratic rotation perpendicular regressive design. The optimum hydrolysis conditions of hydrolyzing the protein of Silver carp by-products were determined to be concentration of enzyme (E/S) 3.33%, pH 8.54, hydrolyzing temperature 58 ℃, reaction time 90 min, concentration of substrate 8%. Nitrogen recovery was more than 75%.
基金This research was partially funded by the Consejo Na-cional de Ciencia y Tecnología(CONACYT),Project“Ciencia Básica 25796”and SIP-IPN(projects:20060445,20070800,and 20082532).
文摘Several protein sources can be used to produce bioactive peptides with angiotensin I-converting enzyme (ACE) inhibittory activity. Protein concentrates from ungerminated and germinated lima bean Phaseolus lunatus seed flours were hydrolyzed with Alcalase 2.4 L or pepsin-pancreatin sequential hydrolysis, and ACE inhibitory activity measured in the different hydrolysis treatments. Protein hydrolysate production was analyzed with a 23 factorial design with four replicates of the central treatment. Evaluated factors were protein concentrate source (ungerminated seeds, PC1;germinated seeds, PC2), enzyme/substrate ratio E/S (1/50 or 1/10) and hydrolysis time (0.5 or 2.0 h for Alcalase;1 or 3 h for pepsin-pancreatin). Degree of hydrolysis (DH) was high for the Alcalase hydrolysates (24.12% 58.94%), but the pepsin-pancreatin hydrolysates exhibited the highest ACE inhibitory activity (IC50 = 0.250 0.692 mg/mL). Under the tested conditions, the hydrolysates with the highest ACE inhibitory activity were produced with sequential pepsin-pancreatin using either PC1 at 1 h hydrolysis time and a 1/10 E/S ratio or PC2 at 1 h hydrolysis time and a 1/50 E/S ratio. Lima bean protein hydrolysates prepared with Alcalase or pepsin-pancreatin are a potential ingredient in the production of physiologically functional foods with antihypertensive activity.
文摘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.
基金supported by Ordu University Scientific Research Projects Coordination Unit(ODU/BAP)with project number BD-1701 and AR-1646.
文摘The recycling of waste from food processing is an important industrial procedure for obtaining protein sources with high added value.In this study,trout(Onchorynchus mykiss),anchovy(Engraulis encrasicolus),and whiting(Merlangius merlangus)wastes were hydrolyzed.The hydrolyzation procedure was investigated under the optimum predicted conditions defined by time,temperature,and enzyme ratio(E/S)using alkaline protease(pH 8),Protamex(pH 7),and Flavourzyme(pH 7).The hydrolysis conditions that showed the best degree of hydrolysis(DH%)were optimized using response surface methodology(RSM)with the central composite design(CCD)and Box-Behnken design(BBD)models.The effects of three independent variables,temperature(40-60℃),time(1-8 h),and enzyme concentrations(1-2%),were examined for model optimization.It was determined that the DH%varies between 50.92%and 74.30% according to the type of fish waste and enzyme.The highest degree of hydrolysis was observed from trout waste(74.30%)and the lowest degree from whiting waste(50.92%)with Flavourenzyme.From this study,it has been shown that different degrees of hydrolysis and protein recovery can be obtained,depending on fish species,waste composition,enzyme type,and hydrolysis method.
