2020 Vol. 35, No. 4
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2020, 35(4)
:1-7.
doi: 10.12187/2020.04.001
Abstract:
The carbon and nitrogen sources of the constitutive Pichia pastoris X-33/pGAPZαA-Man26A-39 fermentation medium were optimized by shake flask experiment,and the fermentation conditions were regulated in a 50 L fermentor by using intermittent feeding strategy,in order to realize high-density fermentation of constitutive Pichia pastoris to produce β-mannanase.The results showed that glucose was the most suitable carbon source for fermentation medium,and its initial centration was 30 g/L;corn syrup was the most suitable nitrogen source,and its initial mass fraction was 6%;during the regulation of intermittent fed fermentation,the pH value of bacteria could be maintained between 5.0~5.5 by intermittent flow adding 25% ammonia hydroxide,50% glucose solution and 20% corn syrup,and make sure the carbon and nitrogen sources of the fermentation medium were sufficient;after 60 h fermentation,took measures to put the fermentater tank,at this time,the maximum enzyme activity was 2 685.5 U/mL,the mass concentration of bacteria reached 331.1 g/L,and the OD600 reached 302.8,which achieved the high expression of β-mannanase.
The carbon and nitrogen sources of the constitutive Pichia pastoris X-33/pGAPZαA-Man26A-39 fermentation medium were optimized by shake flask experiment,and the fermentation conditions were regulated in a 50 L fermentor by using intermittent feeding strategy,in order to realize high-density fermentation of constitutive Pichia pastoris to produce β-mannanase.The results showed that glucose was the most suitable carbon source for fermentation medium,and its initial centration was 30 g/L;corn syrup was the most suitable nitrogen source,and its initial mass fraction was 6%;during the regulation of intermittent fed fermentation,the pH value of bacteria could be maintained between 5.0~5.5 by intermittent flow adding 25% ammonia hydroxide,50% glucose solution and 20% corn syrup,and make sure the carbon and nitrogen sources of the fermentation medium were sufficient;after 60 h fermentation,took measures to put the fermentater tank,at this time,the maximum enzyme activity was 2 685.5 U/mL,the mass concentration of bacteria reached 331.1 g/L,and the OD600 reached 302.8,which achieved the high expression of β-mannanase.
2020, 35(4)
:8-15.
doi: 10.12187/2020.04.002
Abstract:
Error-prone PCR was used to directed evolution β-mannanase in vitro, random introduction of mutations into β-mannanase by adjusting dNTP ratio and setting Mn2+ of different concentrations, a mutant library was constructed, and the enzymatic properties of the mutant enzymes were studied. The results showed that during the construction of the mutation library, the positive conversion rate could reach the highest 80% and the number of amino acid mutations was 2.0 with the concentration of Mn2+ 0.01 mmol/L, which was in accordance with the general principles of error-prone PCR mutation libraries; after two rounds of error-prone PCR, a storage capacity of 4000 was constructed, the mutant enzymes GwMan26A-27 of mutant Pichia pastoris X-33/pGAPZαA-GwMan26A-27 with acid resistance, high temperature resistance and high enzyme activity was finally selected; compared with before mutation, GwMan26A-27 has a wider enzymatic reaction temperature before the mutation and a suitable pH range, the thermal stability and pH stability also had been greatly improved; in the pepsin solution and trypsin solution for water bath 2 h, the digestive enzymes stability of GwMan26A-27 had also been improved.
Error-prone PCR was used to directed evolution β-mannanase in vitro, random introduction of mutations into β-mannanase by adjusting dNTP ratio and setting Mn2+ of different concentrations, a mutant library was constructed, and the enzymatic properties of the mutant enzymes were studied. The results showed that during the construction of the mutation library, the positive conversion rate could reach the highest 80% and the number of amino acid mutations was 2.0 with the concentration of Mn2+ 0.01 mmol/L, which was in accordance with the general principles of error-prone PCR mutation libraries; after two rounds of error-prone PCR, a storage capacity of 4000 was constructed, the mutant enzymes GwMan26A-27 of mutant Pichia pastoris X-33/pGAPZαA-GwMan26A-27 with acid resistance, high temperature resistance and high enzyme activity was finally selected; compared with before mutation, GwMan26A-27 has a wider enzymatic reaction temperature before the mutation and a suitable pH range, the thermal stability and pH stability also had been greatly improved; in the pepsin solution and trypsin solution for water bath 2 h, the digestive enzymes stability of GwMan26A-27 had also been improved.
2020, 35(4)
:16-22.
doi: 10.12187/2020.04.003
Abstract:
With grape as the main raw material,a single-factor test was used to study the comprehensive effects of gellan gum, white granulated sugar and citric acid on the gelation property and sensory quality of grape jelly.Then optimization of the technical formula of grape jelly was made by orthogonal test.The results showed that the best technical formula of grape jelly was 0.75% gelatin gum, 8.00% white granulated sugar and 0.26% citric acid.The grape jelly made according to this technical formula was bright in color, full of luster, with unique grape aroma, sweet and sour, healthy and nutritious.
With grape as the main raw material,a single-factor test was used to study the comprehensive effects of gellan gum, white granulated sugar and citric acid on the gelation property and sensory quality of grape jelly.Then optimization of the technical formula of grape jelly was made by orthogonal test.The results showed that the best technical formula of grape jelly was 0.75% gelatin gum, 8.00% white granulated sugar and 0.26% citric acid.The grape jelly made according to this technical formula was bright in color, full of luster, with unique grape aroma, sweet and sour, healthy and nutritious.
2020, 35(4)
:23-33.
doi: 10.12187/2020.04.004
Abstract:
Taking hairtail as raw material,alkaline protease was selected from 6 kinds of proteases as the best protease for hairtail proteolysis,and the technological conditions of hairtail proteolysis were optimized by single factor test and response surface test.The results showed that the optimum conditions for proteolysis of hairtail were as follows:the substrate mass fraction was 5.3%,the protease mass fraction was 2.7%,the pH value of hydrolysis was 8.3,the hydrolysis temperature was 63℃,and the hydrolysis time was 168 min.Under these conditions,the hydrolysis degree of hairtail protein reached 37.07%,which was basically consistent with the predicted value of regression model of response surface optimization test.
Taking hairtail as raw material,alkaline protease was selected from 6 kinds of proteases as the best protease for hairtail proteolysis,and the technological conditions of hairtail proteolysis were optimized by single factor test and response surface test.The results showed that the optimum conditions for proteolysis of hairtail were as follows:the substrate mass fraction was 5.3%,the protease mass fraction was 2.7%,the pH value of hydrolysis was 8.3,the hydrolysis temperature was 63℃,and the hydrolysis time was 168 min.Under these conditions,the hydrolysis degree of hairtail protein reached 37.07%,which was basically consistent with the predicted value of regression model of response surface optimization test.
2020, 35(4)
:34-39.
doi: 10.12187/2020.04.005
Abstract:
Aiming at the problems that the evaluation results of the existing cigarette sensory quality evaluation methods were not obvious and the change trend was not clear,a new comparative evaluation method of tobacco sensory quality was established. The specific process was as follows:using the expert consultation method and combining with the actual evaluation experience,according to the degree of consumer concern,each sensory quality evaluating indicator of elegance,satisfaction,comfort and ease was given weight. The evaluation results of each smoking evaluation person were calculated by mathematical statistics method,and the sub items and overall scores of each sensory quality evaluating indicator were obtained. According to the scores,the difference degree and change direction of sensory quality were determined. The feasibility verification results showed that the method could distinguish the sensory quality from the score when the change of sensory quality was small. It could not only reflect the difference degree of the overall sensory quality,but also reflect the change trend of the overall and individual sensory quality evaluation indicators,and the differentiation of sensory quality differences was obvious. This method could be applied to the development and quality control of cigarette products.
Aiming at the problems that the evaluation results of the existing cigarette sensory quality evaluation methods were not obvious and the change trend was not clear,a new comparative evaluation method of tobacco sensory quality was established. The specific process was as follows:using the expert consultation method and combining with the actual evaluation experience,according to the degree of consumer concern,each sensory quality evaluating indicator of elegance,satisfaction,comfort and ease was given weight. The evaluation results of each smoking evaluation person were calculated by mathematical statistics method,and the sub items and overall scores of each sensory quality evaluating indicator were obtained. According to the scores,the difference degree and change direction of sensory quality were determined. The feasibility verification results showed that the method could distinguish the sensory quality from the score when the change of sensory quality was small. It could not only reflect the difference degree of the overall sensory quality,but also reflect the change trend of the overall and individual sensory quality evaluation indicators,and the differentiation of sensory quality differences was obvious. This method could be applied to the development and quality control of cigarette products.
2020, 35(4)
:40-45.
doi: 10.12187/2020.04.006
Abstract:
In order to choose an appropriate perforation for improving the quality of slim cigarettes,effects of online laser,off-line laser,plasma and static electricity perforations on filter ventilation efficiency,filter ventilation rate stability and sensory quantity for slim cigarretes were investigated.The results showed that all of the four perforations could meet the design needs of filter ventilation rate.Higher filter ventilation rate could achieved of slim cigarettes perforated by plasma and static electricity when air permeability of tipping paper was fixed.Filter ventilation rate stability of slim cigarettes perforated by plasma and online laser was better comparatively.It was more beneficial for improvement of sensory quantity of slim cigarettes perforated by plasma and online laser.Sensory quantity of slim cigarettes perforated by these two ways was corresponded when the filter ventilation rate was lower,and that perforated by online laser was superior to perforated by plasma when the filter ventilation rate was higher.In conclusion,plasma and on-line laser perforations were better than static electricity and off-line laser perforations as a whole,and were the preferred punching methods in the production of slim cigarette.
In order to choose an appropriate perforation for improving the quality of slim cigarettes,effects of online laser,off-line laser,plasma and static electricity perforations on filter ventilation efficiency,filter ventilation rate stability and sensory quantity for slim cigarretes were investigated.The results showed that all of the four perforations could meet the design needs of filter ventilation rate.Higher filter ventilation rate could achieved of slim cigarettes perforated by plasma and static electricity when air permeability of tipping paper was fixed.Filter ventilation rate stability of slim cigarettes perforated by plasma and online laser was better comparatively.It was more beneficial for improvement of sensory quantity of slim cigarettes perforated by plasma and online laser.Sensory quantity of slim cigarettes perforated by these two ways was corresponded when the filter ventilation rate was lower,and that perforated by online laser was superior to perforated by plasma when the filter ventilation rate was higher.In conclusion,plasma and on-line laser perforations were better than static electricity and off-line laser perforations as a whole,and were the preferred punching methods in the production of slim cigarette.
2020, 35(4)
:46-53.
doi: 10.12187/2020.04.007
Abstract:
With jujube as the main raw material, dried apple and Chinese wolfberry as the auxiliary materials, the dry fruit compound spices were prepared by water extraction, alcohol extraction and enzymatic hydrolysis. The chemical compositions of the compound spices were compared and analyzed by GC-MS, and the odor evaluation and cigarette flavoring application of the compound spice were evaluated. The results showed that 54 kinds of chemical components were detected in the compound spice prepared by water extraction,25 kinds were detected by alcohol extraction, 61 kinds were detected by enzymatic hydrolysis, new aromatic substances such as phenylethanol, hexanal and eugenol were produced by enzymatic hydrolysis, and its unique 2,5-dimethyl-4-hydroxy-3 (2H)-furanone was produced by alcohol extraction. There was a little difference in the aroma of the three kinds of compound spices. The water extract compound spice had the fragrance of jujube and the sour flavor was obvious, the alcohol extract compound spices had the clear and sweet taste, the enzymatic compound spice had the most rich jujube fragrance and the burnt sweet taste. The enzymatic compound spice could enrich the aroma and improve the aftertaste of cigarette.The best flavor adding effect was obtained in cigarette, the second was alcohol extract compound spice, and the worst was water extract compound spice. In general, the aroma effect of enzymatic compound spice was better, and it could be used as a new compound spice in cigarette production.
With jujube as the main raw material, dried apple and Chinese wolfberry as the auxiliary materials, the dry fruit compound spices were prepared by water extraction, alcohol extraction and enzymatic hydrolysis. The chemical compositions of the compound spices were compared and analyzed by GC-MS, and the odor evaluation and cigarette flavoring application of the compound spice were evaluated. The results showed that 54 kinds of chemical components were detected in the compound spice prepared by water extraction,25 kinds were detected by alcohol extraction, 61 kinds were detected by enzymatic hydrolysis, new aromatic substances such as phenylethanol, hexanal and eugenol were produced by enzymatic hydrolysis, and its unique 2,5-dimethyl-4-hydroxy-3 (2H)-furanone was produced by alcohol extraction. There was a little difference in the aroma of the three kinds of compound spices. The water extract compound spice had the fragrance of jujube and the sour flavor was obvious, the alcohol extract compound spices had the clear and sweet taste, the enzymatic compound spice had the most rich jujube fragrance and the burnt sweet taste. The enzymatic compound spice could enrich the aroma and improve the aftertaste of cigarette.The best flavor adding effect was obtained in cigarette, the second was alcohol extract compound spice, and the worst was water extract compound spice. In general, the aroma effect of enzymatic compound spice was better, and it could be used as a new compound spice in cigarette production.
2020, 35(4)
:54-60.
doi: 10.12187/2020.04.008
Abstract:
Based on the base formula, the effect of different emulsifier systems on the performance of essence milk was studied, and the acne-removing conditioning effect of essence milk including 4 active ingredients of acne-removing factor EG, SkinClean AC, SkinRelax LC, and ProNature FX were comprehensively evaluated, the final formula of the essence milk was determined, and then the physical and chemical properties of acne-removing conditioning essence milk prepared under the formula was determined. The results showed that acne-removing conditioning essence milk was prepared by using refreshing mixed fat as the oil phase, S2/S21 (m(S2):m(S21)=1.0:1.5) as emulsifier, the acne-removing factor EG as active component, and the dosage of the three was 8.50%, 3.00% and 8.00% respectively, together with the proper amount of moisturizer, thickener, chelating agent and preservative, it had mild performance, good stability, and ideal acne-removing effect.
Based on the base formula, the effect of different emulsifier systems on the performance of essence milk was studied, and the acne-removing conditioning effect of essence milk including 4 active ingredients of acne-removing factor EG, SkinClean AC, SkinRelax LC, and ProNature FX were comprehensively evaluated, the final formula of the essence milk was determined, and then the physical and chemical properties of acne-removing conditioning essence milk prepared under the formula was determined. The results showed that acne-removing conditioning essence milk was prepared by using refreshing mixed fat as the oil phase, S2/S21 (m(S2):m(S21)=1.0:1.5) as emulsifier, the acne-removing factor EG as active component, and the dosage of the three was 8.50%, 3.00% and 8.00% respectively, together with the proper amount of moisturizer, thickener, chelating agent and preservative, it had mild performance, good stability, and ideal acne-removing effect.
2020, 35(4)
:61-66.
doi: 10.12187/2020.04.009
Abstract:
A dendrobium officinale flower toner with moisturizing skin care effect was prepared by using dried dendrobium officinale flower as raw material,supplying with ethanol of mass fraction 95%,glycerin,butylene glycol,allantoin,hydrocline and other ingredients,and the formula of the toner was optimized through the single factor test and orthogonal test.The results showed that when the added amount of ethanol with mass fraction 95% was 10%,dendrobium officinale flower polysaccharide stock solution was 12%,glycerin was 5%,adding appropriate amount of ingredients,the prepared dendrobium officinale flower moisturizing toner had the best sensory evaluation,good quality and stable performance.
A dendrobium officinale flower toner with moisturizing skin care effect was prepared by using dried dendrobium officinale flower as raw material,supplying with ethanol of mass fraction 95%,glycerin,butylene glycol,allantoin,hydrocline and other ingredients,and the formula of the toner was optimized through the single factor test and orthogonal test.The results showed that when the added amount of ethanol with mass fraction 95% was 10%,dendrobium officinale flower polysaccharide stock solution was 12%,glycerin was 5%,adding appropriate amount of ingredients,the prepared dendrobium officinale flower moisturizing toner had the best sensory evaluation,good quality and stable performance.
2020, 35(4)
:67-80.
doi: 10.12187/2020.04.010
Abstract:
By reviewing the basic principle,advantages and disadvantages of different swine wastewater treatment technologies,it was found out that traditional treatment technologies mainly focused on the removal of pollutants from wastewater,but did not consider the control of total nitrogen,which was difficult to achieve energy saving and resource recycling. New treatment technologies not only reduced the energy and material consumption in the process of total nitrogen removal,but also realized the recycling of resources.So these technologies had a broad application prospect in the future swine wastewater treatment. In order to realize sustainable development strategy and achieve higher effluent discharge standards in the future,existing treatment technologies can be improved in optimizing operating conditions,adding pretreatment measures,and combining multi-technology treatment. In the future,new technologies of swine wastewater treatment will develop towards low consumption,high efficiency and high quality.
By reviewing the basic principle,advantages and disadvantages of different swine wastewater treatment technologies,it was found out that traditional treatment technologies mainly focused on the removal of pollutants from wastewater,but did not consider the control of total nitrogen,which was difficult to achieve energy saving and resource recycling. New treatment technologies not only reduced the energy and material consumption in the process of total nitrogen removal,but also realized the recycling of resources.So these technologies had a broad application prospect in the future swine wastewater treatment. In order to realize sustainable development strategy and achieve higher effluent discharge standards in the future,existing treatment technologies can be improved in optimizing operating conditions,adding pretreatment measures,and combining multi-technology treatment. In the future,new technologies of swine wastewater treatment will develop towards low consumption,high efficiency and high quality.
2020, 35(4)
:81-87,95.
doi: 10.12187/2020.04.011
Abstract:
Aiming at the problem of low accuracy of traditional prediction methods of anti-electricity stealing, a prediction method of anti-electricity stealing based on big data of electric power was proposed. This method firstly constructed samples of electricity stealing data according to abnormal rules, and introduced the growth rate of line loss rate constraint conditions.Then it used four machine learning classification algorithms to build a prediction model on the voltage, current and power factor data sets respectively, combined the users with abnormal data output and users with abnormal line loss to output a list of users suspected of stealing electricity.Experimental results showed that the prediction accuracy of the method was satisfactory,and it was efficient and feasible in identifying users suspected of stealing electricity.
Aiming at the problem of low accuracy of traditional prediction methods of anti-electricity stealing, a prediction method of anti-electricity stealing based on big data of electric power was proposed. This method firstly constructed samples of electricity stealing data according to abnormal rules, and introduced the growth rate of line loss rate constraint conditions.Then it used four machine learning classification algorithms to build a prediction model on the voltage, current and power factor data sets respectively, combined the users with abnormal data output and users with abnormal line loss to output a list of users suspected of stealing electricity.Experimental results showed that the prediction accuracy of the method was satisfactory,and it was efficient and feasible in identifying users suspected of stealing electricity.
2020, 35(4)
:88-95.
doi: 10.12187/2020.04.012
Abstract:
Aiming at the problem of large sparseness and poor scalability of traditional collaborative filtering algorithms,a collaborative filtering algorithm based on the improved singular value decomposition (SVD) algorithm and binary K-means clustering algorithm was proposed.The algorithm firstly used the improved SVD algorithm to reduce the dimensionality of the sparse user-item rating matrix to obtain the user implicit feature matrix,then used the binary K-means clustering algorithm to cluster similar users to improve the scalability of the algorithm,and finally used the nearest neighbor set score to correct the target user's score to make up for the error caused by the loss of user information due to matrix factorization.Experimental results on the MovieLens 100K data set showed that compared with the traditional user-based collaborative filtering algorithm,K-means clustering-based collaborative filtering algorithm and latent factor model (LFM) algorithm,this method could effectively improve the accuracy of recommendation results.
Aiming at the problem of large sparseness and poor scalability of traditional collaborative filtering algorithms,a collaborative filtering algorithm based on the improved singular value decomposition (SVD) algorithm and binary K-means clustering algorithm was proposed.The algorithm firstly used the improved SVD algorithm to reduce the dimensionality of the sparse user-item rating matrix to obtain the user implicit feature matrix,then used the binary K-means clustering algorithm to cluster similar users to improve the scalability of the algorithm,and finally used the nearest neighbor set score to correct the target user's score to make up for the error caused by the loss of user information due to matrix factorization.Experimental results on the MovieLens 100K data set showed that compared with the traditional user-based collaborative filtering algorithm,K-means clustering-based collaborative filtering algorithm and latent factor model (LFM) algorithm,this method could effectively improve the accuracy of recommendation results.
2020, 35(4)
:96-102.
doi: 10.12187/2020.04.013
Abstract:
In order to compare and analyze the network traffic classification effect of different machine learning algorithms in the software defined network (SDN) environment, the Moore dataset was balanced, and four classic machine learning algorithms including KNN, random forest (RF), support vector machine (SVM) and gradient lifting decision tree (GBDT) were supported on the machine learning platform RapidMiner to select different classification features for classification experiments. Experimental results showed that compared with the other three algorithms, the GBDT algorithm could obtain better classification results in a shorter time.
In order to compare and analyze the network traffic classification effect of different machine learning algorithms in the software defined network (SDN) environment, the Moore dataset was balanced, and four classic machine learning algorithms including KNN, random forest (RF), support vector machine (SVM) and gradient lifting decision tree (GBDT) were supported on the machine learning platform RapidMiner to select different classification features for classification experiments. Experimental results showed that compared with the other three algorithms, the GBDT algorithm could obtain better classification results in a shorter time.
2020, 35(4)
:103-108.
doi: 10.12187/2020.04.014
Abstract:
Aiming at the problem that the tranditional total generalized variation (TGV) algorithm could not restrain noise effectively in the process of infrared image super-resolution, a single infrared image super-resolution algorithm based on improved TGV was proposed. Firstly, the algorithm was built by second-order TGV regularization model and first-order graduate sharpening operator. First-order graduate sharpening operator was added during the process of gradient ascent, and the factor of first-order graduate sharpening operator was added during the process of gradient descent, so this algorithm acquired a new kind of infrared image super-resolution regularization model. Then it inferred the high-resolution infrared image with a first-order primal-dual optimization scheme. The experimental results showed that the algorithm was superior to other traditional algorithms in terms of subjective visual effect and objective evaluation index, and could obtain high-quality high-resolution infrared images, effectively suppress noise and reduce the complexity of hardware implementation, and had strong practicality.
Aiming at the problem that the tranditional total generalized variation (TGV) algorithm could not restrain noise effectively in the process of infrared image super-resolution, a single infrared image super-resolution algorithm based on improved TGV was proposed. Firstly, the algorithm was built by second-order TGV regularization model and first-order graduate sharpening operator. First-order graduate sharpening operator was added during the process of gradient ascent, and the factor of first-order graduate sharpening operator was added during the process of gradient descent, so this algorithm acquired a new kind of infrared image super-resolution regularization model. Then it inferred the high-resolution infrared image with a first-order primal-dual optimization scheme. The experimental results showed that the algorithm was superior to other traditional algorithms in terms of subjective visual effect and objective evaluation index, and could obtain high-quality high-resolution infrared images, effectively suppress noise and reduce the complexity of hardware implementation, and had strong practicality.
Journal Information
Founded in 1986， bimonthly
Administered by：The Education Department Henan Province
Sponsored by：Zhengzhou University of Light Industry
Editor-in-chief：Wei Shizhong
Executive Editor-in-Chief：Zou Lin
Deputy Editor-in-Chief：Qu Shuanghong
Edited & published by：Editorial Department of Journal of Light Industry
CN 41-1437/TS
ISSN 2096-1553
Address：136 Science Avenue, Zhengzhou City, Henan Province, China
Postal Code：450001
Tel：(086)0371-86608635
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