The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual...The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.展开更多
Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study...Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study is to analyze the flavor changes in the shrimp paste fermentation process and screen out the key volatile aroma components in the shrimp paste to control the flavor quality of the shrimp paste products.The overall odor profile was detected by the electronic nose.A total of 106 volatile flavor compounds in the shrimp paste samples at different fermentation stages were identified by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)and headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS).The main aroma components alcohols,aldehydes,pyrazines and other substances in the fermentation process showed an overall upward trend.A total of 17 key volatile aroma components in shrimp paste at different fermentation stages were identified by the relative aroma activity value(ROAV)method.The combination of electronic nose,SPME-GC-MS and HS-GC-IMS could comprehensively reflect the changes of volatile components in shrimp paste at different fermentation stages,which helps to further understand the mechanism of shrimp paste flavor formation and provides a basis for the regulation of the flavor quality of shrimp paste products.展开更多
With the rapid development of electronic communication technology,various new technical elements are constantly added to it,bringing many changes to people’s lives and work.The traditional data diversion mode can no ...With the rapid development of electronic communication technology,various new technical elements are constantly added to it,bringing many changes to people’s lives and work.The traditional data diversion mode can no longer truly meet the needs of actual work,and the electronic communication mode plays a huge role and occupies an important position in the communication market.Regarding how to develop and apply intelligent electronic communication technology more perfectly,there will be an overview of the specific principle of intelligent electronic communication technology,from the multi-faceted impact of electronic communication technology on human society.The article put forward the future development trend of electronic communication technology based on intelligent networks,emphasized expanding the scale of technology coverage,improved the comprehensive quality of technical products,optimized the structure of the communication industry,and formed a perfect industrial chain,so as to improve the intelligent level of electronic communication technology.展开更多
Electronic design automation(EDA)technology is the product of the computer age and finds its foundation in CAD,CAM,CAT,and CAE.EDA is a kind of auxiliary tool in the design process,which requires the designer to carry...Electronic design automation(EDA)technology is the product of the computer age and finds its foundation in CAD,CAM,CAT,and CAE.EDA is a kind of auxiliary tool in the design process,which requires the designer to carry out the file design work using hardware language as the foundation.Subsequently,the computer system automatically compiles and integrates the file to achieve simulation goals,and can complete the programming download of the target chip.At present,this technology is widely used in the communication of electronic circuits.This paper summarizes EDA technology and analyzes its specific application in communication electronic circuits,aiming at promoting the application of CDA technology and promoting the further development of the communication field.展开更多
As critical measures to educate and cultivate people’s morality,“Ideology and Politics of Course”has gradually become the focus in actual undergraduate education research in universities.Targeting the single ideolo...As critical measures to educate and cultivate people’s morality,“Ideology and Politics of Course”has gradually become the focus in actual undergraduate education research in universities.Targeting the single ideological and political education mode and students’lack of interest in experimental courses,this paper,through various links,including pre-class preview,in-class teaching,and after-class data analysis,takes the common emitter single tube amplifier experiment as an example to organically integrate the excavated ideological and political elements with practical operation and carry out teaching case design and practice;realize the improvement of students’learning initiative and problem-analysis ability;and achieve the purpose of cultivating people throughout the whole process and in a comprehensive direction.展开更多
Rapid advances in sensor technologies have facilitated the development of high-performance electronic noses that can detect and discriminate volatile compounds in situ. The research and development of electronic noses...Rapid advances in sensor technologies have facilitated the development of high-performance electronic noses that can detect and discriminate volatile compounds in situ. The research and development of electronic noses has resulted in a new qualitative and semi-quantitative detection approach in the field of clinical diagnostics. Electronic noses have a clear potential to be a non-invasive, simple and rapid but above all accurate early diagnostic screening tool. This review collates existing knowledge of recent advances in electronic nose technologies and applications.展开更多
Shrimp paste is a type of condiments with high nutritional value.However,the flavors of shrimp paste,particularly the non-uniformity flavors,have limited its application in food processing.In order to identify the cha...Shrimp paste is a type of condiments with high nutritional value.However,the flavors of shrimp paste,particularly the non-uniformity flavors,have limited its application in food processing.In order to identify the characteristic flavor compounds in Chinese traditional shrimp pastes,five kinds of typical commercial products were evaluated in this study.The differences in the volatile composition of the five products were investigated.Solid phase micro-extraction method was employed to extract the volatile compounds.GC-MS and electronic nose were applied to identify the compounds,and the data were analyzed using principal component analysis(PCA).A total of 62 volatile compounds were identified,including 8 alcohols,7 aldehydes,3 ketones,7 ethers,7 acids,3 esters,6 hydrocarbons,12 pyrazines,2 phenols,and 7 other compounds.The typical volatile compounds contributing to the flavor of shrimp paste were found as follows:dimethyl disulfide,dimethyl tetrasulfide,dimethyl trisulfide,2,3,5-trimethyl-6-ethyl pyrazine,ethyl-2,5-dimethyl-pyrazine,phenol and indole.Propanoic acid,butanoic acid,furans,and 2-hydroxy-3-pentanone caused unpleasant odors,such as pungent and rancid odors.Principal component analysis showed that the content of volatile compounds varied depending on the processing conditions and shrimp species.These results indicated that the combinations of multiple analysis and identification methods could make up the limitations of a single method,enhance the accuracy of identification,and provide useful information for sensory research and product development.展开更多
Four rice samples of long grain type were tested using an electronic nose (Cyranose-320).Samples of 5 g of each variety ofrice were placed individually in vials and were analyzed with the electronic nose unit consisti...Four rice samples of long grain type were tested using an electronic nose (Cyranose-320).Samples of 5 g of each variety ofrice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer sensors.TheCyranose-320 was able to differentiate between varieties of rice.The chemical composition of the rice odors for differentiatingrice samples needs to be investigated.The optimum parameter settings should be considered during the Cyranose-320 trainingprocess especially for multiple samples,which are helpful for obtaining an accurate training model to improve identificationcapability.Further,it is necessary to investigate the E-nose sensor selection for obtaining better classification accuracy.A re-duced number of sensors could potentially shorten the data processing time,and could be used to establish an application pro-cedure and reduce the cost for a specific electronic nose.Further research is needed for developing analytical procedures thatadapt the Cyranose-320 as a tool for testing rice quality.展开更多
The objectives of the present study were to determine the effects of the brewing method on the amount of the major catechins, methylxanthines, total polyphenols and antioxidant capacity in green and black teas, and to...The objectives of the present study were to determine the effects of the brewing method on the amount of the major catechins, methylxanthines, total polyphenols and antioxidant capacity in green and black teas, and to correlate the chemical composition of tea infusions to their sensorial properties by the combined use of the electronic nose and tongue. For this purpose, tea infusions were prepared from 7 green teas and 6 black teas using different extraction times (3 - 5 and 10 min). The extraction of total polyphenols and catechins was increased by prolonging the infusion time from 3 - 5 to 10 min, while the caffeine amounts did not increase. The antioxidant activity of teas was well correlated with polyphenol content. Electronic tongue and electronic nose were able to discriminate green teas from black teas on the basis of their sensorial properties. Considering the taste, green teas were characterized by astringency and aftertaste-astringency and this sensation was increased by prolonging the infusion time;black teas were perceived as more bitter, sour, salty and the extraction time affected the astringent sensation. The aroma of green and black teas was discriminated by specific sensors and the increase of the extraction time produced more richly flavoured infusions. This work adds information about correlation between sensorial properties, antioxidant capacity and chemical composition of green and black teas.展开更多
Background:Magnolia bark(Magnolia Officinalis REHD.&WILS.and Magnolia officinalis REHD.&WILS.VAR.biloba REHD.&WILS,Hou Po in Chinese),is widely applied in clinical prescriptions and Chinese patent medicine...Background:Magnolia bark(Magnolia Officinalis REHD.&WILS.and Magnolia officinalis REHD.&WILS.VAR.biloba REHD.&WILS,Hou Po in Chinese),is widely applied in clinical prescriptions and Chinese patent medicines.Origin place is a crucial factor affecting the quality of Hou Po,and chemical composition is an important index for evaluating its quality,which is closely related to its clinical efficacy.This study aims to develop a novel method for rapidly,accurately and comprehensively identifying the origin places of Hou Po and predicting the contents of its important chemical components.Methods:High performance liquid chromatography was used to analyze the contents of magnolol and honokiol and ultra-performance liquid chromatography the contents of magnocurarine and magnoflorine.The cold soak method was used to determine the contents of water-soluble extracts.The E-nose and colorimeter were used to determine the odor and color characteristics,respectively,of the collected Hou Po samples.Results:Using several statistical algorithms,different discriminant models based on the E-nose and colorimeter data were established to distinguish the origin place of Hou-Po and predict the chemical components of honokiol,magnolol,magnocurarine,magnoflorine and water-soluble extracts.The results showed that the Random Forest classifier combined with the ten-fold cross-validation method provided the highest classification accuracy for origin place,accounting for 99.53%among these models.The correlation coefficients between predicted and experimental values of the five chemical components were all higher than 0.96.Conclusion:This study has indicated that the electronic nose and colorimeter are promising methods for evaluating the quality of Chinese herbal medicines both qualitatively and quantitatively.展开更多
An electronic-nose is developed based on eight quartz-crystal-microbalance (QCM) gas sensors in a sensor box, and is used to detect Chinese liquors at room temperature. Each sensor is a highly-accurate and highly-sens...An electronic-nose is developed based on eight quartz-crystal-microbalance (QCM) gas sensors in a sensor box, and is used to detect Chinese liquors at room temperature. Each sensor is a highly-accurate and highly-sensitive oscillator that has experienced airflow disturbances under the condition of varying room temperatures due to unstable flow-induced forces on the sensors surfaces. The three-dimensional (3D) nature of the airflow inside the sensor box and the interactions of the airflow on the sensors surfaces at different temperatures are studied by computational fluid dynamics (CFD) tools. Higher simulation accuracy is achieved by optimizing meshes, meshing the computational domain using a fine unstructural tetrahedron mesh. An optimum temperature, 30 ℃, is obtained by analyzing the distributions of velocity streamlines and the static pressure, as well as the flow-induced forces over time, all of which may be used to improve the identification accuracy of the electronic-nose for achieving stable and repeatable signals by removing the influence of temperature.展开更多
China is one of the largest meat producing countries in the world. With the growing concern for food safety more attention has been paid to meat quality. The application of conventional test methods for meat quality i...China is one of the largest meat producing countries in the world. With the growing concern for food safety more attention has been paid to meat quality. The application of conventional test methods for meat quality is limited by many factors, andsubjectiveness, such as longer time to prepare samples and to test. A sensor matrix was constructed with several separate air sensors, and tests were conducted to detect the freshness of the beef. The results show that the air sensors TGS2610, TGS2600, TGS2611, TGS2620 and TGS2602 made by Tianjin Figaro Electronic Co, Ltd could be used to determine the degree of freshness but TGS2442 is not suitable. This study provides a foundation for designing and making an economical and practical detector for beef freshness.展开更多
In this work,an electronic nose was used to evaluate the different cultivars and mature stages of melons,so as to establish a scientific method to accurately distinguish the maturity and varieties of melons. Principal...In this work,an electronic nose was used to evaluate the different cultivars and mature stages of melons,so as to establish a scientific method to accurately distinguish the maturity and varieties of melons. Principal component analysis (PCA) and linear discriminant analysis (LDA ) showed that immature melons could be well distinguished from mature melons using electronic nose. When PCA method was used to analyze,electronic nose could completely classify and identify the maturity of melons. Meanwhile,the electronic nose could distinguish different varieties of melons with high discrimination value. The flavor of samples under cut or no cut conditions would slightly change,leading to the variation of discrimination value among different varieties. The samples with similar flavor under no cut condition could be analyzed through cutting mode. The research built a rapid and accurate method to judge the maturity of melons instead of man sense.展开更多
When the electronic nose is used to identify different varieties of distilled liquors, the pattern recognition algorithm is chosen on the basis of the experience, which lacks the guiding principle. In this research, t...When the electronic nose is used to identify different varieties of distilled liquors, the pattern recognition algorithm is chosen on the basis of the experience, which lacks the guiding principle. In this research, the different brands of distilled spirits were identified using the pattern recognition algorithms (principal component analysis and the artificial neural network). The recognition rates of different algorithms were compared. The recognition rate of the Back Propagation Neural Network (BPNN) is the highest. Owing to the slow convergence speed of the BPNN, it tends easily to get into a local minimum. A chaotic BPNN was tried in order to overcome the disadvantage of the BPNN. The convergence speed of the chaotic BPNN is 75.5 times faster than that of the BPNN.展开更多
In order to meet the requirements for miniaturization detection of oil shale pyrolysis process and solve the problem of low sensitivity of oil and gas detection devices,a small bionic electronic nose system was design...In order to meet the requirements for miniaturization detection of oil shale pyrolysis process and solve the problem of low sensitivity of oil and gas detection devices,a small bionic electronic nose system was designed.Inspired by the working mode of the olfactory receptors in the mouse nasal cavity,the bionic spatial arrangement strategy of the sensor array in the electronic nose chamber was proposed and realized for the first time,the sensor array was used to simulate the distribution of mouse olfactory cells.Using 3D printing technology,a solid model of the electronic nose chamber was manufactured and a comparative test of oil shale pyrolysis gas detection was carried out.The results showed that the proposed spatial arrangement strategy of sensor array inside electronic nose chamber can realize the miniaturization of the electronic nose system,strengthen the detection sensitivity and weaken the mutual interference error.Moreover,it can enhance the recognition rate of the bionic spatial strategy layout,which is higher than the planar layout and spatial comparison layout.This bionic spatial strategy layout combining naive bayes algorithm achieves the highest recognition rate,which is 94.4%.Results obtained from the Computational Fluid Dynamics(CFD)analysis also indicate that the bionic spatial strategy layout can improve the responses of sensors.展开更多
Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique wer...Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique were employed to analyse the E-nose and GC-MS data of Longjing tea produced in different locations in Zhejiang province,China.A good discrimination of Longjing tea samples was obtained by E-nose according to the producing area,and a total of 38 compounds were commonly identified from the GC-MS data.Each individual volatile component was related to E-nose response using PLSR and the significance of each component was evaluated by the coefficient R2.Results indicated that isoamyl isovalerate,cis-3-hexenyl hexanoate,cadinene,phenylethylalcohol and linalool played an important role in response on E-nose sensors.It was possible to give a complementary information concerning the individual chemicals interacts with the sensors of E-nose instead of the total volatile components.展开更多
The education model based on outcomes-based education(OBE)emphasizes on taking educational achievements as the guide as well as focusing on student-centered and ability-based concepts.OBE is consistent with the talent...The education model based on outcomes-based education(OBE)emphasizes on taking educational achievements as the guide as well as focusing on student-centered and ability-based concepts.OBE is consistent with the talent output goals of higher vocational and technical education.Using the construction of electronic technology courses in higher vocational and technical colleges as an example,this article takes the course reform as an important carrier to promote ability training and explores the course reform scheme to meet the ability needs of higher vocational talents in the new era based on the concept of OBE in order to provide a useful reference for improving the level of talent training in higher vocational colleges.展开更多
基金supported by China Agriculture Research System of MOF and MARA(CARS-41)Wens Fifth Five R&D Major Project(WENS-2020-1-ZDZX-007)。
文摘The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.
基金support from the National Key R&D Program of China (2019YFD0901903)the Innovation Team Project of Hebei (Province) Modern Agricultural Industry Technology System (HBCT2018170207)the Postgraduate Research & Practice Innovation Program of Jiangsu Province (SJCX20_1426)
文摘Traditionally fermented shrimp paste has a long fermentation period and is susceptible of external factors,which leads to unstable quality and limits its development and application.Therefore,the purpose of this study is to analyze the flavor changes in the shrimp paste fermentation process and screen out the key volatile aroma components in the shrimp paste to control the flavor quality of the shrimp paste products.The overall odor profile was detected by the electronic nose.A total of 106 volatile flavor compounds in the shrimp paste samples at different fermentation stages were identified by solid-phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS)and headspace-gas chromatography-ion mobility spectrometry(HS-GC-IMS).The main aroma components alcohols,aldehydes,pyrazines and other substances in the fermentation process showed an overall upward trend.A total of 17 key volatile aroma components in shrimp paste at different fermentation stages were identified by the relative aroma activity value(ROAV)method.The combination of electronic nose,SPME-GC-MS and HS-GC-IMS could comprehensively reflect the changes of volatile components in shrimp paste at different fermentation stages,which helps to further understand the mechanism of shrimp paste flavor formation and provides a basis for the regulation of the flavor quality of shrimp paste products.
文摘With the rapid development of electronic communication technology,various new technical elements are constantly added to it,bringing many changes to people’s lives and work.The traditional data diversion mode can no longer truly meet the needs of actual work,and the electronic communication mode plays a huge role and occupies an important position in the communication market.Regarding how to develop and apply intelligent electronic communication technology more perfectly,there will be an overview of the specific principle of intelligent electronic communication technology,from the multi-faceted impact of electronic communication technology on human society.The article put forward the future development trend of electronic communication technology based on intelligent networks,emphasized expanding the scale of technology coverage,improved the comprehensive quality of technical products,optimized the structure of the communication industry,and formed a perfect industrial chain,so as to improve the intelligent level of electronic communication technology.
文摘Electronic design automation(EDA)technology is the product of the computer age and finds its foundation in CAD,CAM,CAT,and CAE.EDA is a kind of auxiliary tool in the design process,which requires the designer to carry out the file design work using hardware language as the foundation.Subsequently,the computer system automatically compiles and integrates the file to achieve simulation goals,and can complete the programming download of the target chip.At present,this technology is widely used in the communication of electronic circuits.This paper summarizes EDA technology and analyzes its specific application in communication electronic circuits,aiming at promoting the application of CDA technology and promoting the further development of the communication field.
基金This paper was supported by the 2021 School-Level Education Reform Project of Hainan Tropical Ocean University Fund(RHYjg2021sz03).
文摘As critical measures to educate and cultivate people’s morality,“Ideology and Politics of Course”has gradually become the focus in actual undergraduate education research in universities.Targeting the single ideological and political education mode and students’lack of interest in experimental courses,this paper,through various links,including pre-class preview,in-class teaching,and after-class data analysis,takes the common emitter single tube amplifier experiment as an example to organically integrate the excavated ideological and political elements with practical operation and carry out teaching case design and practice;realize the improvement of students’learning initiative and problem-analysis ability;and achieve the purpose of cultivating people throughout the whole process and in a comprehensive direction.
文摘Rapid advances in sensor technologies have facilitated the development of high-performance electronic noses that can detect and discriminate volatile compounds in situ. The research and development of electronic noses has resulted in a new qualitative and semi-quantitative detection approach in the field of clinical diagnostics. Electronic noses have a clear potential to be a non-invasive, simple and rapid but above all accurate early diagnostic screening tool. This review collates existing knowledge of recent advances in electronic nose technologies and applications.
基金supported by the State Key Program of National Natural Science of China(No.31330060)the National Natural Science Foundation of China(No.31571865)
文摘Shrimp paste is a type of condiments with high nutritional value.However,the flavors of shrimp paste,particularly the non-uniformity flavors,have limited its application in food processing.In order to identify the characteristic flavor compounds in Chinese traditional shrimp pastes,five kinds of typical commercial products were evaluated in this study.The differences in the volatile composition of the five products were investigated.Solid phase micro-extraction method was employed to extract the volatile compounds.GC-MS and electronic nose were applied to identify the compounds,and the data were analyzed using principal component analysis(PCA).A total of 62 volatile compounds were identified,including 8 alcohols,7 aldehydes,3 ketones,7 ethers,7 acids,3 esters,6 hydrocarbons,12 pyrazines,2 phenols,and 7 other compounds.The typical volatile compounds contributing to the flavor of shrimp paste were found as follows:dimethyl disulfide,dimethyl tetrasulfide,dimethyl trisulfide,2,3,5-trimethyl-6-ethyl pyrazine,ethyl-2,5-dimethyl-pyrazine,phenol and indole.Propanoic acid,butanoic acid,furans,and 2-hydroxy-3-pentanone caused unpleasant odors,such as pungent and rancid odors.Principal component analysis showed that the content of volatile compounds varied depending on the processing conditions and shrimp species.These results indicated that the combinations of multiple analysis and identification methods could make up the limitations of a single method,enhance the accuracy of identification,and provide useful information for sensory research and product development.
基金support from the Doctoral Fund of Ministry of Education of China (No 20070224003)oversea research project of Hei-longjiang Province Education Agency, China (No1151HZ01)research project of Heilongjiang Province Education Agency, China (No 10531002).
文摘Four rice samples of long grain type were tested using an electronic nose (Cyranose-320).Samples of 5 g of each variety ofrice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer sensors.TheCyranose-320 was able to differentiate between varieties of rice.The chemical composition of the rice odors for differentiatingrice samples needs to be investigated.The optimum parameter settings should be considered during the Cyranose-320 trainingprocess especially for multiple samples,which are helpful for obtaining an accurate training model to improve identificationcapability.Further,it is necessary to investigate the E-nose sensor selection for obtaining better classification accuracy.A re-duced number of sensors could potentially shorten the data processing time,and could be used to establish an application pro-cedure and reduce the cost for a specific electronic nose.Further research is needed for developing analytical procedures thatadapt the Cyranose-320 as a tool for testing rice quality.
文摘The objectives of the present study were to determine the effects of the brewing method on the amount of the major catechins, methylxanthines, total polyphenols and antioxidant capacity in green and black teas, and to correlate the chemical composition of tea infusions to their sensorial properties by the combined use of the electronic nose and tongue. For this purpose, tea infusions were prepared from 7 green teas and 6 black teas using different extraction times (3 - 5 and 10 min). The extraction of total polyphenols and catechins was increased by prolonging the infusion time from 3 - 5 to 10 min, while the caffeine amounts did not increase. The antioxidant activity of teas was well correlated with polyphenol content. Electronic tongue and electronic nose were able to discriminate green teas from black teas on the basis of their sensorial properties. Considering the taste, green teas were characterized by astringency and aftertaste-astringency and this sensation was increased by prolonging the infusion time;black teas were perceived as more bitter, sour, salty and the extraction time affected the astringent sensation. The aroma of green and black teas was discriminated by specific sensors and the increase of the extraction time produced more richly flavoured infusions. This work adds information about correlation between sensorial properties, antioxidant capacity and chemical composition of green and black teas.
基金supported by the National Natural Science Foundation of China(81573542&81403054)Beijing University of Chinese Medicine(2019-JYB-JS-006).
文摘Background:Magnolia bark(Magnolia Officinalis REHD.&WILS.and Magnolia officinalis REHD.&WILS.VAR.biloba REHD.&WILS,Hou Po in Chinese),is widely applied in clinical prescriptions and Chinese patent medicines.Origin place is a crucial factor affecting the quality of Hou Po,and chemical composition is an important index for evaluating its quality,which is closely related to its clinical efficacy.This study aims to develop a novel method for rapidly,accurately and comprehensively identifying the origin places of Hou Po and predicting the contents of its important chemical components.Methods:High performance liquid chromatography was used to analyze the contents of magnolol and honokiol and ultra-performance liquid chromatography the contents of magnocurarine and magnoflorine.The cold soak method was used to determine the contents of water-soluble extracts.The E-nose and colorimeter were used to determine the odor and color characteristics,respectively,of the collected Hou Po samples.Results:Using several statistical algorithms,different discriminant models based on the E-nose and colorimeter data were established to distinguish the origin place of Hou-Po and predict the chemical components of honokiol,magnolol,magnocurarine,magnoflorine and water-soluble extracts.The results showed that the Random Forest classifier combined with the ten-fold cross-validation method provided the highest classification accuracy for origin place,accounting for 99.53%among these models.The correlation coefficients between predicted and experimental values of the five chemical components were all higher than 0.96.Conclusion:This study has indicated that the electronic nose and colorimeter are promising methods for evaluating the quality of Chinese herbal medicines both qualitatively and quantitatively.
基金Project supported by the National Natural Science Foundation of China(Nos.61876059 and U1501251)
文摘An electronic-nose is developed based on eight quartz-crystal-microbalance (QCM) gas sensors in a sensor box, and is used to detect Chinese liquors at room temperature. Each sensor is a highly-accurate and highly-sensitive oscillator that has experienced airflow disturbances under the condition of varying room temperatures due to unstable flow-induced forces on the sensors surfaces. The three-dimensional (3D) nature of the airflow inside the sensor box and the interactions of the airflow on the sensors surfaces at different temperatures are studied by computational fluid dynamics (CFD) tools. Higher simulation accuracy is achieved by optimizing meshes, meshing the computational domain using a fine unstructural tetrahedron mesh. An optimum temperature, 30 ℃, is obtained by analyzing the distributions of velocity streamlines and the static pressure, as well as the flow-induced forces over time, all of which may be used to improve the identification accuracy of the electronic-nose for achieving stable and repeatable signals by removing the influence of temperature.
文摘China is one of the largest meat producing countries in the world. With the growing concern for food safety more attention has been paid to meat quality. The application of conventional test methods for meat quality is limited by many factors, andsubjectiveness, such as longer time to prepare samples and to test. A sensor matrix was constructed with several separate air sensors, and tests were conducted to detect the freshness of the beef. The results show that the air sensors TGS2610, TGS2600, TGS2611, TGS2620 and TGS2602 made by Tianjin Figaro Electronic Co, Ltd could be used to determine the degree of freshness but TGS2442 is not suitable. This study provides a foundation for designing and making an economical and practical detector for beef freshness.
基金Supported by National Natural Science Foundation of China(30870109)
文摘In this work,an electronic nose was used to evaluate the different cultivars and mature stages of melons,so as to establish a scientific method to accurately distinguish the maturity and varieties of melons. Principal component analysis (PCA) and linear discriminant analysis (LDA ) showed that immature melons could be well distinguished from mature melons using electronic nose. When PCA method was used to analyze,electronic nose could completely classify and identify the maturity of melons. Meanwhile,the electronic nose could distinguish different varieties of melons with high discrimination value. The flavor of samples under cut or no cut conditions would slightly change,leading to the variation of discrimination value among different varieties. The samples with similar flavor under no cut condition could be analyzed through cutting mode. The research built a rapid and accurate method to judge the maturity of melons instead of man sense.
基金the Science and Technology Plan Projects, Department of Education of Jilin Province, P R China (Grant no. 2006026)
文摘When the electronic nose is used to identify different varieties of distilled liquors, the pattern recognition algorithm is chosen on the basis of the experience, which lacks the guiding principle. In this research, the different brands of distilled spirits were identified using the pattern recognition algorithms (principal component analysis and the artificial neural network). The recognition rates of different algorithms were compared. The recognition rate of the Back Propagation Neural Network (BPNN) is the highest. Owing to the slow convergence speed of the BPNN, it tends easily to get into a local minimum. A chaotic BPNN was tried in order to overcome the disadvantage of the BPNN. The convergence speed of the chaotic BPNN is 75.5 times faster than that of the BPNN.
基金This work was supported by the National Natural Science Foundof China(51875245)the Science-Technology Development Plan Project of Jilin Province(20190303012SF,20190303118SF and 20190201019JC)+2 种基金the Special Project of Industrial Technology Research and Development of Jilin Province(2018C036-2)the“13th Five-Year Plan”Scientific Research Foundation of the Education Department of Jilin Province(JJKH20201000KJ and JJKH20201019KJ)the Fundamental Research Funds for the Central Universities.
文摘In order to meet the requirements for miniaturization detection of oil shale pyrolysis process and solve the problem of low sensitivity of oil and gas detection devices,a small bionic electronic nose system was designed.Inspired by the working mode of the olfactory receptors in the mouse nasal cavity,the bionic spatial arrangement strategy of the sensor array in the electronic nose chamber was proposed and realized for the first time,the sensor array was used to simulate the distribution of mouse olfactory cells.Using 3D printing technology,a solid model of the electronic nose chamber was manufactured and a comparative test of oil shale pyrolysis gas detection was carried out.The results showed that the proposed spatial arrangement strategy of sensor array inside electronic nose chamber can realize the miniaturization of the electronic nose system,strengthen the detection sensitivity and weaken the mutual interference error.Moreover,it can enhance the recognition rate of the bionic spatial strategy layout,which is higher than the planar layout and spatial comparison layout.This bionic spatial strategy layout combining naive bayes algorithm achieves the highest recognition rate,which is 94.4%.Results obtained from the Computational Fluid Dynamics(CFD)analysis also indicate that the bionic spatial strategy layout can improve the responses of sensors.
基金financial support from the China Agriculture (tea) Research System (CARS)Chinese Universities Scientific FundScientific Research Project of Zhejiang Education Department (Y201018805)
文摘Electronic nose has been applied in analysis of food products by monitoring their flavours.But it gives an overall response to a mixture of volatile components.In this work,multianalysis and chemometrics technique were employed to analyse the E-nose and GC-MS data of Longjing tea produced in different locations in Zhejiang province,China.A good discrimination of Longjing tea samples was obtained by E-nose according to the producing area,and a total of 38 compounds were commonly identified from the GC-MS data.Each individual volatile component was related to E-nose response using PLSR and the significance of each component was evaluated by the coefficient R2.Results indicated that isoamyl isovalerate,cis-3-hexenyl hexanoate,cadinene,phenylethylalcohol and linalool played an important role in response on E-nose sensors.It was possible to give a complementary information concerning the individual chemicals interacts with the sensors of E-nose instead of the total volatile components.
文摘The education model based on outcomes-based education(OBE)emphasizes on taking educational achievements as the guide as well as focusing on student-centered and ability-based concepts.OBE is consistent with the talent output goals of higher vocational and technical education.Using the construction of electronic technology courses in higher vocational and technical colleges as an example,this article takes the course reform as an important carrier to promote ability training and explores the course reform scheme to meet the ability needs of higher vocational talents in the new era based on the concept of OBE in order to provide a useful reference for improving the level of talent training in higher vocational colleges.
