Investigation on taste characteristics and sensory perception of soft-boiled chicken during oral processing based on electronic tongue and electronic nose

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.

Analysis of the changes of volatile flavor compounds in a traditional Chinese shrimp paste during fermentation based on electronic nose,SPME-GC-MS and HS-GC-IMS

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.

Rapid Identification of Rice Samples Using an Electronic Nose

Four rice samples of long grain type were tested using an electronic nose (Cyranose-320).Samples of 5 g of each variety of rice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer sensors.The Cyranose-320 was able to differentiate between varieties of rice.The chemical composition of the rice odors for differentiating rice samples needs to be investigated.The optimum parameter settings should be considered during the Cyranose-320 training process especially for multiple samples,which are helpful for obtaining an accurate training model to improve identification capability.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 that adapt the Cyranose-320 as a tool for testing rice quality.

Electronic Nose with an Air Sensor Matrix for Detecting Beef Freshness

China is one of the largest meat producing countries in the wodd. 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, and subjectiveness, 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.

Comparison of Algorithms for an Electronic Nose in Identifying Liquors

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.

A novel quality evaluation method for magnolia bark using electronic nose and colorimeter data with multiple statistical algorithms

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.

Using an Electronic Nose to Rapidly Assess Grandlure Content in Boll Weevil Pheromone Lures

Samples of pheromone lures used in boll weevil, Anthonomus grandis （Boheman）, eradication programs are routinely analyzed by Gas Chromatography （GC） to ensure lures are adequately dosed with grandlure, the synthetic aggregation phero- mone produced by male weevils. However, preparation of GC samples is tedious, time consuming, and requires a moderate level of experience. We examined the use of a commercially-available electronic nose （e-nose） for rapidly assessing the grandlure contents of lures. The e-nose was trained to recognize headspace collections of grandlure emitted from new lures and after lures were aged under field conditions for 4 d, 7 d, 10 d, and 14 d. Based on cross-validation of the training set, the e-nose was 82% accurate in discriminating among the different age classes of lures. Upon sampling headspace collections of pheromone from a different set of field-aged lures, the e-nose was 〈50% accurate in discriminating 4 d, 7 d, and 10 d aged lures from the other age classes of lures. However, the e-nose identified new and 14 d aged lure samples with 100% accuracy. In light of these findings, e-nose technology shows considerable promise as an alternative approach for rapidly assessing the initial grandlure contents of lures used in boll weevil eradication programs.

A HYBRID ELECTRONIC NOSES’SYSTEM BASED ON MOS-SAW DETECTION UNITS INTENDED FOR LUNG CANCER DIAGNOSIS

In this paper,a hybrid electronic noses’system(HENS)based on MOS-SAW detection units intended for lung cancer diagnosis is proposed.The MOS gas sensors are used to detect the VOC molecules with low molecular weight(LMW),and the SAW sensors are adopted for the detection of VOC with high molecular weight(HMW).Thus,the novel combination of these two kinds of gas sensors provides higher sensitivities to more of VOC species in breath than that of using only a single kind of sensor.The signals from MOS-SAW detection units are then recognized by a multi-model diagnosis method.Applying four algorithms,six models were established for diagnosis and tested by leave-one-out cross-validation method.The model by artificial neural network(ANN)was selected as the best model to analyze breath samples.89 clinical samples were tested with MOS-SAW ANN diagnostic model,which takes the features derived from both the MOS and SAW sensors.It shows the highest sensitivity of 93.62%,and the highest selectivity of 83.37%.The study shows that,promisingly,our HENS is effective during screening of lung cancer patients,especially among the people of high risk.

Odour Impact Assessment by Means of Dispersion Modeling, Dynamic Olfactometry and Mobile Electronic Nose around Agadir Fishing Port in Morocco

Odorous emissions emitted from various sources including industrial and commercial activities have particular concerns about human health. These malodors emissions are an environmental concern that affects health status and social life of the neighbors. That requires the local authority to set up a management strategy to control this nuisance. The evaluation of odour emissions from fishing port is complex because these emissions depend on several factors such as multiple sources of odor emissions, meteorological conditions, topography and others. That imposes the use of complementary approaches to monitor odours. In this paper, the case of Agadir fishing port is studied, which is adjacent to the tourist area and residential neighborhoods and which hosts a number of points that can generate odors. To assess this odour impact, three methods are used such as dynamic olfactometry, dispersion modeling and mobile electronic nose (e-nose). The use of these three methods in a complementary manner to assess odour impacts around a fishing port allowed both the quantification of the emissions using dynamic olfactometry and the evaluation of their impact on the study area with model dispersion. The results enabled also to identify the most affected areas of the city by odor emissions and to recognize the meteorological parameters maximizing odor impact. The other goal of this work is to compare the results of the odour dispersion modeling and e-nose measurements for one year in terms of frequency of overtaking the set alert thresholds over the same period. Comparison highlights the strengths and weaknesses of both approaches. Modeling can be used predicatively but it does not take into account fugitive emissions reliably in the absence of data on these emissions, modeling based on the hourly average misjudges the odor peaks, while e-nose made it possible to obtain validated data and provides accurate, affordable and real-time odour measurement capability tacking in to account the role of human perception without being able to characterize the extent of the odor nuisance caused by each source. We conclude that these three valuation methods provide complementary information about odor nuisance and reasonable estimates of odors.

Detection and classification of pesticide residues in dandelion(Taraxacum officinale L.)by electronic nose combined with chemometric approaches

In this study,for the first time a suitable pesticide residue detection system for dandelion(Taraxacum officinale L.)was established based on electronic nose to determine and study the concentration of pesticide residue in dandelion.Dandelions were sprayed with different concentrations of pesticides(avermectin,trichlorfon,deltamethrin,and acetamiprid),respectively.Data collection was performed by application of an electronic nose equipped with 12 metal oxide semiconductor(MOS)sensors.Data analysis was conducted using different methods including BP neural network and random forest(RF)as well as the support vector machine(SVM).The results showed the superior effectiveness of SVM in discrimination and classification of non-exceeding maximum residue limits(MRLs)and exceeding MRLs standards.Moreover,the model trained by SVM has the best performance for the classification of pesticide categories in dandelion,and the classification accuracy was 91.7%.The results of this study can provide reference for further development and construction of efficient detection technology of pesticide residues based on electronic nose for agricultural products.

Bionic Optimization Design of Electronic Nose Chamber for Oil and Gas Detection

In this paper, a miniaturized bionic electronic nose system is developed in order to solve the problems arising in oil and gas detection for large size and inflexible operation in downhole. The bionic electronic nose chamber is designed by mimicking human nasal turbinate structure, V-groove structure on shark skin surface and flow field distribution around skin surface. The sensitivity of the bionic electronic nose system is investigated through experimentation. Radial Basis Function （RBF） and Support Vector Machines （SVM） of 10-fold cross validation are used to compare the recognition performance of the bionic electronic nose system and common one. The results show that the sensitivity of the bionic electronic nose system with bionic composite chamber （chamber B） is significantly improved compared with that with common chamber （chamber A）. The recognition rate of chamber B is 4.27% higher than that of chamber A for the RBF algorithm, while for the SVM algorithm, the recognition rate of chamber B is 5.69% higher than that of chamber A. The three-dimensional simulation model of the chamber is built and verified by Computational Fluid Dynamics （CFD） simulation analysis. The number of vortices in chamber B is fewer than that in chamber A. The airflow velocity near the sensors inside chamber B is slower than that inside chamber A. The vortex intensity near the sensors in chamber B is 2.27 times as much as that in chamber A, which facilitates gas molecules to fully contact with the sensor surface and increases the intensity of sensor signal, and the contact strength and time between odorant molecules and sensor surface. Based on the theoretical investigation and test validation, it is believed that the proposed bionic electronic nose system with bionic composite chamber has potential for oil and gas detection in downhole.

Chemoresistive materials for electronic nose:Progress,perspectives,and challenges

An electronic nose(e-nose)is a device that can detect and recognize odors and flavors using a sensor array.It has received considerable interest in the past decade because it is required in several areas such as health care,environmental monitoring,industrial applications,automobile,food storage,and military.However,there are still obstacles in developing a portable e-nose that can be used for a wide variety of applications.For practical applications of an e-nose,it is necessary to collect a massive amount of data from various sensing materials that can transduce interactions with molecules reliably and analyze them via pattern recognition.In addition,the possibility of miniaturizing the e-nose and operating it with low power consumption should be considered.Moreover,it should work efficiently over a long period of time.To satisfy these requirements,several different chemoresistive material platforms including metal oxides,organics such as polymers and carbonbased materials,and two-dimensional materials were investigated as sensor elements for an e-nose.As an individual material has limited selectivity,there is a continuing effort to improve the selectivity and gas sensing properties through surface decoration and compositional and structural variations.To produce a reliable e-nose,which can be used for practical applications,researches in various fields have to be harmonized.This paper reviews the progress of research on e-noses based on a chemoresistive gas sensor array and discusses the inherent challenges and potential solutions.

Bionic Layout Optimization of Sensor Array in Electronic Nose for Oil Shale Pyrolysis Process Detection

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.

Application of electronic nose and GC-MS for detection of strawberries with vibrational damage

Objectives: This study evaluated the potential of using electronic nose (e-nose) technology to non- destructively detect strawberry fruits with vibrational damage based on their volatile substances (VOCs). Materials and methods: Four groups of strawberries with different durations of vibrations (0, 0.5, 1, and 2 h) were prepared, and their e-nose signals were collected at 0, 1, 2, and 3 days after vibration treatment. Results: The results showed that when the samples from all four sampling days during storage were used for modelling, both the levels of vibrational damage and the day after the damage happened were accurately predicted. The best models had residual prediction deviation values of 2.984 and 5.478. The discrimination models for damaged strawberries also obtained good classification results, with an average correct answer rate of calibration and prediction of 99.24%. When the samples from each sampling day or vibration time were used for modelling, better results were obtained, but these models were not suitable for an actual situation. The gas chromatography-mass spectrophotometry results showed that the VOCs of the strawberries varied after experiencing vibrations, which was the basis for e-nose detection. Limitations: The changes in VOCs released by other forces should be studied in the future. Conclusions: The above results showed the potential use of e-nose technology to detect strawberries that have suffered vibrational damage.

Time-dependent categorization of volatile aroma compound formation in stewed Chinese spicy beef using electron nose profile coupled with thermal desorption GC–MS detection

In the present study,flavor profiles of Chinese spiced beef in the cooking process were comparatively analyzed by electronic nose,gas chromatography–mass spectrometry(GC–MS)with a thermal desorption system(TDS),and solid-phase microextraction(SPME).A total of 82 volatile compounds were identified,and 3-methyl-butanal,pentanal,hexanal,-xylene,heptanal,limonene,terpinene,octanal,linalool,4-terpinenol,-terpineol,and(E)-anethole were identified as the characteristic flavor compounds in Chinese spiced beef.Variation in the content of volatile components produced by different cooking processes was observed.In general,a cooking time of 4 h resulted in optimal flavor quality and stability.Results indicated that the electronic nose could profile and rapidly distinguish variation among different cooking time.The volatile profiling by TDS-GC–MS and responses from the electronic nose,in combination with multivariate statistical analysis,are a promising tool for control the cooking process of spiced beef.

Olfaction as a soldier——a review of the physiology and its present and future use in the military

Olfaction is one of our 5 main qualitative sensory abilities. In this review, we have examined the physiology of olfaction from the olfactory receptor to the brain. Through analyzing the physiology of olfaction, we have found that the biochemistry of olfactory nerve stimulation is unique from that of other similar pathways. Upon receiving large amounts of input from the olfactory nerve, the olfactory bulb, followed by several layers of centrifugal and centripetal processing in the brain, has to sort the information from the input as well as integrate it with other inputs from the brain to develop a coherent understanding of the input. We then examined the implications of olfaction in the military, the practical applications of electronic noses and problems associated with injury to olfaction that could affect compensation and combat worthiness of a soldier following injury. In the military, olfaction can allow the army to perform at its best through 4 main methods, namely ensuring olfaction is consistent with other dimensions of perception(ensuring optimal olfaction ability in all soldiers in combat), understanding the impact of different common combat environments on the sense of smell, utilizing odor as a defense mechanism and using olfactory aids when necessary. Electronic noses are olfactory aids that have a large potential in the military ranging from saving lives through the detection of explosives to potential methods for improving combustion efficiency. There are several problems associated with injury to olfaction that should be considered when deciding on compensation and combat worthiness of the soldier following an injury.

Flavor Characteristics of Different Crops of Laver(Porphyra yezoensis)During One Harvest Cycle

The taste and odor analysis of the first,second,fourth and sixth crops of laver(Porphyra yezoensis)was obtained by electronic tongue,taste-related compound,electronic nose and gas chromatography-ion mobility spectrometer(GC-IMS).Through the detection of the electronic tongue,the pleasant tastes such as umami and richness are more intense in the early crops,which is consistent with the analysis results of free amino acids and flavored nucleotides.The electronic nose can clearly distinguish between different laver crops.GC-IMS separated and identified 36 volatile components from lavers,mainly including aldehydes,ketones,alcohols,esters,acids and aromatic substances.For the early harvested crops,nonanal,octanal,hexanal and benzaldehyde have a significant contribution to odor because of the high concentration and low threshold of these compounds.For the later harvested crops,the concentration of most ketones and some aldehydes increased.1-Octen-3-ol,malondialdehyde and heptanal constituted the main odor characteristics.

The Flavor and Antioxidant Activity Change Pattern of Shrimp Head Paste During Fermentation

To study the changes of volatile compounds and antioxidant activity of fast fermented shrimp head paste during the fermentation processing,Penaeus vannamei boone head was used as the raw material,and compound starter was added for fermen-tation.During the 14 days of fermentation,the changes of free amino acids,volatile flavor compounds and main components were determined by SPME-GC-MS and electronic nose.The oxidation-resistance changes of water extract at different fermentation stages were evaluated.The results showed that the total free amino acids increased from original 2320 to 5640 mg(100 mL)^(−1).SPME-GC-MS analysis found that aldehydes,pyrazine compounds increased from 10.80%,1.94%to 24.35%,13.63%respectively during the fermentation process.The HO·scavenging ability of shrimp head paste increased from 52%to 86%.Our results showed that the shrimp paste produced from shrimp head fermentation could obtain good flavor and possess certain antioxidant activity of aquatic fermented condiment.

New sensor technologies in quality evaluation of Chinese materia medica:2010–2015

New sensor technologies play an important role in quality evaluation of Chinese materia medica(CMM) and include near-infrared spectroscopy,chemical imaging,electronic nose and electronic tongue.This review on quality evaluation of CMM and the application of the new sensors in this assessment is based on studies from 2010 to 2015,with prospects and opportunities for future research.

Volatolomics in healthcare and its advanced detection technology

Various diseases increasingly challenge the health status and life quality of human beings.Volatolome emitted from patients has been considered as a potential family of markers,volatolomics,for diagnosis/screening.There are two fundamental issues of volatolomics in healthcare.On one hand,the solid relationship between the volatolome and specific diseases needs to be clarified and verified.On the other hand,effective methods should be explored for the precise detection of volatolome.Several comprehensive review articles had been published in this field.However,a timely and systematical summary and elaboration is still desired.In this review article,the research methodology of volatolomics in healthcare is critically considered and given out,at first.Then,the sets of volatolome according to specific diseases through different body sources and the analytical instruments for their identifications are systematically summarized.Thirdly,the advanced electronic nose and photonic nose technologies for volatile organic compounds(VOCs)detection are well introduced.The existed obstacles and future perspectives are deeply thought and discussed.This article could give a good guidance to researchers in this interdisciplinary field,not only understanding the cutting-edge detection technologies for doctors(medicinal background),but also making reference to clarify the choice of aimed VOCs during the sensor research for chemists,materials scientists,electronics engineers,etc.