Technical status and development trends of electronic tongue / 药学学报

Electronic tongue is one kind of bionic detection technologies, which can objectively reflect the taste of drugs based on electrochemical principle. In this paper, the development histories of electronic tongue both of potential type and voltammetry type were introduced, including their detection principles and key innovation technologies. In order to comprehensively improve the understanding of electronic tongue, its technological progresses, such as the study of dedicated sensors or biosensors for specific tastes, and the development of miniaturized or hybrid devices, were also discussed in detail. And the challenges and countermeasures in the application of electronic tongue were analyzed to provide some suggestions for its further technology promotion.

Formulation optimization and analysis of taste-masking effect of licorzine granules based on sensory evaluation and electronic tongue method / 药学学报

Licorzine granules are common preparations for children zinc deficiency. Considering the long course of treatment, the taste of licorzine granules may become a main factor affecting medication adherence. To date there have been no taste evaluation research into licorzine granules yet. In this study, both sensory evaluation and electronic tongue method were utilized to optimize licorzine granules formulations, evaluate the tastes of licorzine, excipients, optimized formulation in vivo and in vitro. As the results show, bitterness and astringency are the main unpleasant tastes generating from licorzine. Xanthan gum is the main taste-masking excipient, lowering down the bitterness and astringency of licorzine by at least one grade. Good correlation exists between the results of sensory evaluation and electronic tongue method, and an integrated combination of the two helps to obtain objective and rational research conclusions. The adult sensory evaluation study was a research-based clinical trial conducted with informed consent from all subjects in accordance with the ethical requirements of Good Clinical Practice.

Application progress of electronic tongue on taste evaluation for drug products / 药学学报

The taste of oral dosage forms has become a critical factor affecting the drug compliance and adherence to the treatment, and clinical application of the drug product may seriously restricted due to its bad taste. On the basis of the statement for the basic principle and specific performance of existing instruments, the application progress of electronic tongue on drug taste evaluation is addressed in detail. In view of its objective, fatigue-free, less harmful and accurate advantages, electronic tongue has been widely and meaningfully applied in the aspects of bitterness masking, and quality assessment and assurance of drug products. In addition, the reasons limiting the popularization of electronic tongue are mentioned in the paper, and some suggestions might be useful to enlarge the further application in the future.

Identification of taste critical quality attribute and formulation optimization of Xiaoer Qingrening Granules based on electronic tongue and human senses / 药学学报

This study primarily concentrated on scientific problems of poor taste caused by unclear critical quality attributes of oral preparations manufactured by Chinese materia medica, successfully established an identification method for taste critical quality attribute and a taste improvement method combining electronic tongue with human senses, and determined the optimal taste formula, to improve patients' oral medication compliance. The study received ethical approval from the Review Committee of the Beijing University of Chinese Medicine. The results showed that the proportion of bitterness of Xiaoer Qingrening Granule was 61.8%, and its bitterness grade was 3.70, it was determined that bitterness is the critical quality attribute that caused the poor taste of Xiaoer Qingrening Granule. Additionally, the optimal taste formula per milliliter of Xiaoer Qingrening sugar-free intermediate was determined with allowable daily intake, solubility, and sweetness as the limiting conditions, which was 40 mg hydroxypropyl β-cyclodextrin, 180 mg trehalose, and 1.5 mg acesulfame potassium. Compared with the Xiaoer Qingrening Granule, the sensory evaluation score of the optimal taste formula was increased by 37.5 points. In conclusion, this study achieved the taste improvement of Xiaoer Qingrening Granule and formed a set of taste improvement strategies including the identification of taste critical quality attribute, the selection of the type and dosage of corrigent, and the optimization of taste formula, which provided a thought reference for the taste improvement of other oral preparations and a new perspective for quality control of intelligent manufacturing of traditional Chinese medicines.

Research progress of taste masking and evaluation technology of medicine / 中国药科大学学报

@#Most drugs taste bitter and irritating, resulting in poor compliance of patients, and the bad odor affects the therapeutic effect. The successful research and development of a drug should not only conform to the five quality characteristics of effectiveness, stability, safety, uniformity and economy, but also the compliance of patients to drugs with bad odor. The development of taste masking techniques is critical for bitter drugs.This review describes the principles, advantages and drawbacks of traditional taste masking techniques, and introduces the mechanism and application of novel taste masking techniques, such as melt granulation, hot melt extrusion, 3D printing, drug complex preparation, and bitter taste inhibitors. The in vitro evaluation methods of drug taste masking effect, such as functional magnetic resonance imaging, in vitro dissolution, and electronic tongue technology, are described. And introduce in vivo evaluation methods, such as animal and human taste, in the field of taste masking effect. A new strategy of BP neural network prediction model for drug taste evaluation is proposed, with a view to providing theoretical reference for the future research on drug taste masking.

Analysis of Quality Changes of Platycladi Semen Before and After Deterioration Based on HS-SPME/GC-MS and Electronic Sensory Technology / 中国实验方剂学杂志

ObjectiveTo analyze the quality changes of Platycladi Semen before and after the deterioration of moth-eaten and rancidity during storage. MethodFour types samples of Platycladi Semen， including normal， moth-eaten， oxidative rancidity and hydrolytic rancidity， were determined for volatile components， odor， and taste based on headspace solid phase microextraction/gas chromatography-mass spectrometry （HS-SPME/GC-MS） and electronic sensory techniques such as electronic nose and electronic tongue. Volatile components were identified by searching the database and manual comparison， the odor and taste were determined by the response values of the electronic nose and electronic tongue sensors， and the difference between samples before and after deterioration was studied by multivariate statistical analysis. ResultA total of 85 compounds were identified in Platycladi Semen samples. Compared with the normal samples， the number of volatile compounds in samples after hydrolytic rancidity decreased by 5， the number of volatile compounds in samples after moth-eaten and oxidative rancidity increased by 1 and 21， respectively. Aldehydes and acids accounted for majority of types. Among them， the contents of N-hexanoic acid， hexanal and propionic acid in the samples of oxidative rancidity reached 11.49%， 10.21% and 7.52%， which became the key indicators of rancidity. There was significant variance among the odor components corresponding to W1W， W2W and W1S sensors by electronic nose analysis. It was indicated that the value of sourness in deteriorated samples generally increased by mean of electronic tongue analysis. Compared with normal samples， the moth-eaten samples had changed slightly and rancidity samples had changed significantly especially oxidative rancidity samples of volatile components， odor and taste by multivariate statistical analysis. ConclusionIn terms of Platycladi Semen， the oxidative rancidity caused by nature storage for 12 months has the greatest impact on the quality. Therefore， it should be mainly to prevent oxidative rancidity to ensure the quality of Platycladi Semen.

Flavorand taste change rules of Sophora Flavescentis Radix processed using ancient classical method:an exploration based on intelligent sensory analysis / 中国中药杂志

This study was designed to investigate the flavor and taste change rules of Sophora Flavescentis Radix processed using the ancient classical method documented in Master Lei's Discourse on Medicinal Processing(Lei Gong Pao Zhi Lun). The Sophora Flavescentis Radix pieces and the corresponding test samples in each processing stage were first prepared based on the processing method for Sophora Flavescentis Radix recorded in Master Lei's Discourse on Medicinal Processing(Lei Gong Pao Zhi Lun). Then the flavors and tastes of Sophora Flavescentis Radix test samples undergoing the soaking in rice-washed water, washing with clean water, and steaming for different time were compared with the electronic nose and tongue. The results showed that in the preparation of Sophora Flavescentis Radix with the ancient method, such processes as soaking in rice-washed water and washing with clean water had no significant influences on the flavor, which, however, was weakened by steaming. In terms of the taste, soaking with rice-washed water enhanced the bitter taste of Sophora Flavescentis Radix, which remained unchanged after being washed with the clean water. The steaming would also diminish the bitter taste, making it taste similar to the original Sophora Flavescentis Radix medicinal materials. During the steaming for six to eight hours, the flavor did not vary significantly over time, while the bitter taste was first weakened and then intensified. The bitter taste of Sophora Flavescentis Radix steamed for six hours was similar to that steamed for eight hours. In addition, the differences in flavor and taste between Sophora Flavescentis Radix pieces processed by the ancient method in Master Lei's Discourse on Medicinal Processing(Lei Gong Pao Zhi Lun)and those by the modern method in the 2020 edition of Chinese Pharmacopoeia were analyzed. The findings demonstrated that the flavor of Sophora Flavescentis Radix pieces prepared by the ancient method was weaker than that by the modern method, whereas the bitter taste showed the opposite trend. The exploration on the flavor and taste change rules of Sophora Flavescentis Radix in its preparation by the ancient classical method and the differences in flavor and taste between Sophora Flavescentis Radix decoction pieces prepared by ancient and modern methods will lay a foundation for further elucidation of the scientific connotation of the ancient processing method and the medication principles of Sophora Flavescentis Radix in both ancient and modern times.

Taste-Masking Effect of Montelukast Sodium Orally Disintegrating Tablets Using Electronic Tongue Analysis and Human Sensory Evaluation Method / 中国药学杂志

OBJECTIVE: To investigate the taste-masking effect of montelukast sodium orally disintegrating tablets using electronic tongue technology and human sensory evaluation and determine the optimum formulation. METHODS: Orally disintegrating tablets were prepared with five different concentrations of flavoring agents or without flavoring agent.The tastes of those tablets were determined by electronic tongue, and principal component analysis and linear discriminant analysis were used to evaluate differences of different formulations. The taste-masking effect of the tablets was investigated combined with electronic tongue analysis and sensory evaluation of subjects. RESULTS: The taste of orally disintegrating tablet was the best when the total amount of flavoring agent was 1.6 mg, and the ratio of sweetening agent to aromatic agent was 5∶3. CONCLUSION: The combination of electronic tongue and human sensory assess can evaluate the taste-masking effect of orally disintegrating tablets and provide the basis for determining the optimum formulation.

Automatic classification of water samples using an optimized SVM model applied to cyclic voltammetry signals / Clasificación automática de muestras de agua usando un modelo SVM optimizado aplicado a señales de voltametría cíclica

Background: concern about the quality of the water for human consumption has become widespread among the population. The taste and some problems associated with drinking water have been the cause of increased demand for bottled water. Due to this, day to day, a large number of companies has manifested their interest in the production of bottled water. Objective: to evaluate a novel automatic classification model that differentiates bottled water from tap water. Methods: the voltammetric technique consisted of three electrode setup. The output current has been considered for data analysis. From the results of grid search, six pairs of values were pre-selected for the parameters of σ and C whose results were similar. High values of accuracy, specificity and sensitivity were achieved in test dataset. The final decision was made after performing an ANOVA test of 100 repetitions of 5-fold cross-validation, 3000 models were evaluated with the parameter combinations described above for the SVM. Results: the oxidation and reduction peaks of the water samples have been observed to be prominent. Absolute values of current (I) increased in the case of public water samples, possibly due to the largest concentration of chloride ions which have higher contributions to the conductivity. 5-fold cross-validation test mean specificity resulted in C parameters values greater than 0 and between 0 and 30; a σ value greater than 10 and between 0 and 15 were found for tap water and bottled water, respectively. The combination (σ = 10, C = 30) presented best results in accuracy 0.988 ± 0.037, specificity 0.973 ± 0.085 and sensitivity 1 ± 0.09. Conclusions: results of this research work have shown that voltammograms for values of current increased for tap water samples, 9.94e-6µA, compared to 7.99e-6µA due to higher chloride ions concentration in the former. The parameters combination (σ = 10, C = 20) was selected as optimal parameters since there were no significant difference between this and the former.

Antecedentes: en la población hay una preocupación generalizada por la calidad del agua de consumo humano. El sabor y algunos problemas asociados con el agua potable han sido la causa del incremento en la demanda del agua embotellada. Debido a esto, un gran número de empresas han manifestado su interés en la producción de agua en botella. Objetivo: evaluar un nuevo modelo de clasificación automática que diferencie el agua embotellada del agua del grifo. Metodología: la técnica de voltametría consistió en la configuración de tres electrodos. Para el análisis de datos se consideró la corriente de salida y de los resultados de la búsqueda de cuadrícula y se seleccionaron seis pares de valores para los parámetros de σ y C, cuyos resultados fueron similares. Se lograron altos valores de precisión, especificidad y sensibilidad en el conjunto de datos de prueba. La decisión final se tomó después de realizar una prueba ANOVA de 100 repeticiones de validación cruzada de 5 veces y se evaluaron 3000 modelos con las combinaciones de parámetros descritas anteriormente para el SVM. Resultados: se observó que los picos de oxidación y reducción de las muestras de agua son prominentes. Los valores absolutos de corriente (I) aumentaron en el caso de muestras de agua pública, posiblemente debido a la mayor concentración de iones de cloruro que tienen una mayor contribución a la conductividad. La especificidad media de la prueba de validación cruzada 5 veces dio como resultado valores de parámetros C mayores que 0 y entre 0 y 30; se encontró un valor σ mayor que 10 y entre 0 y 15 para el agua de red pública y el agua embotellada, respectivamente. La combinación (σ = 10, C = 30) presentó los mejores resultados en precisión 0,988 ± 0,037, especificidad 0,973 ± 0,085 y sensibilidad 1 ± 0,09. Conclusiones: los resultados de este trabajo demostraron que los voltamogramas para valores de corriente, aumentaron para muestras de agua corriente, 9,94e-6 µA, en comparación con 7,99e-6 µA debido a una mayor concentración de iones de cloruro en el primer caso. La combinación de parámetros (σ = 10, C = 20) se seleccionó como parámetros óptimos, ya que no mostró diferencias significativas entre éste y el primer caso.

Masking Efficiency and Regularity of Bitterness Suppressants to Berberine Hydrochloride Based on Tongue Taste and Electronic Tongue Taste / 中国药学杂志

OBJECTIVE: To explore the masking efficiency and regularity of bitterness suppressants (BS) to a representative bitterness substance berberine hydrochloride (BBR). METHODS: Some quantitative evaluation methods of BS efficiency were established based on relevant literature and our previous research. Efficiency of respectively added into eight kinds of BS such as acesulfame, on bitter degree 3 BBR solution (0.05 mg•mL-1) were evaluated using the established methods. Bitterness masking regularity of BS on BBR solution were explained by respectively establishing the relationships between tongue tasted bitter decreased value (ΔI), electronic tongue tasted bitter decreased value (ΔIe) with BS concentration (ρ). RESULTS: ①Five tongue taste bitter masking efficiency (calibrated masking rate, bitterness revised standard half effect index and so on), two electronic tongue bitter masking efficiency(first taste reduce and aftertaste reduce) were established. ②Seven kinds of bitterness suppressants efficacy indicators can be used to compare the bitterness suppressants efficacy of BS to BBR solution, and the maximum bitterness reduction of 8 kinds of BS to BBR solution is above 1.8. ③ΔI-ρ Weibull regularity models of eight BS and nine ΔIe-ρ models of six BS were brlilt.HP-β-CD, glycine and crystalline fructose had good response to two sensor, stevioside, soluble soybean polysaccharide and acesulfame had a good response to one sensor and xanthan gum and aspartame had no response to any sensor. CONCLUSION: Seven evaluation indexes and methods are built based on human tongue and electronic tongue taste method. Max standard capability index of BS is suitable for the development of bitterness suppressants in taste method and two indicators of electronic tongue are also can be used as indicative indicators. Masking regularity of BS to BBR solution is exposed which could provide reference for the development and application of more BS.

Study on superposition law of drug bitterness based on tongue taste evaluation and electronic tongue evaluation / 中国中药杂志

Traditional Chinese medicine( TCM) decoction contains complex bitterness. In this paper,the simple mixing of TCM monomer bitter substances is used as the entry point to study the law of bitterness superposition. With berberine hydrochloride( alkaloids),geniposide( terpenoids),and arbutin( glycosides) as mother liquor,sophoridine( alkaloids),gentiopicroside( terpenoids),and puerarin( glycosides) as additive substances,these different additive substances were mixed with different mother liquor according to concentration gradients to form different liquid mixtures. The bitterness of the additive solution and the mixtures was evaluated by traditional human taste panel method( THTPM) and electronic tongue; the bitterness-concentration fitting model of the additive solution and the liquid mixtures was established by Weibull and logarithmic curves. By comparing and analyzing the bitterness-concentration model and the bitterness difference( ΔI_0/ΔI_e) of the additive solution and the mixture,the influence of mother liquor on the bitterness of the mixture was investigated. The results showed that both the additive solution bitterness model and the liquid mixture bitterness model were consistent with the Weibull model and the logarithmic model( THTPM: R~2≥0. 887 0,P<0. 01; electronic tongue test:R~2≥0. 753 2,P<0. 05). The fitting degree of the Weibull model was generally higher than that of the logarithmic model; the bitterness difference( ΔI_0) was monotonously decreasing; the fitting equation of tongue bitterness and electronic tongue bitterness: R~2≥0. 874 2,P<0. 01. In this article,through the superposition of different kinds of TCM bitter substances,THTPM and electronic tongue test was combined. It was found that the bitterness after superposition was still in Weibull or logarithmic relationship with the concentration of additive substances; THTPM showed that the effect of bitter mother liquor on the bitterness of the mixture decreased with the increase of the concentration of the additive; the bitterness of the electronic tongue was obviously related to the bitterness of THTPM. However,further verification is needed later by optimizing the concentration gradient and expanding the sample size.

A novel quantified bitterness evaluation model for traditional Chinese herbs based on an animal ethology principle

Traditional Chinese herbs (TCH) are currently gaining attention in disease prevention and health care plans. However, their general bitter taste hinders their use. Despite the development of a variety of taste evaluation methods, it is still a major challenge to establish a quantitative detection technique that is objective, authentic and sensitive. Based on the two-bottle preference test (TBP), we proposed a novel quantitative strategy using a standardized animal test and a unified quantitative benchmark. To reduce the difference of results, the methodology of TBP was optimized. The relationship between the concentration of quinine and animal preference index (PI) was obtained. Then the PI of TCH was measured through TBP, and bitterness results were converted into a unified numerical system using the relationship of concentration and PI. To verify the authenticity and sensitivity of quantified results, human sensory testing and electronic tongue testing were applied. The quantified results showed a good discrimination ability. For example, the bitterness of Coptidis Rhizoma was equal to 0.0579 mg/mL quinine, and Nelumbinis Folium was equal to 0.0001 mg/mL. The validation results proved that the new assessment method for TCH was objective and reliable. In conclusion, this study provides an option for the quantification of bitterness and the evaluation of taste masking effects.

Practice and progress on bionic technology in identification on five tastes of Chinese materia medica / 中草药

Four properties and five tastes are the core content of medicinal theory of Chinese materia medica (CMM), and it is important for modern study of CMM to elucidate the scientific connotation of five tastes based on the application of bionic technology. With the development of bionic technology, electronic nose and electronic tongue have become the objective method to determine the taste and smell in recent years. Based on the taste and odour connotation of five tastes of CMM, the working principle, research method, and identification of flavor substances in CMM of electronic nose and electronic tongue were summarized, and the progress on original variety, production place, growth period, storage life and processing technology of CMM were reviewed in this article. Combined with the practice of our research group on the characterization of medicinal properties, the basic research model of the definition and characterization of the five tastes of effective materials basis was proposed, which would provide a reference method for the medicinal research on five tastes of CMM.

Evaluation of different types of bitterness masking on inhibition of bitterness efficiency and law of four Chinese materia medicine decoctions of Gentianae Radix et Rhizoma, Sophorae Flavescentis Radix, Andrographis Herba, and Nelumbinis Plumula / 中草药

Objective To investigate the effects and the law of anti bitterness efficiency of hydroxypropyl-β-cyclodextrin (HP-β-CD) and other different types bitterness masking at different concentrations on the bitterness decoction of Chinese materia medica (BDCMM) by using the traditional human taste panel method (THTPM) and Electronic tongue (E-tongue). Methods Based on THTPM, the bitterness reduction value (ΔI), the correction rate of bitterness suppression (CRBS), and the correction rate of bitterness suppression potency index (PI50) were used as indicators to evaluate the bitterness suppression effect of four bitterness masking at different concentrations on BDCMM such as Sophorae Flavescentis Radix (SFR), and the relationship model between the concentrations of ΔI and bitterness masking was established to explore the bitterness suppression rule of bitterness masking on different BDCMM. Based on the E-tongue method, the E-tongue taste response information values of HP-β-CD and Acesulfame K to BDCMM such as SFR were measured at different concentrations, and the electronic tongue bitterness reduction value (ΔIe) was used as an index to explore the change rule of ΔIe with bitterness masking concentration. THTPM and E-tongue was combined to establish a prediction model of the effect of bitterness suppression. Results The ΔI, CRBS, and PI50 of four kinds of BDCMM with different concentrations of bitterness masking were measured, which can be used to compare the bitterness suppression effect of bitterness masking; The relation between ΔI and bitterness masking concentration accorded with Weibull curve model; Based on E-tongue, ΔIe was obtained, and the model of the relationship between ΔIe and bitterness masking concentration was established. The relationship between ΔIe and ΔI was established. The model determination coefficients of HP-β-CD for the two types of ΔIe of the two BDCMM were 0.986 1, 0.977 9, 0.989 0, and 0.982 0 respectively (P < 0.01, n = 6). Acesulfame had no response to the sensor and did not establish a model of bitterness suppression law. Conclusion Based on THTPM and E-tongue, a method for evaluating the bitterness suppression effect of bitterness masking on BDCMM was established. The bitterness suppression effect of bitterness masking on BDCMM such as SFR was studied by molecular inclusion, high-efficiency sweetening, and other bitterness suppression mechanisms were inverstigated.

Preparation and Quality Evaluation of Vardenafil Hydrochloride Orally Disintegrating Tablets / 医药导报

Objective To prepare vardenafil hydrochloride orally disintegrating tablets and evaluate their quality. Methods The tablets were prepared by direct power compression method, using crosslinking povidone ( PVPP ) as disintegrants. The preparation method was optimized by response surface test using amount of PVPP, menthol and taste-masking agents as factors with disintegrating time and distance of bitterness as index. The results of taste of orally disintegrating tablets were determined by electronic tongue, comparing to the results of taste tests. At the same time, the properties of the tablets were evaluated using appearance, content uniformity, disintegrating time, et al. as index. Results The optimal formula was as follows:PVPP 13. 26%, menthol 0. 43%, taste-masking agent SGxj 1. 26%. The results on evaluation of electronic tongue were consistent with the results of taste tests. The quality of the prepared tablets was in line with standard. The disintegrating time was (22. 34 ± 0. 34 ) s. Conclusion The preparation technology of orally disintegrating tablets is simple, and controllable in quality.

Application of the Electronic Tongue in the Identification of Cyathula officinalis / 中国药房

OBJECTIVE:To establish the method for "taste" identification of Cyathula officinalis.METHODS:The "taste" of C.officinalis was detected by using electronic tongue:sampling temperature of 25 ℃,sampling time of 120 s,sampling period of 1 s,rolling speed of 1 r/s,cleaning solution of purified water.The response value of electronic tongue sensor at 120 s were used as "taste" analysis data and obtained "taste" related data was analyzed through principal component (PC) analysis and discriminant factor (DF) analysis.C.officinalis and its adulterants,C.officinalis from different regions,different ages and different batches were distinguished.RESULTS:There was significant difference in DF between one batch of C.officinalis and 4 batches of adulterants.The samples from Sichuan Baoxing,Jinkouhe,Tianquan could be clustered together.There was significant difference in DF between annual or biennial samples and triennial or quadrennial samples.There was also significant difference in DF among different batches.CONCLUSIONS:The "taste" is different significantly between C.officinalis and its adulterants,among different regions,different ages and different batches of samples.Electronic tongue can quickly distinguish "taste" of above medicinal materials.

Quantification of astringency for traditional Chinese medicine based on animal preference index and electronic tongue / 中国中药杂志

Current evaluation method for astringency is mainly focused on human sensory evaluation. However, it is subjective, vague, and short of assessment indicators for objective quantification. In this paper, the quantification method for astringent intensity of traditional Chinese medicine was established based on the animal preference index and electronic tongue in vitro and in vivo. Firstly, the standard substance of astringency, tannic acid, was used for the methodology optimization and validation of two-bottle preference test. It was determined that the standard experimental animals were female rats of 140-180 g. The functional relationship between concentration of tannic acid and preference index was obtained Y= ln(1.682 6－0.441 66X), r=0.997 3. Then the typical astringent Chinese herbs Chebulae Fructus, Ardisiae Japonicae Herba, Canarii Fructus, Catechu, and Arecae Pericarpium were evaluated by the optimized method. Their corresponding concentration of tannic acid was converted by the concentration-preference index relationship through preference index. Their astringency was equivalent to 0.56, 0.29, 0.24, 0.34, 0.25 g•L⁻¹ tannic acid. Finally, the results were verified by electronic tongue. The correction analysis between Euclidean distance in PCA and preference index and concentration of tannic acid converted by samples showed a high correlation through pearson correlation analysis. The above results indicated that the method was objective, true and reliable. The method provided a reliable tool for the quantification of astringency and evaluation of taste masking effect for Chinese medicines, and also offered a new idea and model for the quantification of taste in the pharmaceutical and food fields.

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.

Taste comparison of unprocessed and processed Siegesbeckiae puescens based on electronic tongue / 中草药

Objective: To study the taste of unprocessed and processed Siegesbeckiae puescens (SP) and establish a taste discrimination model. Methods: The sour, bitter, astringent, salty, and sweet values of 12 batches of unprocessed and processed SP were measured by electronic tongue using a paired t-test, principal component analysis (PCA), and the linear discriminant factor analysis (LDA) to study the changes of the taste of unprocessed and processed SP. Results: The paired t-test showed that the bitterness and saltiness of processed SP decreased; Astringency, sweetness, and sourness did not significantly change. The PCA can distinguish unprocessed and processed SP. The model of the taste of unprocessed and processed SP was established through the LDA, and conduct cross validation; Its correct rate reached 100%. The fingerprint of taste of unprocessed and processed SP was established through radar-graph. Conclusion: Electronic tongue can identify sour, bitter, astringent, salty, and sweet values of traditional Chinese medicine accurately. It can reflect the numerical change of taste of unprocessed and processed SP combining with statistical method. Based on it, it can be inferred that the relationship between the change of taste and clinical efficacy before and after processing of SP. Besides, the discriminant model can be used to distinguish unprocessed and processed SP.

Application of electronic tongue in pattern study about bitterness inhibition by hydroxypropyl-β-cyclodextrin / 中草药

Objective To study the bitterness inhibition law of hydroxypropyl-β-cyclodextrin (HP-β-CD) concentration (C) on the bitter compounds and bitter Chinese herbal medicine, and to explore the application of electronic tongue in this study. Methods Berberine, oxymatrine, Sophora flavescens, and Andrographis paniculata decoction were used as bitterness vectors to establish two models of bitterness inhibition law about ΔI-C and ΔIe-C, and to explore the prediction model of bitterness inhibition effect about ΔI-ΔIe, based on the oral taste evaluation results (ΔI) and electronic tongue information (ΔIe). Then, fitting precision and fitting goodness of the prediction model were evaluated with cross-validation and residual analysis. Results In this study, good Weibull model of bitterness inhibition pattern about ΔI-C were established for all the four bitterness vectors, the decision coefficient R2 are as followed: 0.999 6, 0.987 9, 0.996 4, and 0.998 4 (P < 0.01); The decision coefficient R2 of six (two sensors per vector) models of bitterness inhibition law about ΔIe-C of berberine, S. flavescens, and A. paniculata decoctions were as followed: 0.996 5, 0.991 6, 0.997 3, 0.989 3, 0.999 6, and 0.999 1 (P < 0.01); The decision coefficient R2 of six corresponding linear prediction models of bitterness inhibition effect about ΔI-ΔIe were as followed: 0.989 1, 0.968 3, 0.989 0, 0.982 0, 0.977 9, and 0.986 1 (P < 0.01); The correlation coefficient R calculated by correlation coefficient of six prediction models above were as followed: 0.986 0, 0.997 3, 0.988 4, 0.960 8, 0.980 2, and 0.983 9 (P < 0.01); No model was established for oxymatrine within the range of tested concentration in this research, as it didn’t respond to the four sensors with varied concentration. Conclusion Based on this method, the bitterness inhibition law of HP-β-CD with changed concentration was obtained. Prediction models based on HP-β-CD concentration or electronic tongue data were also established, they can be used to predict the relative bitterness inhibition effect. Part of the bitter compounds didn't response to the electronic tongue regularly, remain further research and development of electronic tongue technology.