Electronic Tongue Measurements Research Articles

Database, prediction, and antibacterial research of astringency based on large language models

Astringency, a sensory experience causing mouth dryness, significantly impacts the taste of foods such as wine and tea, and astringent molecules may exhibit antibacterial properties. Traditional methods for predicting astringency are costly, and the connection between astringency and antibacterial activity remains largely unexplored. In this study, we present a pioneering computational approach that includes: (1) the creation of the first comprehensive astringency database comprising 238 molecules; (2) the development of a Ligand-Based Prediction (LBP) framework that combines large language models, deep learning, and traditional machine learning for enhanced molecular and peptide prediction; (3) an astringency predictor achieving 0.95 accuracy and 0.90 AUC, validated through electronic tongue measurements; (4) antibacterial predictors for molecules and peptides with accuracies of 0.92 and 0.88, respectively, revealing that 51 % of astringent molecules possess antibacterial properties; (5) accessibility of these predictors via the AstringentPD and ABPD web servers. This work not only enhances the understanding of taste-related molecules but also elucidates the relationship between astringency and antibacterial properties, setting the stage for future explorations in food science and medicinal applications.

Electronic tongue measurements as a predictor for sensory properties of vacuum-packed minced beef – A preliminary study

Changes in meat sensory quality during storage are difficult to assess accurately and objectively. Advanced analytical technologies for sensory assessment could help predict sensory changes. In this study, vacuum-packed (VP) minced beef was incubated at four different temperatures until the end of its quality shelf-life, before conducting instrumental taste analysis with an Insent electronic tongue and analysis of volatile compounds with headspace SPME GC–MS. It was found that storage time and storage temperature variables explained variation in odour, sourness and umami (adjusted R-squared values of 61 %, 58 % and 63 % respectively), with a relationship identified between sourness and umami tastes and the abundance of volatile compounds (2-butanone, methyl butyrate, methyl valerate and ethyl acetate), and trained panel scores of the odour of beef. The results highlighted that instrumental taste measurements could be used as a potential predictor of sensory shelf-life in vacuum packed beef.

Fusion of electronic tongue and NIRS for the detection of heat treatment of honey

Honey is frequently heated during processing/packaging, often in an undeclared manner, leading to consumer misleading. Heating can induce undesirable changes above 50 °C, however, detection is not always simple, especially after exposition to lower temperatures or time periods. The aim of this study was to compare the applicability of near infrared spectroscopy (NIRS), electronic tongue (ET), and their fusion for the detection of heat treatment of honey. Acacia, sunflower and false indigo honeys were heated at 40, 60, 80 or 100 °C for 60, 120, 180 or 240 min. Physicochemical characteristics, color and melissopalynological analyses along with NIRS and ET measurements were performed. Principal component analysis coupled with linear discriminant analysis (PCA-LDA) was applied for the classification of temperature, time and heat treatment level discriminations individually and using a low-level data fusion of ET and NIRS data. Results of ET and NIRS provided good results for the discrimination of the heated samples from the controls, however overlapping occurred for higher heat treatment levels. The model of the fused dataset provided >98% average correct classification of the models and 100% correct classification of the control honeys. Fusion of these methods has a potential in the detection of low-level heat treatment of honey.

Microbiological Composition and Sensory Characterization Analysis of Fermented Sausage Using Strains Isolated from Korean Fermented Foods.

This study aimed to analyze the microbiological composition and sensory characterization of fermented sausage using strains isolated from Kimchi (GK1, Pediococcus pentosaceus SMFM2016-GK1; NK3, P. pentosaceus SMFM2016-NK3), Doenjang (D1, Debaryomyces hansenii SMFM2021-D1), and spontaneously fermented sausage (S8, D. hansenii SMFM2021-S8; S6, Penicillium nalgiovense SMFM2021-S6). The control was commercial starter culture. Nine treatments were applied [GD (GK1+D1), GS (GK1+S8), GDS (GK1+D1+S8), ND (NK3+D1), NS (NK3+S8), NDS (NK3+D1+S8), GND (GK1+NK3+D1), GNS (GK1+NK3+S8), and GNDS (GK1+NK3+D1+S8)] by mixing lactic acid bacteria and yeast, and S6 was sprayed. The microbial composition of fermented sausage was analyzed [aerobic bacteria (AC), Lactobacillus spp. (LABC), Staphylococcus spp. (STPC), and yeast and mold (YMC)], and pH and electronic nose and tongue measurements were taken. The AC, LABC, STPC, and YMC values of the control and treatment groups tended to increase during fermentation (p>0.05). The STPC values of the GD, GS, ND, and GDS groups were similar to that of the control on day 3. The pH of the control on day 3 was significantly lower than that of the GD, ND, and GND groups (p<0.05). Higher levels of 4-methylpentanol, 2-furanmethanol, and propyl nonanoate, which provide a "fermented" flavor, were detected in the GD group compared to in the control and other treatment groups. GD and ND groups showed higher umami values than the control and other treatment groups. Therefore, it is expected that GD can be valuable as a starter culture unique to Korea when manufacturing fermented sausage.

New bladder cancer non-invasive surveillance method based on voltammetric electronic tongue measurement of urine

SummaryBladder cancer (BC) is the sixth leading cause of death by cancer. Depending on the invasiveness of tumors, patients with BC will undergo surgery and surveillance lifelong, owing the high rate of recurrence and progression. In this context, the development of strategies to support non-invasive BC diagnosis is focusing attention. Voltammetric electronic tongue (VET) has been demonstrated to be of use in the analysis of biofluids. Here, we present the implementation of a VET to study 207 urines to discriminate BC and non-BC for diagnosis and surveillance to detect recurrences. Special attention has been paid to the experimental setup to improve reproducibility in the measurements. PLSDA analysis together with variable selection provided a model with high sensitivity, specificity, and area under the ROC curve AUC (0.844, 0.882, and 0.917, respectively). These results pave the way for the development of non-invasive low-cost and easy-to-use strategies to support BC diagnosis and follow-up.

Comparative growth, biochemical and sensory analyses reveal the feasibility of large-scale development of selenium-enriched Tartary buckwheat sprouts

Selenium is an essential trace element in the human diet and has anti-aging, anti-tumor, and immunity boosting effects. In this study, the effects of selenium on Tartary buckwheat (Fagopyrum tataricum L.) sprouts were investigated. A suitable concentration of selenium had no adverse effects on the growth of Tartary buckwheat seedlings. The soluble sugar, protein, total flavonoid, and total phenol concentrations in the selenium-treated sprouts were higher than those in the untreated control sprouts. Electronic tongue measurements indicated that the taste characteristics, especially the sweetness and umami, of the selenium-treated and untreated groups were significantly different. Sensory analysis showed that selenium-treated Tartary buckwheat sprouts had good acceptability. Selenium-enriched Tartary buckwheat sprouts are a promising product, both in terms of flavor and as a useful source of selenium to increase human dietary intake.

Influences of Gender on Meat Quality, Electronic Tongue Measurements and Sensory Characteristics of Pork Loin

Influences of Gender on Meat Quality, Electronic Tongue Measurements and Sensory Characteristics of Pork Loin

Taste masking of propranolol hydrochloride by microbeads of EUDRAGIT® E PO obtained with prilling technique for paediatric oral administration.

The purpose of this study was to develop a new solid paediatric formulation for propranolol hydrochloride (PR). This drug is used to treat various paediatric diseases, and recently received clearance to treat haemangioma. However, PR has a bitter salty taste that does not facilitate high rates of compliance among children, especially in liquid formulations. In addition, the solid formulations are designed for adults and often their dosage is not suitable for children that require a flexible dose based on their weight. Therefore, matrix microbeads of EUDRAGIT® E PO containing PR were manufactured to overcome these limitations. Nine different samples were prepared using the prilling-congealing technique with high yield. Using 2 nozzles, 300 and 450μm (code n), the diameters obtained of microbeads (from 333 to 699μm) were homogenous and appropriate to be swallowed by children. In this study, the ratio drug:matrix for the microbeads was also examined in detail: 1:25 (F1), 1:15 (F2) and 1:10 (F3) in aqueous and tert-butyl alcohol/aqueous (code t) media. Most of the examined microbeads were characterized by high percentage of encapsulation efficiency (22-100%) and drug loading (22-77mg of drug per g of matrix) effective for the administration of low and high doses of PR. SEM analysis revealed a matrix with a radial or a spongy structure, with numerous pores that generated soft floating microbeads in aqueous solution. Release studies confirmed a low release and dissolution of the drug in artificial saliva, mainly F1n>F1>F2nt, and a prompt dissolution in simulated gastric media. Finally, electronic tongue measurements revealed the ability of these formulations to mask the bitter drug taste, especially for the sample with a ratio 1:25 (F1n and F1). These samples were chemically and physically stable for six months. In conclusion, the projected microbeads F1, and F1n reached the goal of the study, and could be proposed as new solid oral formulations dedicated to use by children.

Metabolomics Based on UHPLC-Orbitrap-MS and Global Natural Product Social Molecular Networking Reveals Effects of Time Scale and Environment of Storage on the Metabolites and Taste Quality of Raw Pu-erh Tea

Raw Pu-erh tea (RPT) needs ageing before drinking. However, the influence from environment and time of storage on chemical profile and flavor of RPT is unclear. In this study, the RPTs stored in wet-hot or dry-cold environment for 1-9 years were assessed using metabolomics based on UHPLC-Orbitrap-MS and global natural product social (GNPS) feature-based molecular networking as well as electronic tongue measurement. The results exhibited that the chemical profiles of RPTs were similar at an early stage but started to differentiate from each other at the 5th and the 7th year in wet-hot and dry-cold environments. The discriminating features including N-ethyl-2-pyrrolidinone-substituted flavan-3-ols (flavoalkaloids), unsaturated fatty acids, lysophosphatidylcholines, flavan-3-ols, amino acids, and flavonol-O-glycosides among the three chemical profiles were discovered and analyzed by means of multivariate statistics, GNPS multilibraries matching, and SIRIUS calculation. The metabolomic data were consistent with the results obtained through electronic tongue measurement.

Sensory evaluation and electronic tongue for sensing grafted and non-grafted watermelon taste attributes

The objective of our study was to analyse the results of two measuring methods (sensory evaluation and electronic tongue) and to find differences in taste between grafted and non-grafted watermelon fruit. The trained sensory panel evaluated in two years three differently treated watermelon fruit. The studied fruit samples were produced on the same growing-areas in both years but with different growing technologies. The experiment used the non-grafted/self-rooted watermelon as control sample, while the other two treatments were grafting on two rootstock types: a Lagenaria and an interspecific squash hybrid rootstock. The electronic tongue measurement showed that it is the environment/growing technology that mainly determines the characteristics of the fruit quality, not grafting. The two measurement methods can complement each other in a detailed and practical way, as technology and growing area strongly influence the quality of watermelon fruit. The research also showed that it is possible to have similar watermelon fruit quality, independently from the used rootstock type.

Study on changes in the quality of grass carp in the process of postmortem

Grass carp is an important freshwater fish but little is known about its quality postmortem. We tracked changes in the pH, texture, lactic acid, ATP-related compounds, K value, free amino acids (FAA) contents in grass carp stored at 4°C for 192 hr. Sensory and electronic tongue assessment were also performed. The results showed a consistent trend in the hardness and chewiness. pH were closely correlated with the lactic acid content and hardness. The fresh sweet amino acids gradually decreased with time while the opposite occurred with the bitter amino acids. The content of Hx and HxR increased gradually. The K value remained increased throughout the storage. Sensory assessment followed the opposite trend. The electronic tongue indicated that the differences were distributed in various areas between the first 2 days and the last 6 days. Overall, we recommend that grass carp should be consumed within 6 days when stored at 4°C. Practical applications In fish, the process of quality change after death can normally be divided into four stages: the early biochemical change, rigidity and dissolving, self-dissolution and finally, corruption. Rigidity can delay the process of corruption somewhat as fish in the rigid period are almost as fresh as newly caught fish. Preservation may thus be described as an extension of the period of rigor mortis. Postmortem changes in grass carp meat were studied over a period of 192 hr by measuring its pH, texture properties, lactic acid, ATP-related compounds, K values, and FAA content. Sensory assessment and electronic tongue measurements were also conducted. In addition to establishing a theoretical basis for the quality control and processing of grass carp, these results provide useful information for manufacturers and product developers seeking to improve the quality of their grass carp products and will also provide farmers with valuable insights into quality retention.

Beef Protein-Derived Peptides as Bitter Taste Receptor T2R4 Blockers.

The aim of this work was to determine the T2R4 bitter taste receptor-blocking ability of enzymatic beef protein hydrolysates and identified peptide sequences. Beef protein was hydrolyzed with each of six commercial enzymes (alcalase, chymotrypsin, trypsin, pepsin, flavourzyme, and thermoase). Electronic tongue measurements showed that the hydrolysates had significantly ( p < 0.05) lower bitter scores than quinine. Addition of the hydrolysates to quinine led to reduced bitterness intensity of quinine with trypsin and pepsin hydrolysates being the most effective. Addition of the hydrolysates to HEK293T cells that heterologously express one of the bitter taste receptors (T2R4) showed alcalase, thermoase, pepsin, and trypsin hydrolysates as the most effective in reducing calcium mobilization. Eight peptides that were identified from the alcalase and chymotrypsin hydrolysates also suppressed quinine-dependent calcium release from T2R4 with AGDDAPRAVF and ETSARHL being the most effective. We conclude that short peptide lengths or the presence of multiple serine residues may not be desirable structural requirements for blocking quinine-dependent T2R4 activation.

A Novel Method to Mask the Bitter Taste of Berberine Hydrochloride: Powder Surface Modification.

Background:Berberine hydrochloride (BH) is widely used as a nonprescription drug to treat diarrhea without drug resistance and side effects worldwide. However, its drastic bitterness affects patient compliance severely. Hence, it is essential to mask the bitter taste of BH.Objective:Powder surface modification technology is attempted to mask the bitterness of BH through changing the surface properties in vibromill. The purpose of this study was to apply this technology to mask the bitterness of BH and improve the patient compliance.Materials and Methods:Initially, to prepare the modifier-BH composites, some parameters were optimized, including type of modifiers, ratio between BH and modifiers, and composite time. Then, the contact angles, scanning electron microscopy, and infrared (IR) spectroscopy were utilized to evaluate the microstructure of composites. Moreover, electronic tongue measurement, animal performance test, and bitterness evaluation methods were applied to evaluate the masking effect.Results:Based on the results of bitter taste evaluations, mannitol was chosen as the best modifier, and the optimal ratio of BH and mannitol was 6:4 with grinding together for 2 min in vibromill. For the composites prepared by this process, the IR spectroscopy and surface properties were similar with that of mannitol, and the microstructure was also demonstrated that small particles of mannitol successfully coated on the surface of BH. Special structure of the composites decreased the contact area between BH and external media and finally inhibited the bitterness. This effect was confirmed by three different kinds of methods.Conclusion:Our study provides a novel method to mask the bitter taste of drugs. It will be of great interest to pharmaceutical experts and pharmacists.SUMMARY Powder surface modification, a novel and different from previous technology, is used to prepare modifier-berberine hydrochloride composites to mask the bitter taste of BHElectronic tongue measurement, animal performance test, human sensory test, and chemical evaluation method were simultaneously applied to evaluate the masking effectA novel method to mask the bitter taste of drugs was provided. Abbreviations used: BH:Berberine hydrochloride; CDI: Clostridium difficile infection; ODT: Orally disintegrating tablets; HPLC: High-performance liquid chromatography; CAs: Contact angles; SEM: Scanning electron microscopy; IR: Infrared spectrogram.

Evaluating taste contribution of brown sugar in chicken seasoning using taste compounds, sensory evaluation, and electronic tongue

ABSTRACTIn this study, the taste contribution of brown sugar in chicken seasoning was evaluated. Chicken seasonings containing brown sugar (AB), white sugar (AW), and liquid sugar (AL) were compared by the detection of taste compounds, sensory evaluation, and electronic tongue measurements. The correlation model of the three kinds of data was built by partial least squares regression (PLSR). The contents of the taste compounds in sample AB was higher than in sample AW and lower than in sample AL. Sample AB had the strongest “umami” and “full-body” taste and the highest response values for the UMS and GPS sensors. Combined with the PLSR results, brown sugar could be used to balance the taste of chicken seasoning. In conclusion, brown sugar had a positive effect on flavor quality and could help to improve chicken seasoning recipes.

Floral and Geographical origin Identification of Hungarian Honey With Electronic Tongue and Classical Analytical Methods

Honey has been widely used for health care and as sweetener since the ancient times. Due to its great nutritional value and its high price, honey is one of the most adulterated products on the market. Therefore, there is a need to develop new quick measurement methods to recognize the adulteration. Almost 80 authentic honey samples of different floral and geographical origins were collected for our experiments, focusing mainly on Hungarian honey. Various analytical methods were used for the determination of the nutritional values of the honey samples, e.g. antioxidant capacity, polyphenol content, ash content, pH, conductivity, etc. These measurements aim to complete the scarcely available data on Hungarian honeys. In addition, we determined sensory properties by color and electronic tongue analyses. Electronic tongue enables easy sample preparation and results are delivered in a short time. Evaluating the results by different multivariate statistical methods, determination of the floral and geographical origin of the samples was possible based on the results of the electronic tongue measurements. The results achieved with these classifications methods have proven by building up a robust database electronic tongue can be used for origin authentication of domestic honey samples.

Early pediatric formulation development with new chemical entities: Opportunities of e-tongue besides human taste assessment

The palatability of a pediatric drug formulation is one of the key prerequisites for therapeutic success. Liquid formulations are often chosen for pediatric drug products, and they require special attention regarding their taste, as they have direct contact to the taste buds and a relatively long residence time in the oral cavity. For ethical reasons, the role of electronic tongues in the development of oral drug formulations with new chemical entities (NCEs) for pediatric use is growing, however, little is known about the strategies how this instrumental taste assessment can be performed.The present study illustrates two possibilities to combine in-vitro and in-vivo data for the characterization of the palatability of the new drug candidates CSE3104 and CSE3165. As a first step, the implementation and suitability of electronic tongue measurements has been demonstrated by comparison of in-vivo and in-vitro data. In alignment with the taste assessment results during a single-center, double-blinded, randomized, placebo-controlled, single ascending dose (SAD) study in healthy subjects, the bitter taste perception of CSE3104 was assessed with e-tongue measurements. Moreover, the sensor response pattern showed comparable results of the e-tongue measurements to the human taste study of CSE3165: With increasing concentration, the bitterness values were increased. In addition, the human taste pattern showed increasing values for sourness due to higher volumes of the citric acid buffer. Results of the hedonic descriptor “unpleasant” within the human taste assessments could be related to bitterness in the instrumental taste assessment.For the second step in electronic tongue guided formulation development two possibilities are depicted in the article focusing on the effect of different excipients on the formulation on the one hand and on the assessment and comparison of two drug formulations on the other hand.Based on these results, the low number of healthy volunteers for the taste assessment in a Phase 1 study led to a meaningful interpretation, by applying in addition the electronic tongue. Using this instrumental approach led to reproducible data versus the human taste assessment, without ethical concerns, and with a reduction in time and costs.

Evolution of Taste Compounds of Dezhou-Braised Chicken During Cooking Evaluated by Chemical Analysis and an Electronic Tongue System.

This paper aimed to study the time course changes in taste compounds of Dezhou-braised chicken during the entire cooking process mainly consisting of deep-frying, high-temperature boiling, and low-temperature braising steps. For this purpose, meat samples at different processing stages were analyzed for 5'-nucleotides and free amino acids, and were also subjected to electronic tongue measurements. Results showed that IMP, Glu, Lys, and sodium chloride were the main compounds contributing to the taste attributes of the final product. IMP and Glu increased in the boiling step and remained unchanged in the following braising steps. Meanwhile, decrease in Lys content and increase in sodium chloride content were observed over time in both boiling and braising steps. Intensities for bitterness, saltiness, and Aftertaste-B obtained from the electronic tongue analysis were correlated with the concentrations of these above chemical compounds. Therefore, the electronic tongue system could be applied to evaluate the taste development of Dezhou-braised chicken during processing.

Evaluation of umami taste in mushroom extracts by chemical analysis, sensory evaluation, and an electronic tongue system

Seventeen edible mushrooms commercially available in Korea were analysed for their umami taste compounds (5′-nucleotides: AMP, GMP, IMP, UMP, XMP; free amino acids: aspartic, glutamic acid) and subjected to human sensory evaluation and electronic tongue measurements. Amanita virgineoides featured the highest total 5′-nucleotide content (36.9±1.50mg/g), while monosodium glutamate-like components (42.4±6.90mg/g) were highest in Agaricus bisporus. The equivalent umami concentration (EUC) ranged from 1.51±0.42 to 3890±833mgMSG/g dry weight; most mushrooms exhibited a high umami taste. Pleurotus ostreatus scored the highest in the human sensory evaluation, while Flammulina velutipes obtained the maximum score in the electronic tongue measurement. The EUC and the sensory score from the electronic tongue test were highly correlated, and also showed significant correlation with the human sensory evaluation score. These results suggest that the electronic tongue is suitable to determine the characteristic umami taste of mushrooms.

Vision system and electronic tongue application to detect coffee adulteration with barley

Time consuming and expensive methods have been applied for detection of coffee adulteration based on the literature. In the present work, an optical method (vision system) and the application of an electronic tongue is proposed to reveal the addition of barley in different proportion to coffee in ground and brewed forms. In a range of 1 to 80% (w/w) Robusta coffee was blended with roasted barley. Principal Component Analysis (PCA) accomplished on vision system image data showed a good discrimination of the adulterated samples. The results of Polar Qualification System (PQS) data reduction method revealed even small differences in the right barley content order by point method approach. With Partial Least Squares (PLS) regression the amount of barley in Robusta was predicted with high R2 (0.996) and relatively low RMSEP (∼2%) values in case of vision system data processing. Considering electronic tongue measurements, PCA results showed a good discrimination of samples with higher barley concentration. Misclassification was found in the low concentrated area by Lienar Discriminant Analgsis (LDA). To obtain an accurate model for barley content prediction in coffee, the most sensitive sensor signals were used to apply PLS regression successfully (R2=0.97, RMSEP=3.99% (w/w)).

Lean production of taste improved lipidic sodium benzoate formulations

Sodium benzoate is a highly soluble orphan drug with unpleasant taste and high daily dose. The aim of this study was to develop a child appropriate, individually dosable, and taste masked dosage form utilizing lipids in melt granulation process and tableting. A saliva resistant coated lipid granule produced by extrusion served as reference product. Low melting hard fat was found to be appropriate as lipid binder in high-shear granulation. The resulting granules were compressed to minitablets without addition of other excipients. Compression to 2mm minitablets decreased the dissolved API amount within the first 2min of dissolution from 33% to 23%. The Euclidean distances, calculated from electronic tongue measurements, were reduced, indicating an improved taste. The reference product showed a lag time in dissolution, which is desirable for taste masking. Although a lag time was not achieved for the lipidic minitablets, drug release in various food materials was reduced to 2%, assuming a suitable taste masking for oral sodium benzoate administration.