Intense Bitterness Research Articles

Sensory Attributes Driving Preference for Wild Rocket (Diplotaxis tenuifolia) Leaves Tasted as a Single Ingredient and as a Part of a Recipe.

Two cultivars of wild rocket (Diplotaxis tenuifolia), cv. Denver and Marte, were subjected to chemical determination of flavour-related constituents, sensory descriptive analysis, and measurement of liking by consumer test. Consumers evaluated rocket leaves both as a single ingredient and in a recipe formed by a roll of bresaola with also Grana Padano cheese. Sensory analyses showed that Marte was characterized by a more intense bitterness, hotness, and pungency, which corresponded to a higher total GSL content, mainly due to a higher level of dimeric 4-mercaptobutyl GSL. Five clusters of consumers were identified based on their liking scores. When tasting rocket leaves as a single ingredient, three clusters showed a higher liking for the milder cultivar, one cluster showed an opposite preference, while flavour attributes, such as bitterness and hotness, appeared as the main drivers of liking. Differences in liking were no longer found between the two cultivars when rocket leaves were evaluated in the recipe. Therefore, as rocket leaves are generally consumed as a part of a recipe with other ingredients instead of as a single ingredient, in the assessment of consumer preferences, it should not be neglected the influence of the way in which the product is consumed.

Polysaccharide-coated quercetin-loaded nanoliposomes mitigate bitterness: A comparison of carrageenan, pectin, and trehalose

The intense bitterness of quercetin poses a challenge to its utilization in the food industry. To address this issue, three anionic polysaccharides (carrageenan, pectin, and trehalose) were individually incorporated to fabricate polysaccharide-coated liposome nanocarriers. Electronic tongue analysis revealed a significant decreasing bitterness value (10.34 ± 0.07 mV, sensory score 1.8 ± 0.2, taste weak bitter) in quercetin-loaded nanoliposomes, compared with the bitterness value of quercetin aqueous solution (14 ± 0.01 mV, sensory score 7.3 ± 0.3, taste strong bitter). Furthermore, the polysaccharide-coated nanoliposomes exhibited an even greater capacity to mask the bitterness of quercetin, with carrageenan coated nanoliposomes demonstrating the most pronounced effect. The superior bitter masking ability of carrageenan coated nanoliposomes can be attributed to its high charge and viscosity. In sensory evaluations, gummy incorporated with carrageenan-coated nanoliposomes received the highest ratings, exhibiting enhanced overall palatability and antioxidant activity. This study offers insights into expanding the use of bitter nutrients in food applications and paves the way for more appealing and healthful food products.

Nonconventional yeasts and hybrids for low temperature handcrafted sparkling ciders elaboration in Patagonia

Yeasts play a crucial role in transforming apple must into cider. While Saccharomyces cerevisiae (Sc) has been traditionally associated to cider fermentations worldwide, cryotolerant species such as Saccharomyces uvarum (Su) as well as natural S. cerevisiae × S. uvarum (Sc×Su) hybrids have also been detected in ciders fermented at low temperatures.This study aimed to evaluate the ability of two Patagonian cryotolerant yeast strains (Su and Se) and their interspecific hybrids with a Sc to conduct handcrafted apple must fermentations and a second fermentation process (champenoise method). The main chemical parameters and sensory quality of the resulting sparkling beverages was also analysed.Firstly, Sc×Se and Sc×Su hybrids were evaluated in their fermentative features at laboratory scale. Hybrids were compared with their respective parental species evidencing significant differences in the physicochemical and aromatic composition of the obtained base ciders.Both Su parental strain and the hybrid Sc×Se were selected for performing pilot scale fermentations (250 L) using natural (non-sterilized) apple juice at two different temperatures: 20 °C and 13 °C. Sc parental strain was also evaluated for comparative purposes. All base ciders obtained were then subjected to a second fermentation.A high implantation capacity of both Su and the hybrid was evidenced at the lowest evaluated temperature, while commercial Sc strain was not detected at the final fermentation stage, independently from the temperature. All sparkling ciders exhibited distinct physicochemical profiles. Ciders inoculated with commercial Sc (but effectively fermented with local Sc strains) allowed the development of malolactic fermentation (MLF) in processes carried out at both temperatures. Contrarily, no MLF was observed in ciders inoculated with either Su or the hybrid. Sparkling ciders fermented with Su displayed the highest concentrations of 2-phenylethanol and 2-phenylethyl acetate, regardless of the fermentation temperature. Conversely, ciders fermented with the hybrid at 20 °C exhibited the highest concentrations of ethyl octanoate and ethyl decanoate, contributing to floral and fruity notes in the beverage.Sensory analysis conducted with untrained individuals revealed a preference for sparkling ciders produced with the hybrid strain at both 20 °C and 13 °C. The cider fermented at 20 °C exhibited floral notes, sweetness, and a full body, while ciders fermented at 13 °C displayed moderate acidity and a well-balanced profile. Conversely, a trained panel described the cider fermented at 20 °C with Su as a fruity and acidic beverage, whereas the ciders fermented at 13 °C exhibited intense bitterness and acidity.This study highlights the potential of cryotolerant Saccharomyces species and hybrids in the development of new starter cultures for producing artisanal sparkling ciders with distinctive properties.

Impact of the physicochemical parameters on the sensory characterization of Brazilian coffee by the CATA method

This research aims to evaluate the sensory description of arabica and canephora coffee by consumers, identify how and canephora coffee by consumers, and identify how physicochemical variables affect sensory perception. Three Brazilian coffees (two arabica and one canephora) were determined sensorial attributes by the Check-All-That-Apply (CATA) method with 190 consumers in a home test, and physicochemical (pH and caffeine content) and chromatic parameters. The results showed that visual perception, brightness, and orange coloration are the main means used to distinguish arabica coffee from commercial coffee. In addition, the perception of sweeter aromas (toffee, vanilla, and caramel spread), chocolate with greater intensity, and the less intense bitterness taste were important typicality markers to differentiate arabica coffee (cv. Typica). The analysis of the correlations between caffeine and bitterness, sweetness, and acidity demonstrates the consumer's ability to perceive basic tastes in the different coffee samples. The chromatic parameters obtained significant correlations with visual, olfactory, and gustatory attributes. This study indicated the consumer's ability to establish typical traits for Arabica coffee depending on the place of cultivation. In addition, consumers perceive the influence of physicochemical variables on sensory attributes, highlighting the need for quality in an increasingly demanding and globalized market.

Irrigation of Young Olives Grown on Reclaimed Karst Soil Increases Fruit Size, Weight and Oil Yield and Balances the Sensory Oil Profile.

The influence of different irrigation regimes on olive fruit morphological parameters and on the quantity and quality (marketable indices, phenolic content, fatty acid composition, and sensory profile) of virgin olive oil (VOO) obtained from the Croatian cultivar Oblica, grown on an extremely rocky and dry reclaimed karst soil, was studied over three years. Four treatments were applied: rain-fed and three treatments calculated as 50%, 75%, and 100% of the crop’s irrigation requirement (Irr). Principal component analysis separated growing seasons (GS) that differed in precipitation. In the 2016 season, which had a low number of fruits per kilogram and provided a higher amount of balanced VOO with medium to intense bitterness and pungency (rain-fed treatment), the oil yield increased by irrigation (Irr 75 and Irr 100) up to 18%, while unchanged phenolics, bitterness, and pungency were observed for the VOOs obtained. In the drier GS (2017), which under rain-fed conditions had high fruit per kg, smallest fruit sizes, and lowest oil yield, and in which the VOOs had high phenolic content and intense sensory taste attributes, fruit weight, fruit sizes, and oil yield increased by 35% in all irrigation treatments, while phenols, bitterness, and pungency decreased, balancing the sensory profile of the VOOs. The results obtained here led us to conclude that the irrigation of young olives resulted in a positive effect, with the indication that an abundant water supply is more effective in drought conditions.

Rapid and sensitive quantitation of DDMP (2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one) in baked red jujubes by HS-SPME-GC-MS/MS

Baked red jujube is a common food ingredient used to enrich the nutritional value and enhance the aroma. DDMP (2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one) with intense bitterness and potential toxicity may be present in several baked red jujube-based products but there are no well-defined methods to measure it quickly, sensitively, and accurately. Headspace solid-phase microextraction with gas chromatography-tandem mass spectrometry (HS-SPME-GC-MS/MS) was applied for the analysis of DDMP. The standard curve was linear between the concentrations of 0.01 and 100 μg/mL, with a limit of detection at 0.1 ng/g that below the sensory threshold of DDMP (2.06 μg/g). Five cultivars of baked red jujubes from China were evaluated with the method for DDMP content (4.55–46.50 μg/g). The results indicated that jujube cultivars with a higher molar ratio of proline to glucose, lower moisture content, and stronger ability to resist water stress should be avoided from baking to modulate the formation of DDMP.

Influence of milk-clotting enzymes of animal and microbial origin on the quality and shelf life of soft cheeses

A comparative test was carried out for milk-clotting enzymes (MCE) of animal origin (Naturen® Extra), microbial origin (Marzyme®) and MCE based on recombinant camel chymosin (Chy-max® M) in the production of soft cheese “Lyubitelskiy”. By the end of the shelf life of the cheeses (12 days at a temperature of 3 ± 1 °C), differences were noted in the degree of proteolysis (DP) and the value of the complex modulus G*, which were the following ones for cheeses produced with MCE of the brands: Naturen® — DP = 17.86 ± 0.24%; G* = 4164 ± 587 Pa; Marzyme® — DP = 17.98 ± 0.49%; G* = 4581±786 Pa; Chy-max® M — DP = 9.85 ± 0.63%; G* = 7949 ± 1157 Pa. Cheeses made with Chy-max® M MCE had a denser texture than cheeses made with MCE of Naturen or Marzyme, which did not differ significantly in consistency. In the studied cheeses, the severity of the bitter taste was proportional to the content of water-soluble peptides with a mass of 0.5–3 kDa. Cheeses with Marzyme® MCE had a more intense bitterness than cheeses with Naturen® MCE. There was no bitter taste in cheeses produced with MCE of Chy-max® M. It was concluded that in the production of soft cheeses, recombinant camel chymosin can be used to increase the shelf life, and MCE of microbial origin can be recommended to replace more expensive MCE of animal origin.

Characterization of bitter taste theacrine in Pu-erh tea

Theacrine is a kind of purine alkaloid with a similar chemical structure to caffeine. Caffeine influences the bitterness of tea soup greatly, but the role of theacrine in the taste of Pt (Pu-erh tea) soup remained unclear. In comparison with tableland tea (TT), ancient plant tea (APT) has a more abundant and persistent bitter taste. This paper focused on whether a relationship could be formed between theacrine and the taste difference of APT and TT, and how theacrine affected the characteristic taste of Pt soup. To aims, the study detected the content of theacrine and caffeine in APT and TT, the leaching behavior, and the recognition threshold of theacrine at 25 °C and 45 °C. The leaching of theacrine was slow, about 0.67-fold of caffeine when brewing for 30 min. The overall levels of theacrine of APT were higher than TT. Besides, the recognition threshold of theacrine is 18.45 mg/L and 23.24 mg/L at 25 °C and 45 °C, respectively. In conclusion, the low recognition threshold and a different level of theacrine between APT and TT might lead to APT’s intense bitterness. The leaching of theacrine was a slow process that contributed to the APT’s endurance of repeated brewings.

Inhibition of Bitter Taste from Oral Tenofovir Alafenamide.

Children have difficulty swallowing capsules. Yet, when presented with liquid formulations, children often reject oral medications due to their intense bitterness. Presently, effective strategies to identify methods, reagents, and tools to block bitterness remain elusive. For a specific bitter-tasting drug, identification of the responsible bitter receptors and discovery of antagonists for those receptors can provide a method to block perceived bitterness. We have identified a compound (6-methylflavone) that can block responses to an intensely bitter-tasting anti-human immunodeficiency virus (HIV) drug, tenofovir alafenamide (TAF), using a primary human taste bud epithelial cell culture as a screening platform. Specifically, TAS2R39 and TAS2R1 are the main type 2 taste receptors responding to TAF observed via heterologously expressing specific TAS2R receptors into HEK293 cells. In this assay, 6-methylflavone blocked the responses of TAS2R39 to TAF. In human sensory testing, 8 of 16 subjects showed reduction in perceived bitterness of TAF after pretreating (or "prerinsing") with 6-methylflavone and mixing 6-methylflavone with TAF. Bitterness was completely and reliably blocked in two of these subjects. These data demonstrate that a combined approach of human taste cell culture-based screening, receptor-specific assays, and human psychophysical testing can successfully discover molecules for blocking perceived bitterness of pharmaceuticals, such as the HIV therapeutic TAF. Our hope is to use bitter taste blockers to increase medical compliance with these vital medicines. SIGNIFICANCE STATEMENT: Identification of a small molecule that inhibits bitter taste from tenofovir alafenamide may increase the compliance in treating children with human immunodeficiency virus infections.

Intense bitterness of molecules: Machine learning for expediting drug discovery

Drug development is a long, expensive and multistage process geared to achieving safe drugs with high efficacy. A crucial prerequisite for completing the medication regimen for oral drugs, particularly for pediatric and geriatric populations, is achieving taste that does not hinder compliance. Currently, the aversive taste of drugs is tested in late stages of clinical trials. This can result in the need to reformulate, potentially resulting in the use of more animals for additional toxicity trials, increased financial costs and a delay in release to the market. Here we present BitterIntense, a machine learning tool that classifies molecules into “very bitter” or “not very bitter”, based on their chemical structure. The model, trained on chemically diverse compounds, has above 80% accuracy on several test sets. Our results suggest that about 25% of drugs are predicted to be very bitter, with even higher prevalence (~40%) in COVID19 drug candidates and in microbial natural products. Only ~10% of toxic molecules are predicted to be intensely bitter, and it is also suggested that intense bitterness does not correlate with hepatotoxicity of drugs. However, very bitter compounds may be more cardiotoxic than not very bitter compounds, possessing significantly lower QPlogHERG values. BitterIntense allows quick and easy prediction of strong bitterness of compounds of interest for food, pharma and biotechnology industries. We estimate that implementation of BitterIntense or similar tools early in drug discovery process may lead to reduction in delays, in animal use and in overall financial burden.

4D printing of products based on soy protein isolate via microwave heating for flavor development

The aim of this study is to establish food 4D printing products with the property of automatic flavor change by the post-printing application of microwave as an external thermal stimulus. The combination of a formulation comprised of soybean protein isolate (SPI), k-carrageenan (CAR) and vanilla flavor (VNL) was used as printing material. The change in flavor profile was observed by the level of external heat stimulus as a 4D effect. The results of e-nose revealed a significant difference (P < 0.05) in sensors 2, 5, 6, 9, 10, 12 and 13 in the sample added with vanilla flavor meanwhile GC–MS detected 25 volatiles compounds. Notably, four new generated flavor compounds (1-Octen-3-ol, Maltol, Ethyl maltol and eugenal) were identified when added with vanilla flavor. Moreover, e-tongue results indicated the taste characteristics of the sample with vanilla flavor presenting more intense bitterness, astringency, umami, richness and saltiness. The rheological property and water distribution (LF-NMR) determined at different concentrations levels of carrageenan showed that SPI gel made with 3% (w/v) carrageenan was the most suitable for 3D printing among all three concentrations considered in this study. Overall, the results can conclude that the addition of carrageenan and post-printing microwave heating at an optimum level of microwave power enhanced the printability and flavor of SPI gel.

Determination of chemical parameters and storage stability of extra virgin olive oil extracted by Mobile Olive Oil Processing Unit

The effects of storage time on the stability and quality of cold press extra virgin olive oils (EVOO) extracted from cv. Tavşan Yüreği locally grown in Antalya Region of Anatolia was investigated. The Mobile Olive Oil Processing Unit (TEM Oliomio 500-2GV, Italy) was designed and used for the monocultivar olive oil production. Changes on the free fatty acid, peroxide value, UV absorption values, total phenol content, phenolic and tocopherol profiles, and sensory properties of EVOO samples were determined for 12 months. Results showed that fresh “Tavşan Yüreği” EVOO was classified as EVOO declared by the International Olive Council (IOC) standards-based in terms of chemical and sensory properties. It had a sensory profile with an equilibrated taste of intense fruitiness and medium bitterness and pungency at the end of one year. Although positive attributes (fruitiness, bitterness, and pungency) slightly decreased, color values of EVOO changed from green to yellow. Although total phenols content of EVOO samples were 385.27 ± 0.908 ppm at the beginning of storage, it decreased to 327.58 ± 0.212 ppm after a year storing. Luteolin was the most abundant phenolic compound and its content decreased by 14% at the end of storage, while tyrosol content of EVOO increased from 12 to 36.17 ppm. After twelve months, α-tocopherol contents decreased 22.38%. Using Mobile Olive Oil Processing Unit increased oxidative stability and quality of extracted EVOO.

Insights into the Regulation Effects of Certain Phenolic Acids on 2,3-Dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one Formation in a Microaqueous Glucose-Proline System.

The control of 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP) formation in the Maillard reaction is important to improve the thermally treated food quality as a result of its intense bitterness and potential toxicity. In this work, phenolic acids, such as gallic, protocatechuic, caffeic, and ferulic acids, were applied to modulate DDMP formation in a microaqueous glucose-proline model. The formation of DDMP was inhibited at low concentrations (from 0.1 to 5.0 mM) while enhanced at 10.0 mM gallic, protocatechuic, and caffeic acids. Ferulic acid always inhibited DDMP formation as a result of the absence of catechol groups on its benzene ring. The result indicated that the control of DDMP formation depended upon the concentration and chemical structures of phenolic acids, such as the number of hydroxyl groups. Further studies indicated that the hydroxyl distribution of phenolic acids regulated the peroxide formation in the model reaction system and further changed the development of the oxidation reaction, which affected the degradation of glucose via caramel or Maillard reaction, Amadori rearrangement product oxidation, and 1-deoxyglucosone degradation to form the intermediates.

Determination of Four Bitter Compounds in Caramel Colors and Beverages Using Modified QuEChERS Coupled with Liquid Chromatography-Diode Array Detector-Mass Spectrometry

The 2,3-dihydro-3,5-dihydroxy-6-methyl-4(H)-pyran-4-one (DDMP), 5-hydroxymethylfurfural (HMF), furfural, and 5-methylfurfural (MF) are the components of caramel colors with intense bitterness. In this study, a practical and simple method for the simultaneous analysis of these four bitter compounds in caramel colors and beverages was proposed using high-performance liquid chromatography–diode array detector–atmospheric pressure chemical ionization–mass spectrometry (HPLC-DAD-APCI-MS). For the sample preparation, the extract efficiencies from different extract solvents and quick, easy, cheap, effective, rugged, and safe (QuEChERS) salt pockets were compared. The correlation coefficients (R2) of all analytical curves were ≥ 0.9914. The satisfactory recoveries ranged between 70.1% and 101.5%, with relative standard deviations ranged from 1.7% to 9.1%. The matrix effect was evaluated, and HMF, furfural, and MF showed signal enrichment. This method was successfully applied to the analysis of bitter compounds content in several caramel colors and beverages from a local market in China. Four compounds were found in eight samples, with concentration ranging from 0.5 to 1058.1 mg kg−1.

Influence of Phenylthiocarbamide Taster Status on Sensory Perceptions of Fruits, Vegetables and Nuts

BackgroundThe sensory properties of foods guide food choices and intake, importantly determining nutritional and health status. Variations in sensitivity to the bitter taste of phenylthiocarbamide (PTC) and other thioamide‐containing compounds is well documented. However, there is mixed evidence regarding the association between bitter taste sensitivity, food preferences and metabolic risk factors.MethodsHealthy female (N=174) and male (N=76) participants (age: 18–24 years) with no food allergies or smoking history were recruited to participate in this cross‐sectional study. Participants underwent sensory tests to rate their liking and taste intensities of 18 local foods (name‐blinded) such as fresh and raw fruits and vegetables i.e. pomegranates, strawberries, peach, plums, kiwis, avocado, olives, broccoli, celery, asparagus, spinach, collard greens, cauliflower, green beans and carrots and roasted nuts i.e. almonds, peanuts, pistachios and on 9‐point hedonic and general labelled magnitude scales respectively. In addition, preference tests were conducted for similar foods matched on nutritive value, but differing in cost and availability. Participants sampled PTC strips (3–5 μg/strip) and were categorized as supertasters (extremely bitter) and non‐tasters (tasteless or other taste). Participants also rated importance of several factors influencing consumption of these foods such as taste, cost, convenience, availability, health and nutrition on a 9‐point scale. In addition, participants underwent anthropometric (i.e. BMI, adiposity, waist circumference etc.) and clinical (blood pressure and blood glucose) measurements. Data were analyzed using Kruskal–Wallis test, Chi‐squared tests and multivariate regression.ResultsOver 70% of participants were familiar with all foods except for collard greens which were correctly identified by only 4% of participants. A majority (68%) of participants were categorized as supertasters i.e. perceiving intense bitterness to PTC. Supertasters perceived 20% greater bitterness in collard greens only and consumed them 28% less frequently than non‐tasters (P&lt;0.05). There was no significant difference in liking ratings of any food by taster status. Supertasters also rated cauliflower, broccoli and strawberries as being more important towards health than non‐tasters (P&lt;0.05). Preference test results indicate that greater than 75% of participants preferred avocados (vs. olives), spinach (vs. collard greens), carrots (vs. celery) and pistachios (vs. peanuts). However, there was no significant difference in preferences for paired foods by taster status (assessed as proportion of individuals that preferred one or the other food). In addition, taster status did not predict BMI, adiposity, fasting blood glucose or blood pressure measurements. In conclusion, bitter taste sensitivity influenced frequency of consumption of only unfamiliar foods i.e. collard greens and not the hedonic responses to foods or metabolic risk factors in this cohort. Hence, food choices are likely governed by both sensory as well as non‐sensory factors.Support or Funding InformationBlum Center UC MercedThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Peptidomic screening of bitter and nonbitter casein hydrolysate fractions for insulinogenic peptides

Sodium caseinate hydrolysates (NaCaH) contain biologically active peptides that can positively influence human health. However, their intense bitterness hinders their inclusion in food products. To our knowledge, no studies have investigated whether a correlation between bitterness and bioactivity exists in NaCaH, so it is not yet known what effect selective removal of bitterness has on NaCaH bioactivity. A deeper understanding of the physicochemical characteristics affecting both bitterness and bioactivity is therefore needed. The aim of this study was to use in silico analysis to elucidate the relationship between bitterness and bioactivity of the insulinogenic NaCaH. The NaCaH fractions were generated by membrane filtration and flash chromatography and were subsequently evaluated for bitterness by a sensory panel. In this present study, peptidomic and bioinformatic processing of these NaCaH fractions allowed for the identification of insulinogenic peptides as well as other literature-identified peptides in each of the fractions. The results showed that the most bitter fraction contained the highest abundance of insulinogenic peptides, whereas another bitter fraction contained the highest abundance of other literature-identified bioactive peptides exhibiting angiotensin-converting enzyme-inhibition activity. Although some bioactive peptides were identified in the least bitter fractions, the abundance of these peptides was very low. These observations show a correlation between bitter taste and bioactivity, highlighting potential complications in removing bitterness while maintaining bioactivity. However, as the most bitter fraction contained the highest abundance of insulinogenic peptides, there is potential for using a lower dose of this enriched bioactive fraction to exert health benefits. The second most bitter fraction contained a very low abundance of insulinogenic peptides and other bioactive peptides. Therefore, removal of this fraction could reduce the NaCaH product's bitterness without significantly altering overall bioactive potential.

Interaction of peptides obtained from the enzymatic hydrolysis of soybean meal with cyclodextrins: an evaluation of bitterness reduction

Enzymatic hydrolysis improves the functional and nutritional characteristics of soybean meal proteins. However, the presence of hydrophobic peptides can cause an intense bitterness to the hydrolysate, which is deleterious in terms of final product taste. In this paper we evaluate the interaction of peptides employed for the enzymatic hydrolysis of soybean meal with α-, β- and γ-cyclodextrins, aiming to reduce the bitter taste. Each cyclodextrin was added in mass fractions of 1.5, 2.0 and 2.5% in a hydrolysate of soybean meal prepared with enzyme Alcalase® 2.4 L at 1% concentration (protein/protein). In order to identify possible interactions between the components, several instrumental techniques were employed. NMR H1 spectra evidenced strong interactivities between the peptides’ aromatic and aliphatic regions and the cyclodextrins’ internal cavities. Analysis by an electronic tongue system showed that the addition of α- and β-cyclodextrins to the hydrolysate, at concentrations 1.5 and 2.0% (w/w), respectively, induced the greatest difference with regard to control hydrolysate. The difference was also sensory perceptible to untrained tasters in a bitterness ranking test, and reveal that the treatment was efficient in reducing bitterness compared to the control samples, indicating this method as a suitable approach for masking bitterness in soybean hydrolysates.

Disgust evoked by strong wormwood bitterness influences the processing of visual food cues in women: An ERP study

The perception of intense bitterness is associated with disgust and food rejection. The present cross-modal event-related potential (ERP) study investigated whether a bitter aftertaste is able to influence affective ratings and the neuronal processing of visual food cues. We presented 39 healthy normal-weight women (mean age: 22.5 years) with images depicting high-caloric meat dishes, high-caloric sweets, and low-caloric vegetables after they had either rinsed their mouth with wormwood tea (bitter group; n = 20) or water (control group; n = 19) for 30s. The bitter aftertaste of wormwood enhanced fronto-central early potentials (N100, N200) and reduced P300 amplitudes for all food types (meat, sweets, vegetables). Moreover, meat and sweets elicited higher fronto-central LPPs than vegetables in the water group. This differentiation was absent in the bitter group, which gave lower arousal ratings for the high-caloric food.We found that a minor intervention (‘bitter rinse’) was sufficient to induce changes in the neuronal processing of food images reflecting increased early attention (N100, N200) as well as reduced affective value (P300, LPP). Future studies should investigate whether this intervention is able to influence eating behavior.

Assessing expression of TAS2R16 receptor on the tongue of elderly persons

In conducted study, we assessed expression of TAS2R16 receptor gene on the tongue of elderly persons. The TAS2R16 receptor belongs to family of G-protein coupled bitter taste receptors and is expressed in type 2 taste cells, which are a part of taste buds. The taste buds are distributed across the tongue's surface on the specialised structures called papillae. The TAS2R16 receptor mediates bitter taste in response to β-glucopyranosides such as salicin. The purpose of conducted study was to examine, whether the ageing process influence gene expression and hence the perception of taste at the molecular level. Ageing process is often related to either decreased or total lost perception of taste qualities. It is due to physiological changes in the oral cavity. The changes in taste cell membranes involve altered function of ion channels and receptors, which ultimately lead to decreased tasting ability of elderly people. In addition, various causes, such as oral and systemic diseases, drug administration, lifestyle (i.e. smoking) and some oral conditions (wearing dentures, dental caries and coated tongue), may extracerbate this issue. Loss of taste may become a large factor in reduction of appetite, which may lead to malnutrition. To accomplish the objective of this study, we recruited ten elderly persons. One 25-year old human was used as calibrator. We used non-invasive scrapping method for collecting taste cells from fungiform papillae of each subject. A multiplex TaqMan real-time PCR was performed to amplify cDNA of TAS2R16 and PGK1 genes, whereas the last one served as housekeeping gene. The TAS2R16 gene expression for elderly persons relative to that of young one was calculated according to the 2-ΔCT formula. Results pointed out to increased expression of TAS2R16 gene by 2-fold in 5th and 8th seniors. It is assumed that they perceive more intense bitterness from salicin at the molecular level than 25-year old person. The 2nd, 3rd, 7th and 10th elderly persons have had decreased expression level about 70%, whereas in case of 6th one that was even about 90%. It is supposed that these subjects, in particular last one, respond to salicin very weakly. This data may show evidence of almost total loss of taste. The causes and consequences are discussed in more detail.

Nettle (Urtica dioica L.) extracts as functional ingredients for production of chocolates with improved bioactive composition and sensory properties.

Pursuant to the tendencies of producing functional foods, attractive to a wide range of consumers, in this study chocolates enriched with freeze dried (FD) and concentrated (CE) nettle extracts were formulated, and their polyphenolic and antioxidant capacity stability evaluated during 12months of storage. A simple aqueous extraction procedure of nettle was developed, and the defined extract evaluated for its cytotoxic and antioxidant/prooxidant activity on human colon cancer cell line (SW 480). An increase in total polyphenolic content, chlorogenic acid and flavonoid derivatives (originating from nettle extract) contents was achieved in enriched chocolates. Implementation of FD extract enabled higher increase of polyphenolic content in comparison to CE extract. During storage, fluctuations of polyphenolic content were observed, but the final bioactive parameters did not differ (or increased) from the initial ones. Nettle enriched chocolates exhibited more intense bitterness and astringency, while dark chocolates were preferred over milk and semisweet ones.