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PubMed2004

Evaluation of bottled nutritive drinks using a taste sensor.

The purpose of this study was to evaluate the taste of 20 bottled nutritive drinks, all commercially available on the Japanese market, both in human gustatory sensation tests and using a multi-channel taste sensor. In the gustatory sensation tests, seven trained healthy volunteers were asked to score the drinks in terms of the intensities of four basic tastes (sweetness, saltiness, sourness, and bitterness), for overall palatability (ease of drinking), and for nine components of palatability (astringency, pungency, fruitiness, tasting of a medicinal plant, refreshing, irritating to the throat, seeming beneficial, good aftertaste, and the desire to drink again). The data were analysed to determine the critical factors for overall palatability. There was a positive linear correlation between overall palatability and 'sourness', 'fruitiness', 'refreshing', and 'good aftertaste' scores (r = 0.79, 0.85, 0.74, and 0.70, respectively). There was a negative correlation between overall palatability and 'bitterness intensity', 'tasting of a medicinal plant', 'seeming beneficial', and 'pungency' scores (r = -0.76, -0.64, -0.62, and -0.50, respectively). When evaluated using a multi-channel taste sensor, there was a positive linear correlation between the intensities of sourness and bitterness determined by the human volunteers and those predicted by the taste sensor (r = 0.85 and 0.71, respectively). The pungency intensity, as evidenced in gustatory sensation tests, could be also predicted by sensor output (r = 0.84). The taste sensor seems therefore to be a potentially useful tool in evaluating the palatability of bottled nutritive drinks.

Beverages↗
PubMed2004

PROP taster status and self-perceived food adventurousness influence food preferences.

OBJECTIVE: To determine the influence of 6-n-propylthiouracil (PROP) taster status and food adventurousness on liking of bitter, hot, and pungent foods. DESIGN: Self-reported survey of food likes/dislikes for 70 foods. Subjects were classified as tasters or nontasters of PROP using a standard screening procedure. By their response to a query regarding their perceived frequency of trying unfamiliar foods, subjects were characterized as being more or less adventurous. SUBJECTS: A convenience sample of 232 healthy adults, 18 to 55 years of age, was recruited from the local community. Statistical analyses Individual foods were grouped using Principal Component Analysis. Analysis of variance was used to assess differences in liking of food groups as a function of PROP status and food adventurousness. RESULTS: PROP tasters who were more food adventurous liked chili peppers and hot sauce, other pungent condiments, strong alcohol, and bitter fruits and vegetables more than tasters who were less food adventurous (P< or =.05-.001). Nontasters liked most foods, and food adventurousness had little influence on food liking for these individuals. CONCLUSIONS: Food adventurous PROP tasters liked a wide variety of strong-tasting foods, whereas tasters who were less food adventurous showed the classic dislike of bitter, hot, and pungent foods. Previous studies might have overestimated the influence of PROP taster status on rejection of strong-tasting foods by not distinguishing individuals by food adventurousness.

Adolescent↗
PubMed2003

Physiological phenotyping of cholecystokinin-responsive rat taste receptor cells.

The recent discovery that subsets of rat taste receptor cells (TRCs) express the peptide cholecystokinin (CCK) and that subsets of TRCs respond to CCK with altered potassium currents or elevated intracellular calcium via CCK-A receptor has lead to the hypothesis that CCK may play a novel signaling role within the taste bud, perhaps modifying tastant responses by co-transmission with a classic transmitter. To better understand this phenomenon, CCK-responsive TRCs were characterized for sensitivity to two bitter stimuli, quinine or caffeine, or to the neurotransmitter ACh using a ratiometric procedure with the calcium sensitive dye fura-2. In characterizing TRC responses to quinine, it was observed that quinine-induced elevations of intracellular calcium were not due to endogenous fluorescence of the quinine molecule. Most (60-70%) CCK-responsive cells were also sensitive to either bitter stimuli or to cholinergic stimulation. These data suggest that TRCs expressing CCK-receptors also express receptors to bitter stimuli and/or muscarinic receptors. They further support the notion of a putative modulatory role of CCK with convergence of multiple inputs occurring at the level of intracellular calcium.

Animals↗
PubMed2004

Responses of PROP taster groups to variations in sensory qualities within foods and beverages.

Despite increasing evidence that variations in sensitivity to the bitterness of 6-n-propylthiouracil (PROP) are also reflected in responses to other tastes in solution, there has been little research examining the impact of PROP sensitivity on responses to sensory qualities in foods or beverages. The present studies examined responses of PROP taster groups to systematic variations in tastes and oral irritation in different foods and beverages. In Experiment 1, PROP groups were asked to discriminate variations in bitterness, sweetness, or sourness within two foods (yogurt and cream cheese) and a beverage (orange juice). In most cases, tasters and especially supertasters (STs) were able to discriminate smaller variations in tastant concentration than PROP nontasters (NTs). Differences were most evident with variations in bitterness and sourness. In Experiment 2, PROP taster groups rated the sweetness, sourness, and oral irritation in carbonated fruit drinks that systematically varied in citric acid (CA) and CO2 concentrations. Ratings of sourness and irritation were highest for STs and lowest for NTs, although there were no group differences for sweetness ratings. These data are some of the first to show PROP taster group differences in tastes and irritation within foods and provide a basis for reported differences of PROP groups in their hedonic responses to foods.

Adult↗
PubMed2006

Variation of glucosinolates in vegetable crops of Brassica rapa.

Glucosinolate levels in leaves were determined in a collection of 113 varieties of turnip greens (Brassica rapa L.) from northwestern Spain grown at two sites. Sensorial attributes were also assessed by a consumer panel. The objectives were to determine the diversity among varieties in total glucosinolate content and glucosinolate profile and to evaluate their sensory attributes in relation to glucosinolate content for breeding purposes. Sixteen glucosinolates were identified, being the aliphatic glucosinolates, gluconapin and glucobrassicanapin the most abundant. Other aliphatic glucosinolates, such as progoitrin, glucoalyssin, and gluconapoleiferin were relatively abundant in varieties with a different glucosinolate profile. Indolic and aromatic glucosinolate concentrations were low and showed few differences among varieties. Differences in total glucosinolate content, glucosinolate profile and bitterness were found among varieties, with a total glucosinolate content ranging from 11.8 to 74.0micromolg(-1) dw at one site and from 7.5 to 56.9micromolg(-1) dw at the other site. Sensory analysis comparing bitterness with variation in glucosinolate, gluconapin and glucobrassicanapin concentrations suggested that these compounds and their breakdown products are not the only determinants of the characteristic flavour of this vegetable. Other phytochemicals are probably involved on the characteristic bitter flavour. The varieties MBG-BRS0132, MBG-BRS0082, MBG-BRS0173, and MBG-BRS0184 could be good candidates for future breeding programs since they had high total glucosinolate content and good agronomic performance. The presence of glucoraphanin in some varieties should be studied more extensively, because this aliphatic glucosinolate is the precursor of sulforaphane, a potent anti-cancer isothiocyanate.

Brassica napus↗
PubMed2001

Ethanol perception and ingestion.

Ethanol is a common dietary constituent, but knowledge of its chemosensory properties and their relationship to its ingestion is limited. Twenty-five male and 25 female, light-regular ethanol consumers participated in five test sessions. Sessions involved determination of taste, olfactory and nasal irritation thresholds for ethanol, taste thresholds for tetralone, suprathreshold intensity and quality judgements, determination of phenylthiocarbamide (PTC) taster status, acute oral exposure effect of ethanol on ratings for sucrose, NaCl, citric acid and quinine hydrochloride and hedonic judgments of beers. Questionnaires on personality traits, diet and health were also completed and body composition determined. Diet histories were obtained on three random days. A randomized subset of sensory tests and questionnaires were administered each session. The rank order of ethanol thresholds was taste>nasal irritancy>olfaction and the predominant taste near threshold was bitter. Except for a lower taste threshold in females, no other effects of gender, PTC taster status, ethanol use or body composition were observed. Acute exposure to ethanol suppressed the bitterness of quinine, but enhanced its bitter aftertaste. Ethanol use was not associated with differences in dietary, sensory or textural characteristics. Thus, among light to regular ethanol consumers, no substantive association was observed between sensory responses to ethanol and diet.

Adult↗
PubMed1998

Flavor avoidance learning and its implications in reducing strychnine baiting hazards to nontarget animals.

In reforested areas, underground strychnine baiting to control pocket gophers (Thomomys mazama) poses a hazard to golden mantled ground squirrels (Spermophilus lateralis) and yellow pine chipmunks (Eutamias amoenus). We designed this study to assess whether: 1) chemical insensitivity to bitter tastes might explain the ingestion of strychnine; 2) pocket gophers would avoid four bitter-tasting compounds: quebracho (QUEB), sucrose octaacetate (SOA), quinine hydrochloride (QHCl), and denatonium benzoate (DB); and 3) nontarget species could be trained to avoid strychnine paired with the most aversive compound. Our results showed that while all species readily consumed strychnine, the nontarget species could be conditioned to avoid it. Moreover, while high (0.1%) concentrations of DB, quinine hydrochloride, and quebracho reduced consumption by pocket gophers, 0.05% DB was inoffensive. Nontarget animals readily avoided 0.05% DB, and avoidance was stronger after conditioning. Together, our results suggest that all of the rodents tested are insensitive to strychnine, high concentrations of some bitter tastes may be effective pocket gopher repellents, and lower concentrations of DB may selectively repel nontarget animals from strychnine baits.

Animals↗
PubMed2000

Effects of Lactobacillus strains on the ripening and organoleptic characteristics of Arzúa-Ulloa cheese.

Seven batches of Arzúa-Ulloa, a short-ripened soft cow's milk cheese produced in Galicia (NW Spain), were prepared from pasteurized milk. Two control batches of cheese (CB) were made with an acid-aromatic starter containing Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. lactis var. diacetylactis, isolated from raw-milk Arzúa-Ulloa cheeses. Five batches of cheese (LB) were made with the acid-aromatic starter plus one of five strains of mesophilic homofermentative Lactobacillus spp.: four of them isolated from raw-milk Arzúa-Ulloa cheese (characterized in previous works) and the remaining was a commercial Lactobacillus strain. Higher counts of mesophilic viable bacteria, lactic acid bacteria and citrate-fermenting bacteria were found on days 1 or 15 of ripening, while higher counts of lactobacilli were found on day 30 of ripening. On day 1 of ripening the highest diacetyl-acetoin content was noted in the CB, but after day 15 the diacetyl-acetoin content was similar or higher in three of the five LB. The mean degradation of beta-casein in CB was higher than in LB, while the degradation of alpha(s1)-casein was higher in LB. The mean contents of nitrogen-soluble fractions were slightly higher in the LB than in the CB. Volatile free fatty acid (VFFA) contents were, in general, greater in LB than in CB and maximum amounts were determined on day 15 of maturation. Sensorial analysis indicated a more acid taste was in LB, while bitter and astringent tastes were more intense in CB. A positive correlation was found between beta-casein degradation and bitter taste. Yogurt and butter aromas were more intense in CB and in two of the five LB. Firmness was lower in LB and a negative correlation was found between this parameter and alpha(s1)-casein degradation. Crumbliness showed a positive correlation with beta-casein degradation. The use of the Lactobacillus strains assessed in this study is recommended for Arzúa-Ulloa cheese manufacture, in order to enhance the desirable characteristics of this cheese variety, i.e., a soft texture due to alpha(s1)-casein proteolysis but without the bitter taste due to beta-casein degradation and a spicy and slightly rancid aroma and taste.

Acetoin↗
PubMed2001

Sweet successes.

Mapping of the chromosomal location of genes essential for sweet and bitter taste and identification of the relevant G protein-coupled receptors reveals unanticipated complexity in taste signaling pathways. The distribution of sweet and bitter receptors suggests complete cellular segregation of these taste modalities. Sweet compounds may be distinguished through differential expression of sweet receptors. Novel heterologous expression systems to test bitter and sweet modalities now provide the tools necessary for understanding taste coding.

Animals↗
PubMed1996

Mechanisms of taste transduction.

Taste cells use a wide variety of mechanisms for transduction. Ionic stimuli, such as salts and acids, interact directly with ion channels to depolarize taste cells. More complex stimuli, such as sugars and amino acids, utilize apically located receptors for transduction. Recent molecular biological results suggest that the metabotropic glutamate receptor mGluR4 may function in glutamate taste transduction. New biochemical studies have identified a bitter-responsive receptor that activates gustducin. Unexpected results with knockout mice suggest that gustducin may be directly involved in both bitter and sweet transduction. Electrophysiological experiments indicate that both inositol trisphosphate and cyclic nucleotides function in both bitter and sweet transduction events.

Animals↗
PubMed1983

Growth of an extracellular proteinase-deficient strain of Pseudomonas fluorescens on milk and milk proteins.

An extracellular proteinase-and lipase-deficient mutant of a psychrotroph, Pseudomonas fluorescens strain 32A, has been isolated and the absence of the proteinase enzyme confirmed by growth on differential media, enzyme assay and polyacrylamide gel electrophoresis. Competition between the parent and the mutant was observed when equal numbers of the 2 strains were inoculated together into raw skim-milk at 6 degrees C. Bitterness was detected at 6 degrees C in pasteurized skim-milk inoculated with the parent cells concurrent with the detection of proteolytic activity. In the case of the mutant, slight bitterness which did not increase with increasing cell numbers was detected in the absence of proteolysis. Mutant cells failed to grow on Na caseinate as the sole source of carbon. It was concluded that the extracellular proteinase, while not essential for growth in milk, does provide a selective advantage to the producer organism. This enzyme is, however, essential for growth on milk proteins and contributes to the development of bitterness in pasteurized milk.

Animals↗
PubMed2000

Free polyunsaturated fatty acids cause taste deterioration of salmon during frozen storage.

Increased intensity of train oil taste, bitterness, and metal taste are the most pronounced sensory changes during frozen storage of salmon (Refsgaard, H. H. F.; Brockhoff, P. B.; Jensen, B. Sensory and Chemical Changes in Farmed Atlantic Salmon (Salmo salar) during Frozen Storage. J. Agric. Food Chem. 1998a, 46, 3473-3479). Addition of each of the unsaturated fatty acids: palmitoleic acid (16:1, n - 7), linoleic acid (C18:2, n - 6), eicosapentaenoic acid (EPA; C20:5, n - 3) and docosahexaenoic acid (DHA; C22:6, n - 3) to fresh minced salmon changed the sensory perception and increased the intensity of train oil taste, bitterness, and metal taste. The added level of each fatty acid ( approximately 1 mg/g salmon meat) was equivalent to the concentration of the fatty acids determined in salmon stored as fillet at -10 degrees C for 6 months. The effect of addition of the fatty acids on the intensity of train oil taste, bitterness and metal taste was in the order: DHA > palmitoleic acid > linoleic acid > EPA. Formation of free fatty acids was inhibited by cooking the salmon meat before storage. Furthermore, no changes in phospholipid level were observed during frozen storage. The results suggest that enzymatic hydrolysis of neutral lipids plays a major role in the sensory deterioration of salmon during frozen storage.

Adult↗
PubMed2002

Selection of alternative genetic sources of large-seed size in Virginia-type peanut: evaluation of sensory, composition, and agronomic characteristics.

Jenkins Jumbo, the ancestral source of large-seed size in the Virginia market type (Arachis hypogaea L.), has been shown to have a deleterious effect on flavor of peanut. The pervasiveness of Jenkins Jumbo in the ancestry of large-seeded germplasm contributes to the generally less intense roasted peanut flavor of U.S. cultivars of the Virginia market type. As a remedy to this problem, alternative sources of large-seed size were sought. Nine large-seeded selections, with NC 7 and Florunner as checks, were tested in replicated trials in North Carolina and Florida from 1996 to 1998. Pod yield, grade, weight of 100 seeds, and oil, sugar, and starch contents were measured. A descriptive sensory panel evaluated flavor attributes of a roasted sound mature kernel (SMK) sample from each plot. NC 7 scored low for sweet sensory attribute, high for bitter, and median for roasted peanut. UF714021, a multiline incorporating the Altika cultivar with several sister lines, had the best flavor profile of the large-seeded selections, but it did not have particularly large seeds relative to NC 7. The largest seeded selections were X90037 and X90053, both derived from Japan Jumbo. Flavor scores for X90037 were similar to those for NC 7 for roasted peanut (3.0 vs 2.9 flavor intensity units, fiu) and sweet (2.7 vs 2.6 fiu) but worse than NC 7 for bitter (3.3 vs 3.7 fiu) and astringent (3.5 vs 3.7 fiu). X90053 had intermediate values for roasted peanut and astringent, high value for sweet, and low for bitter. Other lines that had or were likely to have Jenkins Jumbo as a recent ancestor were generally poor in roasted flavor, supporting the hypothesis that ancestry from Jenkins Jumbo imparts poor flavor characteristics. With the exception of the unexpected relationship between astringent attribute and extra large kernel (ELK) content (r = 0.82, P < 0.01), there were no significant correlations between sensory attributes and the important agronomic traits: yield, meat, and ELK content. Among the nine large-seeded lines tested in this study, three appear to have greater potential for use as parents: 86x45B-10-1-2-2-b2-B, UF714021, and X90053.

Agriculture↗
PubMed2004

Polyphenolic profiles of Basque cider apple cultivars and their technological properties.

The polyphenolic compositions of 31 Basque cider apple cultivars were determined in pulp, peel, and juice by high-performance liquid chromatography with diode array detection analysis of crude extracts and after thiolysis. Total polyphenols are distributed in a wide concentration range depending on the cultivar. Procyanidins are the class of polyphenols that present major concentrations in apple. Their average degrees of polymerization range from 4 to 8 depending on the cultivar. Apple cultivars were technologically classified into bitter and nonbitter categories using different classification systems obtained by applying several pattern recognition techniques, such as principal component analysis, K-nearest neighbors, soft independent modeling of class analogy, partial least-squares, and multilayer feed-forward-artificial neural networks, to apple pulp, peel, or juice data (individual polyphenol concentrations, total procyanidin content, and the average degree of polymerization of procyanidins). Bitter apple cultivars present higher contents of flavan-3-ols and/or dihydrochalcones than nonbitter cultivars. Detailed knowledge of the polyphenolic profile of each apple cultivar affords information about their susceptibility to oxidation, their sensory properties (bitterness, astringency), and their possible influence on the characteristics and quality of the final product (juice, cider) when apples are processed.

Beverages↗
PubMed2004

Technological classification of basque cider apple cultivars according to their polyphenolic profiles by pattern recognition analysis.

The polyphenolic compositions of 31 Basque cider apple cultivars were determined in pulp, peel, and juice by high-performance liquid chromatography--diode array detection analysis of crude extracts and after thiolysis. Data sets, consisting of individual polyphenol concentrations, total procyanidin content, and the average degree of polymerization of procyanidins, were evaluated by multivariate chemometric techniques, to develop decision rules for classifying apple cultivars technologically into bitter and nonbitter categories. A preliminary study of the data structure was performed by cluster analysis and principal component analysis in each apple material. Bitter apple varieties presented higher contents of flavan-3-ols and/or dihydrochalcones than nonbitter cultivars. Different classification systems for the two categories on the basis of the chemical data were obtained applying several supervised pattern recognition procedures, such as linear discriminant analysis, K-nearest neighbors, soft independent modeling of class analogy, partial least-squares, and multilayer feed forward artificial neural networks. Excellent performance in terms of recognition and prediction abilities for both categories (100% of hits) was achieved in every case (pulp, peel, or juice). Polyphenolic profiles of apple pulp, peel, or juice provide enough information to develop classification criteria for establishing the technological group of apple cultivars (bitter or nonbitter).

Analysis of Variance↗
PubMed2005

Cloning and molecular analysis of the regulatory factor HlMyb1 in hop (Humulus lupulus L.) and the potential of hop to produce bioactive prenylated flavonoids.

The concentrations of prenylated chalcones and bitter acids were analyzed in Czech hop varieties. The highest levels of (xanthohumol + desmethylxanthohumol) (0.97%, m/m) and of total bitter acids (17.19%, m/m) were observed for cv. Agnus. The concentration ratios of bitter acids to prenylated chalcones varied depending on the genotype, thereby suggesting genetic determination by different set(s) of structural and regulatory genes. Promoter elements of the chs_H1 gene encoding a "true"chalcone synthase, a candidate gene to co-determine the biosynthesis of prenylated chalcones, were analyzed, and several boxes for cis-regulatory elements including Myb transcription factors were discovered. A cDNA library was established from glandular tissue-enriched cones of cv. Osvald's clone 72 and used to screen for Myb regulatory elements. The cDNA of the first Myb regulatory factor from hop, called HlMyb1, was cloned and analyzed. The HlMyb1 open reading frame encodes 272 amino acids (29.8 kDa), and the protein showed highest homology to the light-regulated factor AtMyb68 from Arabidopsis thaliana within the Myb domain, whereas there was no significant homology with known MYB proteins outside this domain. Unlike AtMyb68, which is expressed in mature leaves, HlMyb1 is strongly expressed in hop inflorescences and could participate in the regulation of developmental processes involved in the production of hop cones and bioactive secondary metabolites.

Acyltransferases↗
PubMed2006

Proteomic analysis of human whole and parotid salivas following stimulation by different tastes.

Whole and parotid salivas, collected after stimulation with tastants, were analyzed by 2D electrophoresis and mass spectrometry. In whole saliva, the number of proteins affected by taste stimulation increased in the order sweet < umami < bitter < acid. Annexin A1 and calgranulin A, involved in inflammation, were over-represented after umami, bitter, and sour stimulations. Their low abundance or absence in parotid saliva after bitter stimulation suggested that they originated from other oral glands or tissues.

Annexin A1↗
PubMed1988

Improved buccal delivery of opioid analgesics and antagonists with bitterless prodrugs.

Buccal delivery of opioid analgesics and antagonists is a useful way of improving bioavailability relative to the oral route. These compounds taste bitter, however. Various prodrugs of nalbuphine, naloxone, naltrexone, oxymorphone, butorphanol, and levallorphan, in which the 3-phenolic hydroxyl group was esterified, lacked a bitter taste. This taste difference was not due to differences in water solubility, suggesting that for these compounds the phenolic functional group is important for interaction with the taste receptor. In rats, nalbuphine, naloxone, and naltrexone administered buccally as prodrugs exhibited up to 90% bioavailability. In dogs, the bitter taste of buccally administered nalbuphine and naloxone caused salivation and swallowing, and bioavailability was low. Buccal dosing of the prodrugs of these compounds caused no adverse effects and the bioavailability ranged from 35 to 50%, a significant improvement relative to the oral bioavailability, which is 5% or less. The feasibility of buccal prodrug delivery using an adhesive patch formulation was demonstrated.

Administration, Buccal↗