Sweet Sensation Research Articles

Cephalic phase responses to sweet taste

The sweet taste of nonnutritive sweeteners has been reported to increase hunger and food intake through the mechanism of cephalic-phase insulin release (CPIR). We investigated the effect of oral sensation of sweetness on CPIR and other indexes associated with glucose metabolism using nutritive and nonnutritive sweetened tablets as stimuli. At lunchtime, 12 normal-weight men sucked for 5 min a sucrose, an aspartame-polydextrose, or an unsweetened polydextrose tablet (3 g) with no added flavor. The three stimuli were administered in a counterbalanced order, each on a separate day at 1-wk intervals. Blood was drawn continuously for 45 min before and 25 min after the beginning of sucking and samples were collected at 1-min intervals. Spontaneous oscillations in glucose, insulin, and glucagon concentrations were assessed as were increments (slopes) of fatty acid concentrations during the baseline period. The nature of the baseline (oscillations: glucose, insulin, and glucagon; and slopes: fatty acids) was taken into account in the analyses of postexposure events. No CPIR and no significant effect on plasma glucagon or fatty acid concentrations were observed after the three stimuli. However, there was a significant decrease in plasma glucose and insulin after all three stimuli. Only the consumption of the sucrose tablet was followed by a postabsorptive increase in plasma glucose and insulin concentrations starting 17 and 19 min, respectively, after the beginning of sucking. In conclusion, this study suggested that oral stimulation provided by sweet nonflavored tablets is not sufficient for inducing CPIR.

ストレス状態における味の感受性

In this study, the effects of mood state on taste sensitivity was evaluated in humans who exposed to condition of mental or physical fatigue and tension. Taste responses to quinine sulfate (bitter), citric acid (sour) and sucrose (sweet) were tested. The intensity of the taste sensations were recorded by a computerized time-intensity (TI) on-line system. Subjects performed mental tasks by personal computer or physical tasks by ergometer. Before and after these sessions, the sensation of taste were recorded by the TI system, and in addition, psychological mood state were evaluated with POMS (Profile of Mood State). TI evaluation showed that after the mental tasks, the duration and total amount of taste were reduced in all taste. Furthermore, the maximum intensity was reduced only in bitterness. There were no changes in bitterness and sweetness sensations following physical tasks. However, relative to before the physical task, only the sensation of sourness was reduced by physical task. We also studied the mechanism of the changes of taste sensation by analysis of saliva components.

Plucking

Plucking Patrick Sylvain (bio) I was seven when I first plucked a chicken. Back home, I used to watch older women wetting tiny plumages with their lips and sticking the feathered end into their ears. They sat with their eyes closed, head slightly tilted, and gently rolled a “plume poule” deep inside their ear canal, they hummed and cleared their throats; I thought they were having orgasms. At twenty, I tried to pluck the bass, but my fingers were too slow to thump the groove, a deep resounding pulse that responded AH HUM when Charles Mingus’ fingers stomped “Better get it in your soul,” I felt a sweet sensation slipping into my ear like the way I felt when saints danced in my sleep, or perhaps the way my body slowly jerked when I introduced wet feather into my ear. My eyes froze in the firmament. Last year at the Vertigo, I spotted a post card, five by seven, black and white card, a black man dressed in a tuxedo hugging a double bass. It was 1960, Aaron Bell of the Duke Ellington band at a Jazz festival. His eyes were closed, teeth clenched, he was biting the music. [End Page 929] The bass rested on his left shoulder, back arched, head bent forward; he looked as if he were asking the instrument for forgiveness. Sweat glistened on his forehead, his fingers spread over the strings to control partial tones, creating essential moods. His right hand was busy plucking wire strings at the belly of the bass. Last May, at the Charles Hotel ballroom, Dave Holland’s fingers crawled on four wire strings the way red spiders dash back into their holes. Sound quivered. He was playing for saints while Joe Henderson’s tenor manifested F and C minor inside his red-headed skull. Plucking and striking chords, he stomped his right foot, lifting his bass from the wooden floor in search of notes. I was jolted with joy, knowing that saints could sanctify harmonies, at least for 2 hours, as long as Jazz is present. Patrick Sylvain Patrick Sylvain was born in Port-au-Prince, Haiti. He has published in a variety of periodicals, including African American Review, Agni, Caribbean Writers, Essence, Massachusetts Review, and Ploughshares. He lives in Somerville, Massachusetts. Copyright © 1996 Charles H. Rowell

Bisexuality “a la mode”

Abstract This article suggests that bisexuality is being marketed — both to lesbians and to heterosexual women — as the latest fashion trend. The main effects of this marketing exercise are a depoliticisation of sex and an erasure of over two decades of radical feminist theory. Instead, there is a return to sexual hedonism, with sexual desire clearly privileged over political analysis. The paper looks, first, at the ways bisexuality is marketed to lesbians (as a “sport fuck,” as “hot sex,” as “healing,” and as “transgressive”); and then at way bisexuality is marketed to heterosexual women (as “sweet sensations,” “safer sex,” “weekend lesbianism,” and “purely temporary”). It is argued that such depoliticised trendsetting needs to be replaced by a serious and engaged politics of bisexuality, which neither oversimplifies desire, nor ignores the political context within which it is located and must be understood.

Changes in taste perception following mental or physical stress.

Taste perception depends not only on the chemical and physical properties of tastants, but may also depend on the physiological and psychological conditions of those who do the tasting. In this study, the effects of mood state on taste sensitivity was evaluated in humans who were exposed to conditions of mental or physical fatigue and tension. Taste responses to quinine sulfate (bitter), citric acid (sour) and sucrose (sweet) were tested. The intensity of the taste sensations were recorded by a computerized time-intensity (Tl) on-line system. Subjects performed mental tasks by personal computer or physical tasks by ergometer for 10-40 min. Before and after these sessions, the duration of the after-taste and the intensity of the sensation of taste were recorded by the Tl system, and in addition, psychological mood states were evaluated with POMS (Profile of Mood State). Tl evaluation showed that after the mental tasks, the perceived duration of bitter, sour and sweet taste sensations was shortened relative to the control. Total amount of bitterness, sourness and sweetness was also significantly reduced. Furthermore, the maximum intensity of bitterness was significantly reduced. There were no significant differences in bitterness and sweetness sensations following physical tasks. However, relative to before the physical task, the duration of the after-taste of sourness was significantly shortened by the physical task. After the physical task, the buffering capacity of saliva was significantly increased. Thus mental and physical tasks alter taste perception in different ways; the mechanisms underlying these changes remain to be determined.

Facial expressions and genetic sensitivity to 6- n-propylthiouracil predict hedonic response to sweet

Individuals differ in their hedonic response to sweet: sweet likers show increasing liking with increasing sucrose concentration, while sweet dislikers show increasing dislike with increasing concentration. Our results indicated that naive raters can correctly classify sweet likers and dislikers by observing subjects' facial responses to the taste of sucrose. Also, for both adults and children, the sweet liker/disliker distinction correlated strongly with the genetically determined ability to taste 6- n-propylthiouracil (PROP): PROP nontasters were almost always sweet likers, whereas sweet dislikers were almost always PROP tasters. Sweet dislikers also reported a purer sweet sensation than likers, who perceived nonsweet components in pure sucrose solutions. These results suggest that the sweet liker/disliker distinction is robust and valid, and that sensitivity to PROP may influence preference for sweet by altering the quality of sweet.

X-Ray Analysis of New Crystal Forms of the Sweet Protein Thaumatin

Thaumatin is a plant protein that in the mature form contains 8 disulfide bonds and 207 amino acids. Several forms of this protein occur naturally and each elicits an intense sweetness sensation when tasted in microgram quantities. The two major forms of thaumatin are easily separable by ion exchange chromatography. Crystals of the two proteins (designated here A and B) have been grown by vapor equilibration from solutions containing polyethylene glycol and examined by X-ray diffraction. The thaumatin A crystals are of space group P2(1)2(1)2(1) with a = 44.3 A, b = 63.7 A and c = 72.7 A. The crystals of thaumatin B are of space group C2 with a = 117.7 A, b = 44.9 A, and c = 38.0 A and beta = 94.0 degrees. Both crystals diffract to well beyond 2.3 A and appear suitable for high resolution structure analysis. Four heavy atom derivatives of thaumatin B have been generated and diffraction data to 4 A resolution have been collected. This work is designed to provide a basis for studying the 3-dimensional structure of more than 100 genetically generated thaumatin derivatives, several of which show enhanced stability and improved taste characteristics.

Sampling and Analytical Method for Workplace Monitoring of Aspartame in Air

Abstract Aspartame™ (L-aspartyl-L-phenylalanine methyl ester; Nutra-sweet[rgrave]; Nutrasweet Company, Chicago, Illinois) is a dipeptide methyl ester that imparts a sweet taste sensation. It has been approved for use in the United States since 1981. In the course of a National Institute for Occupational Safety and Health (NIOSH) study to examine potential worker health effects at a food plant in the U.S., a method of sampling aspartame in air, and its analysis, was developed. A walk-through survey of the above-mentioned plant identified potential aspartame exposures to employees during weighing, blending, and packaging of dry dessert mixes. Potential analytical interferences included sodium citrate, ascorbic and fumaric acids, gelatin, maltodextrin, and mannitol. The collection system, using portable high flow (1–5 L/min) air pumps, is suitable for personal and area air sampling in industrial settings. Samples were collected on 1.0 micron pore size, 37-ml diameter polytetrafluoroethylene (PTFE) filters wi...

Expression of synthetic thaumatin genes in yeast.

Thaumatin is a plant protein that contains 8 disulfides and 207 amino acids in the mature form. The protein is of potential commercial interest since microgram quantities elicit an intense sweetness sensation. Two major variants of thaumatin have been identified in our laboratory by using sequence data obtained from thaumatin tryptic peptides. These differ by one amino acid at position 46 (asparagine or lysine), and both proteins differ from previously published sequences. We have synthesized DNA-coding sequences for three of these thaumatin variants using yeast preferred codons. The genes were inserted into an expression vector that contained a yeast 3-phosphoglycerate kinase promoter and terminator, and the vectors were transformed into yeast for expression of the recombinant protein. Upon lysis of the yeast cells, all thaumatin was localized in the insoluble cell fraction. Analysis of the sodium dodecyl sulfate solubilized yeast extracts by gel electrophoresis and Western blotting showed that thaumatin represented about 20% of the insoluble yeast protein. Although expressed at high levels, none of the thaumatins was biologically active (sweet). Preliminary protein folding experiments showed that two of three thaumatin variants could be folded to the sweet conformation.

Sweetening agents of plant origin: Literature search for Candidate sweet plants

The Latin binomials of a number of plants containing sweet constituents hitherto studied bear epithets that indicate sweetness, such asAcer saccharum, Lippia dulcis, Periandra dulcis, Saccharum officinarum, andSynsepalum dulcificum. Based on this observation, a search for plants bearing epithets that may indicate or relate to the sweetness sensation was carried out, by perusal of Index Kewensis. As a result, a large number of plants were found that bear such epithets. These plants are candidates for future investigation for potential sweet constituents.

Sweetness and sweeteners

Although the taste of a chemical compound can still not be predicted, the structural basis of sweetness is slowly beginning to emerge. Defined classes of chemical compound are thought to possess a common structural feature called a ‘glucophore’ which is responsible for the sweet sensation. This allows sweet molecules to orientate themselves and bind to specific sweet receptors located on the tongue. Several thousand sweet compounds are now known but only a few are permitted for food use.

Carbohydrate Composition and Sensory Quality of Fresh and Stored Sweet Corn

Abstract Sweet corn (Zea mays L.) was evaluated for sensory quality and carbohydrate composition at harvest and after storage at 0° or 10°C for 2 weeks. Total sugar (reducing sugar plus sucrose) declined more quickly during storage at 10° than at 0° in all cultivars, but the relative changes in sucrose and reducing sugars during storage were often complex. Hedonic (like/dislike) and sweetness scores awarded by taste panelists were significantly correlated with each other and with reducing sugar, sucrose, and total sugar concentrations only after storage. The highest correlations were between sucrose concentration and hedonic taste scores (r = 0.76, P < 0.01) and between sucrose concentration and sensory sweetness scores (r = 0.73, P < 0.01). Starch concentration varied with cultivar, but was not correlated with sensory quality. Water-soluble polysaccharide concentration varied with cultivar, storage time, and storage temperature, but did not correlate with sensory quality.

Effects of an overfeeding regimen—the affective component of the sweet sensation

In some isolated parts of North Africa, there persists an ancient Berber custom of imposing an overfeeding regimen on young girls before marriage, to achieve an obesity which is regarded as aesthetically pleasing. We have studied the effect of such a regimen, lasting 12--16 weeks, on blood lipids and on the affective reactions to sweet tastes in nine subjects. It is known that the pleasantness of alimentary cues i.e., the feeding behaviour, depends on the subject's nutritional state. Only three subjects gained weight (by 3,5 and 8 kg), in spite of the strong pressure to overeat. No change in plasma lipid concentrations were observed. Nevertheless, at the end of the regimen every subject showed a highly significant decrease in the rated pleasantness of sweet stimuli when they were tested fasting. However, the reduction in sweet pleasantness induced by ingestion of a 200 ml load of 1.4 M glucose solution was not changed by the overfeeding. Thus, pressure to overfeed can reduce hunger, as seen in the attractiveness of sweet foods in fasted subjects, without modifying glucose-induced satiety.

Postharvest Quality of Fresh and Canned Clingstone Peaches as Influenced by Genotypes and Maturity at Harvest1

Abstract Large variations in flesh color, firmness, and composition were found among fresh and canned fruits of 8 clingstone peach [Prunus persica (L.) Batsch] genotypes. Flesh color and titratable acidity of fresh fruits were highly correlated with color and sourness of canned fruits, respectively. Sweetness and peach flavor intensity were highly correlated in canned fruits. Genotypic variations in sensory sweetness and peach flavor intensity were not influenced by maturity stage, but variations in sensory sourness and firmness were dependent upon fruit maturity. For all cultivars, picking fruits more mature resulted in higher color and flavor quality of the canned product. Advanced maturity at harvest was accompanied by decreased flesh firmness, green color, and titratable acidity as well as more intense yellow or orange-yellow flesh color, higher carotenoids, ascorbic acid, soluble solids content, and SSC/TA ratio. As much as 42% of the total carotenoids and 95% of the total ascorbic acid were lost during the canning process.

Potential sweetening agents of plant origin. III. Organoleptic evaluation of Stevia leaf herbarium samples for sweetness.

A total of 184 Stevia leaf samples taken from herbarium specimens, representing 110 species and 121 taxa, were screened organoleptically for their taste sensation. Fragments of a 62-year-old leaf of S. rebaudiana exhibited a potent and prolonged sensation of sweetness, thereby indicating the stability of its sweet ent-kaurene glycoside constituents to drying, preservation, mounting and storage. No other leaf samples exhibited an intensity of sweetness equivalent to that of S. rebaudiana, though 18 species and varieties were considered to exhibit a sweet taste. These taxa appear to be promising candidates for future phytochemical investigation for new and known ent-kaurene glycosides.

Structural functions of taste in the sugar series: Function of the γ‐attribute in the sweet glycophore

AbstractThe tastes of chlorinated derivatives of simple monosaccharides, their alcohols, and the disaccharides maltose and trehalose were examined in relation to existing theories of sweetness sensation. Conclusions have been drawn about the importance of the γ‐lipophilic constituent as the third site in the sweet glycophore and its function as a vector for sweet taste.

St�rungen des Geschmacks durch orale Antiseptika

Taste disorders can be caused by antiseptics containing chlorhexidin or hexetidin even when used correctly. The gustometric results, gained with seven different batches, prepared by pharmaceutical companies, are analysed and discussed. Besides electrogustometry measurements with taste solutions were made to determine the degree and deviations of the four taste-qualities. The influence on the sensation of sweetness is stronger and longer, whereas that of bitter taste is hardly effected.

The structure of monellin and its relation to the sweetness of the protein

The sweet protein monellin [1–3] has been shown to consist of two nonidentical subunits of 50 and 42 amino acid residues, which were separated electrophoretically and chromatographically. Automatic sequential Edman degradation gave the complete sequence of the longer subunit, and a partial sequence of the shorter one. It was found that the sweetness of monellin requires the undissociated molecule. The individual subunits were not sweet, neither did they block the sweet sensation of sucrose or monellin. Blocking of the single SH of monellin abolished its sweetness as did reaction of the single methionyl residue with CNBr. Since the cysteinyl and methionyl residues appear to be adjacent, it is suggested that this part of the molecule is essential for its sweetness.

Effects of denaturants on the sweet-tasting protein monellin.

Effects of the denaturants urea and guanidine-HCl on the sweet-tasting protein monellin have been studied. The pH at which monellin is initially treated with denaturant is an important factor in retention of sweetness, but the pH maintained during subsequent removal of denaturant by dialysis has no effect on activity. Recovery of sweetness of denaturant-treated monellin is favored when denaturation occurs at acid pH. Monellin treated with either 6 M guanidine-HCl or 8 M urea at acid pH retains all of its sweetness following removal of denaturant, but urea treatment at neutral pH leads to some irreversible loss of sweetness. Monellin precipitates from solution under some conditions during removal of denaturant by dialysis, and the precipitated protein is no longer sweet. Precipitation is least under acid conditions. Aggregated protein was demonstrated by gel filtration chromatography. The single sulfhydryl group of monellin was not demonstrable in the precipitated protein, having apparently become oxidized during denaturation and formation of the aggregated protein. The data support the hypothesis that the tertiary structure is important in the ability of monellin to elicit a sweet sensation.

Sweetness and sweeteners

Abstract Although the taste of a chemical compound can still not be predicted, the structural basis of sweetness is slowly beginning to emerge. Defined classes of chemical compound are thought to possess a common structural feature called a ‘glucophore’ which is responsible for the sweet sensation. This allows sweet molecules to orientate themselves and bind to specific sweet receptors located on the tongue. Several thousand sweet compounds are now known but only a few are permitted for food use.