Scales, taste intensity

Basically, there are four major types of measures that are used in taste intensity measurements (a) threshold measures or estimates of the physical level at which the sensation of sweetness begins, (b) equal-sweetness matches between a sugar and other sweeteners, (c) category or rating scales, and (d) ratio scales. Each method has found its adherents and uses, and each possesses specific advantages and defects that indicate its use for one application, but contraindicate its use for another. These methods and their applications have been critically analyzed and reviewed, " " and it is, therefore, superfluous to deal with the topic here. 

Several kinds of taste intensity scales have been established for the four tastes. Typical examples are the gust scale by Beebe-Center (31) and the T scale by Indow (32). In order to deal with the umami on the same basis with the four tastes, we newly established a new subjective taste intensity scale for umami as well as for the four tastes (9, 30). Six solutions for each of the five taste substances were prepared. The taste intensity of... 

In this experiment, only the intensity of taste was rated and the quality of taste was disregarded. Consequently, the same value of S in the above mentioned equations represents the same intesnity of taste. Beebe-Center defined the unit of taste intensity as gust. One gust means the taste intensity of 1% sucrose solution. However, the gust scale is not always convenient because it does not define the upper limit of the scale. 

Determining the threshold value is difficult because subthreshold levels of one compound may affect the threshold levels of another. Also, the flavor quality of a compound may be different at threshold level and at suprathreshold levels. The total range of perception can be divided into units that represent the smallest additional amount that can be perceived. This amount is called just noticeable difference (JND). The whole intensity scale of odor perception covers about 25 JNDs this is similar to the number of JNDs that comprise the scale of taste intensity. Flavor thresholds for some compounds depend on the medium in which the compound is dispersed or dissolved. Patton (1964) found large differences in the threshold values of saturated fatty acids dissolved in water and in oil. 

Giovanni, M.E. and Pangbom, R.M. 1983. Measurement of taste intensity and degree of liking of beverages by graphic scales and magnitude estimation. J. Food. Sci. 48, 1175-1182. 

Stevens SS. (1969) Sensory scales of taste intensity. Percept Psychophys, 6 302-308. Borg G, Diamant H, Strom L and Zotterman Y. (1967) The relation between neural and perceptual intensity a comparative study on the neural and psychophysical response to taste stimuli. J Physiol, 192 13-20. 

Smith, D.V., C.A. Ossebaard, Amiloride suppression of the taste intensity of sodium chloride evidence from direct magnitude scaling, Physiol Behav., 1995(57) p. 773. 

Flavor Intensity. In most sensory tests, a person is asked to associate a name or a number with his perceptions of a substance he sniffed or tasted. The set from which these names or numbers are chosen is called a scale. The four general types of scales are nominal, ordinal, interval, and ratio (17). Each has different properties and allowable statistics (4,14). The measurement of flavor intensity, unlike the evaluation of quaUty, requires an ordered scale, the simplest of which is an ordinal scale. 

The jellies (20 sets) were submitted to a sensory panel (ten panellists from the laboratory staff with some experience in sensory evaluation) requested to give a score (from low to high in a non-structured 10 cm scale) to each of the following characteristics aroma (intensity), taste (sweet, acid and intensity), texture (hardness, spreadability) and overall acceptance. 

Hyposulphite of soda, and other soluble salts of hyposulphurous acid, possess the remarkable property of dissolving all the compounds of silver, even the chloride, and the solution thus formed has a very intense sweet taste, with a metallic after-taste. This property has been made available in the dagaerreotype, for the purpose of dissolving the sensitive coating of iodide from the plate of eilver alter exposure to light, aud thus fixing the image already formed. For this purpose hyposulphite of soda is now prepared on a very considerable scale. 

Subjective Intensity Scale for Umami. Thresholds do not always express the relative potency of different taste stimuli, because the intensity of taste does not increase with concentration in the same manner for each substance. 

The intensity of the odor and taste quality was scored in a scale from 0-3 0= none 1= weak 2= medium 3= strong. Mean value of 6 assessors. 

Despite their widespread use in the brewing literature the use of thresholds has been criticized [28]. Thresholds are but one point on a dynamic concentration continuum . There is no evidence that the intensity/concentration curves for all substances are parallel differing only in the point where they cross the abscissa. Further, taste is not a single instantaneous sensation but has a temporal element. Tasters have been trained to record the intensity on a scale between 0 (none) and 100 (extreme) on a moving recorder chart whereby a time-intensity curve such as Fig. 23.6 is obtained [26-28]. Typically the sample was expectorated, or if beer swallowed, after ten seconds. As would be expected when a sucrose gelatine was expectorated the intensity of the sweet sensation immediately started to fall and declined to zero in about 10 s [26]. 

The subsequent step consists in training assessors to rate the perceived intensity of some descriptors of foods on an evaluation scale. Panelists learn to quantify their perception, initially by ranking series of single odor or taste or texture stimuli with respect to the intensity of a particular characteristic, then quantifying the perception on the evaluation scale. The test samples used are model systems for instance, a single taste or flavor compound in water or other neutral media or solid or semisolid materials differentiated in their texture properties or samples obtained by spiking product samples with a flavor... 

It has been shown quite clearly that children s sensory preferences may differ from those of adults (e.g., Zandstra and de Graaf, 1998), and that growing from childhood into adulthood may alter preferences, in particular for sweet tastes (Desor and Beauchamp, 1987). Children s sensory perceptions may also differ from those of adults, especially when intensity scaling is used (Zandstra and de Graaf, 1998), and to a lesser extent when pair comparisons are used (MenneUa et al., 2003). However, the extent of differences in terms of perceptions between children and adults, or between children from various age groups, is often inferred from hedonic judgements, making a true comparison of children s and adults sensory abilities difficult. One cannot rule out the possibility that children differ more from adults in terms of affective responses than of perceptual abilities. 

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