Taste of sucrose

Sensory perception is both quaUtative and quantitative. The taste of sucrose and the smell of linalool are two different kinds of sensory perceptions and each of these sensations can have different intensities. Sweet, bitter, salty, fmity, floral, etc, are different flavor quaUties produced by different chemical compounds the intensity of a particular sensory quaUty is deterrnined by the amount of the stimulus present. The saltiness of a sodium chloride solution becomes more intense if more of the salt is added, but its quaUty does not change. However, if hydrochloric acid is substituted for sodium chloride, the flavor quahty is sour not salty. For this reason, quaUty is substitutive, and quantity, intensity, or magnitude is additive (13). The sensory properties of food are generally compHcated, consisting of many different flavor quaUties at different intensities. The first task of sensory analysis is to identify the component quahties and then to determine their various intensities. 

The sweet taste of sucrose is its most notable and important physical property and is regarded as the standard against which other sweeteners (qv) are rated. Sweetness is induenced by temperature, pH, sugar concentration, physical properties of the food system, and other factors (18—20). The sweetening powers of sucrose and other sweeteners are compared in Table 3. The sweetness threshold for dissolved sucrose is 0.2-0.5% and its sweetness intensity is highest at 32-38°C (19). 

Fmctose is sweeter than sucrose at low temperatures (- S C) at higher temperatures, the reverse is tme. At 40°C, they have equal sweetness, the result of a temperature-induced shift in the percentages of a- and P-fmctose anomers. The taste of sucrose is synergistic with high intensity sweeteners (eg, sucralose and aspartame) and can be enhanced or prolonged by substances like glycerol monostearate, lecithin, and maltol (19). 

Sweet Taste. The mechanism of sweetness perception has been extensively studied because of its commercial importance. Many substances that vary in chemical structure have been discovered which are similar to the taste of sucrose. Commercial sweeteners include sucralose, acesulfame-K, saccharin, aspartame, cyclamate (Canada) and the protein thaumatin 4), Each sweetener is unique in its perceived sensation because of the time to the onset of sweetness and to maximum sweetness, ability to mask other sensations, persistence, aftertaste and intensity relative to sucrose [TABLE IT. For example, the saccharides, sorbitol and... 

Neophobia to the presence of multiple water bottles and to the taste of sucrose may also confound behavioral results in this model. To avoid this problem, acclimate mice by giving them two bottles, each with the sucrose solution, for 72 h before the test, or with one water and one sucrose bottle for 1 h per day for 1 week. Also, consider lengthening the period of the test to at least 24 h. Researchers may choose to utilize video recording to document all water intake, however, end point analysis of overall sucrose consumption (as described earlier) is acceptable. 

Perhaps one of the most fascinating and complex chemical reactions involving carbohydrates is caramelization. For example, granulated sugar heated at a high temperature in the dry state eventually produces a dark, viscous mass which has a strong and characteristic flavor totally different from the sweet taste of sucrose. 

Clearly, a stable form of sugar that retains the characteristic sweet taste of sucrose, and cannot be readily broken down to form organic acids in the mouth environment may be of real value. 

A great many substances are known to produce the sensation of sweetness but, although this quality must stem from particular features of their chemical structure, it has not, so far, been possible to determine what these are. Most sugars and sugar derivatives have a sweet taste but so do many other totally unrelated compounds. Since the chemical basis of sweetness is unknown it is not possible to measure the property by scientific means and methods of sweetness measurement are necessarily subjective and include (1) equal sweetness matches in which the concentration that produces a sensation equivalent to that of a standard solution, usually sucrose, is determined and (2) threshold measurements, which involve finding the lowest detectable concentration of sweetener. Approximate relative sweetness values are given in Table 10.10 but there are, in addition, certain qualities of sweetness that are not easy to define. Some sweeteners lack the clean clear taste of sucrose and some have an unpleasant aftertaste. 

Salty substances exhibit a variety of pharmacological effects, whose character depends on the type of cation and anion. Some substances are toxic at higher concentrations. The compound consumed in the largest amount is sodium chloride. The daily intake of salt in developed countries is estimated at 8 15g. Sodium chloride supports the perception of taste of foods at the required intensity and fullness, stimulates not only receptors for salty taste, but significantly increases the perception of the sweet taste of sucrose and some other sweet substances, as well as sour taste perception, and suppresses the sensation of metaUic taste and some other... 

Sucrose helps minimize earthy tastes of vegetables, while enhancing inherent flavors and aromas, and preserving color and texture (37). Addition of sucrose inhibits enzymatic browning of canned and frozen fmits, and prevents loss of color, flavor, and aroma from fmit during processing (38). 

A commercially interesting low calorie fat has been produced from sucrose. Proctor Gamble has patented a mixture of penta- to octafatty acid ester derivatives of sucrose under the brand name Olestra. It was approved by the FDA in January 1996 for use as up to 100% replacement for the oil used in preparing savory snacks and biscuits. Olestra, a viscous, bland-tasting Hquid insoluble in water, has an appearance and color similar to refined edible vegetable oils. It is basically inert from a toxicity point of view as it is not metabolized or absorbed. It absorbs cholesterol (low density Hpoprotein) and removes certain fat-soluble vitamins (A, D, E, and K). Hence, Olestra has to be supplemented with these vitamins. No standard LD q tests have been performed on Olestra however, several chronic and subchronic studies were performed at levels of 15% in the diet, and no evidence of toxicity was found. No threshold limit value (TLV), expressed as a maximum exposure per m of air, has been estabhshed, but it is estimated to be similar to that of an inert hpid material at 5 mg/m. ... 

The disaccharide stmcture of (12) (trade name SPLENDA) is emphasized by the manufacturer as responsible for a taste quaUty and time—intensity profile closer to that of sucrose than any other high potency sweetener. The sweetness potency at the 10% sucrose solution sweetness equivalence is between 450 and 500X, or about two and one-half times that of aspartame. When compared to a 2% sugar solution, the potency of sucralose can be as high as 750X. A moderate degree of synergy between sucralose and other nonnutritive (91) or nutritive (92) sweeteners has been reported. 

To meet consumer demands, manufacturers are developing new nonnutritive sweeteners that more closely match the taste and mouthfeel of sucrose. There are several nonnutritive sweeteners currentiy pending FDA approval for use in soft drinks. They include sucralose [56038-13-2] aUtame [80863-62-3] encapsulated aspartame, cyclamates, and acesulfame-K [55589-62-3] also known as paUtinit. 

The taste of D-fructose has been widely studied, and numerous relativesweetness intensity-scores have been assigned to it. Shallenberger and Acree reported that the crystalline solid is 1.8 times as sweet as sucrose. Verstraeten claimed that it is 8 times as sweet, but this must have been a misinterpretation of a statement made by E. G. V. Percival. ... 

The taste of mono-O-methylsucrose derivatives again substantiates some of the conclusions already put forward. 4-O-Methylsucrose (49) was found to be considerably less sweet than sucrose. This, together with the extremely low sweetness of ga/ac/o-sucrose (50) (which has an axial... 

It is also interesting that, although the ( )-viboquercitol mixture is sweet, (-)-viboquercitol (96) has only trace sweetness. Therefore, (+)-viboquer-citol (95) would be expected to have a fairly strong, sweet taste, probably close to that of sucrose or o-fructose it has not, however, yet been obtained in pure form to permit testing of the speculation. 

Birch and coworkers studied the time-intensity interrelationships for the sweetness of sucrose and thaumatin, and proposed three thematically different processes (see Fig. 47). In mechanism (1), the sweet stimuli approach the ion-channel, triggering site on the taste-cell membrane, where they bind, open the ion-channel (ionophore), and cause a flow of sodium and potassium ions into, or out of, the cell. Such a mechanism would correspond to a single molecular event, and would thus account for both time and intensity of response, the intensity of response being dependent on the ion flux achieved while the stimulus molecule binds to the ionophore. 

The taste of aqueous quinine hydrochloride solution with and without sucrose was examined in four volunteers (males, aged 23 28). All considered 1 mM quinine hydrochloride quite bitter, ImM quinine hydrochloride and 100mM sucrose bitter-sweet, and 1 mM quinine hydrochloride and 500 mM sucrose sweet though bitter. Sucrose is thus shown to lessen the bitterness of quinine hydrochloride solution, as generally already known. Quinine hydrochloride and sucrose are bitter and sweet substances, respectively, and thus a sweet substance may alter oscillation, when a bitter substance is present, to that corresponding to a sweet substance. 

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