Sweet taste thresholds

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). 

Colorless to white crystals with a penetrating, sweet, mothball or almond-like odor. At 40 °C, the average odor threshold concentration and the lowest concentration at which an odor was detected were 18 and 4.5 pg/L, respectively. Similarly, at 25 °C, the average taste threshold concentration and the lowest concentration at which a taste was detected were 32 and 11 pg/L, respectively (Young et al, 1996). A detection odor threshold concentration of 73 pg/m (121 ppbv) was reported by Punter (1983). 

Last but not least, it must be mentioned that sodium chloride (often referred to as the poor man s flavour enhancer ) has a flavour enhancing effect at usage levels below and above its taste threshold (370 to 5000 ppm). Without salt, many foods (both sweet and savoury) have a flat taste. Salt may enhance sweemess and mouthfeel and decrease bitter, sour and metallic sensations [4, 32]. Even in sweet foods such as cakes, candies and toffees, salt has its place. However, its presence is most critical for... 

An increase in molecular weight, that is, extending a homologous series, often changes from sweet to bitter. Further increases in homologation reduce drug solubility below taste threshold values... 

Powerful, woody-phenolic, medicinal, yet rather sweet odor, somewhat to the anisic type (Arctander, 1967). In a wine it recalls horse manure (Dubois, 1983). Kim Ha and Lindsay (1991) report phenolic, sheep pen-like descriptions when neat, with odor threshold in water of 600 ppb and taste threshold of 100 ppb. 

Methylguaiacol has a sweet-spicy, phenolic-leathery odor with distinctly vanilla-like undertones, balsamic-warm sweetness, but overall too medicinal to become classified as a versatile, floral-balsamic ingredient (Arctander, 1967). Wasserman (1966) noted smoky, phenolic, sweet odor and smoky, phenolic, bitter taste with an odor threshold in water 90 ppb and a taste threshold of 65 ppb. 

Sensory properties were presented in the same publication. The aroma strength of this mercaptan is very far from that of prenyl mercaptan (Q.10) which is also formed under roasting conditions. The pure substance has a sweet, soup-like odor, which is perceived as cooked meat and spicy when diluted in water to ca 0.1 ppm. Odor and taste thresholds, 2-6 and 8-10 ppb respectively, are relatively high compared to those of Q.10 and Q.20. The use of this alcohol and of its formate (see below) for artificial aromatizing of various foods has been patented (DE Patent 23.16465, 1973). At a concentration of 0.1 ppm it is characterized by a meaty, sulfury, skunky, cabbage flavor (Chemisis, 1999). 

Intensely sweet taste, licorice aftertaste- Strongly cationic, isoelectric pt greater than or equal to 11,7. uv max 278 nm (pH 5 6) 283, 290 nm (pH 13.0). About 750-1600 times sweeter than sucrose on a wt basis 30,000-i 00 000 times on a molar basis. Threshold values are near 10 %. The proteins lose sweetness on heating on splitting of disulfide bridges and also at pHs <2.5 which points to the importance of the tertiary structure for the sweetness, See Korver et a l, foe. cit. 

In order to analyze for putative taste modifiers enhancing the sweetness of the sugars present in beef bouillon, the fractions of another aliquot of the GPC fractionation were dissolved in the same amount of an aqueous 2-fold hyperthreshold sucrose solution. Each solution was stepwise diluted 1+1 with water until the sweetness threshold was reached. As this so-called Taste Dilution (TD) factor, obtained for each fraction, is related to its sweet taste activity in water, the ten GPC fractions were rated in their relative taste intensity (Fig. ure 1). 

In order to study the influence of the pH value on the sweetness enhancing effect of the novel Maillard reaction product, binary mixtures of the tasteless alapyridaine and the sweet tasting compounds glucose, saccharose, or L-alanine were sensorially evaluated in a triangle test using water with pH 5.0, 7.0 and 9.0, and the sweet detection thresholds determined were compared to the threshold concentrations of aqueous solutions containing the sweet tastants alone (Table I). 

Table I. Effect of Alapyridaine on the Detection Thresholds of Sweet Tasting Compounds...

The taste threshold concentrations were determined by a triangle test using tap water (pH 5.0, 7.0, 9.0) as the solvent. Factor by which the threshold of the sweet tastant was decreased in the presence of alapyridaine. 

The test subject shall don the testenclosure. Throughout the threshold screening test, the test subjectshallbreathethroughhis/her slightly open mouth with tongue extended. The subject is instructed to report when he/she detects a sweet taste. 

Ten squeezes are repeated rapidly and then the testsubject is asked whetherthe saccharin can be tasted. If the test subject reports tasting the sweet taste during the ten squeezes, the screening test is completed. The taste threshold is noted as ten regardless of the number of squeezes actually completed. 

In taste the polyols range from faintly sweet to extremely sweet, the threshold value for erjrthritol being considerably less than for sucrose 12S). 

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