Taste synergistic effect

Acesulfame-K—aspartame blends exhibit a significant synergistic effect (Fig. 4) (65,66). This synergy provides large cost savings for the diet foods industry. The blend also has a more rounded taste. Each sweetener apparendy masks the off-taste associated with the other. Increased blend usage is expected. 

Acesulfame potassium is used with other sweeteners such as aspartame because it has a long shelf life, and tastes sweet right away. It also has a synergistic effect with other sweeteners, so less of each is necessary to achieve the same sweetness. 

Otagiri et al. (22) used model peptides composed of arginine, proline, and phenylalanine to ascertain the relationship between bitter flavor and chemical structure. They reported that the presence of the hydrophobic amino acid at the C terminus and the basic amino acid at the N terminus brought about an increase in the bitterness of di- and tripeptides. They further noted a strong bitter taste when arginine was located next to proline and a synergistic effect in the peptides (Arg)r(Pro) ,-(Phe) (/ = 1,2 m, n = 1, 3) as the number of amino acids increased. Birch and Kemp (23) related the apparent specific volume of amino acids to taste. 

Today there is a tendency to use blends of sweeteners. When two or more sweeteners are combined, blends with increased stability, longer shelf life, lowered production costs, improved taste and flavor, and decreased side and aftertastes result. Also, mixtures of sweeteners can exhibit additive and synergistic effects. Furthermore, since lower amounts of each sweetener will be used, the average daily intake of each sweetener will decrease, minimizing the health risk from any one sweetener (2,4,9,25). 

Development of this sensor was based on a concept very different from that of conventional chemical sensors, which selectively detect specific chemical substances such as glucose or urea. However, taste cannot be measured in those terms even if all the chemical substances contained in foodstuffs are measured. Humans do not distinguish each chemical substance, but express the taste in itself the relationship between chemical substances and taste is not clear. It is also not practical to arrange so many chemical sensors with respect to the number of chemical substances, which amounts to over 1000 in one kind of foodstuff. Moreover, there exist interactions between taste substances, such as the synergistic effect or the suppression effect. A taste sensor should measure these effects the intention is not to measure the amount of each chemical substance but to measure the taste itself, and to express it quantitatively. The recently developed sensor satisfies this request. In fact, this sensor could detect the interactions between saltiness and sourness. 

Let us now proceed to umami substances. Monosodium glutamate, di sodium inosinate and disodium guanylate exhibit umami. Umami is a Japanese term implying "deliciousness of meat, mushrooms, some vegetables and cheese, but is now acknowledged widely as the fifth taste [5], Umami substances exhibit a very interesting phenomenon, i.e., a synergistic effect. In the coexistence of MSG and IMP, we experience drastic increase in umami. 

Amino acids are generally classified into several groups which correspond to each characteristic taste. Since amino acids show mixed tastes as above, the taste interactions such as synergistic effect and repression effect are automatically included in their taste. The taste sensor should express this situation. The present study is the first trial to study the taste of amino acids using artificial sensing devices. 

Comparison of the taste threshold with estimated concentration in orange juice (where available) in Table I reveals that in all cases except octyl acetate and a-pinene, the concentration in orange juice exceeds the taste threshold in water for most values reported. Patton and Josephson (17) postulated that components present in a food at above threshold level make a positive contribution to the flavor, while those present at below threshold level make little or no contribution to flavor. This generalization is now considered an oversimplification, for synergistic effects among food constituents have been shown to decrease the threshold level of some compounds, and nonvolatile constituents are known to either increase or decrease the taste threshold of certain volatile and nonvolatile constituents. 

Finally, the two pentacosene isomers, 7-P and 9-P, are apparently tasted during male licking and induce a synergistic effect on the frequency and duration of attempted copulation. The copulatory effect of 9-P was supported by the discovery that males can learn to associate this CHC with unconditional aversive stimuli produced by an unreceptive fly -conditioned flies attempted to copulate less frequently and less intensively with flies carrying more 9-P (Siwicki et al., 2005). 

Mathematical Consideration of the Synergistic Effect. Generalizing the above-mentioned results, we can introduce a concept of an umami taste space. The umami solution of any combination of the two groups of umami substances can be expressed as a point in a space of 2-dimensions, say, G, defined as follows ... 

In order to determine the possible enhancement or suppression of the synergistic effects of umami substances, it was examined whether equation (1) held or not in the presence of various other taste substances. 

Effects of the Four Taste Substances. The concentration of MSG equivalent in the umami intensity to an MSG-IMP mixture (point of subjective equality) was determined both in pure water and in the four taste solutions. The results are shown in Table V. The equi-umami concentration of MSG obtained in the presence of each of the four taste substances was almost the same as that in pure water. Thus the synergistic effects of umami substances were seen to be unaffected by the four taste substances. 

Applications. Sarcosinates show low irritation potential and are good foamers. Due to these properties they find applications in personal care products where synergistic effects with other surfactants may also be exploited. In combination with other anionics, sarcosinates will often detoxify the formulation and give improved foaming and skin feel. Sarcosinates are also used for their hydrotropic properties - the addition of sarcosinate to other anionics often gives a reduced Kraft point or a raised cloud point if combined with non-ionic surfactants. Lauroyl sarcosinate is used to formulate SLS-free toothpastes which are claimed to have improved taste profile. 

The synergistic effect of umami substances is exceptional. The subjective taste intensity of a blend of monosodium glutamate and disodium 5 -inosinate was found to be 16 times stronger than that of the glutamate by itself at the same total concentration (Yamaguchi 1979). 

Monosodium aspartate also elicits an umami taste, although its intensity is not as high. It has also been reported to have a synergistic effect with IMP. 

Determining the molecular sites of action of bioactive medicinal plant constituents is clearly important for establishing the chemical and physiological basis for herbal medicinal efficacy, for quality control of commercial herbal preparations and for the discovery of lead compounds for synthetic (or semi-synthetic) pharmaceutical development. Of course, it must be recognized that medicinal plant efficacy may derive from complex synergistic effects or even from quasi-placebo effects connected with the taste, mild effects and appearance of the preparation. While recognizing these possible holistic complications, in order to find out how such preparations work, it is clearly important to initially isolate, structurally characterize and define the biochemical targets of plant bioactive substances. 

L-Glu and Asp are sour stimuli in dissociated state, but their sodium salts dissociate on solution and elicit the umami taste. Free L-glutamate is contained in natvu al foods, as shown in Table 2 and contributes to the savory taste of foods as its sodium salt. Ibotenlc and tricholomlc acids (lA and TA) discovered in mushrooms are the derivatives of oxyglutamic acid and are also umami substances (, 5). The umami taste intensity of lA or TA is A to 25 times that of MSG. As these compounds are not amino acids commonly found in an animal system, they have not been used as seasoners. The umami taste or TA-5 -ribonucleotide mixture is much more Intense only MSG, lA or TA. Among 5 -ribonucleotides, 5 -guanylate have synergistic effects in a mixture with This phenomenon is called the synergistic effect of... 

Though amino acids can elicit any one of the primary tastes, the threshold value of taste of each amino acid is high. As the levels of some free amino acids in natural foods are lower than their threshold values, it may be thought that they may not contribute directly to food taste. However, they may have an Important role in making the food savory because of the synergistic effect. 

Synergistic effects for combinations of sweeteners have been reported, e.g., acesulfame potassium with aspartame or sodium cyclamate. A ternary combination of sweeteners that includes acesulfame potassium and sodium saccharin has a greater decrease in sweetness upon repeated tasting than other combinations. ... 

Synergistic effects between MSG and sodium chloride have also been reported [8], For maximum palatability of a clear soup, more MSG must be added if only small amounts of salt are used, and vice versa. Optimum amounts of salt and MSG are 0.8 % and 0.4 %, respectively. Thaumatin, an intensely sweet tasting protein has been reported to have a similar synergistic effect to that of 5 -ribonucleotides on MSG, but at significantly lower dosages [8]. Other umami substances with synergistic effects on each other include various amino acids (e.g. L-cysteine, D,L-homocysteine, cysteine S-sulfonate), polypeptides, cycloalliin, and histamine [8]. 

Yoshii K, Yokouchi C, Kurihara K (1986) Synergistic effects of 5 -nucleotides on rat taste responses to various amino acids. Brain Res 367 45-51... 

Acesulfame potassium is heat stable under moderately acidic or basic conditions but unstable at low pH. It is approved for safety everywhere and is often blended with other sweeteners. These blends are reputed to give a more sugar-like taste where each sweetener masks the other s aftertaste, and to exhibit a synergistic effect wherein the blend is sweeter than its components. 

---