Taste dilution analysis

Additionally, in the last 5-10 years an emerging number of low-volatile tastemodifying molecules were found using sophisticated analytical methods based on liquid chromatography (LC), namely taste dilution analysis, LC-MS or LC-NMR methods. 

Bitter compounds are also formed in solutions of alanine with xylose and rham-nose.284 Twenty-six HPLC fractions were obtained, seven of which were shown to have high impact on taste dilution analysis. Structures 37-41 accounted for 57% of overall bitterness. The compounds have low threshold values introduction of methyl groups into the furyl rings increase the threshold value. On the contrary, substituting the furyl ring-0 by S (42) lowered the threshold value to almost 104 times lower than that of caffeine on a molar basis. 

Ottinger el al.2S6 have applied their comparative taste dilution analysis (cTDA) to examine the extractable products from heated aqueous D-glucose and L-alanine that were not solvent-extractable. One HPLC fraction proved to be a strong sweetness enhancer. It was isolated and submitted to LC-MS and NMR, both ID and 2D the results, together with its synthesis from HMF and alanine, unequivocally identified it as the inner salt of /V-( I -carboxycthyl)-6-(hydroxy-methyl)pyridinium-3-ol (alapyridaine, Structure 45). It has no taste on its own, which in many applications would be an advantage. Depending on the pH, it lowers the detection threshold of sweet sugars, amino acids, and aspartame, the... 

H. Ottinger, T. Soldo, and T. Hofmann, Discovery and structure determination of a novel Maillard-derived sweetness enhancer by application of the comparative taste dilution analysis (cTDA), J. Agric. Food Chem., 2003, 51, 1035-1041. 

Frank, O., Ottinger, H., Hofmann, T. Characterization of an intense bitter-tasting l//,4H-quino-lizinium-7-olate by application of the taste dilution analysis, a novel bioassay for the screening and identification of taste-active compounds in food. J. Agric. Food Chem. 2001,42, 231-238... 

As previously discussed, there is a tendency (e.g. in Europe) to reduce the amount of certain compounds (e.g. MSG, salt). Current research aims at identifying alternatives for these molecules without compromising quality. By applying state-of-the-art screening tools, such as taste dilution analysis (TDA) [16], receptor-based assays [17] and molecular modelling [18[, a number of MSG alternatives have recently been reported (Fig. 5.51). 

Aimed at investigating taste enhancers in beef bouillon, taste activity-guided fractionation combined with the comparative taste dilution analysis led to the discovery of the presence of a sweet enhancing compound. Model Maillard reactions, spectroscopic and synthetic experiments revealed the previously unknown 1 - 1 -carboxyethyl)-5-hydroxy-2-... 

In order to identify such thermally generated taste compounds, we recently developed the so-called Taste Dilution Analysis (TDA), which is based on the detemiination of the detection threshold of taste compounds in serial dilutions of chromatographic fractions (7-9), offering the possibility to rate food components according to their relative taste impact. 

The comparative taste dilution analysis revealed a high TD factor of 16 for sweetness in fraction III (Figure 1). As this fraction showed no sweetness in the absence of sucrose, this fraction was assumed to contain a reaction product enhancing the sweetness of the sucrose solution by a factor of eight. Because sweetness enhancing compounds were not yet reported in beef bouillon, the following identification experiments were focused on the sapid taste modifier present in GPC fraction III (Figure 1). 

In order to further resolve GPC fraction III into distinct sensory active compounds and to rate them in their relative taste impacts, this fraction was then separated by RP-HPLC (Figure 2) into 16 subfractions. Application of the comparative taste dilution analysis using sucrose as the basic tastant revealed the highest TD factor for sweetness for fraction III-5, thus indicating the presence of a sweetness enhancing compound in that fraction. 

Ottinger H., Bareth A., Hofmann T. Characterization of natural cooling compounds formed from glucose and L-proline in dark malt by application of taste dilution analysis. Journal of Agricultural and Eood Chemistry, 49 1336 1344 (2001). 

Deibler, K.D., Lavin, E.H., and Acree, T.E. 2002. Solid phase microextraction application in GC/olfactometry dilution analysis. In Analysis of Taste and Aroma (J.F. Jackson and H.F. Lin-skens, eds.) pp. 239-248. Springer, Berlin. 

Ferreira, V., Lopez, R., and Aznar, M. (2002). Olfactometry and aroma extract dilution analysis of wines. In Analysis of Taste and Aroma", J. Jackson and H. F. Linskens, (Eds), pp. 89-122. Springer-Verlag, Berlin. 

KD Deibler, EH Lavin, TE Acree. Solid phase microextraction apphcation in GC/olfactometry dilution analysis. In JF Jackson, HF Lrnskens, eds. Analysis of Taste and Aroma Molecular Methods of Plant Analysis, Vol. 21. Berlin Springer, 2002, pp 239-248. 

Analysis of these products usually includes the various determinations made on spirits (see General Methods). In some cases it is necessary to test for certain vegetable substances with a hot, biting taste, such as various kinds of pepper, ginger, mustard, etc., which it is customary to add to dilute eaux-de-vie (sometimes below 30%) to increase their apparent... 

Historical. — In 1797, HaQy, a mineralogist, found that the minerals beryl and emerald had the same physical structure, hardness, and specific gravity. He asked Vauquelin to make a chemical analysis to see if they were not of the same composition. In the course of the analysis Vauquelin found that while these two minerals were of the same composition they both contained an oxide very similar to alumina but differing from it in the fact that it was precipitated from its KOH solution by boiling. Further study showed other peculiarities its salts had a sweet taste its hydroxide was soluble in dilute ammonium carbonate and its sulfate formed irregular crystals but no alum with KjS04. 

Taste and odor No health-based guideline value. The threshold odor number (TON) is the greatest dilution of sample with odor-free water yielding definitely perceptible odor SC No value set 3TCN Flavor profile analysis... 

Food flavor, taste, and texture sensations are perceived over time during consumption, and intensity of flavor perception can change over time. The temperature of the product, after time, equilibrates with the mouth temperature. Physical manipulations such as tongue movements, mastication, and salivary dilution affect the product and its sensory characteristics over time. The classic methods of descriptive sensory analysis do not take into account this temporal dimension. For that purpose, dynamic methods such as time-intensity analysis were developed [13]. 

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