Taste Description

Many materials used for food and beverage packaging have characteristic odors or sensory active compounds (Torri et ah, 2008). The intensity and description of the odor may be affected by the number and type of volatile compounds that are released under environmental conditions at the time of evaluation. Chemical composition of the material and polymer morphology may play a role in the sensory characterization. Sensory descriptors do not define a specific chemical compound but may be related to different compounds, a blend of compounds, and even a limited concentration range of a compound or class of compounds. For example, frans-2-nonenal in water changes in sensory (taste) description from "plastic (0.2 gg/1) to "woody" (0.4-2.0 p.g/1), "fatty" (8-40 pg/1), and "cucumber" (1000 gg/1) (Piringer and Ruter, 2000). Such terms are descriptive of the sensation and perception by human response to the chemical stimuli (Table 2.1). 

Table 13-2 Variation of taste description of lrans-2-nonenal with concentration in water.

O Mahony, M., and Ishii, R., 1985a, A comparison of English and Japanese taste languages Taste descriptive methodology, codability and the umami taste, Brit. J. Psychol., in press. 

O Mahony, M., and Manzo Alba, M. del C., 1980a, Taste descriptions in Spanish and English, Chem. Senses, 5 47. 

The role of fragrances since ancient times has been to cover unpleasant smell and to provide a pleasing impression (e.g., fmity, floral, marine etc.). Fragrance and flavor raw materials are obtained either from natural sources (e.g., terpenes, plant essential oils, animal secretions or from chemical synthesis. As the enantiomers of many odorant molecules differ in strength and in odor/taste description, the selective (and often catalytic) synthesis of the more appreciated isomer is of great interest. This avoids the dilution effect by the non-desired isomer and reduces the amount of active ingredient in the final product. Table 5.3.19 shows the example of (Sj-citronellol, an important perfumery raw material with a rose note. 

Chemical compounds having odor and taste number in the thousands. In 1969 a description of the odor characteristics of more than three thousand chemical compounds used in the flavor and perfume industries were described (41). The Hst of volatile compounds found in food that may contribute to odor and taste is even larger (42), and the Hst of all possible flavor compounds, including those that have yet to be synthesized, is greater than a thousand. Many different compounds have the same flavor character or quaUty, differing perhaps in their relative intensity but indistinguishable in the type of flavor they ehcit. The exact number of different flavor quaUties is not known, but it appears to be much less than the total number of compounds with flavor. 

The interest, economics and changing tastes together indicated the most important phenomenon, which pushed cocktails into center stage—the acceptance by women of cocktail drinking as a social form, and a new equality of enjoyment in going out. The cocktail scene, as opposed to the bar scene, was sexually comfortable and independent—mutually neutral territory where a group of any description could spend a few hours or an evening over a few conversation-piece drinks or a few favorites. 

Another valuable tool in food package development is the taste/odor Profile Test (18). Developed by the Arthur D. Little Company, this method uses a small panel of four to eight people specially trained in the procedure. Their analysis develops a full descriptive terminology for the product in question and assigns a numerical rating to each component of the taste/odor complex. 

Studies on the biochemistry of the taste system should take into account results obtained at other levels, such as electrophysiological recordings and, particularly, behavioral responses to taste stimuli. The term sweetness should strictly be used only in studies conducted on humans, because the description of taste modality is a verbal response. It is usually concluded that positive behavioral responses in animals, that is, preferences, or electrophysiological response to a stimulus compound that is known to be sweet to man, are due to the sweet taste. This may not necessarily be true in some cases, because behavioral or electrophysiological response may result from other taste modalities. It is, therefore, critical that comparative aspects be carefully interpreted. 

Scientific inquiry, which requires the definition of a model, the examination of the results, then, if neeessaiy, the elaboration of another model, in a sequence of steps, is a eomplex taste in whieh interpretation (or description) plays a cmcial role. I hope that the introduetion of three levels, or steps, in the process of interpretation will be of some help for our task. 

A description as a MMCT transition is not very obvious for this case. However, there is no essential difference between the physical origin of the colors of Pb(N02)2 and, for example, CU2WO4. Unfortunately the literature shows sometimes discussions on the nature of their excited states in terms of either MMCT or metal-ion-induced CT transitions. To us, such a discussion does not seem to be very fruitful. In the classification it is a matter of taste which nomenclature is used, in the (more difficult) characterization it is essential to determine the coefficients which indicate the amount of configuration interaction. The latter describe the nature of the excited state. 

An acid is classically known as a substance whose aqueous solution (i) turns blue litmus red (ii) neutralizes bases (iii) reacts with active metals with the evolution of hydrogen and (iv) possesses a sour taste. A base is again classically known as a substance which in aqueous solution (i) turns red litmus blue (ii) neutralizes acids (iii) tastes offensive and (iv) gives a soapy feel. These given descriptions of acids and bases may also be regarded as being operational or or experimental definitions. 

Hexachloroethane vapors smell like camphor. You can begin to smell hexachloroethane in air when there are 150 parts present in a billion parts of air (ppb). You can smell it in water at 10 ppb. Neither a description of the taste nor the amount of hexachloroethane that gives a taste to water were found. 

DETAILS - A crude extract of hemlock was used by the ancient Greeks to execute enemies of the state. Plato s description of the death of Socrates is a very detailed account of the symptoms and their progression. Pure coniine has a burning taste similar to low-grade hot sauce and a characteristic odor which should be masked. Hard liquor or pungent spicy foods are best for this. Coniine poisoning is a relatively painless process, but takes several hours and the victim is conscious and aware to the very end. 

Assessment of taste is achieved by sensory analysis, from very simple experiments such as triangular tests aiming at determining detection thresholds to complex descriptive analysis approaches. A method referred to as time-intensity that consists in recording continuously the intensity of a given sensation over time under standardized conditions has been applied to study flavonoid bitterness and astringency properties. 

Measurements of acetaldehyde accumulation were reported in some of the earliest descriptions of the MOX process, where 5 months of MOX at 3 mL/L/month was found to raise the acetaldehyde concentration to 33 mg/L, compared to a control wine at 13 mg/L (Moutounet et ah, 1996). Further trials at Oenodev for a Syrah wine in 300-L tanks, and subject to elevated O2 delivery rates of 30,60, or 90 mL/L/month for 3 weeks, have shown that acetaldehyde will progressively accumulate to be perceived by a tasting panel from an early stage. Increased concentrations of acetaldehyde by GC were cordirmed for all treatments over the control by the end of the trial, with very high concentrations (50 mg/L) seen in the 90-mL/L/month MOX treatment (Oenodev, 2009). 

Ac-Phc-Lys-OH, enzymatic synthesis, 156f Acesulfame K, stnicture, 7f Acetoin, in reactions of aldehydes with ammonium sulfide, 36-54 Acid chelators, 57-58 Acid synergism, description, 58 Acidic amino acid peptides, taste,... 

AH-B theory, description, 28 Alanyl-containing 0-aminoacyl sugars, taste variation, 164r Alcohol fermentation, koji autolytical, 206/207... 

The most frequently used tests in quality control in the flavour industry are paired-sample comparison tests, and triangle tests, which are often combined with the description of deviation from a reference item. For the selection and training of panellists, further test methods are used, for example ranking tests for colour, taste and odour, threshold detections (taste, off-flavour), colour blindness tests and odour identification tests [6]. 

It was with great pleasure that I read the first book of Yifan Yang in 2002. This was Chinese Herbal Medicines Comparisons and Characteristics. What was so refreshing about Comparisons and Characteristics was the clear and detailed description of the functions of the different temperature and taste properties, so that the reader understood why different herbs have different actions. The author then developed this into the excellent contrasts of similar herbs based on differences in temperature, taste, and action. This is vital to the clinical practice of herbal medicine. If the practitioner does not understand the detailed differences between herbs, then they cannot make effective herb combinations. 

Description Colourless liquid with a bitter taste (Budavari, 1996 Lide, 997) Boiling-point 150.2°C (Lide, 1997)... 

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