Odor, characteristics substances

Ketones are most widely represented and include cyclopentanone derivatives, such as the jasmin fragrance substances, and cyclic ketones with 15-17-membered carbon rings, such as muscone and civetone, which are constituents of the extremely expensive animal products, musk and civet. Cyclopentadecanone, a natural musk fragrance, and the unsaturated 5-cyclohexadecen-l-one, which has not yet been found in nature, have odor characteristics similar to those of muscone and civetone and are more easily synthesized. They are, therefore, often used as substitutes. 

Sulfur compounds play a major role in determining the flavor and odor characteristics of many food substances. Often sulfur compounds are present in trace levels in foods making their isolation and quantification very difficult for chromatographers. This study compares three gas chromatographic detectors the flame photometric detector, sulfur chemiluminescence detector and the atomic emission detector, for the analysis of volatile sulfur compounds in foods. The atomic emission detector showed the most linearity in its response to sulfur the upper limit of the linear dynamic range for the atomic emission detector was 6 to 8 times greater than the other two detectors. The atomic emission detector had the greatest sensitivity to the sulfur compounds with minimum detectable levels as low as 1 pg. 

Flavor orFlavorant. A substance, added to food, whose significant function is to affect odor, imparting a characteristic flavor to that food. 

FlavorEnhancer. A substance added to supplement, modify, or enhance the original taste and/or aroma of a food without imparting a characteristic taste or odor of its own. 

Present-day nomenclature is partly the result of the conflict and interplay of two functions the need to communicate in speech and on the printed page on the one hand, and the need for archival storage of information and its efficient, reliable retrieval. The former function came first, and laid the basis for the nomenclature most commonly used even today, and gave birth to a wealth of trivial names (i.e. names that give little or no information on structure). These were often coined on the basis of the origin of the substance, as in the case of collidine, obtained from distillation of bones in glue factories, or were derived from a special characteristic, as in the case of skatole, which has a fecal odor. Such names are short and generally euphonious, but they must be memorized they cannot be deduced from the structure. 

Isoamyl acetate is the common name of the substance most responsible for the characteristic odor of bananas. Write a structural formula for isoamyl acetate, given the information that it is an ester in which the carbonyl group bears a methyl substituent and there is a 3-methylbutyl group attached to one of the oxygens. 

The physical and chemical characteristics of the liazardous substance must be listed. Tliese include items such as boiling and freezing points, density, vapor pressure, specific gravity, solubility, volatility, and product s general appearmice and odor. These characteristics provide important iiiformation for designing safe and healtliful work practices. 

Essence of Vanilla.—The substance sold under this name is, properly, a spirituous extract of the vanilla bean. Many samples, however, are little more than alcoholic solutions of artificial vanillin, coloured with caramel. Some samples, which cannot be described as adulterated, contain a little coumarin or other odorous substance, added to varj- the characteristic vanillin odour and flavour somewhat. 

In addition to the VOCs produced in sewers under anaerobic conditions, such components may originate from external sources, e.g., industries (Corsi et al., 1995 Olson et al., 1998). Typically, these VOCs are hydrocarbons and similar products. The emission is influenced by a number of sewer system parameters, hydraulic conditions, wastewater characteristics and physicochemical properties for the VOC component. The emission of such incoming VOCs thereby follows the general approach described in this text for odorous substances. 

When designing sewer networks, particularly gravity sewers, reaeration is the major process that should be focused on to reduce sulfide formation and the formation of organic odorous substances (cf. Section 4.4). A number of hydraulic and systems characteristics can be managed to increase the reaeration rate and avoid or reduce sulfide-related problems. The hydraulic mean depth, the hydraulic radius, the wastewater flow velocity and the slope of the sewer pipe are, in this respect, important factors that are dealt with in Section 4.4. It should be stressed that it is not necessarily the objective to avoid sulfide formation (in the sewer biofilm), but the sulfide that occurs in the bulk water phase should be at a low concentration level. Therefore, the DO concentration in the bulk water phase should not be lower than about 0.2-0.5 g02 m-3, sufficiently high to oxidize sulfide before a considerable amount is emitted to the sewer atmosphere. 

Odor Threshold The minimum concentration of a substance at which a majority of test subjects can detect and identify the substance s characteristic odor. 

Many pharmaceutic ingredients may be utilized in preparing the desired dosage form of a drug substance. Some of these agents may be used to achieve the desired physical and chemical characteristics of the product or to enhance its appearance, odor, and taste. Other... 

Blind studies with chemical substances that have a characteristic odor or irritant effect are difficult to manage. If, as with ozone, the odor sense tends to diminish, then odor sham protocols are possible. However, keeping the subjects and the investigators (other than the safety officer) truly uninformed about the nature of a particular experiment is not a trivial problem. 

A mineral is a naturally occurring, crystalline inorganic compound with a specific chemical composition and crystal structure. Minerals are commonly named to honor a person, to indicate the geographic area where the mineral was discovered, or to highlight some distinctive chemical, crystallographic, or physical characteristic of the substance. Each mineral sample has some obvious properties color, shape, texture, and perhaps odor or taste. However, to determine the precise composition and crystal structure necessary to accurately identify the species, one or several of the following techniques must be employed optical, x-ray diffraction, transmission electron microscopy and diffraction, and chemical and spectral analyses. 

Attempts to label dangerous substances with either characteristic or outright unpleasant odors have not been successful with children, the primary victims of accidental poisonings by toxic household products. Children tolerate odors that adults find unpleasant, such as that of butyric acid. The range between the most pleasant and unpleasant odors is much narrower for children around 4years of age than for adults, and also much narrower than for taste stimuli. This means that olfactory cues are not suited to produce aversive responses in children (Engen, 1974b, Cain, 1978). 

Most nickel is used to make stainless steel. Compounds of nickel combined with many other elements, including chlorine, sulfur, and oxygen, exist. Many of these compounds dissolve fairly easily in water and have a characteristic green color. Nickel and its compounds have no characteristic odor or taste. Nickel compounds are used for nickel plating, to color ceramics, to make some batteries, and as substances known as catalysts that increase the rate of chemical reactions. 

Phenethyl alcohol is qualitatively and quantitatively one of the most important fragrance substances that belongs to the class of araliphatic alcohols. Its lower homologue (benzyl alcohol) and higher homologue (dihydrocinnamic alcohol) also have characteristic odor properties, but are more frequently used in the form of their esters. Cinnamic alcohol, the most important unsaturated araliphatic alcohol, is valuable for both fragrances and flavors. 

Uses. Most essential oils are used directly as starting materials in the production of flavor and fragrance compositions. However, some essential oils are fractionated or concentrated by distillation, partitioning, or adsorption. Substances that are important for the desired characteristic odor and taste are thus concentrated, and other components, which possess either an unpleasant or very faint odor or are unsuitable for the application in question, are removed. 

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