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Moisture analysis. Moisture analysis covers a variety of methods for measuring the moisture content in solids, liquids, or gases. For example, moisture (usually measured as a percentage) is a common specification in commercial food production. [1] There are many applications where trace moisture measurements are necessary for manufacturing and ...
Food moisture analysis is the determination of the concentration of water in a food sample. A variety of techniques may be used including Karl Fischer titration and loss on drying. Many technical standards exist which define test methods for determining moisture in different types of food. Food moisture content can impact food safety, food ...
t. e. Water activity (aw) is the partial vapor pressure of water in a solution divided by the standard state partial vapor pressure of water. In the field of food science, the standard state is most often defined as pure water at the same temperature. Using this particular definition, pure distilled water has a water activity of exactly one.
An increase in a w is usually accompanied by an increase in water content, but in a non-linear fashion. This relationship between water activity and moisture content at a given temperature is called the moisture sorption isotherm. These curves are determined experimentally and constitute the fingerprint of a food system.
For modern humidity-measuring instruments, see hygrometer. Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance's molecules, adsorbing substances can ...
Moisture is the presence of a liquid, especially water, often in trace amounts. Moisture is defined as water in the adsorbed or absorbed phase. [ 1 ] Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapor present in the air.
The Dean–Stark method is commonly used to measure moisture content of items such as bread in the food industry. This equipment can be used in cases other than simple removal of water. One example is the esterification of butanol with acetic acid catalyzed by sulfuric acid. The vapor contains 63% ester, 29% water and 8% alcohol at reflux ...
The moisture sorption properties of food products are recognized as critical factors in determining their storage, stability, processing and application performance. [ 8 ] [ 9 ] DVS is also used to measure moisture and flavor diffusion properties for packaging and barrier applications.