|
Humectant
A humectant is a hygroscopic (water-absorbing) substance used to keep things moist. They are used in many products, including food, cosmetics, medicines and pesticides. When used as a food additive, a humectant has the effect of keeping moisture in the food. Humectants are sometimes used as a component of antistatic coatings for plastics. A humectant attracts and retains the moisture in the air nearby via absorption, drawing the water vapor into or beneath the organism's or object's surface. This is the opposite use of a hygroscopic material where it is used as a desiccant used to draw moisture away. In pharmaceuticals and cosmetics, humectants can be used in topical dosage forms to increase the solubility of a chemical compound's active ingredients, increasing the active ingredients' ability to penetrate skin, or its activity time. This hydrating property can also be needed to counteract a dehydrating active ingredient (e.g., soaps, corticoids, and some alcohols), which is why ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Additive
Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar (pickling), salt (salting), smoke (smoking), sugar (crystallization), etc. This allows for longer-lasting foods such as bacon, sweets or wines. With the advent of processed foods in the second half of the twentieth century, many additives have been introduced, of both natural and artificial origin. Food additives also include substances that may be introduced to food indirectly (called "indirect additives") in the manufacturing process, through packaging, or during storage or transport. Numbering To regulate these additives and inform consumers, each additive is assigned a unique number called an "E number", which is used in Europe for all approved additives. This numbering scheme has now been adopted and extended by the '' Codex Alimentarius'' Commission to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hygroscopic
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 become physically changed, e.g., changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to collection of moisture from the surrounding environment. ''Deliquescent'' materials are sufficiently hygroscopic that they absorb so much water that they become liquid and form an aqueous solution. Etymology and pronunciation The word ''hygroscopy'' () uses combining forms of '' hygro-'' and '' -scopy''. Unlike any other ''-scopy'' word, it no longer refers to a viewing or imaging mode. It did begin that way, with the word ''hygroscope'' referring in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboxyl Group
In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids. Deprotonation of a carboxylic acid gives a carboxylate anion. Examples and nomenclature Carboxylic acids are commonly identified by their trivial names. They at oftentimes have the suffix ''-ic acid''. IUPAC-recommended names also exist; in this system, carboxylic acids have an ''-oic acid'' suffix. For example, butyric acid (C3H7CO2H) is butanoic acid by IUPAC guidelines. For nomenclature of complex molecules containing a carboxylic acid, the carboxyl can be considered position one of the parent chain even if there are other substituents, such as 3-chloropropanoic acid. Alternately, it can be named as a "carboxy" or "carboxylic acid" substituent on another ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
