Moisture is the presence of a liquid, especially water, often in trace amounts. Moisture is defined as water in the adsorbed or absorbed phase. Small amounts of water may be found, for example, in the air (

humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation (meteorology), precipitation, dew, or fog t ...

), in foods, and in some commercial products. Moisture also refers to the amount of

water vapor Water vapor, water vapour, or aqueous vapor is the gaseous phase of Properties of water, water. It is one Phase (matter), state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from th ...

present in the air. The soil also includes moisture.

Moisture control in products

Control of moisture in products can be a vital part of the process of the product. There is a substantial amount of moisture in what seems to be

dry matter The dry matter or dry weight is a measure of the mass of a completely dried substance. Analysis of food The dry matter of plant and animal material consists of all its constituents excluding water. The dry matter of food includes carbohydrate ...

. Ranging in products from cornflake cereals to washing powders, moisture can play an important role in the final quality of the product. There are two main aspects of concern in moisture control in products: allowing too much moisture or too little of it. For example, adding some water to cornflake cereal, which is sold by weight, reduces costs and prevents it from tasting too dry, but adding too much water can affect the crunchiness of the cereal and the freshness because water content contributes to bacteria growth. Water content of some foods is also manipulated to reduce the number of

calories The calorie is a unit of energy that originated from the caloric theory of heat. The large calorie, food calorie, dietary calorie, kilocalorie, or kilogram calorie is defined as the amount of heat needed to raise the temperature of one liter o ...

. Moisture has different effects on different products, influencing the final quality of the product.

Wood pellet Pellet fuels (or pellets) are a type of solid fuel made from compressed organic material. Pellets can be made from any one of five general categories of biomass: industrial waste and co-products, food waste, agricultural residues, energy crops, an ...

s, for instance, are made by taking remainders of wood and grinding them to make compact pellets, which are sold as a fuel. They need to have a relatively low water content for

combustion efficiency Combustion efficiency refers to the effectiveness of the burning process in converting fuel into heat energy. It is measured by the proportion of fuel that is efficiently burned and converted into useful heat, while minimizing the emissions of po ...

. The more moisture that is allowed in the pellet, the more smoke that will be released when the pellet is burned. The need to measure water content of products has given rise to a new area of science,

aquametry Aquametry, in analytical chemistry, is the use of analytical processes to measure the water present in materials. The methods widely used in aquametry encompasses Karl Fischer titration, distillation, chromatography, infrared spectroscopy, and grav ...

. There are many ways to measure moisture in products, such as different wave measurement (light and audio),

electromagnetic field An electromagnetic field (also EM field) is a physical field, varying in space and time, that represents the electric and magnetic influences generated by and acting upon electric charges. The field at any point in space and time can be regarde ...

s, capacitive methods, and the more traditional weighing and drying technique.

References

{{Authority control Hydrology

Moisture control in products

See also

References