Food Technology Glossary

A chart relating dry bulb temperature, wet bulb temperature, humidity ratio, relative humidity and enthalpy of moist air.

Heating a grain quickly under pressure or high heat so trapped moisture turns to steam and makes the grain expand and become light and crisp.

The factor by which a reaction rate changes for a 10 °C rise in temperature.

Deterioration of fats producing off-flavours. Hydrolytic rancidity releases free fatty acids by lipase or water; oxidative rancidity is a free-radical chain reaction with oxygen at unsaturated bonds.

The average daily amount of a nutrient considered enough to meet the needs of most healthy people in a given age and gender group.

A sugar with a free aldehyde or ketone group that can act as a reducing agent — glucose, fructose, lactose and maltose are reducing sugars. Sucrose is not, because both anomeric carbons are involved in the glycosidic bond.

The ratio of the partial pressure of water vapour in air to its saturation pressure at the same temperature, as a percentage.

The rate at which harvested produce consumes oxygen and releases carbon dioxide, heat and water.

A pressure vessel used to sterilise food after sealing in its container, allowing temperatures above 100 °C.

Sealing food in a flexible, heat-resistant pouch and then sterilising it with heat, similar to canning but using a pouch instead of a rigid can.

The re-association of gelatinised starch chains, mainly amylose, into an ordered crystalline structure during cooling and storage, expelling water (syneresis).

A filtration method that pushes water through a very fine membrane under pressure, removing dissolved salts, minerals, and other impurities.