Search results
Results from the WOW.Com Content Network
The moisture content of grains is an essential property in food storage. The moisture content that is safe for long-term storage is 12% for corn, sorghum, rice and wheat and 11% for soybean [ 1 ] At a constant relative humidity of air, the EMC will drop by about 0.5% for every increase of 10 °C air temperature.
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. [2] BET theory (Brunauer-Emmett-Teller) provides a calculation to describe the physical adsorption of gas molecules on a solid ...
The saturation with respect to water cannot be measured much below –50 °C, so manufacturers should use one of the following expressions for calculating saturation vapour pressure relative to water at the lowest temperatures – Wexler (1976, 1977), [1] [2] reported by Flatau et al. (1992)., [3] Hyland and Wexler (1983) or Sonntag (1994 ...
The Penman equation describes evaporation (E) from an open water surface, and was developed by Howard Penman in 1948. Penman's equation requires daily mean temperature, wind speed, air pressure, and solar radiation to predict E. Simpler Hydrometeorological equations continue to be used where obtaining such data is impractical, to give comparable results within specific contexts, e.g. humid vs ...
In food science, water activity (a w) of a food is the ratio of its vapor pressure to the vapor pressure of water at the same temperature, both taken at equilibrium. [1] Pure water has a water activity of one. Put another way, a w is the equilibrium relative humidity (ERH) expressed as a fraction instead of as a percentage.
Typical rates in aluminium foil laminates may be as low as 0.001 g/m 2 /day, whereas the rate in fabrics can measure up to several thousand g/m 2 /day. [citation needed] Often, barrier testing is conducted on a sheet of material. Calculations based on that can be useful when designing completed structures, clothing, and packages.
An ice cream topping cold well needs an adjustment or service by November to ensure food storage temperatures are at 41 degrees or below. While noncritical, rusted shelves inside a reach-in cooler ...
The Köhler curve is the visual representation of the Köhler equation. It shows the saturation ratio – or the supersaturation = % – at which the droplet is in equilibrium with the environment over a range of droplet diameters. The exact shape of the curve is dependent upon the amount and composition of the solutes present in the atmosphere.