Impurity
anything that is added to a completely pure substance
Intermolecular
between molecules, much weaker than covalent bonds
Water activity
the measure of of the partial water pressure over a food
Anhydrous
compounds that have the water driven off when heated
Hydrated
full of water
Nonpolar covalent bond
is electrically neutral because the electrons are shared equally
Hydrate
any chemical compound that is loosely bound with water
Free water
liquid easily separated from food tissues, can be pressed or squeezed from the food
Polar covalent bonds
there is an unequal sharing of electrons within the molecule
Hydrogen bond
the positive hydrogen end of one water molecule is drawn toward the negative oxygen ends of other water molecules
Contaminate/pollutant
anything that makes a substance impure or unsuitable
Surface tension
the force between molecules at the outside edge of a substance
Nutrient
a food component necessary to sustain life, which includes water, carbohydrates, fats, proteins, vitamins, and minerals
Bound water
tied to the structure of large molecules
Atmospheric pressure
the force of this weight pressing down on a surface