Glossary: H

Here you will find definitions of terms used in resources on the Foodsource website. You will also find these definitions on the right-hand side within chapters. If you have any suggestions for new glossary items, let us know here.

2 (1) | A (13) | B (6) | C (15) | D (6) | E (8) | F (12) | G (4) | H (3) | I (7) | L (5) | M (12) | N (7) | O (4) | P (9) | R (7) | S (10) | T (1) | U (2) | W (4) | Y (1) | Z (2)

Habitat fragmentation

Habitat fragmentation describes the breakup (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay.


Hydrogenation is a chemical reaction between a hydrogen molecule (H2) and another molecule or element in the presence of a catalyst such as palladium, platinum or nickel. In the food industry, hydrogenation is often used to turn liquid oils into solid fats. The partial hydrogenation of oils is used to produces trans-fats. Hydrogenated fats and trans-fats are contested for their health impacts.

Hydroxyl (OH) radicals

Hydroxyl (OH) radicals are highly reactive molecules responsible for the initial reaction leading to most methane destruction in the atmosphere, and also important for the removal of many other atmospheric pollutants. Radicals are molecules or atoms with an unpaired electron, often making them very reactive.