METER Food

Knowledge Base

Hurdle technology, also known as combined processes or barrier technology, employs the intelligent combination of different preservation factors or techniques to achieve mild but reliable preservation effects.

How do manufacturers keep intermediate moisture foods microbially safe during a lengthy shelf-life? The answer is humectants–ingredients such as glycerine, sugar, and different types of salts.

Microbial growth

Microbial growth is the reason water activity began to be used in the food industry. Before the discovery that water activity controls microbial growth, food producers didn’t know why some batches molded and others didn’t. They suspected it had something to do with water, but everyone knows that high-moisture salt pork doesn’t mold, while low moisture nuts still do.

Water activity definition

Water activity is derived from fundamental principles of thermodynamics and physical chemistry. As a thermodynamic principle there are requirement in defining water activity that must be met. These requirements are; pure water (aw = 1.0) is the standard state, the system is in equilibrium, and the temperature is defined.