Lesson 4g - M is for Moisture
All microorganisms must have an abundant supply of water to grow. Perishability of a food is related to the moisture content, and the water activity level.
All microorganisms must have an abundant supply of water to grow. Perishability of a food is related to the moisture content, and the water activity level.
Microorganisms that need oxygen (air) to grow are called aerobic.
pH Levels
The degree of acidity or alkalinity (base) of a substance is measured by its pH. pH is measured on a scale from 0 to 14.0. An environment with a pH of 7.0 is exactly neutral. Foods with a pH below 7.0 are acidic; a pH above 7.0 is alkaline. The lower the pH, the higher the acidity; the higher the pH, the lower the acidity.