Food microbiology and food poisoning

This chapter helps the reader to understand the role of certain factors that affect microbial growth and survival. It introduces the important micro-organisms responsible for food poisoning and spoilage. The chapter explains how to prevent food poisoning and minimise food spoilage. It also introduces the concept of Food Safety Programs and the principles of the Hazard Analysis and Critical Control Point system. The six most important factors affecting the ability of micro-organisms to survive, grow or multiply in foods are: time, available nutrients, moisture (available water), temperature, pH, and gas atmosphere. Other factors that influence the viability of micro-organisms are the oxidation-reduction (redox) potential of the food, the presence of natural inhibitors (for example, lysozyme in raw eggs and milk), stresses (for example, physical) and interaction between factors. Some estimates suggest that up to one-third of food is wasted due to spoilage during growth, harvesting, processing, storage, distribution and preparation for consumption.