Book excerpt: The physical and chemical properties of food products have central roles in biotechnology and the pharmaceutical and food industries. Understanding these properties is essential for engineers and scientists to tackle the numerous issues in food processing, including preservation, storage, distribution and consumption.This book discusses models to predict some of the physical-chemical properties (pH, aw and ionic strength) for biological media containing various solutes. In recent years, food production has involved less processing and fewer additives or preservatives. If health benefits for consumers are obvious, it is not only necessary to adapt current processing and preservation processes but also to verify that appropriate technological and health properties are preserved.The authors present established models, but also introduce new tools for prediction with modeling methods that are part of a more general approach to understand the behavior of fluid mixtures and design new products or processes through numerical simulation. - Describes the construction of a tool to allow you to predict the physical-chemical properties of foods and bacterial broths - Shows you how to apply this tool with complex medias to predict water activity and pH levels and how to integrate this tool with a process simulator - Full with theoretical equations and examples to help you apply the content to your data