This article is part of a collection entitled "Models for Safety, Quality, and Competitiveness of the Food Processing Sector," published in Comprehensive Reviews in Food Science and Food Safety. It has been peer-reviewed and was written as a follow-up of a pre-IFT workshop, partially funded by the USDA NRI grant 2005-35503-16208.ABSTRACT: Modeling, in particular physics-based modeling, can be an important tool to food product, process, and equipment designers by reducing the amount of experimentation (thus reducing the time and expenses involved) and by providing a level of insight that is often not possible experimentally. Food processes involve unique physics and challenges compared to other types of materials processing such as polymers and ceramics. These include complex multiphase transport and multiphysics that are difficult to implement in the available software, and often drastic changes in material properties during processing for which data are unavailable. Such unique and challenging features have made it difficult to embrace modeling as a tool in the food industry. This article discusses, in the context of design use of models, the nature and the state of modeling of food processes, emphasizing the more complex scenarios in both modeling and material properties needed for the models.