Emmanuel Purlis

Editorial: Food engineering technologies: Solutions to build sustainable and resilient food systems, and increase food and nutrition security

Volume change and large deformation occur in different solid and semi-solid foods during processing, e.g., shrinkage of fruits and vegetables during drying and of meat during cooking, swelling of grains during hydration, and expansion of dough during baking and of snacks during extrusion and puffing. In addition, food is broken down during oral processing. Such phenomena are the result of complex and dynamic relationships between composition and structure of foods, and driving forces established by processes and operating conditions. In particular, water plays a key role as plasticizer, strongly influencing the state of amorphous materials via the glass transition and, thus, their mechanical properties. Therefore, it is important to improve the understanding about these complex phenomena and to develop useful prediction tools. For this aim, different modelling approaches have been applied in the food engineering field. The objective of this article is to provide a general (non-systematic) review of recent (2005–2021) and relevant works regarding the modelling and simulation of volume change and large deformation in various food products/processes. Empirical- and physics-based models are considered, as well as different driving forces for deformation, in order to identify common bottlenecks and challenges in food engineering applications.

The baking process has received quite attention during the last three decades, due to its economic and industrial relevance, and since it is associated with staple foods like bread. Because of the composition and structure of dough, a series of complex, simultaneous and coupled phenomena occur in the product inside the oven, which make very difficult the design, control and optimization of the process. For these tasks, the use of mathematical models appears as an adequate solution, although they still represent a complex approach for industrial purposes and their use is limited. In this paper, we focus on prediction of water loss, which is relevant for different aspects of the process, for example, texture and sensory properties, economic impact, energy demand. Two simple models are developed based on knowledge about transport phenomena of bread baking. Both methods involve the estimation of a mass transfer coefficient, which can be related to operating conditions. Good prediction performance is found in both cases, in a common range of baking conditions. Finally, the use of water loss as a design and control variable of the process is discussed, and we propose the construction of a baking diagram with moisture loss as independent variable.Practical applications: Overall, there is a lack of simple and accurate prediction methods for baking, in contrast with other traditional food process operations, since the complexity of the process makes very difficult the task of developing user‐friendly models. This work proposes two simple models to predict water loss variation during bread baking, based on knowledge about transport phenomena of the process. Implementation of the proposed methods needs simple adjustment of parameters, which can be related to operating conditions (oven temperature and apparent heat transfer coefficient). Besides, the construction of a baking diagram is discussed.