Proteins on Steel

Physical (protein/mineral) fouling – and subsequent cleaning – are important sustainability and cost factors of many processes in the food industry. On average fouling is responsible for more than 50% of the carbon footprint of food processing and 10 to 20% of the production costs. Excessive or premature fouling during heat treatment results in unnecessary down-time, reduction of production capacity, additional product loss and extra cleaning. Most existing heat treatment and cleaning processes are not optimal and, in case of new or adapted formulations, unexpected fouling behaviour is often observed. The latter problem is often related to the fact that protein – containing products are increasingly complex, such as specialty foods for infants, elderly and athletes, often combining added vitamins and minerals and proteins from multiple sources. Adequately addressing the challenges presented by these products requires extension of the insight into the mechanisms of fouling and cleaning. More specifically, knowledge gaps with respect to protein adsorption mechanisms causing the onset of fouling and the mechanisms responsible for subsequent fouling layer formation caused by heat induced effects on components and interactions between components resulting in wall deposition, need to be addressed.

To examine these phenomena in detail an innovative lab scale fouling device will be developed that can be used to measure the fouling and cleaning behaviour (i.e. fouling layer thickness and composition as a function of time and subsequent fouling layer removal) for different formulations at a range of industrially relevant processing conditions. The onset of fouling by protein adsorption will be investigated on molecular level by applying a range of spectroscopic and microscopic techniques using samples produced by the lab scale fouling device under industrially
relevant conditions . Finally, predictive models incorporating observed mechanisms responsible for the onset of fouling and subsequent fouling layer formation will be developed and validated. This will also facilitate future deployment of the knowledge acquired in this project for cases.

The outcome of this project enables science based improvement of heat treatment and cleaning processes. Benefits for existing productions include increased runtime, energy savings, minimal cleaning time and costs, reduced of product loss, reduced water usage and increased production capacity. In case of new product development, the project outcome can be used for a priori prevention of fouling and cleaning issues. This will prevent costly trial-and-error experimentation and unnecessary down time and will significantly reduce time to market for new products. Finally, the project results can also be used to improve the design of heat treatment equipment, wall pre-treatment and materials, and cleaning processes. This will results in further increase in runtime, reduction of cleaning time and operational costs.