Valorisation potential and challenges of food side product streams for food applications: A review using the example of Switzerland

Food processing generates significant quantities of side streams or by-products, which often pose challenges for waste management and environmental sustainability. Concretely, most of the roughly 1 million tonnes of food losses generated annually in Switzerland in the food processing industry represent side streams. However, these side streams contain valuable components that could be harnessed through valorisation processes, leading to the development of a more efficient circular economy in the food industry. This review paper focuses on the application of side stream valorisation in the food sector. It provides a comprehensive overview of benefits and challenges of side streams in general and a deeper insight for 14 side streams representing different key food categories with the exception of meat products. The selected side streams are either available in high quantities or cause an especially high ecological impact. Further, a guiding protocol is suggested that supports food processors in assessing the key challenges of their side stream products for valorisation. Lastly, the review gives insight into the status of technological advancement in side stream valorisation necessary to promote sustainability and resource efficiency in the food industry, and an overview of commercially available products containing side streams.