**6. Summary and future perspectives**

As awareness grows around the sustainability impacts of food waste, investigation into technologies that increase the value of by-product resources becomes more salient. Extrusion processing is one such technology that has been proposed to upcycle biomass by-products into higher value food across a range of different product types. This chapter explores the challenges and opportunities associated with the incorporation of by-products into extruded food products, in addition to case studies that share success stories of commercialised products that incorporate biomass by-products. Lastly, the emerging industry of insect protein is introduced as an opportunity for waste valorisation and sustainable food production.

Looking ahead, there are several important areas for future exploration in the field of extruded food development incorporating by-products. Firstly, addressing the logistical challenges related to the collection and transport of by-products is crucial. Investing in manufacturing hubs located strategically at regional waste generation hotspots could facilitate the transformation of low-value by-products into valuable resources, promoting a transition to a circular economic model. In addition, more focus needs to be place on strategies to overcome the issue of low radial expansion when incorporating by-products. Currently, the level of by-product addition is limited by this issue, which creates uncertainty around the value proposition of byproduct incorporated snacks if their functional properties degrade above 5% addition.

Overall, addressing these challenges and taking advantage of emerging opportunities in this area will require enhanced collaboration and knowledge exchange between stakeholders across the food supply chain, including primary producers, postproduction, primary food processing industry, waste management sector, consumer markets, and research institutions covering this topic. Extruded food manufacturers will have to integrate into existing activities in this space to overcome challenges include by-product transportation and logistics, food safety, and product acceptance.

*From Biomass to Biobased Products*
