Upcycling Broccoli By-Products: Formulation of a Novel Freeze-Dried Snack from Stalk Powder

In the contemporary food landscape, consumers increasingly seek snacks that combine convenience, sensory pleasure and demonstrable nutritional benefits. This trend aligns with global priorities regarding sustainability and food waste reduction, driving the industry to move away from ultra-processed formulations towards functional, eco-responsible alternatives. Within this context, the valorisation of plant-based by-products is a vital strategy for the circular economy. This study focuses on broccoli stalks (Brassica oleracea var. italica), an under-exploited biomass rich in dietary fibre, protein and phenolic compounds, all recognised for their antioxidant and anti-inflammatory properties. An innovative snack prototype was developed by incorporating freeze-dried broccoli stalk powder, resulting in an enhanced nutritional profile: high fibre (33.73 g/100 g) and protein (24.30 g/100 g), with moderate energy density (295.33 kcal/100 g). Results demonstrated microbiological and bioactive stability over four months, with no significant losses in total phenolic content, antioxidant capacity, or α-glucosidase inhibitory activity. These findings substantiate the product’s classification as a functional snack. This research underscores the dual significance of broccoli stalk valorisation: mitigating agri-food waste and promoting public health through the transition towards more circular, sustainable and resilient food models.