Antioxidant capacity, arabinoxylans content and in vitro glycaemic index of cereal-based snacks incorporated with brewer's spent grain

•Brewer's spent grain (BSG) addition in cereal-based snacks increased antioxidants.•Phenolic content increased 4 fold in extruded snacks and 7 fold in breadsticks.•BSG addition (20-25 g/100 g) in extruded and baked snacks increased arabinoxylans.•Breadsticks with medium glycaemic index (63) obtained with BSG addition (35 g/100 g).•Cereal-based snacks richer in antioxidants and fibre and with low glycaemic index.

Extruded snacks and breadsticks were formulated with increasing levels of brewer's spent grain (BSG). The phenolic content increased by 4 and 7 fold with BSG addition in extrudates (40 g/100 g) and in breadsticks (35 g/100 g), respectively. Consequently, antioxidant capacity (DPPH, FRAP) also increased despite a recorded loss of phenolic compounds in extruded snacks. Arabinoxylans content increased up to 20 and 25 g of BSG addition/100 g of formulated extruded snacks and breadsticks, respectively. Further addition of BSG did not improve the content of arabinoxylans due to the possible formation of polysaccharide-protein complexes. Medium GI breadsticks were obtained with 35 g of BSG incorporation/100 g formulation. Phenolic content, arabinoxylans content and antioxidant capacity increased in the final products with BSG addition while the glycaemic response decreased. BSG can be incorporated as an ingredient in the formulation of extruded snacks and breadsticks generating products richer in antioxidants and fibre and with low GI.