Heat-induced denaturation and aggregation of protein in quinoa (Chenopodium quinoa Willd.) seeds and whole meal

[Display omitted] •Physical barriers hinder extraction of 20–25% of protein from quinoa whole meal.•Maximally 37% of seed proteins form SS-linked covalent aggregates during boiling.•11S Globulin monomers which easily dissociate are most prone to aggregate.•Albumins do not aggregate but partially leach into the boiling water.•Presence of disrupted food matrix constituents hinders protein aggregation. Physical barriers hinder about 20–25% of the protein from being extracted from whole meal. Heat-induced denaturation and aggregation of protein in quinoa seeds and in whole meal was investigated. Maximally 37% of the protein in seeds covalently aggregate when boiling for 15 min. Although embryonic cell walls surrounding protein bodies remain intact during boiling of seeds, protein aggregation is not hindered. 11S Globulin monomers first dissociate into their acidic and basic subunits which further assemble into large (> 500 kDa) mainly disulfide-linked aggregates. 2S Albumins are not involved in covalent aggregation but partially leach during seed boiling. The presence of disrupted food matrix constituents in whole meal delays denaturation and causes less aggregation of protein in whole meal than in seeds. Globulins still dissociate into their subunits but less and mainly small covalent aggregates (ca. 100–500 kDa) are formed. These novel insights allow developing new quinoa-based food products.