Wheat bread enriched with raspberry and strawberry oilcakes: effects on proximate composition, texture and water properties

Oilcakes from the oilseed industry are rich in dietary fibre and protein by-products. We assessed the impact of wheat flour replacement with raspberry and strawberry oilcakes on the proximate composition of bread, colour, texture and water behaviour. The substitution influenced the ash, fat and protein content causing an increase in the content of each of the analysed macronutrients. The crumb colour components (CIE L*a*b*) were shifted toward red while the saturation of yellow decreased. Texture analysis showed that the hardness and chewiness of crumb with oilcakes increased as well as springiness decreased. It was found that flour substitution with oilcakes limited significantly water transport and also influenced the molecular dynamics of water in the bread crumb. H-1 NMR measurement results of relaxation times demonstrated that the free water in relation to the bound water in the examined systems depended on the amount of the flour replaced by the oilcake, as well as on the botanical origin of the oilcakes.