UNLABELLED: This work was aimed to investigate the effects of three factors on cookie quality: brewers' spent grain (BSG) composition [65% malted barley and 35% of unmalted durum (DA) or soft (RI), or emmer (EM) wheats]
geographical origin of the cereals used in brewing (Daunia or Salento)
and percentages of BSG in cookie formulation (30 or 40%). A control made of 100% Manitoba flour was produced. Statistical analyses were performed to evaluate the effects of those factors (Analysis of Variance), the possibility to distinguish the various types of cookies (Principal Component Analysis), and the relationships among variables (Pearson Correlation Analysis).The single and interactive effects of the three factors were significant for almost all variables. Cookies with 40% EM spent grains showed the highest ash, dietary fibre, and total phenolic contents but cookies with 30% DA or RI spent grains received the highest overall quality scores due to the higher intensity of their fresh baked flavour and their lower hardness and fibrousness. Based on the nutritional and sensory characteristics, cookies fortified with RI and DA were the best to consume. Although few physicochemical differences can be attributed to geographical origin, a slightly higher overall sensory score was assigned to those produced with Salento cereals. Principal Component Analysis showed a clear separation between the control made of 100% Manitoba flour and the group of fortified cookies. Among the latter, the cookies produced with RI and DA spent grains were indistinguishable from each other due to their similar quality characteristics. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-024-06064-3.