Prediction of proteins technological quality of composite flour with non-traditional products

Fortification of wheat flour by different plant materials should fulfil two aims - to enrich offered final products portfolio and to balance nutrition score of wheat flour-based goods. The era of forgotten foreign even frequently oversea plants is partially on retreat, and crops domestic on the Europe continent take the battalion. Undoubtedly, such materials represent barley or linseed; both are rich donors of dietary fibre, the latter also of unsaturated fatty acids. Seeds of linseed could be used as they are, or milled into whole (full-fat) flour. More efficient utilisation seems to be separation of the oil and producing the press-cake flour, so-called linseed fibre. Application of such plant, naturally gluten-free material may bring some technological difficulties, so prediction of protein quality is in place. Traditionally, the Zeleny sedimentation test is used for this purpose, and a modern method represents the solvent retention capacity profile. The presented work offers a statistical comparison of both analytical methods to predict protein quality in flour tri-composites based on wheat flour-linseed fibre premix (both golden and brown linseed applied). Tested non-traditional materials were wholemeals from dark chia, yellow quinoa and brown-red canahua seeds plus nopal flour, added into premix up to 10 wt. % (32 tri-composite samples). For the Zeleny test, its robustness to quantify protein quality was confirmed, and the combined effect of the non-traditional crop type and the addition level was verified as principal. Retention capacities depended mainly on the complete triple of the studied factors. By cluster analysis, potential to specify differences in protein quality for wheat flour composites was confirmed for the retention capacity of lactic acid.