Abstract : Interest of consumers in natural, unconventional and nutritional foods led to the development of new specialty foods based on grain blends. Components of such foods are often so-called „ancient wheats“ which were never the subject of modern breeding programmes. Grain amaranth provides an ideal amino-acid composition for human consumption and therefore interest in fortifying wheat flour is evident. Composite fours were prepared by mixing spelt flour (Tr. spelta L.) with amaranth flour at substitution levels of 5, 10, 15 and 20 % (w/w). Pure spelt flour was used for comparison. Indirect baking parameters and rheological properties of dough were investigated in four replicates.  Wet gluten content was determined according to ICC Standard No 155 by the Glutomatic 2200 (Perten), sedimentation index – Zeleny Test according to ICC 116/1 and ISO 5529, extensibility of gluten was determined using STN 461011-9. To assess the rheological properties of composite flours, Brabender farinograph and standard procedures ICC No 115/1 was used. The following parameters were derived from farinographs: water absorption, stability, softening of the dough, quality number. The analyses were performed in four replicates. Wet gluten content, its extensibility and sedimentation values are indicators related to the baking quality of flour. The content of wet gluten in spelt flour was very high (42.7%) and substitution of spelt four with amaranth flour significantly and proportionally lower its content in composite flours. With increasing share of amaranth flour increased the gluten extensibility from 16.7% (pure spelt flour) to 20.7 cm (20% amaranth flour). The water absorption of composite flour increased with amaranth substitution rate also the stability time increased and was the highest for 20% amaranth rate (not significant). Significant improvement of quality number was observed with increasing rate of substitution. The amaranth addition to blends improve some indirect baking quality properties and rheological properties of flour. Amaranth can be attractive as blending source for processed food fortification for its high quality proteins, relatively high fat content, iron content, resulted in improvements of amino acid balance of baked products.
spelt – amaranth composite flour, technological properties
Presentation: oral