DOI: 10.11118/978-80-7701-048-1-0248

PREDIKCE TECHNOLOGICKÉ KVALITY LEPKU PŠENIČNO-ŽITNÝCH A ŽITNO-PŠENIČNÝCH SMĚSÍ / PREDICTION OF THE TECHNOLOGICAL QUALITY OF GLUTEN OF WHEAT-RYE AND RYE-WHEAT MIXTURES

Ivan Švec¹, Petra Smrčková¹

¹ Ústav sacharidů a cereálií, Fakulta potravinářské a biochemické technologie, VŠCHT v Praze, Technická 5, 166 28 Praha 6 – Dejvice

The technological quality of gluten in binary blends from wheat white flour (Pš) and rye bread flour (ŽCh), or rye wholemeal one (ŽCz) was determined using our own modification of the Gluten Index (GI; method AACC 38-12.02). During standard washing of gluten from aqueous suspensions 90Pš : 10ŽCh and 90Pš : 10ŽCz on the Perten’s Glutomatic device, the sieve was clogged with swollen rye arabinoxylans. An alternative extraction procedure was created based on the internationally established method Retention Capacity Profile (SRC, AACC 56-11.01). The quality of the control wheat flour sample corresponded to the "strong gluten" category, since the values of both the standard and modified GI were higher than 80% (GI 90.07 ± 4.24; GI_modif 82.20 ± 0.01). As expected, the higher proportion of rye flour in the binary mixture, the lower GI_modif value. For the 50Pš:50ŽCh mixture and ŽCh alone, the GI_modif values were 47.33 ± 0.02 and 17.60 ± 0.02, respectively; for the wholegrain counterparts, these values were 48.05 ± 0.02 and 28.22 ± 0.02. The increased quality of rye wholegrain flour and its blends is apparent only – the higher GI_modif values can be attributed to the absorption capacity of linear arabinoxylans, present in a higher portion. The accuracy of the prediction by a linear regression analysis was satisfactory for both 2 separate sets of 11 samples (R² = 0.963 and 0.971).

Keywords: wheat flour; rye flour; bread flour; wholegrain flour; binary mixture; gluten quality; Gluten Index; correlation; regression

pages: 248-255, online: 2025