Changes in Baking Quality of Composite Wheat/Hemp Flour Detected by Means of Mixolab

The quality of wheat-hemp composites prepared with different amounts of hemp flour (5, 10, 15 and 20%) was characterised by the mixolab rheological test. The present study is related to three defatted hemp flour types addition, K1 and K2 gained from seeds bred conventionally, and K3 in bio-planting regime. Wheat flour of good baking quality was provided by a Czech commercial mill. Besides the mixolab profiles, basic baking quality parameters were also determined. By analytical methods, protein content, Zeleny's value and Falling Number were determined. Dough baking quality was tested with the help of three rheological apparatuses, namely farinograph, extensigraph and amylograph. Moreover, laboratory baking test was performed, and specific bread volume was calculated. Mixolab torque data was strongly affected by substitution level than hemp flour type. The most precise distinguishing of samples was observed during the mixing and starch retrogradation phases of the test. Correlation analysis confirmed proper relationships between mixolab and rheological parameters related both to protein properties (C1, C2, C1-C2 vs. farinograph and extensigraph ones) and starch or starch gel properties (C3, C4, C5 vs. amylograph ones). In the former case, the strongest relationship was found between C1 and the dough development time (-0.80, p < 99%), while in the latter between the amylase activity estimation (C3-C4) and the amylograph viscosity maximum (-0.87, p < 99%). Bread specific volume could be predicted by all five basic mixolab C's. The best fitting correlation was found for C3 readings (starch gelatinization rate, r = 0.87, p < 99%), while links of C1 or C2 (maximum torque as gluten strength and protein weakening) were softer (r - 0.73 and 0.70, respectively, p < 99%).