The effect of ascorbic acid on the rheological properties of wheat fermented dough from forty three wheat flour samples, represented two groups of flours, characterised (according to the ash content, protein content and Zeleny sedimentation value) the main Czech flour type has been studied. Standard analytical parameters (ash and protein contents, wet gluten, falling number, Zeleny sedimentation value), rheological investigation (maturograph, oven rise recorder), and laboratory baking test were used for the characterisation of flours and doughs. It was stated that the influence of the ascorbic acid addition on the fermented dough behaviour depends on the flour composition particularly in the proofing stage. Oven rise characteristics of dough and specific bread volume revealed smaller changes without significant differences between flours with lower (up to 0.6%) and higher (up to 0.7%) ash contents. An important correlation (r = 0.51-0.68) significant at 0.01 level has been found between specific bread volume and final rise of dough.

Grain hardness of winter wheat cultivars was evaluated during 1997-2001 using several methods: wheat hardness index WHI (DO-Corder Brabender), 0.140 mm sieve threw ratio PPS (DO-Corder Brabender), grain hardness by NIR (Inframatic 8611 Perten), particle size index PSI (LM 3303 Perten). All tested methods showed varietal (genetic) origin of grain hardness trait and it is possible to use these methods for grain hardness determination. NIR method have had the lowest coefficient of variation (12.6%), WHI and PSI coefficient of variation was 32.8 and 30.6%, respectively. A significant influence of year-class was found only for PPS method. A high value of correlation coefficient was found between methods: WHI × NIR (r = 0.84), WHI × PPS (r = -0.79), and NIR × PPS (r = 0.74). During 2000-2001 was correlation coefficient r = -0.93 for PSI × NIR. The coefficient of variation for PSI method was 28.5%.