Technological quality changes of wheat flour were studied in relation to its partial replacement (5, 10, 15, 20, 25 or 30%) by white rice flour (RF). In dependence on level added, RF lowered water absorption up to about 10%. Dough stability was multiplied reversely as well as its overmixing tolerance -softening degree of dough lessened from 60 Brabender units (BU) for wheat flour to 20 BU for wheat-rice flour blend 70:30. Baking quality of flour composites was worsened owing to changes in dough

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... elasticity and extensibility (i.e. dough machinability), summarised by extensigraph energy (as an area under curve) decrease from 140 cm2 to 70 cm2 comparing the same samples. Gelatinisation temperatures and amylograph maxima reversely increased -optimal values were recorded for wheat:rice composite 80:20 yet (viscosity between 575 -790 BU). Fermentation process was affected equivocally -gases volumes had increased up to about 11% because of glucosidase present in RF, but dough volumes lowered due to gluten net weakening. It resulted into lowering of control bread volume to a half for the bread containing 30% of RF (from 319 to 154 ml/100 g, respectively). Bread crumb chewiness was affected seriously; bread samples higher level of RF than 20% were less acceptable (fall of crumb penetration from 10.6 mm to 2.2 mm). Quality changes of biscuits containing RF were of smaller extent -the substitution of 5% caused specific volume increase about ca 15% (from 143 to 203 ml/100 g). Sizes of other fortified biscuits were gradually diminished to level of the wheat control ones. Volumes of control and WRF5 composite bread could be considered as comparable with respect to measurement repeatability. Sizes of composite bread richer in RF were affected seriously (diminishing approximately about 51%), but differences between WRF20, WRF25 and WRF30 bread samples were found to be non-significant (Table 1a) . Within the tested set, BrS values were statistically indifferent − it ranged from 0.60 to 0.52 (W vs. WRF5 and WRF30, respectively; Table 1a ). Measured PEN values corresponded with oven rise bread volume well (Fig. 2) . Verifiable differences were found between samples W-WRF5, WRF10-WRF15 and WRF30. However, the PEN lower than 5-7 mm represents very firm crumb, unacceptable by consumers. Sensory profiles of enhanced bread were worsened by higher RF ratio in recipe, too − proportion of visually noticeable rough crust and a rate of sandy/chalky taste increased. Quantified, standard and WRF5-WRF10 bread reached common quality (11-12 points at minimum of 9). Further, WRF15 and WRF20 bread had a somewhat worse score (14 and 17 points, respectively), while profile of WRF25 and WRF30 ones approach to bread of unacceptable quality (20 and 21 points; maximum of 27). Lee et al. (1979) reported the BrV decrease from 780 cm 3 (control wheat bread) to 720, 685 and 650 cm 3 for wheat-rice composites of 90:10, 80:30 and 70:30 (w/w) (i.e. diminishing about 8%, 12% and 17%, respectively). Total sensorial score of these bread samples have been worsened about 5%, 14% and 25%, respectively. However, Nakamura et al. (2009) valued as still acceptable bread prepared from wheat-rice composites 70:30 and 60:40, respectively. Biscuit Quality Biscuit recipe enhancement by RF was reflected in product size similarly to bread. Biscuit volumes containing WRF5 or WRF25 and WRF30 were verifiably distinguished from the others (Table 1b) . Considering the BiV repeatability, all differences were provable slightly. The BiS was partially improved by all tested RF additions, but observed differences were insignificant. Biscuit colour was in all cases defined as typical, light beige tint, so effect increasing RF portion in biscuits was not proved. Taste of biscuits up to 10% of the RF was typical and adequate for that type of biscuits. Baking powder taste could be identified in the other tested samples (WRF15-WRF30), which has increased to nearly unpleasant intensity. Reason for this could be an incomplete activity of NaHCO3, which led to lower biscuit volumes, too. There is a similarity to bread profile determination -consumer's quality of WRF15 and others composite bread was provably worse than one of bread prepared according to standard formula (pure wheat) and with WRF5 or WRF10 flour composites. White rice flour affected dough machinability by protein elasticity increase and extensibility diminishing. It resulted into bread volume lowering as well as crumb hardening without effect on buns vaulting. Sandy by-taste was tolerable to 15% of rice flour. Prepared biscuits have acceptable overall quality up to 10% of rice flour only.