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 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.
This study documents white rice flour effect on chemical composition and rheological behaviour of wheat flour. Within Europe, laboratory prepared wheat-rice bread and biscuits represent innovation in bakery products manufacturing. Study brings knowledge of 15% and 10% of rice flour in bread and biscuits recipe should be accepted by consumers.
Goffman, F., S. Pinson and C. Bergman, 2003. Genetic diversity for lipid content and fatty acid profile in rice brain. Journal of Agricultural and Food Chemistry, 80(5): 485-490.
Lee, C.Y., S.K. Kim and P.E. Marston, 1979. Rheological and baking studies of rice-wheat flour blends. Korean Journal of Food Science and Technology, 11(2): 99-104.
Nakamura, S., K. Suzuki and K. Ohtsubo, 2009. Characteristics of bread prepared from wheat flours blended with various kinds of newly developed rice flours. Journal of Food Science, 74(3): 121-130.
Nicoli?, N., N. Radulovi?, B. Momcilovi?, G. Nikoli?, M. Lazi? and Z. Todorovi?, 2008. Fatty acids composition and rheology properties of wheat and wheat and white or brown rice flour mixture. European Food Research and Technology, 227(5): 1543-1548.
Noomhorm, A., D.C. Bandola and N. Kongseree, 1994. Effect of rice variety, rice flour concentration and enzyme levels on composite bread quality. Journal of the Science of Food and Agriculture, 64(4): 433-440.
Reyes-Aguilar, M.J., P. Palomo and R. Bressani, 2004. Development of bakery products for greater adult consumption based on wheat and rice flour. Achivos Latinoamericanos de Nutricion, 54(3): 314-321.
Sabanis, D. and C. Tzia, 2009. Effect of rice, corn and soy flour addition on characteristics of bread produced from different wheat cultivars. Food and Bioprocess Technology, 2(1): 68-79.
Seyam, A.M. and F.C. Kidman, 1977. Rheological properties and bread quality of wheat and rice starch composite flours. Staerke, 28(6): 216-220.
Švec, I., M. Hrušková, J. Blažek and O. Jirsa, 2004. Baking parameters of wheat variety from international breeding test. Getreidetechnologie, 58(3): 145-151.
Takano, H., 1984. Development of novel processed rice products. Report of Research Project of Research Council of Agriculture, Forestry and Fisheries, Japan, No. 161. pp: 117-130.
Takano, H., Y. Koyanagi and Y. Takana, 1980. Bread making properties of rice flour. II. On the fermentation properties of wheat flour-yeast dough mixed with rice flour and its change in sugar content during fermentation. Journal of the Japanese Society for Food Science and Technology, 27(10): 522-528.