Potravinarstvo Slovak Journal of Food Sciences Volume 12 202 No. 1/2018 Potravinarstvo Slovak Journal of Food Sciences vol. 12, 2018, no. 1, p. 202-208 doi: https://doi.org/10.5219/888 Received: 9 February 2018. Accepted: 1 March 2018. Available online: 21 March 2018 at www.potravinarstvo.com © 2018 Potravinarstvo Slovak Journal of Food Sciences, License: CC BY 3.0 ISSN 1337-0960 (online) THERMO-MECHANICAL PROPERTIES OF DOUGH ENRICHED WITH WHEAT BRAN FROM DIFFERENT WHEAT VARIETY Michaela Lauková, Jolana Karovičová, Zlatica Kohajdová, Lucia Minarovičová ABSTRACT Wheat bran is the by-product derived from the wheat milling and represents a good source of dietary fiber. Consumption of wheat bran is associated with many health benefits. The hydration properties (water holding, water retention and swelling capacity) and oil binding capacity of bran from various wheat variety were investigated. It was showed that the water holding capacity of bran ranged from 2.27 to 2.98 g.g -1 , which were approximately four times higher compared to wheat flour. Also, it was observed that commercial wheat bran was characterised with the highest swelling capacity (5.21 mL.g -1 ) and the lowest water retention and oil binding capacities (1.38 and 1.35 g.g -1 , respectively). Mixing and pasting properties of wheat dough with addition of bran at different level (5, 10 and 15%) were studied using Mixolab. From the results it was concluded that water absorption and dough development time increased with addition of different bran, while dough stability decreased. Moreover, with increasing addition level of different bran significantly affected the thermo-mechanical properties of wheat dough. The lowest effect on protein weakening was found after addition of spelt bran. The higher starch pasting ability of enriched dough was recorded after incorporation of bran from crossbreed Lubica. Furthermore, it was found that dough enriched with the commercial wheat bran was characterized by the lowest values of C3 (lower starch pasting ability), C4 (lower stability of hot formed gel) and C5 (lower starch retrogradation) parameters. Keywords: wheat bran; spelt bran; functional properties; dough rheology; Mixolab INTRODUCTION Triticum aestivum L. is one of the major crop worldwide and mainly in the Mediterranean-type temperate zones, it is used for production of staple food (Gotti et al., 2017). The quality of wheat is genetically conditioned and influenced by soil conditions, climate, technology, diseases and pest attack. Therefore, in order to have the chance to harvest quality wheat it is absolutely necessary to cultivate a variety that has the potential to develop that quality and for people to provide conditions for the wheat to achieve its potential (Constantinescu et al., 2011). Interest in the development of dietary fiber enriched foods has grown significantly as a result of increasing health awareness among consumers and food industry. As a complement of wheat flour in milling, one of the most obvious sources of dietary fiber in the baking industry is wheat bran (Jacobs et al., 2015). Wheat bran is mainly composed of epidermis, peel, seed, nucellus layer, and aleurone layer (Yan et al., 2015). Regarding the different types of bran fraction, there are quantitative and qualitative differences among the different cereal grains. Different types of bran have a different chemical composition; it depends on grain genetics, the agricultural background, and the milling process (Jefremova et al., 2015). The wheat bran is rich in total dietary fiber (36.5 – 52.4%, w/w), and >90% of that is water-insoluble, thus the wheat bran might have significant prebiotic and antioxidant activities in lowing the risk of cardiovascular diseases, and provide the best protections against tumor, cancer and neurodegenerative diseases mainly because of the phenol compounds (Jefremova et al., 2015). However, addition of bran has negative consequences on bread volume and organoleptic properties, depending on wheat cultivar, particle size, and the other treatment applied to bran (Gómez et al., 2011). Rheological tests on dough can predict their behaviour in a bakery, although only if the applied stress and the extent of the deformation are in the same range as those encountered during dough processing (Rodriguez- Sandoval et al., 2012). The traditional instruments, which provide practical information for the cereal industry, measure the power input during dough development caused by a mixing action (farinograph, mixograph) and determine the extensional deformation of a prepared dough (extensigraph, alveograph) (Minarovičová et al., 2017). Mixing and pasting properties of wheat flour dough can be