Effect of glucose oxidase addition on the textural characteristics of wheat-maize dough and bread

a ISSN 0101-2061 (Print) ISSN 1678-457X (Online) Food Science and Technology DDOI: https://doi.org/10.1590/fst.27117 Effect of glucose oxidase addition on the textural characteristics of wheat-maize dough and bread Jean Didier KOUASSI-KOFFI1,2, Alina STURZA1, Adriana PĂUCEAN1, Simona MAN1, Andruța Elena MUREȘAN1, Georgiana PETRUȚ1, Vlad MUREȘAN1*, Sevastița MUSTE1 Abstract The aim of this study was to assess the effect of adding glucose oxidase (GOX) on wheat-maize dough and bread textural characteristics. It strengthens the importance and need of replacing wheat flour with maize flour in regions where extensive cultivation of wheat is not possible. For improving the rheological properties of bread, GOX was added to wheat and wheat-maize flours. Wheat and maize flours were used in several ratios, but the best results were obtained for (on flour basis): 80:20, 75:25, 70:30, where the highest values correspond to the wheat flour. Wheat-maize dough and bread volume were slightly influenced by GOX addition. Dough strength was higher in the case of dough without GOX addition than the samples enriched by GOX, while crumb strength of GOX enriched maize bread was higher than the samples without GOX. The obtained data might be useful for future studies, while it was demonstrated here the effect of GOX addition on wheat-maize dough and bread. Keywords: dough rheology; bread freshness and hardening; glucose oxidase; maize flour. Practical Application: Enhanced wheat-maize bread for countries where extensive wheat cultivation is not possible. 1 Introduction Bread is one of the oldest and popular foods of mankind, being a good source of calories. This product is obtained mainly from wheat flour, water, yeast and salt (Dewettinck et al., 2008), but not all geographic areas allow the extensive cultivation of wheat, because of climate, soil etc. Among the cereal flours, only wheat flour forms viscoelastic dough when mixed with water. The viscoelasticity is determined by gluten proteins which are water compatible and thus, swell and interact. The gluten protein network develops and sets generally in wheat-based food. The nonlinear viscoelastic behavior of wheat flour dough is mainly due to the continuous gluten matrix and starch granules embedded in it. It has typical properties of both solid and liquid bodies, and an intermediary rheological behavior between the ideal solid and fluid bodies. Therefore, an accurate characterization of the dough requires rheological measurements (Banu et al., 2011). The functional properties of bread dough greatly depend on the proteins forming the gluten network (Caballero et al., 2005). Prominent reactions include sulfhydryl (SH) oxidation and SH-disulfide (SS) interchange, which lead to SS cross-links. Other covalent bonds are also formed. The type of protein being cross-linked appears to be more important than the type of cross-link formed and it is highly correlated with the character of qualitative changes in the final product. The HMW (high molecular weight) glutenin subunits are correlated with the strength of gluten network and the bread volume, while albumins and globulins are more important for textural and crumb grain properties (Caballero et al., 2005). During baking, starch gelatinisation and pasting and heat-setting of gluten proteins occur, resulting in the typical solid foam structure of baked bread (Sievert et al., 2007; Steffolani et al., 2012). These unique properties account for wheat, which is cultivated in large quantities throughout the world (Day et al., 2006). Although, the knowledge about its chemistry and rheology has expanded enormously during last decades, the reactions responsible for the dough and gluten formation are still challenging. Maize is the main cereal grain as measured by production, but ranks third as a staple food after wheat and rice (Gwirtz & Garcia-Casal, 2014). The maize flour is gluten free and can be used in bakery as a low-priced, nutritive and tasty additive (Bilgiçli et al., 2006); in United States of America and other countries (Canada, France, Germany, England, Spain), different types of maize are used in bread making, animal feed, fuel and beverage (e.g. ethanol production) (Rose et al., 2010). Enzymes are used in bread making for optimizing different quality aspects of bread (Steffolani et al., 2010). Glucose oxidase (GOX) (β-D-glucose: oxygen: 1-oxidoreductaze; EC 1.1.3.4.) is an enzyme obtained from different fungal sources, mainly from Aspergillus niger (Singh & Verma, 2013; Kerman et al., 2014). GOX is used for many industrial applications: in baking, dry Received 25 Aug., 2017 Accepted 18 June, 2018 1 Food Engineering Department, Faculty of Food Science and Technology, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Cluj, Romania 2 Unité de Formation et de Recherche en Science et Technologie des Aliments, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire *Corresponding author: Food Sci. Technol, Campinas, 39(1): 127-133, Jan.-Mar. 2019 127/133 127 Textural characteristics of wheat-maize dough and bread egg powder production, wine, gluconic acid production, etc. (Wong et al., 2008), being generally recognized as safe (GRAS) under Food and Drug Administration (FDA) classification (Food and Drug Administration, 2002). Various oxidizing agents are used into bakery formulations where the gluten network is too weak to exert its optimum activity; therefore, one of its purposes is to strengthen gluten, thereby, improving the bread’s final volume and texture (Decamps et al., 2012). Traditionally, potassium bromate (KBrO3) was used (Figoni, 2003), but its use has been banned in many countries after being recognized as a carcinogen (Moore & Chen, 2006). Nowadays, a safe alternative such as GOX is used in bakery (Hanft & Koehler, 2006; Bonet et al., 2006); it is an effective oxidant to produce bread with improved texture and increased loaf volume (Vemulapalli et al., 1998; Rasiah et al., 2005). In the meantime, GOX is known to cause cross-linking of dough protein (Rasiah et al., 2005) and exerts effects such as reducing the sulfhydryl content as well as increasing viscosity in the water soluble portion of dough (Vemulapalli & Hoseney, 1998). Consequently, the aim of this study was to assess the effect of adding glucose oxidase on wheat-maize dough and bread textural characteristics. To reach to this objective, GOX was added to the bread dough in order to improve its rheological properties, while maize flour addition ranged from 20% to 30%; the optimum level of maize flour addition being also tested. 2 Materials and methods 2.1 Materials All-purpose wheat flour (type 550) variety “Apache” obtained from Boromir Group (Romania) was used without any chemical or proteins supplementation (12.3 wt % water, 11.6 wt % proteins and 0.58 wt % ash (moist basis). White maize flour sweet variety was obtained from a local market in Abidjan, South-western Ivory Coast, also withou (...truncated)