Influence of water and barley b-glucan addition on wheat dough viscoelasticity Adriana Skendi a , Maria Papageorgiou b , Costas G. Biliaderis a, * a Laboratory of Food Chemistry and Biochemistry, Department of Food Science and Technology, School of Agriculture, Aristotle University, P.O. Box 256, Thessaloniki 541 24, Greece b Cereal Institute, N.AG.RE.F, P.O. Box 60411, 57001 Thessaloniki, Greece article info Article history: Received 16 June 2009 Accepted 13 August 2009 Keywords: Dough rheology b-Glucan molecular weight Water content Creep-recovery Flour quality Response surface methodology Dynamic rheometry abstract The effects of the addition of two barley b-glucan isolates (0.2–1.0% of wheat flour), differing in molecular weight, and water (53–63% in a poor breadmaking wheat flour, cv. Dion, and 58–68% in a good bread- making wheat flour, cv. Yekora) on the viscoelastic properties of wheat flour doughs were investigated. A response surface model (CCF) was used to evaluate the effects observed on the dynamic and creep- recovery parameters of the dough. The evaluation was done separately for each combination of b-glucan isolate (BG1 of 10 5 Da and BG2 of 2  10 5 Da) and flour type. Besides the contents of b-glucan and water, the molecular size of the polysaccharide and the flour quality were important determinants of the dough’s viscoelastic behavior. Compared to BG1, the higher molecular weight b-glucan (BG2) brought about major changes on all the rheological responses of the fortified doughs. The addition of appropriate levels of b-glucans and water in the poor breadmaking cultivar (Dion) doughs could yield similar visco- elastic responses to those observed by a non-fortified good breadmaking quality flour dough (Yekora). Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Consumer concerns regarding healthy diets and convenience foods have significantly increased in the last decade. Nowadays, consumers are interested in the quality, nutritive value and safety of the products they eat. Cereal non-starch polysaccharides are considered as food ingredients with a significant impact on human health. The beneficial health effects of b-glucans, one of the major non-starch polysaccharides of cereal grains, include both serum cholesterol lowering and the insulin and glucose-attenuating effects (Behall, Scholfield, & Hallfrisch, 2004; Cavallero, Empilli, Brighenti, & Stanca, 2002; Kerckhoffs, Hornstra, & Mensink, 2003; Wang, Newman, Newman, & Hofer, 1992). The physiological improvements induced by b-glucans have been related to the abil- ity of these polysaccharides to increase intestinal viscosity (Wood, Weisz, & Blackwell, 1994). Two important factors among others that influence the viscosity of b-glucans are molecular weight and concentration of these polysaccharides (Lazaridou, Biliaderis, & Izydorczyk, 2003; Skendi, Biliaderis, Lazaridou, & Izydorczyk, 2003; Vaikousi, Biliaderis, & Izydorczyk, 2004; Wood, Weisz, & Blackwell, 1991). The potential use of b-glucans as fibre-enriching agents in breadmaking, mainly in the form of flour fractions that are isolated from various cereals, has been reported by different authors (Cavallero et al., 2002; Chaudhary & Weber, 1990; Izydorczyk, Hussain, & MacGregor, 2001; Knuckles, Hudson, Chiu, & Sayre, 1997). A major difficulty when dealing with flour fractions rich in b-glucans is their detrimental effect on the dough handling properties and the volume and the color of the fortified bread (Dhingra & Jood, 2004; Knuckles et al., 1997). These disadvantages together with the health benefits present a major challenge for the food scientists to produce b-glucan-enriched breads of comparable quality to white breads. Many authors have reported that due to the b-glucans ability to absorb high quantities of water, doughs fortified with b-glucans display a significant increase in the farinograph water absorption values (Cavallero et al., 2002; Knuckles et al., 1997; Skendi, Biliaderis, Papageorgiou, & Izydorczyk, 2009; Skendi, Papageorgiou, & Biliaderis, 2009). It is generally recognized that water plays the most important role on the viscoelastic properties of the dough during mixing; i.e. the distribution of the dough materials, their hydration, and the gluten protein network development strongly depend on the quantity of added water. Small deformation dynamic rheological tests and creep-recov- ery measurements are often employed for dough characterization and the derived rheological data are explored as predictors of breadmaking performance (Collar & Bollain, 2004; Edwards, Dex- ter, Scanlon, & Cenkowski, 1999; Edwards, Peressini, Dexter, & Mulvaney, 2001; Safari-Ardi & Phan-Thien, 1998). A previous study on the rheological behavior of b-glucan-enriched doughs prepared to achieve a maximum consistency of 500 BU (Brabender Units) has revealed the importance of flour quality, concentration and molecular size of the polysaccharide added (Skendi, Papageorgiou et al., 2009). In all previous works on breadmaking of fortified wheat doughs emphasis has been placed on the effect of added 0963-9969/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2009.08.012 * Corresponding author. Tel.: +30 2310 991797/991716; fax: +30 2310 991797. E-mail address: biliader@agro.auth.gr (C.G. Biliaderis). Food Research International 43 (2010) 57–65 Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres