Relationship between gluten-free dough properties and bread quality: effect of different additives

LORENA S. SCIARINI; PABLO D. RIBOTTA; ALBERTO E. LEÓN; GABRIELA T. PÉREZ

Santiago de Chile

Conferencia; II Conferencia Latinoamericana ICC; 2011

ICC- GRANOTEC

The objectives of this work were to evaluate the effect of different additives on gluten-free batter and bread characteristics formulated with low water content, and to relate batter properties to bread quality parameters. Bread formulation included (flour basis): rice flour (45%), cassava starch (45%), active soy flour (10%), water (65%), shortening (2%), salt (2%) and yeast (3%). Additives used were hydrocolloids (xanthan gum -XG-, carboxymethylcellulose -CMC-, alginate -Al- and carrageenan -C-), proteins (whey protein concentrate -WPC- and powdered whole egg -PWE-), emulsifiers (DATEM and SSL) and enzymes (glucose oxidase -GOX- and a-amylase -Am-). Batters were characterized using large and small deformation tests by means of a penetration test (TA-XT2i texturometer); and frequency sweep (oscillatory rheometer, Anton Paar). Batter calorimetric properties (gelatinization and retrogradation) were studied using a differential scanning calorimeter (DSC). Bread quality was determined evaluating bread specific volume (BSV), crumb hardness, staling rate and crumb structure. To determine the association between different parameters, Pearson coefficients were obtained. As breads with hydrocolloids were formulated with 75% water, which resulted in higher bread quality, it was expected that batter resistance under large deformation conditions was not modified (control batter was made with 65% water). Only C addition resulted in higher G’, G’’ and viscoelasticity (lower tan delta values). C and CMC addition led to higher BSV, while all hydrocolloids diminished crumb hardness and staling rate. XG and C led to crumbs with an opener structure. Although protein incorporation increased G’ and G’’, batter resistance was not increased. Protein addition slightly enhanced BSV, whereas crumb hardness and staling rate were augmented by PWE addition though enthalpy for amylopectin retrogradation was higher for breads with WPC. Crumb structure was not significantly changed. SSL increased batter resistance while it was decreased by DATEM; nevertheless, both emulsifiers increased dynamic moduli and DATEM presence diminished tan delta, indicating higher viscoelasticity. Unexpectedly, emulsifier addition did not reduce amylopectin retrogradation. Neither emulsifier presence increased BSV, nor diminished crumb hardness and staling rate. Enzymes addition led to lower batter resistance. GOX augmented dynamic parameters (G’ and G’’). Am presence decreased amylopectin retrogradation, as measured by DSC. Crumb hardness was reduced by enzyme addition. Correlation analysis demonstrated that lower tan delta values corresponded to higher BSV (r= -0.58). Batters with higher G’ led to breads with harder crumb (r=0.85). In this work, a negative correlation was found between the batter resistance to penetration and BSV (r=-0.80). Previous works showed that higher batter consistencies were associated to higher BSV (Sciarini et al., 2010); although this behavior depends on system characteristics, such as water content. Different additives exerted different effects on batter and bread characteristics, although these effects did not necessarily lead to higher bread quality. Overall, control formulation displayed very good baking properties.References- Sciarini L, Ribotta P, León A, Pérez GT. 2010. Influence of gluten free flours and their mixtures on batter properties and bread quality. Food and Bioprocess Technology, 3, 577-585.