Development of fibre-enriched gluten-free bread: a response surface methodology study.

The enrichment of gluten-free (GF) baked products with dietary fibre (DF) seems to be necessary since it has been reported that coeliac patients have generally a low intake of DF due to their GF diet. Response surface methodology was used to optimize a fibre-enriched GF bread formulation based on corn starch, rice flour and hydroxypropylmethyl cellulose. Maize fibre and water were the predictor variables (factors), and loaf specific volume, crumb firmness and crumb L value were the dependent variables (responses) used to assess the product quality. The optimal formulation, determined from the data, contained 6.5% maize fibre and 102.5% water, starch/flour base. The developed mathematical models for the measured responses could be successfully used for their prediction during baking. Shelf-life study of the optimized formulation revealed that bread stored under modified atmosphere packaging exhibited lower crumb firmness and moisture content values, and thus remained softer through storage. Scanning electron microscopy of the crumb showed a continuum matrix between starch and maize fibre, in the optimized formulation, obtaining a more aerated structure.