Efeito das gomas xantana e/ou guar na textura de pães isentos de glúten elaborados com farinhas de arroz e de milho

• Author(s): Botelho, Fabiana de Souza
• Date: 2012
• Persistent ID: http://hdl.handle.net/10400.5/5324
• Origin: Repositório da UTL
• Subject(s): gluten-free bread; celiac disease; xanthan; guar; corn; rice
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Mata, Maria Paulina; Raymundo, Anabela Moreira
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Ciências Gastronómicas - Instituto Superior de Agronomia / Faculdade de Ciências e Tecnologia. Universidade Nova de Lisboa

The production of gluten-free bread poses a technological challenge that involves the creation of viscoelastic dough without the support of the gluten network (present on bread from wheat). For that purpose the, industry usually uses hydrocolloids. However the resulting bread is pricy and less accessible. The objective of this study is to adapt this technique to the home production of gluten-free bread. The effects of xanthan and guar gums in bread doughs, as well as in the final texture of such bread, were studied. Gluten free doughs were evaluated regarding their rheologic properties and texture parameters. Bread was evaluated in terms of texture and colour. Different gum proportions were studied in a total concentration of 1% (w/w). The proportion of 1:1 mixture originated a dough with an improved technological characteristic and a bread less firm than the control. For this proportion, a reduction of the total gum concentration to 0.5% was evaluated, resulting in an improvement of the characteristics of the bread. Previous hydration of gums was also evaluated (30 and 60 min) showing no significant effect on final bread characteristics. Aging curves showed that bread firmness significantly increases with time, but gums effects are sustained