In a study published in the Carbohydrate Polymers journal, Jaroslav Korus and other Polish researchers found that it is the water binding properties of inulin that are mainly responsible for changes to dough properties. Findings showed that this could be limited by selecting inulin with adequate degrees of polymerisation and adjusting water in the recipe.
Earlier studies found that inulin could enrich gluten-free bakery with functional properties.
Inulin can unlock functionality
Korus et al. said that gluten-free products had a significantly lower nutritional value compared to conventional bread.
“The introduction of nutritional or dietary supplements is difficult, due to its fragile structure that could easily be overloaded with applied additives,” they said.
Inulin, a polysaccharide, has been touted to have a prebiotic function in gluten-free bakery, but could modify the dough properties.
Korus et al. therefore decided to analyse the influence of degrees of polymerization on properties of gluten-free dough supplemented with inulin.
They confirmed that inulin significantly modified the rheological and thermal properties of gluten-free dough, but changes could be offset by careful recipe selection.
“In the design phase of gluten-free products with added inulin it is then especially important to choose a preparation with appropriate degree of polymerization (DP) and properly adjust amounts of water used in the recipe,” they said.
Inulin with the highest DP was found to have the strongest impact on viscoelasticity in the dough.
The researchers also suggested that an added benefit of inulin could be extended shelf-life.
“The addition of inulin significantly reduces enthalpy of retrograded amylopectin, which may suggest its role in bread staling retardation,” said the study.
Citation: Lesław Juszczaka, Teresa Witczakb, Rafał Ziobroc, Jarosław Korusc, Ewa Cieślikd, Mariusz Witczakb (2012) ‘Effect of inulin on rheological and thermal properties of gluten-free dough’ Carbohydrate Polymers, ISSN 0144-8617, 10.1016/j.carbpol.2012.04.071.