Effects of barley β-glucan-enriched flour fractions on the glycaemic index of bread

Abstract

The aim of this research was to evaluate β-glucan-enriched flours, obtained from barleys with either normal or waxy starch, for their effects on the glycaemic index (GI) and the quality of bread. Rheological results confirmed that when barley flour was included in the dough the overall quality of bread slightly worsened. However, positive consequences on glycaemia were obtained with the normal starch barley: the GI of all-wheat bread (82.8 ± 7.2) was significantly reduced (57.2 ± 7.9) when 40% of wheat flour was substituted with β-glucan-enriched barley flour (6.0% ± 0.1 β-glucan in the final flour blend). In contrast, this positive effect was significantly reduced (GI: 70.1 ± 9.1) when 40% of wheat flour was substituted with the β-glucan-enriched flour of a waxy barley (CDC Alamo; 6.6 ± 0.2 β-glucan in the final flour blend), suggesting that the ability of β-glucans to lower the GI was affected by the barley starch-type.

Keywords::

• functional foods
• barley
• β-glucans
• glycaemic index
• waxy starch

Declaration of interest. This work has been supported by the following projects: ‘Alimenti funzionali a base di cereali’ of the Ministry of the University and Research (MIUR) and ‘Filiera orzo per alimenti funzionali’ of the Regione Emilia Romagna and CRPV. The authors declare that there are no financial and/or personal relationships with other people or organizations that could inappropriately influence (bias) their work.