Glycaemic response to frozen stored wheat rolls enriched with inulin and oat fibre

The aim of this study was to examine the effect of dietary fibre addition to partially baked and frozen wheat rolls on the glycaemic index (GI).Healthy humans volunteers (n = 15) took part in the study. They were asked to attend six times in the early morning, over three weeks. Each tested four types of wheat rolls – two without dietary fibre addition: (1) fully baked, non-frozen (FBNF), (2) partially baked and frozen (PBF); and two with the addition of 10% dietary fibre: (3) fully baked, non-frozen (FBNF + F), (4) partially baked and frozen (PBF + F). Glucose solution was used as a reference food and tested twice. Blood glucose concentrations were measured before consumption, as well as at 15, 30, 45, 60, 90 and 120 min after the start of the meal. Dietary fibre consisted of oat fibre (75%) and of inulin (25%).It was concluded that both factors (freezing and fibre), applied to the wheat rolls at the same time, reduced statistically significantly (P ≤ 0.05) the glycaemic index by 34% – PBF + F (GI = 53 ± 7) compared to control – FBNF roll (GI = 87 ± 11). This effect was not observed when fibre supplementation or frozen storage were applied separately.

► Effect of fibre added to frozen stored rolls on glycaemic index was tested in vivo.
► Both factors (freezing and fibre) reduced significantly the glycaemic index.
► Fibres addition applied alone to rolls has not influenced the glycaemic response.
► Frozen storage applied alone to rolls did not affect glycaemic index.