| Viscosity of cereal beta-glucan depends on concentration and molecular weight (MW). We investigated whether the postprandial glycaemia lowering effect of beta-glucan in oat bran muffins is related to its solubility. Solubility of beta-glucan decreased as the number of freeze-thaw cycle increased, while MW distribution was unchanged. Peak blood glucose rise (PBGR) after fresh muffins was significantly lower than that after muffins treated with 4 freeze-thaw cycles (1.84+/-0.17 vs. 2.31+/- 0.14mmol/L, p=0.007). Compared to the control, the reduction in incremental area under the glucose curve (AUC) alter fresh muffins was nearly twice that after 4 freeze-thaw cycles (43.3+/-4.4% vs. 27.0+/-5.4%, p=0.016). A significant inverse linear relationship was found between log [concentration] of beta-glucan and PBGR (r 2=0.85, p=0.009), AUC (r2=0.72, p=0.034) and AUC expressed as a percentage of that after the control (r2=0.80, p=0.017). The ability of oat beta-glucan (of constant MW) to lower postprandial glycaemia was influenced by changes in solubility. |
