Sensory acceptability of white bread with added Australian sweet lupin (Lupinus angustifolius) kernel fibre and its glycaemic and insulinaemic responses when eaten as a breakfast

The aim of this study was to determine whether lupin kernel fibre (LKF) could lower the glycaemic and insulinaemic responses of bread without reducing palatability. Healthy adults (n = 21) consumed control (white) bread (2.7% total dietary fibre (TDF)) once and LKF bread (8.5% TDF) once, as 50 g available carbohydrate breakfasts, in random order on different occasions. Venous blood samples were taken fasting, then post-prandially over 2 h and analysed for plasma glucose and insulin. Incremental areas under curves (IAUC) for glucose and insulin, glycaemic index (GI) and insulinaemic index (II) were calculated. Sensory acceptability of a control (white) bread (3.5% TDF) and two LKF breads (6.6 and 8.3% TDF) was determined (n = 54). A reduction of 18.8% (P < 0.05) was seen in IAUC for insulin of LKF bread compared with the control (white) bread breakfast. No significant differences were seen in the other glucose or insulin measures. Mean sensory ratings for all breads were acceptable, with no significant differences between the ratings of the breads. In conclusion, LKF can be formulated into palatable bread and beneficially influenced the IAUC for insulin. Further studies are required to determine unequivocally whether LKF has beneficial effects on blood glucose and insulin measures.