Positive postprandial glycaemic and appetite-related effects of wheat breads enriched with either α-cyclodextrin or hydroxytyrosol/α-cyclodextrin inclusion complex.

PURPOSE: Enrichment of wheat bread with either α-cyclodextrin (α-CD) or an inclusion complex of hydroxytyrosol (HT) and α-CD was performed to examine potential postprandial benefits. METHODS: Ten healthy normoglycaemic adults were provided with either a glucose solution (reference food, GS), white wheat bread (WB), wheat bread enriched with α-CD (α-CDB) or wheat bread enriched with HT/α-CD complex ((HT + α-CD)B), with 1-week intervals in amounts that yielded 50 g of available carbohydrates. Venous blood samples were collected before consumption and at 15, 30, 45, 60, 90, 120 and 180 min, postprandially. Glycaemic, insulinaemic and appetite hormone responses as well as glycaemic index (GI) and subjective appetite ratings were evaluated. RESULTS: Both enriched breads were characterized as low GI foods (α-CDB:49.7, (HT + α-CD)B:40.0) and presented similar reduction in glucose, insulin and GLP-1 responses. Significant differences were found in glucose values 45 min after (HT + α-CD)B consumption compared to α-CDB (P < 0.05) as well as in serum ghrelin, 120 min postprandially, between (HT + α-CD)B and WB in (- 90.55 ± 29.17 and 16.53 ± 21.78 pg/dL, respectively, P < 0.05). Neither of the enriched breads prevailed regarding the induced self-reported satiety. However, their consumption led to a lower desire for the next meal compared to WB. CONCLUSION: Enrichment of bread with α-CD resulted in positive effects on postprandial glycaemia and induced satiety. Incorporation of encapsulated HT offered similar overall acceptability, due to the bitter taste-masking effect provided by α-CD, and a slightly additional positive effect in postprandial glycaemia and satiety. The development of foods with favorable metabolic effects is of great importance for the prevention of chronic diseases. The study was prospectively registered in clinicaltrials.gov (NCT04725955, date: 27th January 2021).

Enrichment of bread with beta-glucans or resistant starch induces similar glucose, insulin and appetite hormone responses in healthy adults.

PURPOSE: ß-Glucans (ßG) and resistant starch (RS) are known for their effects on the improvement of glucose tolerance and enhancement of insulin sensitivity. Enrichment of bread with ßG or RS was performed to examine potential postprandial benefits regarding gastrointestinal hormone responses. METHODS: Ten healthy normoglycaemic adults participated in the study and were provided with either a glucose solution (reference food, GS) or bread enriched with ß-glucans (ßGB) (3.6 g/30 g available CHO) or bread enriched with resistant starch (RSB) (15% of total starch), with 1-week intervals in amounts that yielded 50 g of available carbohydrates. Venous blood samples were collected before consumption and at 15, 30, 45, 60, 90, 120 and 180 min postprandially. Glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) responses as well as glycaemic index (GI) and subjective appetite ratings were evaluated. RESULTS: Ingestion of ßGB and RSB elicited lower incremental area under the curve (iAUC) for glycaemic response compared to GS (P < 0.05). Both breads demonstrated a low GI (ßGB: 48, RSB: 40). There were no significant differences in insulin response, ghrelin, GLP-1 or PYY between the two breads. A significantly lower desire to eat and higher fullness were detected 15 min after ßGB and RSB consumption and until 180 min (P < 0.05 compared to GS). CONCLUSION: Enrichment of bread with either ßG or RS produced a low GI product but the two breads were not significantly different in relation to insulin, ghrelin, GLP-1 and PYY responses. The development of bread products which cause improved metabolic effects is of great importance for the promotion of public health.