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

Abstract

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. 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 50g of available carbohydrates. Venous blood samples were collected before consumption and at 15, 30, 45, 60, 90, 120 and 180min, postprandially. Glycaemic, insulinaemic and appetite hormone responses as well as glycaemic index (GI) and subjective appetite ratings were evaluated. 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 45min after (HT + α-CD)B consumption compared to α-CDB (P < 0.05) as well as in serum ghrelin, 120min postprandially, between (HT + α-CD)B and WB in (-90.55 ± 29.17 and 16.53 ± 21.78pg/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. 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).