The glycemic and insulinemic index of plain sweet biscuits: relationships to in vitro starch digestibility.
BACKGROUND
Among the various classes of processed starchy foods, wheat-based cereal products exhibit a wide range in glycemic and insulinemic responses. Understanding starch behavior during cooking and processing may help identify strategies that lower postprandial glycemia and insulinemia.


OBJECTIVE
To determine the relationship between the in vivo glycemic index (GI)/insulinemic index (II) and in vitro digestibility and composition characteristics (rapidly available glucose and slowly available glucose, RAG and SAG respectively) of 24 plain sweet biscuits (cookies).


METHODS
The products were commercially available and selected on the basis of their high starch content. In vivo responses (GI and II) were measured by standardised methods over 7 studies, with 12 subjects in each study (30 males, 42 females). In vitro digestibility characteristics were measured by the Englyst procedure.


RESULTS
The observed GI ranged from 38 to 60 (low to moderate) with the majority between 40 and 50, and correlated strongly with the observed insulinemic index (r = 0.76, P < 0.0001). The digestibility profile of carbohydrates was significantly correlated to in vivo responses (SAG and GI: r = -0.41; p = 0.04; SAG and II: r = -0.52; p < 0.01; RAG and GI: r = 0.5; p = 0.01; RAG and II: r = 0.34; p = 0.1) and explained in vivo responses better than fat, protein and fiber content amongst this selection of plain sweet biscuits.


CONCLUSIONS
The findings indicate that plain sweet biscuits have a low GI and a moderate II and that these characteristics are correlated to in vitro starch digestibility and are dependent on the type of processing.
Garsetti
Marcella
M
Danone Vitapole, Route Départementale 128, 91767 Palaiseau Cedex, France. marcella.garsetti@danone.com
Vinoy
Sophie
S
Lang
Vincent
V
Holt
Susanna
S
Loyer
Stephanie
S
Brand-Miller
Jennie C
JC
D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis* / Q000378:metabolism; D001939:Bread / Q000032:analysis; D004040:Dietary Carbohydrates / Q000378:metabolism / Q000493:pharmacokinetics*; D004063:Digestion; D005260:Female; D005511:Food Handling / Q000379:methods*; D038321:Glycemic Index; D006801:Humans; D066298:In Vitro Techniques; D007328:Insulin / Q000032:analysis* / Q000378:metabolism; D008297:Male; D019518:Postprandial Period; D013213:Starch / Q000378:metabolism / Q000493:pharmacokinetics*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin; D013213:Starch