Inulin lowers GI of chocolate
the gut, also lowers the glycaemic index of dark chocolate,
according to a new study, suggesting the ingredient could be used
in products targeted at blood sugar control.
The research carried out by UK-based consultancy Leatherhead Food tested the glycaemic response to dark chocolate and ice cream formulated with a variety of different non-digestible carbohydrates instead of sucrose.
Chocolate containing Sensus Frutafit brand inulin and other carbohydrates had a significantly lower glycaemic response - between 4 and 26 - than the control chocolate (44).
The glycaemic response measures how the body's blood sugar levels respond to digestion of a particular food and gives the product a value on the glycaemic index (GI).
Foods with a low GI value keep the body's blood sugar levels relatively steady throughout the day, regulating appetite and reducing the tendency to snack. Although there is no evidence to show that a low-glycaemic index diet is any more effective than a low-fat, high GI diet for weight loss, low GI foods are increasingly being positioned as weight management foods, partly because they may also have benefits in preventing obesity-related disease like type 2 diabetes.
Inulin producer Sensus has been one of the first to promote this application, and scientific director Diederick Meyer points to research that shows a relation between low-GI food and an effect on satiety.
He also adds that inulin is low in calories and therefore, replacing sugar in chocolate with the healthy carbohydrate could also help in weight management (inulin has 1.5 kcal/g versus 4 kcal/g for sucrose).
In the Leatherhead study, all GI testing was done according to WHO/FAO recommendations. Fourteen healthy volunteers were asked to consume either 250ml of a glucose reference drink (containing 25g of glucose), a control chocolate bar with 25g of available carbohydrate, or a modified chocolate bar with the same weight as the control bar that replaced 25g of sugar with the test ingredient.
Blood glucose levels were determined over a two-hour period by finger-prick samples, and the glycaemic response was compared with that of glucose set at 100.
The research also looked at the physical and sensory properties of the chocolates. Texture, flavour and mouthfeel of an inulin chocolate did not differ significantly from the sucrose-based control bar, according to Dr Meyer.
But he added: "If you compare with sucrose, there are differences but inulin was well-accepted. It's probably not a matter of taste but more of a change in texture."
The study also tested eight different sugar replacers in ice cream. Orafti claims that ice cream containing its Raftilose oligosaccharides gave a glycaemic response that was 70 per cent lower than the glycaemic response produced after eating the traditional ice cream.