Formulation of low glycaemic index biscuits suitable for diabetics from unripe banana, okra, and stevia leaves / jujube fruit

Abstract

Abstract Biscuits are the largest category of consumed snacks among bakery products, but their simple sugar and fat high content associate to low fiber content make them unsuitable for diabetics. This study aimed to formulate biscuits with low glycaemic index from the blend of unripe banana, okra and stevia leaves or jujube fruit for diabetics. To achieve this goal, unripe banana, fresh okra, stevia leaves and jujube fruits were purchased from a main market in Ngaoundere and processed into flours. Proximate composition of the flours was determined, and then, Design Expert software was used to formulate two different blends, Banana/Okra/Stevia (BOS) and Banana/Okra/Jujube (BOJ). According to the results of preliminary sensory tests done in the laboratory, three biscuits with stevia (BOS1, BOS2, BOS3), three biscuits with jujube (BOJ1, BOJ2, BOJ3), and a witness biscuit with table sugar as sweetener were formulated. After the physicochemical characterisation of formulated biscuits, animal experimentation was carried out in order to evaluate the postprandial evolution of blood glucose in rats after having ingested the biscuits, and the Glycaemic Index (GI) of produced biscuits. A hedonic test with 30 consumers was done, parameters assessed including colour, texture, taste, flavour, and overall acceptability. The results obtained show that unripe banana is mostly made of complex carbohydrates, while okra and stevia are good sources of fibers, confirming their importance in diabetic’s diet. All the biscuits produced with stevia and jujube did not raise the blood glucose compared to the witness biscuit made with table sugar. Biscuits produced with stevia leaves had a lower GI than those produced with jujube fruit among the biscuits produced with stevia leaves, BOS2 had the lowest GI, then the lowest increase of postprandial blood glucose in rats, and was the most appreciated by the consumers in terms of appearance, flavour, taste and overall acceptability. Therefore, BOS2 could be recommended as snack for diabetics. Graphical Abstract

Keywords

• Snacks
• Diabetics
• Glycaemic index
• Banana
• Okra
• Stevia