Development and Evaluation of Gluten-Free Rice Biscuits: Impact on Glycaemic Index and Bioactive Compounds

Area of Science:

• Food Science
• Nutritional Science
• Cereal Chemistry

Background:

• Traditional wheat biscuits pose challenges for gluten-intolerant and diabetic individuals due to high glycemic index (GI).
• Rice flour offers a gluten-free alternative, but its nutritional profile and GI can be further optimized.

Purpose of the Study:

• To develop gluten-free biscuits using rice flour and rice bran.
• To evaluate the impact of rice bran incorporation on biscuit nutritional quality, glycemic index, and bioactive compounds.
• To assess consumer acceptance of the developed gluten-free biscuits.

Main Methods:

• Two rice varieties (Type III and Ariete) were used, with varying proportions of rice bran replacing milled and brown rice flour.
• Physicochemical analyses were conducted to determine starch digestibility, protein content, and bioactive compounds (phytic acid, γ-oryzanol, γ-aminobutyric acid).
• Glycemic index (GI) was assessed, alongside spread ratio, brittleness, and sensory evaluation for consumer preference.

Main Results:

• Biscuits with rice bran exhibited lower starch digestibility and reduced GI (57.06-62.75) compared to controls (66.23-66.95).
• Rice bran incorporation significantly increased beneficial bioactive compounds and protein content while decreasing starch content.
• No significant differences in consumer preference were observed across formulations, with Type III biscuits showing a favorable nutritional and bioactive profile.

Conclusions:

• Gluten-free biscuits incorporating rice bran are a viable option for healthier diets.
• Rice bran enhances the nutritional and functional properties of rice biscuits, reducing their GI.
• Type III rice biscuits with an equal blend of milled flour and rice bran present a promising, well-balanced alternative for gluten-free and low-GI diets.