Evaluation of pasting and functional properties of composite flour from Indonesian local tubers and its application in gluten-free biscuits

Biscuits, typically made from wheat flour containing gluten, can pose issues for individuals with celiac disease due to gluten intolerance. To address this, alternative flours like cassava (Manihot esculenta), suweg (Amorphophallus paeoniifolius), and arrowroot (Maranta arundinacea L.) are combined into a composite flour, providing a gluten-free option for biscuit production. The study aimed to determine the formulation of gluten-free biscuits made from composite flour with the closest characteristics to biscuits made from wheat flour. The formulation ratios of Indonesian tubers such as modified cassava flour (MF), suweg flour (SF), and arrowroot flour (AF) used in composite flour are F1 (70:25:5), F2 (70:20:10), and F3 (70:15:15). The results showed that the lower SF ratio, the higher ash content, and the lower fat content of the composite flour. The pasting temperature and solubility increased, and swelling volume, peak viscosity, breakdown viscosity, and setback viscosity decreased with a decrease of the SF ratio. AF contributed to composite flour’s higher lightness, hue, and whiteness index. Biscuits from composite flour with a higher SF ratio had lower hardness and fracturability, but higher lightness, hue, and whiteness index. Biscuit preference parameters generally increased with a reduced SF ratio in composite flour. Gluten-free biscuits made from MF, SF, and AF with a ratio of 70:15:15 have texture characteristics and sensory preferences closer to wheat flour biscuits.