Effect of type and amount of modified corn starches on qualitative properties of low‐protein biscuits for phenylketonuria

The effect of corn starches (natural, pregelatinized, and cross‐linked) in four levels on quality of low‐protein biscuit was evaluated. First, the microscopic structure, thermal properties, and low‐branched chains content of them were evaluated. Water absorption capacity (WAC) and gelatinization properties of combined starches and physicochemical properties of products were assessed. Cross‐linked starch had the highest glass transition temperature (T(g)). The maximum and minimum WAC was observed in samples containing 100% pregelatinized and 100% cross‐linked starches, respectively. An increase in the amount of pregelatinized starch was accompanied by a decrease in the maximum viscosity and gelatinization temperature. Pregelatinized starch improved sensory and textural characteristics of samples, while cross‐linked starch affected baking properties of the product. The best sample containing 30% of pregelatinized and 70% cross‐linked starch with 1.27 g protein and 12 mg phenylalanine in 100 g biscuit is introduced as the low protein and safe product for Phenylketonuria.