Effect of ingredients on the quality of gluten-free steamed bread based on potato flour.

Response surface methodology was used to analyze effects of the amounts of pregelatinized potato flour (PGPF), hydroxypropylmethylcellulose (HPMC), egg white protein (EWP), and water on the dough fermentation and physical properties of gluten-free (GF) steamed bread based on potato flour. The results showed that PGPF, HPMC, EWP, and water at the appropriate amounts improved the maximum dough height (H_m), specific volume (SV) and hardness, as well as H_m correlated with SV (R² = 0.6993) and hardness (R² = 0.7273). Moreover, the optimal formulation contained 4.84 g/100 g PGPF, 1.68 g/100 g HPMC, 5.87 g/100 g EWP, and 69.69 g/100 g water, potato flour basis. Furthermore, the dietary fiber, total polyphenol content, antioxidant activity, and estimated glycemic index of the steamed GF bread were, respectively, 3.17-, 1.56-, 1.44-, and 0.75-fold of those of steamed wheat bread. The optimized steamed GF bread was found to be acceptable according to the results of sensory analysis. Information collected within this study may provide further insight for optimizing the formulation of steamed GF bread based on potato flour.