Elm (Ulmus pumila L.) bark flour as a gluten substitute in gluten-free whole foxtail millet bread

J Food Sci Technol. 2023 Mar;60(3):1163-1174. doi: 10.1007/s13197-023-05670-x. Epub 2023 Jan 27.

Abstract

Elm bark (Ulmus pumila L.) flour is a nutritious and sustainable edible material for developing the macromolecular network in the food matrix. In this study, the effects of Elm bark flour and water addition on technological and sensory characteristics of gluten-free whole foxtail millet bread were investigated. Structural analysis methods such as SEM, X-ray diffraction, and FTIR were used to supplement the rheological properties and baking quality. Results showed that Elm bark flour improved gelatinization characteristics and rheological properties (tanδ < 1) of gluten-free dough. Moreover, the porous and network structure of gluten-free bread was observed by image analysis and further confirmed by Fourier transform infrared spectroscopy and X-Ray diffraction, endowing higher specific volume (1.98 ± 0.13 cm3/g), and a decrease hardness from 97.43 to 11.56 N. Additionally, with the incorporation of Elm bark flour-water combination, specific volume (2.15 ± 0.09 cm3/g) and hardness (6.83 ± 0.50 N) were further optimized. Combined with the results of rheological properties and bread structure, Elm bark flour at 15% ratio and water addition at 120% level exhibited the most potent improvement of gluten-free bread. These results might contribute to the potential utilization of Elm bark flour as the sustainable resource in gluten-free products.

Supplementary information: The online version contains supplementary material available at 10.1007/s13197-023-05670-x.

Keywords: Bread quality; Elm bark flour; Gluten-free bread; Whole foxtail millet grain.