Comparative study of the effect of starches from five different sources on the rheological properties of gluten-free model doughs

Ferreira LM, A. Peres J, R. N. A. Barros AI, Raymundo A. Impact of Acorn Flour on Gluten-Free Dough Rheology Properties

Gluten is a fundamental ingredient in breadmaking, since is responsible for the viscoelastic behaviour of the dough. The lack of gluten has a critical effect on gluten-free dough, leading to less cohesive and less elastic doughs, and its replacement represents a challenge for bakery industry. However, dough rheology can be improved combining different ingredients with structural capacity and taking advantage from their interactions. Although acorn flour was used to bake bread even before Romans, nowadays is an underexploited resource. It presents good nutritional characteristics, particularly high fibre content and is naturally gluten free. The aim of this study was to use acorn flour as a gluten-free ingredient to improve dough rheology, following also market trends of sustainability and fibre-rich ingredients. Doughs were prepared with buckwheat and rice flours, potato starch and hydroxypropylmethylcellulose. Two levels of acorn flour (23% and 35% w/w) were tested and compared with control formulation. Micro-doughLAB was used to study mixing and pasting properties. Doughs were characterised using small amplitude oscillatory measurements (SAOS), with a controlled stress rheometer, and regarding Texture Profile Analysis (TPA) by a texturometer. Dietary fibre content and its soluble and insoluble fractions were also evaluated on the developed breads. Acorn flour showed promising technological properties as food ingredient for gluten-free baking (improved firmness, cohesiveness and viscoelasticity of the fermented dough), being an important fibre source.

Chemical, physical, rheological and sensory properties of biscuit fortified with protein hydrolysate from cephalothorax of Pacific white shrimp

Chemical, physical, rheological and sensory properties of biscuits fortified with shrimp protein hydrolysate powder (SHP) at various levels (0-7.5%, flour substitution) were investigated. The addition of 7.5% SHP slightly decreased diameter of biscuit and thickness was decreased as SHP at levels of 2.5-7.5% was incorporated. Hardness and fracturability of biscuit decreased as the levels of SHP was higher than 1.25 and 2.5%, respectively. Surface of biscuit became more reddish and yellowish as SHP was added. The addition of 5% SHP increased likeness score of resulting biscuit. Fortification of SHP affected the viscoelastic properties of dough. Deformation resistance and strength of dough decreased with increasing levels of SHP. Additional volatile compounds including aldehyde, ketone, alkane and ether, were detected when 5% SHP was incorporated, thus more likely contributing to odor and flavor of resulting biscuit. The addition of 5% SHP into biscuit resulted in the increased protein content with reduction of carbohydrate. Therefore, the biscuit could be fortified with 5% SHP and had higher nutritional value and increased sensory properties.