The effect of thermo-mechanical processing on physical properties of processed amaranth and oat bran composites

Authors: Liu, Sean; Chen, Diejun; Inglett, George; Xu, Jingyuan - James

Submitted to: Journal of Food Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2017
Publication Date: 3/8/2017
Publication URL: http://handle.nal.usda.gov/10113/5852173
Citation: Liu, S.X., Chen, D., Inglett, G.E., Xu, J. 2017. The effect of thermo-mechanical processing on physical properties of processed amaranth and oat bran composites. Journal of Food Research. 6(2):82-91.

Interpretive Summary: Amaranth (amaranthus caudatus) grains, a class of ancient grains that can grow in drier regions of the world, contain many nutrients found in other cereal and pseudo-cereal grains and about thirty percent more protein than cereals like rice, sorghum and rye and naturally gluten free. Despite of its nutritional prowess, amaranth is underutilized due to it unfamiliarity to consumers and food producers and lack of necessary physical properties such as high viscosity and water holding capacity for certain food manufacturing processes. We developed amaranth-oat composites using amaranth flour with oat bran concentrate (OBC) containing ß-glucan, a soluble fiber known for lowering blood cholesterol and higher viscosity. Amaranth flour and OBC composites (1:4) were processed using different technologies, including dry mixing, baking, steaming, cold wet blending, Polytron with cold water, and Polytron with hot water. The results showed that water holding capacities, pasting, and rheological properties were dramatically increased by wet blended, Polytron with cold water, and Polytron with hot water followed by drum drying. The new healthful food materials possess excellent physical properties for food product development and will be affordable for people who suffer from celiac disease or gluten-intolerant due to simple low-cost thermomechanical processes employed. These innovated gluten-free functional food ingredients can be easily incorporated into many food products providing millions of consumers, who are sensitive to gluten, with gluten-free foods with high soluble dietary fiber and other high-quality nutrients.

Technical Abstract: Amaranth-oat composites were developed using gluten free amaranth flour containing essential amino acids and minerals with oat products containing ß-glucan, known for lowering blood cholesterol. Amaranth flour and oat bran concentrate (OBC) composites (1:4) were processed using different technologies, including dry mixing, baking, steaming, cold wet blending, Polytron with cold water, and Polytron with hot water. The results showed that water holding capacities, pasting, and rheological properties were dramatically increased by wet blended, Polytron with cold water, and Polytron with hot water followed by drum drying. The processing procedures created dissimilar physical properties that will enhance the application of ancient grains and oat for functional foods that are suitable for people who are gluten-intolerant. In addition, the dietary fiber contents of composites were increased by the incorporation of OBC. The composites can be inexpensively prepared and processed. The new healthful products will be affordable for people who suffer from celiac disease or gluten-intolerant. These innovated gluten-free functional food products will help millions of consumers who are sensitive to gluten enjoy heart-healthy functional foods.