Novel gluten-free amaranth and oat flour cookies fortified with soybean hulls

Authors: Liu, Sean; CHEN, DIEJUN

Submitted to: Food and Nutrition Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/5/2023
Publication Date: 8/14/2023
Citation: Liu, S.X., Chen, D. 2023. Novel gluten-free amaranth and oat flour cookies fortified with soybean hulls. Food and Nutrition Sciences. 14(8):699-719. https://doi.org/10.4236/fns.2023.148046.
DOI: https://doi.org/10.4236/fns.2023.148046

Interpretive Summary: Soybean hulls contain rich phytochemicals, fibers, proteins, and minerals. Soybean hulls have never been used in commercial food products. Potential ingredient compatibility issues of soybean hulls with other food ingredients are the major concerns. Issues range from the effects of soybean hulls on food product textural characteristics and nutritional values, to the impact on processibility of food ingredient blends. These issues need to be investigated and the data analyzed. We substituted 25% either amaranth flour or whole oat flour in the gluten free cookie formulations with soybean hulls. Composition, nutritional values, water-holding capacities, correlation between properties, and pasting and material properties of soybean hulls, amaranth, and whole oat flour as well as their blends were measured and then compared to those of wheat flour. Water loss, cookie texture, and geometrical properties of the cookies that contain soybean hulls were examined. We found that the cookies made from soybean hulls have excellent nutritional profile. Water-holding capacities of ingredients increased after replacing portions of amaranth and whole oat flours with soybean hulls while textural characteristics of both the ingredient blends and the cookies are good. Soybean hulls in the formulation showed remarkable elastic material behavior, an important characteristic in some applications. The soybean hulls blended in amaranth or whole oat flour cookie formulations greatly improved nutritional value of the cookies, the water retention and moisture content along with acceptable physical properties when compared to those of wheat flour cookies. This study explored the feasibility and potential of utilizing soybean hulls in gluten-free bakery products and other food applications.

Technical Abstract: Soybean hulls, an abundant byproduct of soybean processing, contain rich phytochemicals, fibers, proteins, and minerals. Currently soybean hulls are primarily used as animal feeds. For value-added soybean hull utilization, 25% soybean hulls were substituted for amaranth or whole oat flour (WOF) in novel gluten-free cookies. Composition, nutritional values, water-holding capacities, correlation between properties, and pasting and rheological properties of soybean hulls, amaranth, and WOF were evaluated in comparison to wheat flour. Water loss, cookie texture, and geometrical properties of the cookies were examined. The results disclosed that soybean hulls, amaranth and WOF contain higher protein content, minerals, fiber, special amino acids, and critical vitamins (C and K) than wheat flour. Considerably higher total amino acid content was found in soybean hulls (18.33%) than wheat flour (12.77%). Water-holding capacities increased by replacing amaranth and WOF with soybean hulls. Soybean hulls exhibited higher rheological elastic properties than amaranth, WOF and wheat flours. The soybean hulls utilized in amaranth or WOF cookies greatly improved their nutritional value, the water retention and moisture content along with acceptable physical properties when compared to wheat flour cookies. This study explored the feasibility and potential of utilizing soybean hulls with amaranth and WOF in gluten-free bakery products and other food applications.