|YAZAR, GAMZE - University Of Iowa|
|KOKINI, JAZEF - Purdue University|
Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/25/2023
Publication Date: 5/29/2023
Citation: Yazar, G., Kokini, J., Smith, B. 2023. Comparison of mixing and non-linear viscoelastic properties of carob germ glutelins and wheat glutenin. Food Hydrocolloids. 143 Article 108922. https://doi.org/10.1016/j.foodhyd.2023.108922.
Interpretive Summary: Gluten proteins from wheat allow for high quality baked goods and is commonly used to produced texturized proteins for used as meat extenders and meat analogs. Because wheat is a major food allergen, other, other gluten-like proteins need to be defined better. Carob germ proteins are known to have some biochemical and physical similarities to wheat. In this study the mechanical properties of carob germ glutelins were defined by large amplitude oscillatory shear tests. It was found that carob germ glutelins and wheat glutenin showed similarities and differences in their molecular weight distributions, mixing characteristics, and viscoelastic properties probed in linear and non-linear regions. It was found that carob germ glutelins were stiffer and more prone to shear thinning than wheat glutelins.
Technical Abstract: Molecular weight distributions, mixing and non-linear viscoelastic properties of carob germ and wheat glutenins were compared in this study, while the impact of mixing on non-linear rheological properties of these protein fractions were evaluated over short (4-minute) and long (35-minute) mixing times. Development time was 13 minutes for carob germ glutelins, while reaching 500 BU consistency took 34 minutes for wheat glutenin, suggesting slower hydration for wheat glutenin due to its higher molecular weight distribution and more hydrophobic nature. Phase angle values revealed similar linear viscoelastic properties for both proteins after 4-minute and 35-minute mixing. However, Large Amplitude Oscillatory Shear (LAOS) tests indicated type I non-linear behavior for carob germ glutelin and type III non-linear behavior for wheat glutenin after 35-minute mixing at which both proteins had similar consistencies, pointing out to weaker stability for carob germ glutelins when exposed to large deformations. Higher degree of strain stiffening and shear thinning behaviors were found for carob germ glutelins in the non-linear region. Increasing mixing time caused a decrease in the strain stiffening behavior of wheat glutenin under large strain-high frequency deformations, while strain stiffening behavior of carob germ glutelin remained similar. Comparing the mixing and LAOS properties of carob germ glutelin to those of wheat glutenin unraveled the processing needs of dough systems where carob germ glutelin could be used as a non-gluten protein to produce alternative gluten-free products with improved loaf volume.