Location: Dairy and Functional Foods ResearchTitle: Rheology and composition of processed citrus fiber Author
Submitted to: Journal of Food Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/17/2013
Publication Date: 10/28/2013
Publication URL: http://handle.nal.usda.gov/10113/59482
Citation: Lundberg, B., Pan, X., White, A.K., Chau, H.K., Hotchkiss, A.T. 2013. Rheology and composition of processed citrus fiber. Journal of Food Engineering. 125:97-104. Interpretive Summary: Current byproducts of the U.S orange juice industry are used for low value animal feed. Dietary fiber has been commercially produced from citrus pulp that provides a valuable food ingredient with applications limited due to taste and texture changes. Our analysis of citrus fiber composition demonstrated that pectin is an important component that determines water holding capacity and viscosity. Particle size is an important parameter to consider when using citrus fiber in bakery products to maintain moisture and replace fat. This study further describes how the citrus fiber structure swells during hydration providing more surface area to hold water. These results will enable citrus fiber to be used as a functional food ingredient in more food matrices, which will add value to U.S. specialty crops and benefit consumer health.
Technical Abstract: While fibrous byproducts are abundant in supply, using them in food products in such a way to not degrade taste or texture can be challenging. Citrus fibers have been shown to have high water holding and viscous properties. However, to better incorporate dried orange pulp into foods, their properties, composition, and rheology need to be better understood. A specific aim of this study was to characterize the properties, composition, and rheology of processed citrus fibers. Pectin was found to be major component of citrus fiber and particle size also made a significant difference in its functional properties. The flow properties of citrus fiber solutions were clearly non-Newtonian and the type of model that best fits the citrus fiber varied depending on its particle size. As citrus fibers hydrate, the structure clearly swells and this study provides further clarification and understanding showing how this happens.