Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2008
Publication Date: January 15, 2009
Citation: Lee, S., Biresaw, G., Kinney, M.P., Inglett, G.E. 2009. Effect of Cocoa Butter Replacement With a Beta-glucan-rich hydrocolloid (C-trim30) on the Rheological and Tribological Properties of Chocolates. Journal of the Science of Food and Agriculture. 89(1):163-167. Interpretive Summary: Chocolate produced by replacing cocoa butter with an oat hydrocolloid, C-trim30, was prepared and evaluated by rheology, tribology, and sensory properties. The new oat beta-glucan-rich hydrocolloid could successfully reduce the cocoa butter fat in chocolate formulations. Some changes in the texture and rheology occurred, but acceptable chocolate was obtained. Significant amounts of the soluble oat fiber from the C-trim30 could not be added to make a label health claim involving the benefits of the beta-glucan soluble dietary fibers. However, a health benefit of allowing consumers to enjoy chocolate with reduced content of fat and calories are important in the struggle against obesity. Also, the friction measurements of the chocolate could be used to simulate mouth-feel resulting from the replacement of fat with the oat hydrocolloid and could be very valuable for future studies.
Technical Abstract: Cocoa butter in chocolates was replaced with C-trim30 (5, 10, 15% by weight), a beta-glucan-rich hydrocolloid containing elevated amount of beta-glucan (32%, db). Then, the effects of the C-trim30 on the rheological, tribological, and textural properties of chocolates were investigated. The viscosity of molten chocolates increased with increasing levels of C-trim30. Also, when their flow behaviors were fitted with the Casson model, there was a significant dependence of the Casson viscosity and yield stress on C-trim30 which increased with increasing levels of C-trim30. For the tribological testing, the friction forces of thin-film chocolates were measured by using a ball-on-flat tribometer and their coefficients of friction were calculated. Improved boundary lubrication property was observed in the chocolate samples containing C-trim30. In addition, the hardness of chocolates were measured by a penetration probing test, showing that replacement of cocoa butter with C-trim30 produced chocolates with softer texture.