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United States Department of Agriculture

Agricultural Research Service

Title: The Effect of Transglutaminase Crosslinking on the Rheological Characteristics of Heated Peanut Flour Dispersions

Authors
item Gharst, Gregory - NC STATE UNIVERSITY
item Clare, Debra - NC STATE UNIVERSITY
item Davis, Jack
item Sanders, Timothy

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 20, 2007
Publication Date: June 7, 2007
Citation: Gharst, G., Clare, D.A., Davis, J.P., Sanders, T.H. 2007. The Effect of Transglutaminase Crosslinking on the Rheological Characteristics of Heated Peanut Flour Dispersions. Journal of Food Science and Technology 72(7):C369-C375.

Interpretive Summary: Peanut flour is a high-protein ingredient prepared after the partial extraction of oil from roasted peanut seed. Previous work has shown that the enzyme, transglutaminase (TGase), can be used to modify the functionality of peanut flour. The current paper expands this theme by documenting rheological properties of peanut flour dispersions treated with Tgase both in the presence and absence of amidated pectin, a charged polysaccharide common in food applications. High molecular weight protein polymers were formed in TGase-treated peanut flour dispersions both in the presence and absence of AP; however, polymer formation was more rapid in PF dispersions without AP. Resulting rheological properties are discussed. Collectively, these data suggest potential applications of TGase-treated PF dispersions, both in the presence and absence of AP, for use in peanut-base food products, including protein bars, shakes, and value-added baked goods.

Technical Abstract: Peanut flour (PF) is a high-protein ingredient prepared after the partial extraction of oil from roasted peanut seed. Microbial transglutaminase (TGase) catalyzes protein crosslinking via acyl-transfer reactions, resulting in the modification of functional properties such as viscosity, gelation, solubility, and water holding capacity. This work was conducted to observe changes in rheological properties of peanut flour (PF) dispersions in the presence and absence of TGase and amidated pectin (AP). Dispersions were characterized across a range of conditions, including controlled heating and cooling rates under both large- and small-strain deformations. Gelation occurred at temperatures above 78 °C using PF dispersions treated with TGase compared to untreated dispersions devoid of the enzyme (about 68 °C). The addition of AP (0.5%) resulted in a general increase in viscoelasticity for all dispersions. AP addition also minimized the shift in gel point temperature caused by TGase polymerization reactions. High-molecular-weight polymers were formed in TGase-treated PF dispersions both in the presence and absence of AP; however, polymer formation was more rapid in PF dispersions without AP. Ortho-phthaldialdehyde assays indicated about 40% protein coupling in PF dispersions treated with TGase compared to about 20% in those containing both AP and TGase. Collectively, these data suggest potential applications of TGase-treated PF dispersions, both in the presence and absence of AP, for use in peanut-base food products, including protein bars, shakes, and value-added baked goods.

Last Modified: 12/25/2014
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