Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/2/2008
Publication Date: 11/1/2008
Citation: Clare, D.A., Gharst, G., Maleki, S.J., Sanders, T.H. 2008. The effects of transglutaminase catalysis on the functional and immunoglobulin binding properties of peanut flour dispersions containing casein. Journal of Agricultural and Food Chemistry. 56(22):10913-10921. Interpretive Summary: Oftentimes, the characteristics of a particular ingredient are important for predicting the performance traits in a given food product. Thus, functional analyses can serve as a means to evaluate operational parameters, such as, viscosity and gelation. Most foods are neither ideal solids nor liquids, but instead may be considered “viscoelastic”, meaning that they exhibit both viscous (fluid) and elastic (solid) properties). Such parameters can and were quantitatively measured based on instrumental determinations in this work. Aggregates of peanut and casein are formed using a specific enzyme known to cause aggregate formation and change in the characteristics, which can enhance the original form. We also assessed the immunological properties and found that they were also changed. It seems like the aggregation of peanut and milk proteins caused masking of some of the immunoglobulin E or IgE binding sites that are involved in allergic reactions. Therefore, in this research we found that while improving the properties (the water holding capacity) of an existing product, we may also reduce the allergenic properties.
Technical Abstract: The functionality of light roasted peanut flour (PF) dispersions containing supplemental casein (CN), was altered after polymerization with microbial transglutaminase (TGase). The formation of high molecular weight covalent cross-links was observed with potential formation of PF-PF, PF-CN, and CN-CN polymers. The gelling temperature of enzyme treated PF-CN test samples was increased; moreover, the viscosity and yield stress were lower compared to control dispersions. Notably, the water holding capacity of PF fractions containing 5% CN was enhanced after extended catalysis. The immunological properties were also changed, in which case, IgE binding to TGase treated PF-CN fractions was lower compared to equivalent polymeric PF dispersions lacking supplemental CN and control PF-CN samples. Likely, covalent modification masked at least some of the IgE peanut protein binding epitopes. Casein proved to be an effective co-substrate, with PF suggesting the potential for using Tgase treated PF-CN dispersions as a novel high protein food ingredient.