Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 3/6/2007
Publication Date: 4/11/2007
Citation: Hojillaevangelist, M.P. 2007. SOYBEAN meal: a low cost-product with potential high-value application. Meeting Abstract. Renewable Resource for Industrial Nonfood Utilization. Published digital media..
Technical Abstract: Soybean meal is the predominant co-product from soybean processing and the most inexpensive ($0.17/kg) among the various soy protein products. Because of its abundant quantity, ready availability, and low cost, soybean meal has been and continues to be an attractive starting material for developing bio-based products. At the U.S. Department of Agriculture's National Center for Agricultural Utilization Research, our research group has been developing new uses for the proteinaceous co-products from soybean and cereal processing. We successfully developed a soy flour-based foamed plywood glue that is now being used commercially and are now focusing on soybean meal as an alternative protein extender in plywood adhesives. We found from our previous study that soybean meal had poor solubility and foaming properties, and was thus not suitable for foamed glues. However, we noted that the major protein sub-units were still present in soybean meal in a pattern that was similar to those of undenatured water-extractable soybean proteins. This finding suggested that it may be possible to make the soybean meal protein more reactive by physical (e.g. grinding) and/or chemical means. The highly alkaline pH of plywood glues (as high as pH 12) could be an ideal environment for modifying the meal. When we ground the meal to 40-mesh particle size, there was increased amount of soluble protein extracted at neutral and alkaline pHs, indicating that grinding was a beneficial step. Solubility is important because it affects the dispersion of the protein during the initial mixing step in glue production. Three soybean meal-based formulations for sprayline glues were selected based on their desirable mixing properties and acceptable viscosities. Their bonding strengths in 3-ply wood panels were tested. The standard glue containing wheat flour extender had wet tensile strength that was just marginally better than those obtained for the soybean meal glues. We are presently making adjustments in the mixing protocol and formulations to improve bonding strengths of the soybean meal plywood glues. However, our results are already showing that soybean meal has strong potential to be an alternative protein extender in plywood glues for sprayline coater.