Mila P. Hojilla-Evangelista

Extraction, composition, and functional properties of dried alfalfa (Medicago sativa L.) leaf protein.

BACKGROUND Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein. RESULTS Dried alfalfa leaves contained 260 g kg-1 dry basis (DB) crude protein, with albumins being the major fraction (260 g kg-1 of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg-1 DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg-1 soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m2  g-1 protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0. CONCLUSIONS It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product.

Evaluation of corn germ protein as an extender in plywood adhesive

This study was conducted to evaluate the potential of wet-milled corn germ protein as an extender in plywood adhesive. Partially defatted dried corn germ from wet-milling, containing 2.1% (dry basis, db) crude oil and 24.7% (db) crude protein, was ground to 40-mesh particle size to produce the meal. The predominant water- and saline-soluble proteins were extracted from the corn germ meal (CGM) by using 0.1 M NaCl as solvent in a method that used homogenization, centrifugation, dialysis, and freeze-drying. The recovered freeze-dried protein extract (FDPE) was substituted (on protein content basis) for wheat flour in the standard adhesive mix for sprayline coaters. Adhesive containing CGM was also prepared in the same manner. Mixing and adhesion properties of the corn germ-based adhesives were compared with those of the industry standard adhesive. The adhesive containing FDPE showed dispersibility and mixing behaviors, as well as viscosity values that were almost identical to those of the industry standard and superior to those of CGM adhesive. The mean wet tensile strength of the adhesive containing FDPE was notably greater (1.71 MPa) than that of CGM-based adhesive (1.34 MPa) and wheat-based standard adhesive (1.38 MPa), which indicated stronger bonding. The results demonstrated that corn germ protein has the potential to be an alternative protein extender in plywood adhesives for sprayline coaters.

Maize Proximate Composition and Physical Properties Correlations to Dry-Grind Ethanol Concentrations

Dry-grind ethanol plants incur economic losses because of seasonal variations in ethanol yields. One possible cause associated with ethanol yield variability is incoming grain quality. There is little published information on factors causing variation in dry-grind ethanol concentrations. The objective of this study was to determine relationships between rapidly measurable corn quality attributes (physical parameters and chemical composition) and dry-grind ethanol concentrations. Corn samples obtained from a Midwestern ethanol plant were analyzed for physical quality parameters (test weight, kernel weight, true density, percent stress cracks, and moisture content) and composition (starch, protein, oil, and soluble sugars contents) and then processed with a laboratory-scale dry-grind procedure. There were significant (P < 0.05) variations in corn quality parameters and ethanol concentrations. Correlation coefficients were significant (P < 0.05) but low (–0.50 < r < 0.50) between starch content and final eth...