1. Postdoctoral research associate and professor, respectively, Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583-0919.
2. Corresponding author. E-mail: djackson1@unl.edu. Fax: 402-472-1693.
3. USDA-ARS, 362C Plant Science Hall, University of Nebraska, Lincoln, NE 68583-0915. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable.
4. Professor, Department of Biometry, University of Nebraska, Lincoln, NE 68583-0712.