Vegetable shortening was studied to determine if its peroxide value was stable enough after storage for one year to be used as a quality control reference material. Shortening samples were deliberately oxidized to contain low, medium, and high levels of peroxide and were then stored at 4°C for one year. Peroxide value was measured approximately every 14 d during this year. A total of 27 different determinations was made at each of the three different peroxide levels. The results indicated minimum variability within each level of peroxide during the year, and suggested that shortening would serve well as a reference material for quality control in the fats and oils industry and in food and nutrition research.
*Current address: Department of Environmental Practice, College of Veterinary Medicine, University of Tennessee, Knoxville, TN 37901-1071.