Sample preparation of some shelled treenuts and peanuts in a vertical cutter-mixer for mycotoxin analysis

A procedure has been devised for more rapid preparation of large samples of nutmeats (10-80 lb) for mycotoxin analysis without the use of grinding aids, by combining the grinding and mixing steps into one operation. Ease of cleaning equipment facilitates the preparation of several samples in a short time. The procedure was tested using shelled raw and roasted peanuts, and raw almonds, walnuts, and pecans. The reduction of particle size to pass a 20 mesh screen was attained using a 25 qt Hobart vertical cutter-mixer (VCM) equipped with standard serrated blades and a 40 qt VCM using either a standard serrated blade or a smooth-edge blade modified with sharp-edge notches to increase its cutting ability. Portions of ground composite were removed at various time intervals and particle sizes were measured. Original and check analyses of 12 naturally contaminated samples over a 3 year period indicate that this procedure is practical and reproducible.