Roasted peanuts of China and India origin were ground in a commercial ultra-high speed grinder operated at 20,000 rpm for 2.0-5.0 min for natural peanut butter production. Grinding characteristics of both peanuts were evaluated in terms of specific energy consumption, E-sc with respect to its grinding time and mean particle size. The E-sc increased with grinding time with China peanuts having higher E-sc than India peanuts. The specific energy consumption modeled to the size reduction ratio of China and India peanuts was predicted more accurately using a linear and exponential model respectively compared to the classical models by Bond, Rittinger and Kick. From the comparison of Bond's working index, W-i, the ultra-high speed grinder is said to be more energy efficient than other comminutors in terms of its capability to produce finer particle size in shorter time than the rest. (C) 2014 The Authors. Published by Elsevier Ltd.