Cereal Chem. 70:443-447   |  VIEW ARTICLE

Enzyme Treatment of Popcorn Ears to Facilitate Shelling.

P. J. Wu, A. Song, and S. R. Eckhoff. Copyright 1993 by the American Association of Cereal Chemists, Inc. 

An apparatus that measures shelling torque and energy during shelling of popcorn ears was used to determine the degee of kernel-to-cob attachment. The shelling energy was strongly affected by the cob moisture content, increasing exponentially as moisture content increased. To reduce the force and energy required for shelling, a commercial pectolytic enzyme was used to depolymerize the pectin substance in the abscission zone of the kernel-to-cob attachment. The enzyme absorption and equilibrium moisture content of enzyme-treated samples increased with increasing enzyme concentration. The factors and associated levels studied were: 1) enzyme concentration (0, 5, 15, 50%); 2) dipping time (1 min, 3 min; 3) holding time (1 hr, 24 hr); and 4) holding temperature (5 C, 20 C). The optimal conditions for enzyme treatment of popcorn ears in this study were 50% enzyme concentration with 1 min of dipping, held at 20 C for 1 hr after treatment. When samples were treated with 50% enzyme solution, a large variation in shelling energy and expansion volume was observed. The pectolytic enzyme reduced the maximum shelling torque and shelling energy per kernel, but no conclusions could be made about the effect of long-term storage on expansion volume and unpopped kernels.