INDIVIDUAL KERNEL MOISTURE-CONTENT OF PRESHELLED AND SHELLED POPCORN AND EQUILIBRIUM ISOTHERMS OF POPCORN KERNELS OF DIFFERENT SIZES

Commercial ear popcorn was hand-shelled at 16.5 and 13.6% bulk moistur e content. The individual kernel moisture content of ear popcorn incre ased from the tip to the butt. The maximum difference was four percent age points. No trend was observed in kernel moisture content around th e same ring on the cob. Because of this finding, a survey was conducte d of individual kernel moisture content for commercially packaged popc orn in glass jars. A wide range (11.5-16.8%) of kernel moisture conten t was detected. This variation appears to be caused by factors such as growing conditions, mixture of hybrids, and postharvest processing an d storage conditions, such as hysteresis caused by overdrying. In addi tion, an investigation was conducted to determine the equilibrium isot herms of two varieties of commercial shelled popcorn with different ke rnel sizes. No significant difference was found in equilibrium moistur e content with respect to kernel sizes.