QUALITY CHANGES OF SWEET CORN CULTIVARS DURING COLD STORAGE

Corn (Zea mays L.) is one of the most important food crops in world agricultural economy, being the staple food crop of several American civilizations. It is the most efficient converter of the sun’s energy into food and has a great potential as a food for the “new world agriculture” in the future.

Corn maturity is commonly assessed by moisture content, silk color, and visible appearance of kernel juice. Kernel moisture content should be 70- 75 % on a fresh weight basis, silk color should be brown, and the best kernels are considered to be those in the “milk” stage. The nail test is used for the determination of “milk” stage kernels, in which the thumbnail is thrust into the kernel to detect the appearance of milky exudates. Corn of this quality is harvested for fresh consumption (Kasım et al., 1997).

Undesired post-harvest quality changes in corn include shriveling, denting, increases in pericarp mass, and conversion of sugar to starch. These undesirable changes can be controlled or attenuated by storage at low temperature and by packaging. Sweet corn is not sensitive to chilling injury, and thus its storage temperatures should be reduced to as low as 0 ° C with relative humidity kept between 90- 98 %.