Cereal Chem 54:466 - 474.  |  VIEW ARTICLE
Chitin as a Measure of Fungal Growth in Stored Corn and Soybean Seed.

W. W. Donald and C. J. Mirocha. Copyright 1977 by the American Association of Cereal Chemists, Inc. 

A method of measuring the degree of fungal invasion of stored soybean and corn was developed using the analysis of chitin, measured as glucosamine, as a criterion. Soybeans at moisture contents of 10, 15.8, 19.8, and 22.3% and corn at moisture contents of 11.5, 17.6, 20.6, and 23.2% were stored for 1 month at 26 C and analyses were made weekly. The percentage of seed that yielded fungi after surface disinfection of the seed was used to confirm the information gained from chitin analyses. The chitin content of hand-picked, properly stored, wholesome corn (100-178 microgram/seed) was substantially greater than that of properly stored, wholesome soybeans (20-43 micrograms/seed). Likewise, after storage of corn at 23.2% moisture content and storage of soybeans at 22.3% moisture content for 4 weeks, mold development in corn measured as chitin content averaged 979 microgram/g seed, and that in soybean averages 261 microgram/g seed. Fungi appeared to be inhibited on soybean seed. We conclude that chitin content is an accurate and reliable measure of fungal invasion of stored seeds, and results obtained in the laboratory were substantiated by those obtained in a field case of stored corn which had molded. The method is relatively rapid (4-6 hr) when compared to the plating-out method (5-7 days) of measuring fungus invasion. The method has applicability in measuring the storability of corn and soybean seeds.