EVALUATION OF SOYBEAN SEED-COAT CRACKING DURING DRYING .2. USING MRI

MRI techniques were developed and employed for non-destructive and non invasive study of seedcoat cracking in low moisture soybean kernels du ring heated air drying. Proton density image and transient moisture di stribution profile of a single soybean kernel can be obtained using MR I. These MRI techniques proved to be particularly useful for the conti nuous observation of initiation and propagation of seedcoat cracking d uring the entire period of drying process without interruption. The pr oton density images of soybean kernels showed that seedcoat cracking w as initiated perpendicular to the long axis of the kernel near the hil um. The transient moisture distribution profiles in soybean kernels du ring drying indicate that moisture gradient developed during drying wa s higher in the seedcoat than in the cotyledon. Drying temperature and initial average moisture content were positively correlated with the soybean seedcoat cracking, The location of the cracks was also associa ted with the moisture gradient. The length of the cracks could be meas ured using MRI images.