Detection of chalk in single kernels of long‐grain milled rice using imaging and visible/near‐infrared instruments

Background and objectives To maintain the competitiveness of U.S. long‐grain rice in U.S. and foreign markets, having translucent whole milled grain is critical. An objective technique to detect grain chalk, opaque areas in the grain, will provide breeders and industry with an effective tool for developing low‐chalk varieties or agronomic practices that reduce chalk occurrence. Two instruments developed at the Center for Grain and Animal Health Research, U.S. Department of Agriculture‐Agricultural Research Service (USDA‐ARS), a single‐kernel near‐infrared (SKNIR) tube instrument and a silicon‐based light‐emitting diode (SiLED) high‐speed sorter, were compared with two commercially available imaging instruments, WinSEEDLE and SeedCount used for chalk quantification. Three 2‐way chalk classifications were defined for single kernels based on visual inspection: (a)