Bright greenish‐yellow fluorescence and aflatoxin in recently harvested yellow corn marketed in north carolina

Abstract

AbstractCorn kernels that exhibited bright greenish‐yellow fluorescence (BGYF) under long‐wave ultraviolet light were hand‐picked from samples of yellow corn produced in eastern North Carolina. The BGYF kernels from 113 4‐kg samples contained an average of 8665 parts per billion (ppb) aflatoxin compared to an average of 46 ppb in the non‐BGYF kernels. A regression analysis between the ppb aflatoxin concentration and the wt % BGYF kernels in 2,304 4.5‐kg samples produced the regression equation: ppb in sample =197 (wt % BGYF). The correlation coefficient for the analysis was 0.90. Testing programs to reduce aflatoxin concentrations in purchased lots of corn based on either the BGYF method or the AOAC chemical assay method were compared. The average aflatoxin concentration in lots accepted by the AOAC method was 4 ppb, 10 ppb or 18 ppb when an acceptance level of < 20 ppb, < 50 ppb or < 100 ppb, respectively, was used. For the BGYF method, the average aflatoxin concentration in accepted lots was 10 ppb, 16 ppb or 22 ppb when an acceptance level of < 0.10% BGYF, < 0.25% BGYF or < 0.50% BGYF, respectively, was used. Approximately the same percentage of lots were accepted by both methods when either the low, medium or high acceptance level was used.