P. John Rayapati

Fate of Maize DNA During Steeping, Wet-Milling, and Processing

ABSTRACT The fate of DNA during steeping, wet-milling, and subsequent processing of maize was examined using a sensitive polymerase chain reaction (PCR-based) detection system. The system used specific amplification of maize DNA sequences by primers generated toward plant nuclear- and chloroplast-encoded genes. The PCR method facilitated analysis of DNA content in food products, which is an important issue in use of genetically modified organisms. In a conventional laboratory wet-milling countercurrent steep system, DNA was detected in maize kernels throughout the process but was not found in steepwater. After kernels were wet-milled, DNA was detected in the starch, germ, coarse fiber, and wet gluten fractions but not in the fine fiber fraction. When dried by heating at 135°C for 2 hr, DNA was degraded to undetectable levels in the wet-milled gluten fraction and hydrated kernels. DNA was not detected in feed pellets, starch, dextrose, sorbitol, or high-fructose maize syrup made from industrial wet-milled ...