Impact of Radiant Heating of Corn on Sensory and Functional Quality Indices during Drying and Decontamination

摘要

Radiant heating offers great promise to achieve simultaneous corn drying and decontamination of mycotoxin-producing molds. However, the heating process needs to be optimized so that food-grade corn quality is not compromised. The objective of this study was to investigate the impacts of infrared (IR) heating for drying and decontamination of corn on product sensory and functional quality indices. A newly-built, single-zone, continuous IR heating system, which utilizes catalytic IR heaters was testedto dry freshly-harvested corn at initial moisture contents of 16%, 20%, and 26% to safe storage moisture content of 13% (wet basis). Tests were conducted at three levels of IR intensity regulated by gas supply (lowest, medium and highest gas levels herein designated by Intensity 0, Intensity 50 and IntensitylOO, respectively), three IR heating durations per pass (30, 50 and 90 seconds), product-to-emitter-gap size of 450 mm, and set belt vibration intensity and air circulation levels. The corn samples were allowed to cool, after each IR heating pass, to room temperature. Corn quality indices related to drying including stress-crack formation, dried corn color and pasting properties were determined. Based on the results, there was no significant difference in the color parameters (L* a* b ) of control and experimental samples. Overall, the IR treatment did not adversely affect the corn pasting parameters. However drying parameters have to be optimized to reduce stress crack formation due to IR heating.These findings suggest that IR drying of corn could be optimized to maintaining sensory and functional quality indices the dried corn.