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Corn Export Cargo Quality Report 2016/2017

Contents

  1. Export Cargo Quality Highlights
  2. Introduction
  3. Quality Test Results
  4. Moisture
  5. Chemical Composition
  6. Physical Factors
  7. Mycotoxins
  8. U.S. Corn Export System
  9. U.S. Corn Export Flow
  10. Impact of the Corn Market Channel on Quality
  11. U.S. Government Inspection and Grading
  12. Survey & Statistical Analysis Methods
  13. Survey Design and Sampling
  14. Statistical Analysis
  15. Testing Analysis Methods
  16. Moisture
  17. Chemical Composition
  18. Physical Factors
  19. Mycotoxin Testing
  20. U.S. Corn Grades And Requirements
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C. CHEMICAL COMPOSITION

NIR Proximate Analysis

The chemical composition (protein, oil, and starch concentrations) of corn is measured using near-infrared (NIR) transmittance spectroscopy. The technology uses unique interactions of specific wavelengths of light with each sample. It is calibrated to traditional chemistry methods, to predict the concentrations of oil, protein, and starch in the sample. This procedure is nondestructive to the corn.

Chemical composition tests for protein, oil, and starch concentrations in fall 2016 and continuing in spring 2017 were conducted using a 550- to 600- gram sample in a whole-kernel Foss Infratec 1241 NIR transmittance instrument. The instrument was calibrated to chemical tests, and the standard error of predictions for protein, oil, and starch concentrations were about 0.27%, 0.25%, and 0.66%, respectively. Comparisons of the Foss Infratec 1229 used in previous reports to the new Foss Infratec 1241 on 21 laboratory check samples showed the instruments averaged within 0.25%, 0.26%, and 0.25% of each other for protein, oil, and starch concentrations, respectively. Results are reported on a dry basis percentage (percent of non-water material).