Why Your Corn Flour Might Be Failing ? How to Test It ?
Chemical and Physical Quality Control Parameters of Corn Kernels and Corn Flour
Corn (Zea mays L.) is one of the most important cereal crops worldwide in terms of production and applications. Corn kernels and the flour produced from them are used as raw materials for human food, animal feed, and a wide range of industrial products such as starch, oil, and biofuels. Therefore, ensuring the quality of corn kernels and flour is critical for nutritional value, processability, and shelf life.
Within corn quality control, chemical parameters (moisture, ash content, protein, fat, starch level, etc.) and physical parameters (kernel hardness, color, particle size distribution, i.e., granulometry) are analyzed. These quality parameters directly affect the suitability of corn for different applications and the safety of the product.
Moisture content determines storage stability — high moisture accelerates mold growth and mycotoxin formation — while kernel hardness affects milling efficiency and the texture of the final product. This article reviews the main quality control parameters of corn kernels and corn flour, presents typical value ranges, and emphasizes their importance.
Chemical and Physical Characteristics of Corn for Quality Control
Standard methods are used for measuring chemical and physical parameters: moisture content is usually determined by drying at 105 °C or under vacuum (ISO 6540, AACC 44-15.02). Ash content is measured by burning the sample in a muffle furnace at 550 °C (ISO 749). Protein is determined by the Kjeldahl or Dumas method, converting nitrogen to protein (AACC 46-16.01). Fat content is determined by Soxhlet extraction (AOAC 920.85). Starch content can be measured enzymatically or indirectly and typically ranges from 60–75%.
Physical properties are analyzed through color measurement (CIELAB L*, a*, b*), kernel hardness (floatation test, crushing/grinding devices, or hectoliter weight), and granulometry (sieving or laser diffraction). All measurements are performed on representative samples, with control samples ensuring accuracy.
Bastak Solution
Moisture Measurement: The Bastak 16000 allows moisture measurement of 40 types of raw materials in 8–10 seconds using a dielectric principle.
Ash Content: The Bastak 12000 measures ash; whole grain flour: 1.2–1.5%; refined flour: 0.3–0.5%.
Protein Measurement: Corn protein content is generally 8–11%; slightly lower in refined flours.
Fat Content: Whole grain flour: 3–5%; lower in flour with removed germ.
Starch Content: 60–75%; measured using the Bastak polarimeter.
ICC Standardization and Global Solution:
Chemical and physical analysis determines the suitability, nutritional value, and safety of corn. Process optimization is ensured with 54 different Bastak devices certified to ICC 189 and 192 standards.
