Corn is also called maize (derived from Zea mays) is one of the most widely grown cereal grains in the world. It is a versatile feed source for raw industrial material, feed stick that makes it important in many countries.
Many people are familiar with corn as a vegetable as corn-based items like popcorn, corn syrup, and corn meal, with its complex composition, which describes its nutritional value, storage properties, and industrial applications. Nutritionists, manufacturers, exporters, food scientists, and farmers need to know about corn grain composition.
Structure of a Corn Kernel
A corn has 4 components- the outer for protection, the starchy food storage endosperm, the living germ, and a small tip cap that connects it to the cob, working side by side to nourish a growing plant. It means a corn kernel is classified as a caryopsis, which is like a simple dry fruit. Basically, the kernel has 3 main parts like pericarp, the germ, and the endosperm. These parts have unique nutritional and biochemical properties.
- Pericarp (Bran)
It is the external layer of the corn kernel and provides its protection. It is composed of hemicellulose, cellulose, and a smaller amount of lignin. However, it contains only a small portion of total kernel weight, rich in dietary Fiber, making it effective for animal feed and human digestion.
It plays an important role in kernel durability, but its strength and thickness affect how the grain resists pests, storage, and mechanical loss in the harvesting process. In addition, it contains phenolic compounds that act as antioxidants and contribute to overall health stability and benefits.
- Germ (Embryo)
It is the reproductive part of the corn kernel, active for the growth of a new corn plant. It represents only 10-12% of the weight of the kernel. It is a powerhouse of nutrients. It is rich in:
- Lipids (fats): It has corn oil, which may cause of unsaturated fatty acids like oleic and linoleic. This oil is used for industrial purposes and cooking.
- Proteins: It has high-quality proteins, which are important for both animal and human nutrition.
- Vitamins and Minerals: This is a perfect source of vitamin E, iron, magnesium, B-complex, and phosphorus.
- Endosperm
The endosperm covers the maximum part of the corn kernel, accounting for 85% of the weight. It provides high energy in the germination process. It is composed of starch and protein, and non-starch polysaccharides.
- Starch: It is based on complex carbohydrates, which is made from amylopectin and amylose. If we consider amylose, then it is a linear polymer, while amylopectin is branched, which influences industrial, gelatinization, and digestibility. Corn is used in industries as a sweetener, thickener, and stabilizer.
- Protein: Corn endosperm protein is also called zein, which is deficient in some essential acids, especially lysine, and amino acids, and tryptophan. Corn is a complete source of protein. Endosperm has functional properties like film-forming ability and water insolubility in industrial applications.
- Non-Starch Polysaccharide: It has Fiber and cellulose that contribute to the structural integrity of the kernel. It is used for animal feed.
Nutritional Composition of Corn Grain
- Carbohydrates: 70–75% (mostly starch)
- Proteins: 8–11%
- Fats: 3–5%
- Fiber: 7–9%
- Ash (minerals): 1–2%
Carbohydrates & Energy Content
Carbohydrate especially starch, is the main energy source in it. It is classified on digestibility, starch-resistant, like Fiber provides health benefits like promoting microbiota and reducing glucose in the blood.
Protein Quality
It is mixed with legumes or other supplements as a balanced diet with amino acids. Corn is a gluten-free item that serves as protein-rich feed for dairy animals.
Lipids
It contains polyunsaturated fatty acids (PUFAs_, which is beneficial for our health. It contains tocopherols act as natural antioxidants.
Minerals and Vitamins
Corn has minerals like zinc, iron, magnesium, and vitamins B1, B3, and B6. It is a source of vitamin EM and supports the immune system and cellular health.
Industrial And other Applications
Its composition determines a wide range of applications:
- Food Industry:
- Used in backing and cooking, like Corn flour, acorn starch, cornmeal for baking and cooking
- Sweeteners like corn syrup (high fructose)
- Corn cooking oil
- Animal Feed:
- It is used as a basic feed ingredient for cattle, poultry, and swine.
- Corn gluten meal provides protein, while the whole kernel supplies energy
- Biofuel and Industrial Use:
- Strach is converted into ethanol for fuel
- Corn oil is used in plastics, soaps, and cosmetics
Muhammad Arif CEO, MBA in Finance and Marketing from South Korea University. 15 years plus experience in Agriculture Waste and Animal Feed Production, Facility Management & Export