Maize is the most versatile crop as it is loaded with rich nutrients and widely consumed worldwide, both in raw and processed forms. Until the industrial modification of crops into starch, it was primarily used in papyrus bonding, paper production, and cosmetic creams. Today, maize is the primary source of modified starch, contributing to over 85% of the starch produced worldwide. The demand for starch from maize has increased multifold due to the rising population and disposable income of consumers.
Maize starch is applied in various industries such as food & beverages, pharma, textiles, and paper & board, to name a few. Besides being used as a sweetener, maize starch enhances the quality and usability of the end-product by acting as a binding agent, thickening agent, stabilizer, adhesive, and providing stiffness and smooth texture.
Maize has the highest starch content among the whole grain, making it one of the starchiest staple foods. Maize starch is produced by extracting a fine powder from the starchy centre of maize kernels known as the endosperm. The process of “maize wet-milling” enables utilizing each part of the grain to produce quality products. Further processing of maize starch generates different kinds of modified starch products, such as Maltodextrin, Dextrose, Glucose Syrups, Polyols, etc., used in different industrial applications.
In the starch-making process, many by-products are released in the form of maize bran, gluten, maize germ and steep liquor. These are nutrient-rich substances and contain carbs, proteins, oils and minerals. Previously discarded as “waste,” these by-products are now utilized in other industries, such as poultry, animal feed, and edible oil production. (For instance, maize gluten is extremely rich in proteins and is used as animal fodder. Maize germ is used as a raw material in producing edible oil.)
The annual maize production in India is around 21 million metric tonnes. Most of the maize produced in India is consumed in its unprocessed form.
Maize is one of the most vital raw materials in modified starch production. Consequently, its usage is highly diverse and present in many operations and applications.
The starch amylose and amylopectin molecules have distinctive characteristics that provide a wide array of properties. The functional diversity of amylose and amylopectin molecules with a wide array of distinctive properties makes native and modified maize starch an adaptable and valuable industry resource. Therefore, these starches are widely applied as the food industry’s thickener, gelling agent, bulking agent, and water retention agent. Meanwhile, about 40% of maize starch from wet-milled processing is applied for the non-food industry, such as paper-making, textiles, laundry, gypsum wallboard, adhesives, bio-plastics, and glass-fibre sizing.
Food industry
Maize starch is used in the food industry as a binding and thickening agent for sauces, gravies and soups. In addition, it is used as a texture enhancer in foods and beverages. It is usually mixed with a cold liquid to create a slurry and then added with a hot liquid to thicken. This usually forms a translucent mixture.
It is gluten-free since it lacks proteins, fats, and fibres. As a result, it is widely used in the gluten-free baking of bread, confectionaries, pasta etc. It is also used as a substitute for eggs in baking.
Pharmaceuticals
Maize starch was one of the earliest used excipients for medicinal dosage due to its non-toxic and non-irritant properties. Modified maize starch is used as a disintegrant, diluent and binder. It ensures that the tablets and medicines break down easily and dissolve, enabling the drug to release easily.
It is an anti-sticking agent in medical products using latex-like surgical gloves, condoms and diaphragms.
Furthermore, it also acts as an energy source, and its intake helps prevent low blood sugar.
Dry maize starch powder is used as a filler in certain cosmetic products.
Paper Industry
The paper industry generally uses maize starch as an adhesive and bonding agent. It increases the dry strength and improves the surface and stiffness of the paper, which ensures higher productivity in the production process. In addition, it is used as a surface sizing agent as it improves appearance, restrains ink penetration and creates a firm surface suitable for better writing and printing. Finally, as a coating agent, maize starch enhances printability and provides a glossy and fine texture for the paper.
Textile Industry
Textile industries use maize starch to provide stiffness and add weight to the cloth. It is a significant component in enhancing the strength and elasticity of textiles while also helping in improving the appearance of the fabric. Furthermore, it works as a penetrating agent, binder, emulsifier, softener and lubricant ensuring the uniform binding of the yarn.
Modified maize starch plays an essential role in textiles and fabrics mixing, printing and finishing. Moreover, the fabrics made from maize fibre are easy to care for, cheap and very comfortable to wear.
Oil and gas
During oil and natural gas drilling, there are huge amounts of fluid loss due to the increased usage of carboxymethyl cellulose (CMC). To prevent this, maize starch has been used to improve the properties of water-based muds under these high-pressure, high-temperature (HPHT) conditions. The modified starch-added muds replace the CMCs since they can withstand the HPHT conditions.