Juhi Ranjan, Rupesh Kumar and Rohit Anand
Ph.D. Scholar, Division of Agricultural Engineering,
 ICAR-IARI, New Delhi

Millet, classified within the Poaceae family, are diminutive-seeded grains. They offer notable health advantages and possess higher nutraceutical value when compared to major cereal crops. Theyare referred to as "Nutri-cereals." Millets serve as a significant source of human sustenance, and their cultivation has progressively risen in recent decades to cater to the dietary needs of the expanding global population. These grains are an exceptional reservoir of essential nutrients, including proteins, carbohydrates, fats, minerals, vitamins, and bioactive compounds. Millets encompass a group of cereal crops characterized by small seeds, adapted for growth in a variety of tropical and subtropical climates, and can thrive with minimal inputs.India holds the position of the world leader in millet production, contributing around 40% of the global output, with an annual production of about 16 million metric tonnes. The country is also the second-largest millet exporter. Millet cultivation spans across 21 states within the country, with significant focus in regions such as Rajasthan, Maharashtra, Karnataka, Andhra Pradesh, Tamil Nadu, Kerala, Telangana, Uttarakhand, Jharkhand, Madhya Pradesh, Haryana, and Gujarat. Among food grains in India, sorghum ranks fourth in terms of both area (3.84 million hectares) and production (4.31 million metric tonnes), trailing behind rice, wheat, and maize. Bajra (pearl millet) contributes over 50% of the nation's millet acreage, with its production matching this percentage closely. India leads the world in the production of specific millet varieties: Barnyard (99.9%), Finger (53.3%), Kodo (100%), Little millet (100%), and pearl millet (44.5%), generating approximately 12.46 million metric tonnes from an 8.87-million-hectare expanse. Notably, millets have gained popularity due to their gluten-free nature. Nutritionally, millets are abundant in polyphenols, antioxidants, and dietary fiber, crucial for optimal bodily functions.Given the increasing global importance of millets and the declaration of the International Year of Millets (IYoM) 2023 by the United Nations General Assembly, it is crucial for India to take the lead in popularizing millets and integrating them into common diets.

Fig. 1. Major millet producing countries in the world in 2022. (Source: United States Department of Agriculture & YES BANK Analysis)

Millet processing:

Traditional primary processing method:

Modern Processing methods:

Cleaning:Cleaning millet is an essential step in its processing that involves removing impurities, debris, and any foreign matter to ensure its safety, quality, and nutritional value. Millet is a group of small-seeded grains that are highly nutritious and have gained popularity due to their gluten-free nature and health benefits. Proper cleaning of millet ensures that the final product is free from contaminants and maintains its integrity.

Dehulling: Also known as hulling or husking, is the process of removing the outer layer of a millet grain, known as the hull or husk. The hull is the protective covering that surrounds the edible part of the grain. Dehulling millet is often done to improve the texture, digestibility, and cooking properties of the grain.

Sorting: Sorting millet is a crucial step in its processing that involves separating the grains based on their size, color, and quality. Sorting ensures that only uniform and high-quality millet grains make their way into the final product, enhancing its appearance, nutritional value, and overall market value.

Polishing: Polishing millets is a process that involves removing the outer layer of the grains to achieve a smoother and more refined appearance. This process can improve the texture and visual appeal of millet grains, making them more desirable for consumption and enhancing their market value. The polishing process for millets typically involves abrasion, friction, or mechanical action to remove the outer layer of the grains.

Grading: Grading millet is a pivotal step in the processing and packaging of millet grains, involving the classification of grains based on various characteristics such as size, shape, color, and quality. Grading ensures that the final product meets specific standards, allowing for consistency and uniformity in appearance, texture, and overall quality.

Size Grading: Size grading involves categorizing millet grains into different size groups to achieve uniformity, ensuring even cooking and appearance in the final product.

Screens and Sieves: Use screens or sieves with varying mesh sizes. As the grains pass through the screens, they are separated into different size categories. Grains that don't fit through a specific mesh size are collected separately.

Color Grading: Color grading focuses on segregating millet grains based on their color to achieve uniformity and visual appeal.

Visual Inspection: Trained personnel visually inspect the grains and manually remove any grains that do not meet the desired color standards.

Quality Grading: Quality grading involves separating millet grains based on their overall quality, which can encompass factors like defects, foreign particles, and damage.

Milling: Milling millet involves the process of transforming whole millet grains into various forms such as flour, meal, or grits. This process breaks down the grains to make them more suitable for cooking and consumption. Milling machines play a pivotal role in this process by mechanically grinding, crushing, or breaking down the millet grains into smaller particles.The milling process involves breaking down the millet grains into smaller particles. Some milling machinesare using for milling as-

Stone Mills: Stone mills are traditional milling machines that use two grinding stones, usually made of granite or other durable materials. The millet grains are fed into the gap between the rotating upper and stationary lower stones. The grinding stones crush the grains, gradually reducing them to smaller particles.

Hammer Mills: Hammer mills use rotating hammers or blades to crush the grains.The millet grains are fed into the grinding chamber, where the hammers repeatedly impact the grains, breaking them into smaller pieces. The resulting particles pass through a screen that controls the size of the final product.

Roller Mills: Roller mills consist of two or more rollers that rotate in opposite directions.The millet grains are fed between the rollers, which crush and flatten them, producing particles of uniform size. Roller mills are often used for producing flour or semolina.

Disc Mills: Disc mills use rotating discs to grind and break down the millet grains.The grains are fed into the gap between the discs, and the friction between the rotating discs and the grains crushes them into smaller particles. Disc mills are efficient for producing fine flour or meal.

Roasting: Roasting millet is a cooking technique that involves dry-heating millet grains over direct heat to develop flavour, aroma, and texture. Roasting not only enhances the nutty and earthy taste of millet but also changes its overall characteristics, making it suitable for various culinary applications. The roasting process involves applying dry heat to the millet grains to achieve the desired flavor and texture.

Germination: Germination of millet involves the process of soaking and sprouting millet grains, which enhances their nutritional value, digestibility, and potential culinary applications. Germinated millet is often used to create sprouted millet products, which offer increased nutrient content and unique flavors. Germination involves allowing the millet grains to absorb water and initiate sprouting.

Fermentation: Fermentation of millet is a natural and traditional process that involves the breakdown of millet grains through the activity of microorganisms such as bacteria and yeast. This process can lead to the production of various fermented millet products that offer unique flavors, improved nutritional value, and enhanced digestibility. Fermenting millet involves the natural activity of microorganisms that break down the millet's components. The specific process can vary based on the desired end product and the traditional practices of a particular region.

Puffing: Puffing of millet grains, also known as "puffed millet," is a process that involves subjecting millet grains to high heat and pressure, causing them to rapidly expand and create a light and airy texture. This technique is similar to the process used to make popcorn and puffed rice.

Flaking: Flaking of millet grain, also known as "flaked millet," is a process that involves flattening millet grains to create thin, flattened flakes. This process enhances the texture, appearance, and versatility of millet, making it suitable for various culinary applications. Flaked millet can be used in breakfast cereals, baked goods, and more.

Extrusion: Extrusion of millet is a food processing technique that involves forcing millet-based dough through a specialized machine called an extruder. This process uses heat, pressure, and shear to transform the dough into a variety of shapes and textures. Extrusion is commonly used to create various snack foods, breakfast cereals, and other processed millet products.Extrusion equipment uses a specialized extruder, which consists of a barrel, screw, die, and cutting mechanism.The extrusion process involves passing millet-based dough through an extruder to create the desired shape and texture. The prepared dough is fed into the extruder's barrel. The barrel is heated to create the necessary conditions for cooking and forming the dough.Inside the barrel, screws rotate and push the dough forward. As the dough moves through the extruder, it is subjected to heat and shear, which cooks the dough and transforms its texture.The combination of pressure and heat causes the dough to soften and expand. Steam is generated within the dough, leading to its expansion.As the dough reaches the end of the barrel, it passes through a specially designed die that shapes the extruded product into a specific form, such as rings, loops, or flakes.After passing through the die, the extruded product is cut into the desired lengths. The product is then rapidly cooled to set its shape and texture.After extrusion, the product can be flavored or coated with seasonings or additives. Once flavored, the extruded millet product is packaged in airtight containers to maintain its texture and freshness.

Value addition: Value addition of millet products involves taking raw millet grains and transforming them into processed or manufactured items that offer enhanced nutritional content, improved shelf life, diverse culinary applications, and increased market appeal. These value-added millet products cater to consumer preferences, convenience, and health benefits. Some value-added millets-based products are- Sorghum Roti, ugali, popped sorghum, malt food, snack/roasted mix grains. Pearl millet Roti, ugali, fermented food products, pizza, roasted mix grains, finger millet Roti, dumpling, popped millet, malt food and many more.

Sustainable millet processing practices have emerged as a beacon of hope for our planet's health and well-being. By adopting innovative techniques that preserve nutrients, reduce waste, and minimize environmental impact, we are not only nurturing our bodies but also safeguarding our precious ecosystems. Millet's versatility in the kitchen, combined with its resilience in the field, makes it a valuable asset in the fight against food insecurity and climate change. It is a reminder that our choices as consumers and producers can have a profound impact on the future of our planet. By embracing millets and sustainable processing methods, we can contribute to a healthier world for ourselves and generations to come.


1. Dayakar Rao, B., Bhaskarachary, K., Arlene Christina, G. D., Sudha Devi, G., Vilas, A. T., &Tonapi, A. (2017). Nutritional and health benefits of millets. ICAR_Indian Institute of Millets Research (IIMR) Rajendranagar, Hyderabad, 2.

2. Kadam, S. R., Bhingarde, B. B., Gore, T. B., &Baheti, H. S. (2023). Millets: Magical Health Promoting Nutritious Crops. Just Agriculture Multidisciplinary newsletter, 3(8), 327-335.

3. Ranjan J, Ramya CS and Sahni RK. 2023. Millet Production in India: Nurturing Sustainable Futures. Ropan (RNI No. CHHBIL/2020/79641), September 2023. Pp. 33-36.

4. Saleh, A. S., Zhang, Q., Chen, J., & Shen, Q. (2013). Millet grains: nutritional quality, processing, and potential health benefits. Comprehensive reviews in food science and food safety, 12(3), 281-295.

5. United States Department of Agriculture & YES BANK Analysis.