Introduction:
Finger millet is a type of plant that grows in Africa and Asia. People plant it to eat as a grain. It’s a type of grass that pollinates itself, and it probably came from another similar wild plant called Eleusine Africana. People grow it to eat because it can survive in dry areas and high places like mountains. It doesn’t need much water, and the grains it produces can be stored for a long time.
Main cultivation areas:
- Eastern and southern Africa
- Parts of India and Nepal
Structure of finger millet:
- Finger millet grains are round and usually brown but can also be white or red.
- Unlike other millets, finger millet grains have a special structure called an utricle instead of a true caryopsis.
- This unique structure allows the outer layer to be easily removed by rubbing the grains. Finger millet grains also have a five-layered testa, contributing to their high dietary fiber content.
- The main parts of finger millet grains are the pericarp (glume), germ, and endosperm. The pericarp consists of three layers: the epicarp (outer), mesocarp (middle), and endocarp (inner). Before further processing, the non-edible pericarp is removed from the kernel. The endosperm, which is the largest part, is used to make flour.
Products from processing of finger millet:
Germination:
Germination is a traditional process involving soaking whole unhusked FM grains for a period of 2 to 24 hours.
Following soaking, the grains are spread on a damp cloth or incubated at a temperature of approximately 30°C for up to 24 to 48 hours.
Germination facilitates the softening of the kernel structure and improves the nutritional composition of the grains.
This process results in increased concentrations of carbohydrates, minerals, vitamins, and essential amino acids, thereby enhancing the functional properties of the grains.
Malting:
Malting is a combined process that includes steeping, germination, drying, toasting, grinding, and sieving.
Steeping involves soaking the grains in water, followed by germination to initiate sprouting.
After germination, the grains are dried, toasted, ground into flour, and sieved to achieve desired particle size.
Malting enhances the nutritional quality of the grains by increasing fiber, crude fat, vitamin B, and mineral content.
Additionally, malting reduces antinutritional activities, such as tannins and phytic acid, resulting in grains of superior quality.
This process is commonly used in Africa, where malted FM grains are considered of the highest quality compared to other malted grains.
Millet Flour:
Milling or grinding is a traditional processing method used to convert dried and moistened FM grains into flour.
This process typically involves using wooden or stoned mortar and pestle to grind the grains into flour.
Prior to grinding, the grains may require dehulling and debranning to remove husk and bran components.
A small amount of water (approximately 10%) may be added during milling to facilitate the removal of fibrous husk.
Milling helps to remove the fibrous coarse bran or seed coat of the grains, improving digestibility and absorption of starch.
Additionally, milling removes some phytochemicals, such as phytates and tannins, thereby enhancing the bioavailability of iron in the flour.
Fermentation:
Fermentation utilizes microorganisms to ferment FM grains at room temperature.
It enhances the sensory quality, nutritional value, and inhibits spoilage microorganisms.
Fermentation products are common in Africa and contribute to the preservation of food products.
Cooking:
Cooking involves boiling FM grains until soft, then mashing or mixing with water for soups or porridge.
It reduces microbial load and improves sensory quality.
Puffing or Popping:
This method involves soaking grains, then heating with sand to produce crunchy, porous products.
It enhances digestibility, dietary fiber, and decreases antinutritional factors.
Roasting:
Roasting is a traditional method similar to puffing but with higher volume expansion.
It removes antinutritional compounds and improves shelf-life.
Extrusion:
Extrusion is a modern method for preparing ready-to-eat foods with various shapes and textures.
It increases protein digestibility and energy savings.
Radiation Process:
Food irradiation technology utilizes controlled ionizing radiation to preserve foods and improve nutritional quality.
It reduces antinutritional compounds and extends shelf-life.
Soaking:
Soaking involves immersing finger millet (FM) grains in distilled water at temperatures ranging from 30 to 60°C.
The soaking period typically lasts overnight to ensure the grains are fully steeped in water.
After soaking, the water is discarded, and the grains are thoroughly cleaned and washed with clean water to remove any foreign materials.
The cleaned grains are then dried in a hot air oven at 60°C for 90 minutes.
Soaking serves to reduce the levels of antinutritional compounds present in the grains, such as phytic acid, thereby enhancing the bioavailability of minerals like zinc.
These processing methods collectively contribute to enhancing the nutritional quality, sensory attributes, and shelf-life of finger millet and its derived products
Nutritional information of Ragi
| Characteristic | Values (g/100g) |
| Moisture | 6 |
| Crude fat | 8 |
| Ash content | 2.51 |
| Crude protein | 9 |
| Crude fibre | 2.5 |
| Carbohydrate | 73 |
Health Benefits of finger millets:
- Bone Health: Finger millet is rich in natural calcium, vital for strong bones, especially for children and the elderly. It prevents bone problems like osteoporosis and fractures.
- Antioxidant Properties: It contains antioxidants like phytates, polyphenols, and tannins, which combat aging and metabolic diseases.
- Blood Sugar Control: Phytochemicals in finger millet slow digestion, helping to stabilize blood sugar levels. It’s beneficial for diabetics, with lower glycemic response compared to rice and wheat.
- Weaning Food: Ragi flour is recommended for weaning in South India due to its rich nutrient profile.
- Anemia Recovery: High in iron, finger millet aids in anemia recovery, making it suitable for pregnant women and the elderly.
- Relaxation and Health: Finger millet consumption promotes relaxation, benefiting conditions like anxiety, depression, insomnia, and migraines.
- Green Ragi Benefits: Green ragi is suggested for blood pressure, liver disorders, asthma, weak hearts, and lactating mothers with low milk production.
Conclusion:
Finger millet, cultivated in Africa and Asia, flourishes in arid regions. Its unique structure and processing methods yield a variety of products. Germination and malting enhance nutrition, while cooking and fermentation improve flavor. Puffing and roasting extend shelf life, and extrusion offers modern options. Soaking reduces antinutritional compounds. Ragi, boasting 305 kcal/100g, is abundant in calcium, promoting bone health, and antioxidants combat aging. It stabilizes blood sugar, making it ideal for diabetics, and serves as a weaning food in South India. Green ragi benefits heart health and lactating mothers.