Millet Processing

1. Dr. R. B. Modi,
Assistant Professor,
College of Food Processing Technology and Bio Energy,
Anand Agricultural University, Anand

2. Introduction
Millets are collective group of small
seeded annual grasses that are grown as
grain crops, primarily on marginal land in
dry areas of temperate, sub tropical and
tropical regions.
• Earliest evidence found in Indus
civilization : 3000 BC.
• Ancient food grains first plants
domesticated for food.
• Grown in 131 countries. Millets
traditional food for 59 crore people in
Asia & Africa.
MILLETS: NUTRI-CEREALS

3. Origins and common names of millets
English Names Gujarati Names
Sorghum Jowari, Juar
Pearl Millet Bajri
Finger Millet Nagli, Bavto
Little Millet Gajro, Kuri
Foxtail Millet Kang
Proso Millet Cheno
Kodo Millet Kodra
Barnyard Millet Sama
Browntop Millet Hari Kang

4. Nutritional significance
1. Rich in Nutrients
2. Gluten-Free
3. High in Fiber
4. Low Glycemic Index
5. Cardiovascular Health: fiber, magnesium, potassium
6. Weight Management
7. Rich in Antioxidants
8. Bone Health: phosphorus, calcium
9. Aid in Reducing Inflammation
10.Easy to Digest

5. Challenges: millet consumption
• Limited Awareness
• Cultural Preferences
• Accessibility and Availability
• Perceived Inconvenience
• Marketing and Promotion
• Processing and Culinary Knowledge
• Limited Product Diversity: Economic Considerations
• Policy Support
• Limited Integration in Food Programs

6. Why? Processing Millets
• Removalof Outer Hulls
• ImprovingNutrient Bioavailability
• Diversificationof Products
• Extension of Shelf Life
• Creationof Value-AddedProducts
• CommercialViability
• Enhanced Accessibility: convenience, Ready-to-use
• AddressingConsumer Preferences
• Reduction of Anti-NutritionalFactors
• Contribution to Food Security
• Integrationinto Food Programs
• Preservation of TraditionalCrops

7. Technologies for Millet Processing
 In recent years, many researchers have developed various
technologies for millet processing
 For systematic millet processing
 with a scientific approach,
 by suitably applying and validating the existing cereal processing
technologies for millet processing.
 Classified as,
1. Post-harvest processing methods,
2. Non-thermal processing methods and
3. Thermal processing (dry and wet) methods

8. Millet Processing Technologies
Post-harvest
Processing
Dehusking
Decortication
Pearling
Irradiation
Milling
Sieving
Non-thermal
Processing
Soaking
Germination
Malting
Fermentation
Enzyme
Hydrolysis
High-Pressure
Thermal
Processing
Dry Heating
Roasting
Puffing
Popping
Microwave
Processing
Extrusion
Processing
Wet Heating
Blanching
Hydro-thermal
treatment
Nixtamalization
Acid Treatment

9. Traditional Processing
 Manual dehulling:
• Hand or using simple tools
• Small-scale operations
 Stone grinding:
• Households for small-scale milling
 Pounding:
• A mortar and pestle
• Labor-intensive
 Winnowing:
• Tossing the milletmixtureinto the air, allowing the wind
to blow away the husks while the heavier grains fall
back.
 Sun Drying:
 Fermentation:
• Fermentedporridge or fermentedflatbreads
• Natural, ↑ digestibilityand nutritionalvalue
 Traditional Cooking Techniques:
• Boiling, steaming, and roasting: to preparevarious
millet-baseddishes
 Earthenware and Cooking Pots:
• Contributeunique flavours and textures
 Matting and Threshing:
• Mats are often used for threshing milletafter harvest.
• Millet stalks are beatenon the mats to separatethe
grains from the plant material.
 Community-Based Processing:
• In many traditional settings, millet processing is a
communalactivity.
• Families or communitiescome togetherfor tasks such
as dehulling, milling, and preparing millet-basedfoods.

10. Advanced Millet Processing Technologies
◦ Precision dehulling machines:
◦ Minimum grain breakage
◦ Improvedoverall processing efficiency
◦ Opticalsorting:
◦ High-quality products
◦ Mechanized millingsystems:
◦ Efficient grinding, milling
◦ Roller mills, hammer mills, automated
equipment
◦ Consistent particle size, quality
◦ Extrusion processing lines:
◦ Wide range of millet-based snacks, breakfast
cereals etc.
◦ Advanced controls and automation for precise
processing
◦ Flash drying technology:
◦ Crispy textures in snacks and cereals
◦ Cryogenic grinding:
◦ Minimizing heat-related degradation
◦ Enzyme-assistedprocessing:
◦ Use of enzymes to break down complex
moleculesin millets
◦ Improving nutritional availability and enhancing
product characteristics
◦ Hyperspectralimaging:
◦ Rapid assessment of millet quality
◦ Quality control and ensures the consistency of
processedmillet products.
◦ Smart packaging:
◦ Monitor the freshness and quality of millet
products
◦ Extend shelf life
◦ Robotics and automation:
◦ Increase efficiency, reduce labor costs, enhance
overallprocessing capabilities
◦ Blockchain for traceability:
◦ Verifying the authenticity, origin, and
sustainability of millet products.

11. Effects of processing on nutrition of millets
Sr.
No.
Processing
methods
Positive effects Negative effects
1. Dehulling and
milling
Removing the tough outer hulls
Improve palatability and digestibility
Increase the availability of nutrients by
breaking down cell walls
The outer layers of millets may
contain some nutrients, including
fibers
2. Cooking Improves digestibility and makes certain
nutrients more bioavailable.
Heat can break down complex
carbohydrates and proteins, making them
easier for the body to absorb.
Overcooking or using excessive
water may lead to nutrient losses,
particularly water-soluble
vitamins like B vitamins
3. Fermentation Improve acceptability
Increase the bioavailability of certain
nutrients, such as minerals, and may
contribute to the synthesis of certain
vitamins
Some anti-nutritional factors may
be reduced during fermentation,
but the specific impact depends on
the type and duration of
fermentation.
4. Extrusion
processing
Long shelf life
More acceptable millet snacks
Improve the digestibility of millet-based
products
Break down complex carbohydrates and
enhance the nutritional quality
High-temperature processing can
lead to nutrient losses, particularly
heat-sensitive vitamins.
Fortification may be needed to
compensate for these losses

12. Cont.. Effects of processing on nutrition of millets
Sr.
No.
Processing
methods
Positive effects Negative effects
5. Fortification Adding essential vitamins and
minerals to millet products,
addressing specific nutrient
deficiencies
The stability of added nutrients during
processing and storage is crucial.
6. Puffing and
popping
Expanded, crunchy products
Generally do not significantly impact
the nutritional content
The addition of oils or other
ingredients increase overall calorie
content of the product.
7. Roasting Enhance the flavor and aroma
The process generally does not result
in significant nutrient losses.
The addition of fats or oils during
roasting may contribute to the overall
calorie content of the product.
8. Storage and
shelf life
Proper storage helps prevent
spoilage and maintain the nutritional
quality of millet productsover time
Extended storage, exposure to light,
and improper conditions can lead to
nutrient degradation, particularly for
sensitive vitamins

13. Effects of Millet Processing on Anti-nutrients
Anti-nutrients Effective Processing methods Implications
Phytic acid  Binds to minerals
 Soaking, fermenting, and sprouting
 Soaking millets before cooking or
incorporating fermentation in processing can
reduce phytic acid levels, improving mineral
absorption
Tannins  Inhibit the absorption of iron and other
minerals.
 Milling and cooking
 Proper milling and cooking practices can
contribute to lowering the tannin content,
making minerals more bioavailable.
Oxalates  Form insoluble crystals and interfere with the
absorption of calcium.
 Cooking and boiling
 Boiling millets, can help reduce oxalate content
and improve calcium absorption
 Fermentationalso may help
Protease inhibitors  Interferewith protein digestion.
 Cooking, roasting, and other heat treatments
 Heat treating millets thoroughly helps break
down protease inhibitors, making proteins
more digestible
Lipase inhibitors  Lipase inhibitors can interfere with fat
digestion.
 Cooking and roasting
 Adequate cooking ensures that lipase
inhibitors are deactivated, improving fat
digestion
Lectins  Lectins are proteins that can interfere with
nutrientabsorption.
 Soaking, cooking, and fermenting
 Proper processing techniques contribute to
lower lectin content, improving the overall
nutritional quality of millets
Trypsin inhibitors  Trypsin inhibitors can interfere with protein
digestion.
 Cooking and heat treatments
 Proper cooking methods are essential to
inactivate trypsin inhibitors, enhancing protein
digestibility

14. Effects of Millet Processing on Its Functionalities
Sr.
No.
Functionality Apt processing
methods
Effects / Implications
1. Particle size Milling and
grinding
• Texture, hydration, and cooking properties
• Finer particles may lead to smoother textures in
products like flours and porridges
2. Hydration
properties
Dehulling and
milling
• Expose the inner grain structure, influencing how
millets absorb and retain water during cooking or
soaking
• Important for optimizing cooking times and
ensuring the desired texture
3. Gelatinization Heat treatment:
cooking or
extrusion
• Induce gelatinization of starch in millets,
impacting their ability to form gels and influence
product texture
• Crucial in production of millet-based snacks,
influencing their structure and mouthfeel.
4. Viscosity and
thickening
properties
All processing • Processing of millets can alter their viscosity and
thickening properties
• Important for formulating products like soups,
sauces, or gluten-free baked goods
5. Gelling and
binding
Extrusion or
fermentation
• Impact the gelling and binding properties of
millets, affecting the texture and structure

15. Cont… Effects of Millet Processing on Its Functionalities
Sr.
No.
Functionality Apt processing
methods
Effects / Implications
6. Oil absorption
capacity
All processing • Structural changes, protein changes, alteration in
charges
• Important for optimizing the formulation of
extruded or fried millet-based products
7. Color and
appearance
Roasting,
toasting, or
extrusion
• Color changes due to maillard reactions and other
browning reactions
• Essential attribute influencing consumer
perception
8. Nutrient
availability
Milling, dehulling,
and cooking
• Affect the availability of nutrients in millets
• Fortification
9. Texture and
mouthfeel
All processing • Tailoring processing methods to achieve the
desired texture is essential for consumer
acceptance of millet products
• Ex. Puffing or popping can create a crispy texture
10. Shelf stability Processing and
packaging
• Ensuring stability over time is crucial for
maintaining the quality and safety of millet-based
products during storage

16. Millet based Products
 Millet Porridge or Congee
 Millet Pilaf or Pulao
 Millet Salad
 Millet Biryani
 Millet Soup
 Millet Stir-Fry
 Millet Bread
 Millet Pancakes or Crepes
 Millet Cookies and Biscuits
 Millet Granola
 Millet Pudding
 Millet Cereal
 Millet Snacks
 Millet-based Pasta
 Millet Beverages

17. Millet based products developed at
AAU, Anand
◦ Technology for nutrient rich food for women
◦ Main ingredients: Ragi, Mothbean, barley Malt
◦ Processes employed: Soaking, Germination, Kilning, Roasting, Cooking, Drying
◦ Technology for Extruded product
◦ Farali and Non-farali
◦ Ingredients: Amaranth, Corn flour, Rice flour, potato flour, WPC
◦ Processes employed: milling, extrusion cooking
◦ Technology for galactagogue laddoo
◦ Ingredients: Ragi, Garden cress,
◦ Processes employed: Soaking, Germination, Kilning, Milling, Pan Roasting

18. Moth bean
Germination (36 Hours)
Soaking (12 Hour)
Drying (60 ˚C) Drying (60 ˚C)
Roasting (150 ˚C for 60 s) Roasting (160 ˚C for 60 s)
Milling and Sieving Milling and Sieving
Moth bean flour Finger millet flour
Mixing BarleyMalt Extract
Skim milk
Heating gruel for 5 minutesat 100⁰C
Vacuumdrying (70⁰C, 700 mm of Hg)
Grinding and Sieving
MicronutrientRich Powder
Packaging and storage
Finger Millet
Germination (24 Hours)
Soaking (12 Hour)
Preparation of the
micronutrient rich
powder for women

19. 19
Process for
manufacture of
Farali Extruded
Snack
Dry ingredients
 Amaranth flour (52.5%)
 Whey protein concentrate (4.63%)
 Potato flour (42.87%)
 Salt (1.5g per 100g flour mix)
Mixing and Sieving
Pre-Conditioning
(Overnight under refrigeration, 5±1°C)
Extrusion Processing
 Barrel temperature: 129 °C
 Screw Speed: 287.5 rpm
 Feed rate: 86.2 g/min
Drying of Extrudates
(60 °C for 1 h in tray drier)
Cooling to room temperature
Packaging in metalizedlaminates
Ambientstorage (32±2°C)
Moisture adjustment of
the flour mix, 14.0 %
Sieving

20. Finger millet,
Gerden cress
Cleaning
Washing
Soaking Germination
Drying
Roasting
Milling Milled flour
Mixing with
ghee (30%) and
sugar (40%)
Forming
laddoo
Process for Galactagogue Laddoo

21. Conclusions
◦ Understanding the effects of processing on the Nutritional
and Functional properties is essential for the food
technologists, nutritionists, chefs and product developers.
◦ Millets are wonder grains, use them as much as possible in
your daily diet for healthy living.
THANK YOU