Extrusion cooking

1. Dr. R. T. Patil, PS & Ex-Director, CIPHET, Ldh.
Central Institute of Agricultural Engineering,
Bhopal 462 038 (MP)
Application of Extrusion Cooking in
Soy Coarse Cereal Processing

2. Nutritional Values of Soybeans
• Soybeans are very high in
protein content,
• Contains a lot of fibre and are
rich in calcium, magnesium
• Soy protein has a high
biological value and contains
all the essential amino acids.
• Soy oil is rich in unsaturated
fatty acids and low in
saturated fatty acids
• Phytochemicals found in soy
are isoflavones, genistein,
saponins, beta-sitosterol,
daidzein.
SOYABEAN: Glycine max Merr.
Moisture (g): 8.1
Protein (g): 43.2
Fat (g): 19.5
Minerals (g): 4.6
Crude Fiber (g): 3.7
Carbohydrates (g): 20.9
Energy (Kcal): 432
Calcium (mg): 240
Phosphorus (mg): 690
Iron (mg): 10.4
Carotene (mcg): 426
Thiamine (mg): 0.73
Riboflavin (mg): 0.39
Niacin (mg): 3.2
Folic Acid (free) (mcg): 8.65
Folic Acid (Total) (mcg): 100

3. Nutritional Values of Coarse Cereals
Ragi:
Eleusine Coracana
Sorghum:
Sorghum vulgare
Pearl Millet:
Pennisetum typhoideum
Moisture (g): 13.1
Protein (g): 7.3
Fat (g): 1.3
Minerals (g): 2.7
Crude Fiber (g): 3.6
Carbohydrates (g): 72.0
Energy (Kcal): 328
Calcium (mg): 344
Phosphorus (mg): 283
Iron (mg): 3.9
Carotene (mcg): 42
Thiamine (mg): 0.42
Riboflavin (mg): 0.19
Niacin (mg): 1.1
Folic Acid (F) (mcg): 52
Folic Acid (T) (mcg): 8.3
Moisture (g): 11.9
Protein (g): 10.4
Fat (g): 1.9
Minerals (g): 1.6
Crude Fiber (g): 1.6
Carbohydrates (g): 72.6
Energy (Kcal): 349
Calcium (mg): 25
Phosphorus (mg): 222
Iron (mg): 4.1
Carotene (mcg): 47
Thiamine (mg): 0.37
Riboflavin (mg): 0.13
Niacin (mg): 3.1
Total B6 (mg): 0.21
Folic Acid (F) (mcg): 14.0
Folic Acid (T) (mcg): 20.0
Moisture (g): 12.4
Protein (g): 11.6
Fat (g): 5.0
Minerals (g): 2.3
Crude Fiber (g): 1.2
Carbohydrates (g): 67.5
Energy (Kcal): 361
Calcium (mg): 42
Phosphorus (mg): 296
Iron (mg): 8.0
Carotene (mcg): 132
Thiamine (mg): 0.33
Riboflavin (mg): 0.25
Niacin (mg): 2.3
Folic Acid (F) (mcg): 14.7
Folic Acid (T) (mcg): 45.5

4. Health Benefits of Soybeans
• Reduction of triglycerides and
LDL cholesterol due to soybean
protein as well as isoflavones.
• Soy isoflavones also help to
ease menopausal symptoms and
reduce the risk for certain cancer,
including prostate cancer and
breast cancer.
• Genistein inhibits the enzyme
tyrosine kinase, which plays a
role in cell division and tumor
growth.
• Saponins have an anti-
thrombotic and liver protecting
action.
• Soy isoflavones may help
to reduce body weight.

5. • A single machine conveys, mixes, kneads,
cooks and forms in one continuous
process.
• The energy input comes mainly from the
conversion of mechanical to thermal
energy.
• Extruded food materials undergo various
transformations like starch gelatinization,
fragmentation and protein denaturation
• It is widely used to manufacture breakfast
cereals and snacks and other emerging
application to increase process efficiencies.
Extrusion Processing

6. • Low-shear (forming) extruders: used to increase
density of material that is generally high in moisture
(e.g. pasta) using low screw speeds.
• Medium-shear stress: used to process raw materials
with lower moisture content with higher energy
inputs (e.g. pet foods, aquatic feeds, texturized
vegetable protein).
• High-shear stress: where extrusion speeds and
energy inputs are high to process low-moisture raw
materials in a short length-to-diameter ratio barrel.
Highly expanded products are obtained (e.g. snacks,
breakfast cereals).
Classification of Extrusion Processes

7. Single-screw extruders
Consists of a rotating extruder shaft with screw elements (may be
segmented screws and shearlocks), a stationary barrel housing
(maybe segment sections), and a die and knife assembly.
Twin screw extruders
•Counter-rotating twin-screw extruders (screws move in opposing
directions, low speeds and long residence times) for production of
gum, jelly and licorice confections.
•Co-rotating twin-screw extruders(screws move in same direction,
high degree of heat transfer but not forced conveyance) for snack
products.
•An intermeshing screw producing a positive pumping
action, efficient mixing and self-cleaning.
•Non-intermeshing screws depend on friction for extrusion,
like single-screw extruders
Classification of Extruders

9. • Second generation snacks: are those that
expand when they come out of the extruder.
This is the most popular type of expanded
snack.
• Third generation snacks: or pellets do not
expand when they come out of the extruder.
After storage, the pellets are puffed by frying,
microwave heating or hot air puffing.
Expanded Snacks Produced
by Extrusion

10. • Capacity 100 kg /h
• Oil recovery 65 – 70 % in
single pass
• Good quality MFSF (Protein
48 %, Fat 6-8 %, TI
Inactivation up to 70 %)
•Development of commercial
unit ( 250 kg /h) in progress
in collaboration with a
manufacturer
Integral Extrusion Expelling Unit

11. Application of Expander in Oil Extraction
This is used for Soya beans, cotton seed, wet corn
germ, sunflower seed, rapeseed, salseed and
many of the seeds and (fully or pre-pressed) oil
cakes to make the meat porous and homogenous.

12. At CIPHET Ludhiana, we developed
• Ready-To-Eat snack foods from minor millet viz.,
foxtail millet, proso millet, little millet, barnyard millet
and kodo millet using low cost collet extruder.
• The retexturized fruit bars were prepared
incorporating dehulled bengal gram blended maize
extrudates with banana (Musa paradisaca L.), mango
(Magnifera indica L.) and papaya (Carica papaya L.)
fruit pulps. Using twin screw extruder
Extrusion of millets/fruit pulp
for health foods

13. Extruded Products from Coarse Cereals
• Extrusion is a novel technology
to produce expanded blended
products under high
temperature short time regime
• CIPHET has modified the low
cost collet extruder to produce
expanded ready to eat snacks
using rice and pulse brokens.
• The cost of the unit is Rs 2
Lakh, capacity 25 kg/h, cost of
accessories Rs. 2 lakh and thus
earn about minimum of Rs.
50,000 per month

14. Extruded Products from Soy-Coarse
Cereals Blends
Soy-Sorghum 15% soy
flour
Soy-Pearl Millet 5-10%
soy flour
Coarse cereals 60%,
30% soy flour and 10%
NFSM
Pearl Millet
Sorghum & Millets

15. • More homogeneous and consistent cooking
process minimum waste.
• Extrusion is a very efficient and clean process,
since all steps can be done in-line: mixing,
cooking, forming, cooling, and cutting.
• Modular designs allow changing from one
product to another product, color, or shape to
be done within minutes—a significant process
efficiency.
• Twin-screw extruders are largely self-cleaning,
an advantage from the viewpoint of both
sanitation and labor savings.
Conclusion

16. Extrusion is a clean technology
to deliver variety of designer &
nutritionally balanced foods
Thanks