This document discusses extruded snack foods and the extrusion process. It describes two types of extrusion - low shear extrusion for ready-to-cook products like pasta and vermicelli, and high shear extrusion for ready-to-eat snacks. The high shear process uses higher temperatures and pressures to gelatinize starch, denature proteins, and sterilize the product. Diagrams and descriptions are provided for extrusion process flows and parameters for pasta, snacks, and analogues made from rice, soy, and other ingredients. Examples of single and twin screw extruders are shown.

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Extruded Snack Foods
S.Thiruchenduan
FST 2014/018

2. Extruded Foods
2
LOW SHEAR
(Cold Process)
Ready-to-Cook Products
Single Screw Extrusion
VERMICELLI
MACARONI
PLAIN NOODLES
PASTA
HIGH SHEAR
(HTST Process)
Ready-to-Eat Products
Single / Twin Screw
EXPANDED SNACKS
FLAT BREAD / FLAKES
BREAKFAST CEREALS
PILLOW SNACKS
MEAT ANALOGUE (TVP)
(Rice / Dal Analogue) *
(Snack Pellets) ** Ready-to-Cook Products

3. Process Flow: Low Shear Extrusion (Pasta)
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Durum Semolina
Dough Mixing
Cold Extrusion
Shaping (Die)
Drying
Cooling
Packaging

4. Pasta Varieties
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5. Process Flow Sheet - HTST - Snack Food
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Maize Flour Wheat Flour Rice Flour BG Flour Salt
Weighing
Blending
Pre – Conditioning
Extrusion-Cooking
Rotary Cutting
Drying
Oil & Flavor Application
Automatic Packing

6. Process Parameters - HTST
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Moisture Content: 10 to 20%
Temperature: 150 to 200 °C
Retention Time: 1 minute
Energy Applied: Mechanical & Thermal
Product Bulk Density: 30 to 600 g/litre
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Starch Gelatinisation + Protein Denaturation
+ Microbial Sterilisation

7. EXTRUDED SNACKS
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Courtesy: Bakerperkinsgroup.com

10. SINGLE SCREW EXTRUDER
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Courtesy: www.clextral.com

11. TWIN SCREW EXTRUDER
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Courtesy: www.clextral.com

12. Twin Screw Advantages
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Fat content 2%˃
Sticky Raw Materials
High Screw Life
Energy Saving

13. TWIN SCREW EXTRUDER - Lab. Model
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Courtesy: ANGRAU, Hyderabad

14. Lab Extruder Trial Production
14 Courtesy: ANGRAU, Hyderabad

15. TWIN SCREW EXTRUDER
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Courtesy: www.clextral.com

16. TWIN SCREW EXTRUDER LINE
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EXTRUDER SYSTEM

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SOYA DAL ANALOGUE

19. Rice Analogue - Process Flow
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Courtesy: Buhler Ltd.

20. Rice Analogue
20 Courtesy: BUHLER Ltd

21. FRK & Blended Rice
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Courtesy: WFP

22. Baked Extruded (Designer) Snacks
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