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II Congresso sobre Tecnologia da Produção de Alimentos para Animais
Extrusion Processing – Aquatic Feed
Sajid Alavi, Ph.D.
Professor
Dept. of Grain Science & Industry
Kansas State University
U.S.A.
September 3, 2013
CBNA, Brazil
Applications - Aquatic Feed
Assortment of aquatic feed products
• Aquatic Feeds
• Floating
• Catfish
• Carp
• Slow Sinking
• Salmon
• Trout• Trout
• Fast Sinking
• Shrimp
• Piece density
• Nutritional quality
• Water stability
Product Properties:
Wenger Mfg., Inc.
Raw
Materials
Extrusion System for Aquatic Feed
The extruder is
considered
the heart of the system.Mixer
Extruder
Finished Product to Packaging
Dryer/ Cooler
Coater
Raw Materials for Aquatic Food
Raw Material Selection Criteria
• nutrition
• processability
• economic viability
• uniformity
• inclusion of high levels of fat• inclusion of high levels of fat
• water stability
• floating versus sinking feed
Type of Aquatic Feed
Floating
Sinking
Aquatic Feed Ingredients - Starch/ Cereal Grain
Minimum Starch
20
10
•Starch is structure forming – provides binding, expansion
•Also caloric source
•Source: wheat, wheat byproducts, corn, barley, rice, brewer’s
rice, tuber starches, etc.
0.75
100% floating
80
64
Role of starch in binding and expansion
15.5% 25.5%
0.25
Bulk density requirements
(pre-dryer, moisture 25-27%):
Floating: 320-400 g/L
Sinking: 450-550 g/L
Aquatic Feed Ingredients - Proteins
• Balanced amino acid profile required for proper growth
and body maintenance
• Proteinaceous ingredients up to 70% of formulation
• Protein sources: animal vs. plant• Protein sources: animal vs. plant
Protein - animal sources
• Example, fish meal, poultry meal, etc
• Good amino acid profile
• Drawbacks:
-high cost
-usually low PDI and binding characteristics
-do not contribute structurally because they do not -do not contribute structurally because they do not
expand or combine with other ingredients in the
same manner as plant proteins
- mineral deposits in screw and die; phosphorous
and calcium from fish meal with extra salt
Protein - plant sources
• Examples, soybean meal, other legumes, corn gluten
meal, etc
• High protein dispersibility index (PDI) - degree of
water solubility, compatibility with other ingredients
• Good binding; can contribute to structure
• Higher oil absorption levels possible in coating
operations
• Low cost
• Drawback: limited amino acid profile
Effect of Vegetable Protein Levels On Extrusion Moisture*
23
25
27
29
31Extrusion Moisture (%)
15
17
19
21
10 15 20 25 30 35 40
Vegetable Proteins in Recipe (%)
Extrusion Moisture (%)
* Maintaining same density and binding characteristics
Pumping fresh meat slurries into preconditioner
and extruder barrel
Pumping fresh meat slurries into preconditioner
and extruder barrel
Aquatic Feed Ingredients – Lipids
• Caloric density - more energy than starch
• Increased palatability, attracts fish
• Deliver essential free fatty acids and fat-soluble
vitamins
• Drawback: lubrication
• Usually < 15% in extruded formulations; additional • Usually < 15% in extruded formulations; additional
lipids added post-extrusion
• Sources: fish oil, soybean oil, etc.
Effects of Internal Fat Level on Expansion
% ADDED
FAT
BULK DENSITY
g/l Lb/ft3FAT g/l Lb/ft
0
5
10
15
253
308
408
528
16.0
19.3
25.5
33.0
(Wenger Mfg.)
To Maximize Lipid Inclusion Levels
• Use lipids indigenous to other ingredients
• Heat lipids to 40 - 60° C prior to inclusion
• Add late in process
• Maintain starch/functional protein levels
• Maximize mixing with extruder screw configuration
Liquid Addition
System
Product From DryerSurge Hopper
Weigh Hopper
Water Separator
Vacuum Pump
To Atmosphere
Liquid
Vacuum Fat Inclusion
Vacuum Mixer
Vessel
Finished Product
Counterflow Cooler
Water Separator
Aquatic Feed Ingredients – Fiber
• Bulking agent
• Wheat midds or bran
• Drawback – poor structure and binding
Aquatic Feed Ingredients – Micronutrient Premixes
• Fat soluble vitamins (A, D and E) are fairly stable, only
15 to 20% losses
• Water soluble vitamins (B and C) are not heat stable,
higher overages are recommended
Wenger Mfg., Inc.
20
30
850
600
1.00
3.00
U.S. Standard
Sieve
Openings
in Microns
Percent
on Sieve
Aquatic Feed Ingredients – Particle Size
30
40
50
60
80
Pan
600
425
300
250
180
0
3.00
28.0
29.0
21.0
14.0
4.0
Typical particle size for pet food and aquatic feed; 1.5 mm screen
Geometric Mean Diameter: 327 Microns
Geometric Standard Deviation: 1.58
Benefits of Proper Particle Size
• Smooth product surface
• Reduced incidence of die orifice plugging
• Ease of cooking, binding, expansion, • Ease of cooking, binding, expansion,
floatability
• Reduced product breakage and fines
• Increased water stability
• Improved retention of liquid coatings due to
small cell structure
Guidelines for Grind of Recipe
• Maximum particle size = 1/3 of die opening
• Not to exceed 1.5mm grind
800 micron 1.5 mm
Generic Formulation for Floating Aquatic Feed
Soybean meal 10
Wheat flour 28
Wheat midds 5
Fish meal 53
Premixes 2
Fat/ oil 2
Total 100%
External fat 20%
Processing of Starter Feed/ Micro
Aquatic FeedAquatic Feed
Micro Aquatic Feeds
(Starter feed, ornamental aquatic feed; 0.3 – 1.2 mm)
0.3 mm 1.2 mm
Challenges with processing of micro-
sized aquatic feeds
• High pressure development
• Throughput
• Particle size of ingredients
4R
QP∝
P = pressure, Q = throughput, R = die radius
Processing Methods for Micro Aquatic
Feeds
• Large pellet extrusion followed by crumbling
• Direct extrusion
• Spheronization• Spheronization
Drying / Cooling
Crumbling
Mixing
Sifting
Micro Aquatic Feeds – Crumbling Process
Recycle
or waste
Packaging
Crumbling
Cooking
Extrusion
Sizing
Micro Aquatic Feeds - Crumbling
Advantages Disadvantages
Low Yields
Final product sifting
Unattractive appearance
High rates
Easy recipe preparation
Low cost Unattractive appearance
Sinking only
Poor water stability
Non-homogeneous
Low cost
No special equipment
Drying / Cooling
Mixing
Micro Aquatic Feeds - Direct Extrusion
Pulverizing
Recycle
or wastePackaging
Sifting
Cooking
Extrusion
Sizing
Twin-Screw Extrusion
• better flow and operational stability• better flow and operational stability
• allows intricate shapes and small product sizes
• diversity of products and formulations
- high fat and moisture formulations
- broader range of raw materials
- high levels of fresh meat
-
• ease in cleaning (self-wiping)
Raw Material Preparation
• Hammer Mill– Limited to 2/64” (0.8mm) grind
Size
– Not suitable for micro aquatic
feed (<1.2 mm size)feed (<1.2 mm size)
• Air Swept Pulverizer– 40 mesh (420 microns)
– 80 mesh (177 microns)
Note: Ground Materials must be sifted prior to extrusion!!!
Processing Notes for Direct Extrusion
� Production rates lower for smaller size feed
� 100% sinking product can be guaranteed
� 100% floating product can not be guaranteed for � 100% floating product can not be guaranteed for
products less than 2mm
� Single screw extruder is not recommended for product
less than 1.2 mm
� Even a twin screw extruder might not be adequate for
product less than 0.8 mm
Micro Aquatic Feeds - Direct Extrusion
Advantages Disadvantages
Pasteurized
Excellent appearance
Good water stability
Low rates
Requires dedicated line (twin
screw extrusion)Good water stability
Partial floating possible
Good durability
Homogeneous product
screw extrusion)
High cost / unit of throughput
Recommendations for direct-extruded
micro-aquatic feeds
• Pulverizer (100% through 250 microns)
• Sifter (300 micron screen)
• Extruder (with oil, steam, and water injection streams screened through 250 microns)streams screened through 250 microns)
• Pneumatic conveying system
• Dryer (screen size < 250 microns)
• Sifter for sizing final product
Extruded / Flaked Aquarium Feed
Extruded pellets are flaked before drying and coating
Filled Pellets
� Antibiotics
� Vitamins
� Probiotics
� Heat Sensitive Ingredients
Co-extrusion or Filling Die
Extrudate from Extruder
FillingExtrudate from Extruder
Filled-Extruded Aquatic Feed
• Process involves one extruder plus filling pump(s)
• Post-extrusion cutting/shaping
• Prefer twin, but single can be used • Prefer twin, but single can be used
• Filling typically 15-20% of weight
• Rates of 2 ton/hr or less
• Applications for heat-sensitive fillings
• System can also be used to produce micro-pellets
Micro Aquatic Feeds - Spheronization Process
• Spheronizer
• Marumerizer
• Sphere-izer®Agglomeration System (SAS)
Spheronization
Process
• Hatched grooves - most efficient for
speherical shapes
• Radial grooves - gentler process
• Disc speeds: 200-1000 rpm
• Processing time: 3-8 min
http://spheronizer.com/html/spheronization.html
Drying / Cooling
Mixing
Process Flow for Spheronization
Pulverizing
Recycle
or wastePackaging
Sifting
Forming
Extrusion
Sizing
Sphere-izer®
Product Size (mm) System Rate (kg/h)
0.3 140-230
0.5 680-770
Product Capacities for SAS System
0.8 950-1020
1.0 1360-1450
1.2 1630-1725
Note: Any single or twin screw extrusion system can be configured for this
process as long as it can deliver the above rates.
Micro Aquatic Feed - Spheronization Process
Advantages Disadvantages
Low temp process
Moderate Investment
No pasteurization
Final product sifting
Homogeneous Product Low production rate
Low product durability
Dedicated line
Sinking feeds only
Bioprocessing and Industrial Value-Added Program (BIVAP) Facility
KSU Extrusion LabKSU Extrusion Lab
KSU Extrusion LabKSU Extrusion Lab
PilotPilot--scale twinscale twin--screw extruder screw extruder
(TX(TX--52 Wenger Manufacturing, Sabetha, KS)52 Wenger Manufacturing, Sabetha, KS)
KSU Extrusion LabKSU Extrusion Lab
PilotPilot--scale singlescale single--screw extruder screw extruder
(X(X--20, Wenger Manufacturing, Sabetha, KS)20, Wenger Manufacturing, Sabetha, KS)
KSU Extrusion LabKSU Extrusion Lab
PilotPilot--scale doublescale double--pass dryer/cooler pass dryer/cooler
((4800 4800 Series, Wenger Manufacturing, Sabetha, KS)Series, Wenger Manufacturing, Sabetha, KS)
KSU Extrusion LabKSU Extrusion Lab
LabLab--scale American Leistritz Microscale American Leistritz Micro--18 twin screw extruder18 twin screw extruder
KSU Extrusion LabKSU Extrusion Lab
KSU Extrusion LabKSU Extrusion Lab
KSU Extrusion LabKSU Extrusion Lab
KSU Extrusion LabKSU Extrusion Lab
Michael Gibson, M.S. student
Dry expanded pet food – A comparative study of
extrusion and baking processes
Michael Joseph, Ph.D. student
Novel delivery mechanisms for food assistance
and nutrition via grain sorghum and other
commodities processed using extrusion
Anubha Garg, M.S. student
Stochastic modeling of process dynamics and
structure formation in extruded cellular products
Ryan Roberts, M.S. student
Texturized vegetable proteins – understanding of
processing and chemical interactions
Impact of ‘rework’ on dry expanded pet food
processed using extrusion
Pavan Harshit Manepalli , M.S. Student
Heat and mass transfer modeling of the
extrusion process.
Natarajan Padmanabhan, M.S. student
Sorghum-based micronutrient fortified blended
foods using extrusion
Dr. Lijia Zhu
Post-doctoral research associate
Digestibility of starch and protein and
micronutrient retention in extruded products,
Dr. Bode Adedeji
Post-doctoral research associate
Value-added utilization of sorghum and
sorghum by-products using extrusion;
Sorghum distillers dried grain in aquatic
feed
Eric Maichel
Operations manager and M.S. student
Pet food processing via extrusion and
impact of different hydration regimens
KSU “Extrusion Processing – Technology
and Commercialization” Short Course
10th edition; August 2014
Thanks!