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!