Benefits Of Using Extruders To Process Aquatic Feed

Digital re-print - March | April 2009 Feature: Extruders Feature title: Benefits of using Extruders to process aquatic feed International Aquafeed is published five times a year by Perendale Publishers Ltd of the United Kingdom. All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies, the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of information published. ©Copyright 2009 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058

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Picture 3: A closed loop system used to add wet slurry in preconditioner

Benefits of using

Operation of a pellet mill was not a complex process. On the other hand it was very difficult to make floating fish feed with the pellet mill. This means there was no control over buoyancy. At the same time micro aquatic feed (less than 2.00mm) was not possible with the pellet mill. The cooking temperature in the pelleting process was too low to be adequate for destruction of anti-nutritional factors, pathogenic organisms and viruses in the feed.

Extruders to process aquatic feed by Dr Mian N Riaz, Head Extrusion Technology Program, Texas A&M University, USA

T

here are wide varieties of methods that can be used to process aquatic feeds. For examples, in early days the most common method to feed the fish was hand feeding of mixed, homeblended diets and trash fish. Then fish farmers started using cold forming of moist diets. Pelleting presses then became popular and a majority of the fish feed were processed using pellet mill technology. Today extrusion technology is the method of choice to process aqua feed

TPC (CFU/g)

Raw Recipe

After Extrusion

240,000

9,300

Coliform 22,600 <10 because of the benefits it offers Mold count 54,540 <10 to fish farmers. Each method had its advanClostridium 16,000 <10 tages and disadvantages. Listeria positive negative The initial days of aquaculSalmonella negative negative ture were very simple which involved hand feeding of ‘trash fish’ or home-blended diets. These diets disease and virus transmission was very were simulated natural diets and were common in fresh trash fish. Feeding the very palatable but the availability was not fresh trash fish in large ponds was very consistent and providing fresh feed every labor intensive and water pollution was a day was difficult. huge issue in the ponds. Storage of the fresh fish was a problem. Pelleted aqua feed Farmers need to store these fish in cold The next phase in aquatic feed processstorage or use only fresh. At the same time

Also, Newcastle disease virus is inactivated by the extrusion and drying process where temperatures exceed 75ºC for one minute. Growth inhibitor, allergens

Floating and sinking

Table 1: Effect of Extrusion on Microbial Populations

Microbe

Extruders

Picture 2: Quick test for floating and sinking feed during extrusion

ing was use of pellet mills. Pelleted aquatic feed offered several advantages over the hand fed natural diets. For example, pelleted feed was denser and lower in moisture than the natural feed, so the long-term storage was better. Pelleting also reduced the segregation of the ingredients which was a very common problem in homemade diets. Since feed was pelleted there was less waste of feed in the water and that resulted in some improvements in water pollution IAF03-OEEFishfeed 10.12.2008 10:54 Uhr and quality. As a result, pelleting offered low processing cost and a higher processing rate to the aquatic feed industry.

Current aquatic feed manufacturing practices seem to fit into two simple categories; floating and sinking. Today 100 percent floating feed is extruded and nearly 60 percent sinking feed is extruded. Whereas, the rest of the 40 percent sinking feed is still pelleted. This is just simply because extrusion cooking offers several benefits to the aquatic feed manufactures. Following is the brief description of the advantages of the extruded feed.

Picture 4: Addition of wet slurry in the extruder barrel

Hygienic quality of extruded feed Ingredients are cooked at high temperatures and pressures. Therefore, extrusion cooking provides hygienic processing of feed destroying the pathogens and most viruses and reducing the toxin levels in the feed ingredients. Seite 1 In extrusion cooking avian influenza virus is destroyed during the processing (greater than 70ºC).

and other anti-nutritional factors largely inactivated during extrusion cooking. Table 1 shows the effect of extrusion on microorganism and their survival.

Option of producing floating or sinking feed There are many aquatic species that are cultured today. Some of them prefer to eat the pellet on the bottom of the pound where as some of species like to come on the surface to

KAHL Extruder OEE for Fish Feed ● ● Flexible Flexible production production ● ● Hydraulically Hydraulically adjustable adjustable die die ● ● Production Production of of floating, floating, slowly slowly sinking, sinking, and and water water stable stable pellets pellets ● ● Fat Fat content content up up to to 30 30 % % ● ● Pellet Pellet diameter diameter 2 2 -- 12 12 mm mm

Picture 1: Floating and sinking requirements of different species 18 | InternatIonal AquAFeed | March-april 09

AMANDUS KAHL GmbH & Co. KG, Dieselstrasse 5-9, D-21465 Reinbek / Hamburg, Phone: +49 40 727 71 0, Fax: +49 40 727 71 100 [email protected], www.akahl.de

March-april 09 | InternatIonal AquAFeed | 19

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Extruders Size of the fish and pellet

take pellet and some are column feeders 640g/l bulk density for sea water at 20C (taking the feed as it slowly sinks through (three percent salinity) and > 600g/l for the water). fresh water at 20C. For examples catfish, carp and tilapia like floating feed where as shrimp and river crab require sinking feed. On the other hand salmon, trout, sea bass/sea bream, and cod like to eat the pellet when it is slowly sinking. Picture 1 shows different species Picture 6: Micro aquatic feed made using twin screw requirements for extruder floating and sinking. Extrusion allows buoyancy control to make floating, To make slow sinking pellet it requires sinking or slow sinking feed by controlling 580-600g/l for sea water and 540-560g/l the processing parameters on one extruder. for fresh water. At neutral buoyancy pellets To make the pellet float in fresh or sea should have 520-540g/l for sea water and water requires <480g/l bulk density. In 480-520g/l for fresh water. order to make pellet sink fast requires > Extrusion cooking provides ultimate

control of the density of the products and thus buoyancy properties are managed. Picture 2 shows a quick test for floating and sinking while making feed with extruder.

The use of wet material in the pellet Extrusion allows raw aquaculture wastes and undercooked waste to be used in final feed without any problem. A reclamation system to recover wet, under-processed product that cannot be recycled through the dryer as dry rework are available to be used in extrusion processing. These are closed loop systems designed for recycling wet product with extruders. These systems allow us to use wet slurries at levels ranging from 22 to 42 percent (as a percentage of the dry recipe) depending upon the moisture contents of the slurries in single screw extruders. In a twin-screw extruder, addition of wet slurries can be as high as 60 percent depending upon the final moisture contents of the wet slurry. Picture 3 shows a closed looped system that can be used for wet material addition during extrusion in preconditioner. Picture 4 shows addition of wet slurry (more than 40 percent) in the extruder barrel.

High fat pellets

BEFORE

-

AFTER

Picture 7: Pellet soaked in water and then pressed

20 | InternatIonal AquAFeed | March-april 09

The main purpose of lipids (fats and oils) in feeds are as an energy source; to increase palatability; provide essential fatty acids; carrier for fat soluble vitamins; modified texture; density control and dust reduction. Fat level in fish diets can vary depending upon the species of the fish. Some fish, like salmon, need feed with up to 40 percent fat in PREVIOUS PAGE

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Dry with 20-50% less energy

Geelen Counterflow / T +31-475-592315 Geelen Counterflow USA Inc. / T +1-772-559-4338 Geelen Counterflow América Latina / T +54-9-2362-418899 E [email protected] / I www.geelencounterflow.com

Extruders

"Different shapes & sizes of aquatic feed can be produced using extrusion technology. Depending upon the size of the fish the pellet size can range from 0.6mm to 60mm"

Picture 9: Pellet made with extruder with very little or no fines the pellet. Extrusion processes allow feed manufacturers to produce high fat feed. With twin screw extruder a 20 percent fat can be added during extrusion of feed.Where as in single screw it is limited to around 12 percent fat addition during extrusion. Additional fat is added to the pellet using different coating systems (vacuum or atmospheric). Extruded feed can absorb more fat externally in the coating steps as compared to pelleted feed. Nowadays aquatic feed is processed to contain almost 50 percent fat which is only possible by using extrusion technology.

Different Sizes of the Pellets Different shapes and sizes of aquatic feed can be produced using extrusion technology. Depending upon the size of the fish the pellet size can range from 0.6mm to 60mm. The size of the pellet is important for the fish from juvenile to adult. A very small fish

is not going to eat 10mm pellet since the size of the pellet is bigger than the mouth. Picture 5 (behind the headline) shows different sizes of the feed made with extruders at Texas A&M University extrusion pilot plant. Picture 6 shows micro aquatic feed made using twin-screw extruder.

Extrusion processing allows us to make pellets which are very stable in water for a long duration. Picture 7 shows pellet soaked in the water and then pressed with spatula to see if it will break or not. If it breaks that means it will not be water stable.

Manufacturing soft aquatic pellets

Extrusion moisture content during processing can be controlled over a wide range, which helps to increase the water stability of the final feed. These pellets absorb more water, retains shapes for longer time and results in reduced losses of nutrients. Water Absorption and integrity after hydration is very important. It benefits pellet technical qualities and fish health. Picture 8 shows pellets disintegrate in the water after some time.

Some species like blue fin tuna prefer very soft pellet. Extrusion processing allows us to make a very soft pellet (moisture content up to 30 percent in finished feed), which is not possible by pelleting or other methods. This is accomplished using a preservation system in aquatic feeds (final product moisture of 16-28 percent) during extrusion processing. Lower Aw, (water activity) below 0.70 can be controlled with humectants at 10-12 percent levels and by reducing pH to 4.0-4.5 with acids at 1-2 percent levels or with fish silage/ solubles. Mould inhibitors are also added at 0.20.5 percent level in the formulation. Recent developments indicate that soft, gel-like aquatic pellets can be processed by coupling alkaline extrusion with a postextrusion acid bath to adjust ph and set or ‘firm up’ the texture and pellet integrity.

Water stable pellet

Picture 8: Pellet disintegrate in the water after soaking

Pellets that break down quickly in water will lose nutrients. Some farmers hydrate feed in water and nutrient solution prior to feeding and require rapid and excellent water stability for handling and feeding purposes. Pellets that breakdown quickly in the stomach of fish loses nutrients (during regurgitation) and may contribute to GDAS (Gastric dilation and air sacculitis) in certain species. 22 | InternatIonal AquAFeed | March-april 09

Water absorption of pellets

conversion rates (10 - 20 percent); higher production yields; improved digestibility and reduced feed cost. Picture 9 shows pellet made with extruder with very little or no fines.

World demands extruded feeds According to experts, the global aquatic feed market is expected to grow by over six percent per year. This estimate is based on feed sales of 21,000,000 tonnes/year in 2005. The global aquatic feed market is expected to be 28,000,000 tonnes by 2010. Based on the assumption that an extruder would run an average 5000h/year, there

is a continuing demand for extrusion lines - approximately 50-60 - to meet future demand. More

inforMation:

Dr Mian N Riaz, Head Extrusion Technology Program Food Protein R&D Center Texas A&M University College Station Texas 77843, USA, Email: mnriaz@tamu. edu

Extrusion

Superior performance, quality and controllability

Related companies: Wenger Manufacturing Inc | Contact: Doug Baldwin Tel no: +1 816 8919272 | Website: www.wenger.com Buhler AG | Contact: Christopher Rubin Tel no: +41 71 9551317| Website: www.buhlergroup.com/extrusion

MADE IN HOLLAND

Mechanical resistance of pellets Feed made using extrusion technology is more resistant to mechanical durability and produces fewer fines in the finished feed during transportation. Extruded feed has an internal matrix system which tends to increase resistance to mechanical handling of feed. Extruded feed produces approx oneto-two percent fines in the finished products during bulk handling, where as pelleted feed normally generates fiveto-eight percent fines during handling in bulk or bag form. Extrusion reduces 75 percent of the amount of fines which normally enters the water and ends up decaying on the bottom of the pond. In other words, fewer fines means: increased water stability; clearer ponds; lower fatality rates; less undesirable bacteria growth; increased

Extruder 1250 with Flextex and ECS

AL30O High capacity extruders and expanders.

Andritz Sprout

Extrusion features:

extruders provide the

• Starch cook control

newest technology for

• Bulk density control

production of the most

• Raw material flexibility

demanding extrudates

• Nutrient advantages

within aquatic feed and • Optimal product uniformity pet food industries.

• Unique visual appearance

www.extruder.nl

www.andritzsprout.com [email protected]

Almex b.v., Verlengde Ooyerhoekseweg 29, 7207 BJ Zutphen The Netherlands, tel. +31 (0)575 572666, fax +31 (0)575 572727 E-mail [email protected], www.almex.nl

GLOBAL PRESENCE Denmark · Netherlands · Germany · France · UK · USA Venezuela · Brazil · Chile · Mexico · Australia · P.R. China

March-april 09 | InternatIonal AquAFeed | 23

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It‘s the mix that makes the difference. Feed manufacturers desire high durability, reliability and sanitation. Quality feed with minimum operating costs is a must. Your needs are Buhler‘s first priority. That is why we commit ourselves to delivering seamless solutions meeting your highest requirements. Get in touch with one of our specialists worldwide and we will deliver a complete process design package, equipment, automation and customer service. You and Buhler – the perfect mix.

Bühler AG, Feed & Biomass, CH-9240 Uzwil, Switzerland, T +41 71 955 11 11, F +41 71 955 28 96 [email protected], www.buhlergroup.com

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LINKS

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The use of dietary acidifiers in salmonid nutrition Adding value to feathermeal Extruders Benefits of using Extruders to process aquatic feed

Functional aquafeeds: Dietary supplements in breakthrough pledge

Ipil ipil leaf meal as supplements to soybean and fish meal

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To purchase a paper copy of the magazine, or to subscribe to the paper edition please contact our Circulation and Subscriptions Manager on the link above. Picture 3: A closed loop system used to add wet slurry in preconditioner

conversion rates (10 - 20 percent); higher production yields; improved digestibility and reduced feed cost. Picture 9 shows pellet made with extruder with ver y little or no fines.

World demands extruded feeds According to experts, the global aquatic feed market is expected to grow by over six percent per year. This estimate is based on feed sales of 21,000,000 tonnes/year in 2005. The global aquatic feed market is expected to be 28,000,000 tonnes by 2010. Based on the assumption that an extruder would run an average 5000h/year, there

is a continuing demand for extrusion lines - approximately 50-60 - to meet future demand. More

inforMation:

Dr Mian N Riaz, Head Extrusion Technology Program Food Protein R&D Center Texas A&M University College Station Texas 77843, USA, Email: mnriaz@tamu. edu

Extruders

Operation of a pellet mill was not a complex process. On the other hand it was very difficult to make floating fish feed with the pellet mill. This means there was no control over buoyancy. At the same time micro aquatic feed (less than 2.00mm) was not possible with the pellet mill. The cooking temperature in the pelleting process was too low to be adequate for destruction of anti-nutritional factors, pathogenic organisms and viruses in the feed.

Extrusion

Superior performance, quality and controllability

Also, Newcastle disease virus is inactivated by the extrusion and drying process where temperatures exceed 75ºC for one minute. Growth inhibitor, allergens

Floating and sinking

ADVERTISERS LINKS Related companies:

Picture 2: Quick test for floating and sinking feed during extrusion

Wenger Manufacturing Inc | Contact: Doug Baldwin Tel no: +1 816 8919272 | Website: www.wenger.com Buhler AG | Contact: Christopher Rubin Tel no: +41 71 9551317| Website: www.buhlergroup.com/extrusion

ing was use of pellet mills. Pelleted aquatic feed offered several advantages over the hand fed natural diets. For example, pelleted feed was denser and lower in moisture than the natural feed, so the long-term storage was better. Pelleting also reduced the segregation of the ingredients which was a very common problem in homemade diets. Since feed was pelleted there was less waste of feed in the water and that resulted in some improvements in water pollution IAF03-OEEFishfeed 10.12.2008 10:54 Uhr and quality. As a result, pelleting offered low processing cost and a higher processing rate to the aquatic feed industry.

It‘s the mix that makes the difference. Feed manufacturers desire high durability, reliability and sanitation. Quality feed with minimum operating costs is a must. Your needs are Buhler‘s first priority. That is why we commit ourselves to delivering seamless solutions meeting your highest requirements. Get in touch with one of our specialists worldwide and we will deliver a complete process design package, equipment, automation and customer service. You and Buhler – the perfect mix.

MADE IN HOLLAND

Current aquatic feed manufacturing practices seem to fit into two simple categories; floating and sinking. Today 100 percent floating feed is extruded and nearly 60 percent sinking feed is extruded. Whereas, the rest of the 40 percent sinking feed is still pelleted. This is just simply because extrusion cooking offers several benefits to the aquatic feed manufactures. Following is the brief description of the advantages of the extruded feed.

INFORMATION FOR ADVERTISERS - CLICK HERE Picture 4: Addition of wet slurry in the extruder barrel

Hygienic quality of extruded feed Ingredients are cooked at high temperatures and pressures. Therefore, extrusion cooking provides hygienic processing of feed destroying the pathogens and most viruses and reducing the toxin levels in the feed ingredients. Seite 1 In extrusion cooking avian influenza virus is destroyed during the processing (greater than 70ºC).

and other anti-nutritional factors largely inactivated during extrusion cooking. Table 1 shows the effect of extrusion on microorganism and their survival.

conversion rates (10 - 20 percent); higher production yields; improved digestibility and reduced feed cost. Picture 9 shows pellet made with extruder with ver y little or no fines.

Option of producing floating or sinking feed

World demands extruded feeds

There are many aquatic species that are cultured today. Some of them prefer to eat the pellet on the bottom of the pound where as some of species like to come on the surface to

According to experts, the global aquatic feed market is expected to grow by over six percent per year. This estimate is based on feed sales of 21,000,000 tonnes/year in 2005. The global aquatic feed market is expected to be 28,000,000 tonnes by 2010. Based on the assumption that an extruder would run an average 5000h/year, there

Bühler AG, Feed & Biomass, CH-9240 Uzwil, Switzerland, T +41 71 955 11 11, F +41 71 955 28 96 [email protected], www.buhlergroup.com

KAHL Extruder OEE for Fish Feed

Extruder 1250 with Flextex and ECS

AL30O High capacity extruders and expanders.

Andritz Sprout

Extrusion features:

extruders provide the

• Starch cook control

newest technology for

• Bulk density control

production of the most

• Raw material flexibility

demanding extrudates

• Nutrient advantages

More

inforMation:

Dr Mian N Riaz, Head Extrusion Technology Program Food Protein R&D Center Texas A&M University College Station Texas 77843, USA, Email: mnriaz@tamu. edu

Extrusion

Superior performance, quality and controllability

Related companies: Wenger Manufacturing Inc | Contact: Doug Baldwin Tel no: +1 816 8919272 | Website: www.wenger.com Buhler AG | Contact: Christopher Rubin Tel no: +41 71 9551317| Website: www.buhlergroup.com/extrusion

● ● Flexible Flexible production production ● ● Hydraulically Hydraulically adjustable adjustable die die ● ● Production Production of of floating, floating, slowly slowly sinking, sinking, and and water water stable stable pellets pellets ● ● Fat Fat content content up up to to 30 30 % % ● ● Pellet Pellet diameter diameter 2 2 -- 12 12 mm mm

MADE IN HOLLAND

AMANDUS KAHL GmbH & Co. KG, Dieselstrasse 5-9, D-21465 Reinbek / Hamburg, Phone: +49 40 727 71 0, Fax: +49 40 727 71 100 [email protected], www.akahl.de

within aquatic feed and • Optimal product uniformity pet food industries.

is a continuing demand for extrusion lines - approximately 50-60 - to meet future demand.

• Unique visual appearance

18 | InternatIonal AquAFeed | March-april 09

Extruder 1250 with Flextex and ECS

March-april 09 | InternatIonal AquAFeed | 19

Andritz Sprout

www.andritzsprout.com [email protected]

www.extruder.nl Almex b.v., Verlengde Ooyerhoekseweg 29, 7207 BJ Zutphen The Netherlands, tel. +31 (0)575 572666, fax +31 (0)575 572727 E-mail [email protected], www.almex.nl

IAF0902.indd 19

12/03/2009 10:02

AL30O

GLOBAL PRESENCE Denmark · Netherlands · Germany · France · UK · USA Venezuela · Brazil · Chile · Mexico · Australia · P.R. China

March-april 09 | InternatIonal AquAFeed | 23

High capacity extruders and expanders.

Almex b.v., Verlengde Ooyerhoekseweg 29, 7207 BJ Zutphen The Netherlands, tel. +31 (0)575 572666, fax +31 (0)575 572727 E-mail [email protected], www.almex.nl 12/03/2009 10:04 03.02.2009 15:51:05

22 | InternatIonal AquAFeed | March-april 09

• Raw material flexibility • Nutrient advantages

within aquatic feed and • Optimal product uniformity pet food industries.

• Unique visual appearance

GLOBAL PRESENCE Denmark · Netherlands · Germany · France · UK · USA Venezuela · Brazil · Chile · Mexico · Australia · P.R. China

20 | InternatIonal AquAFeed | March-april 09

Geelen Counterflow / T +31-475-592315 Geelen Counterflow USA Inc. / T +1-772-559-4338 Geelen Counterflow América Latina / T +54-9-2362-418899 E [email protected] / I www.geelencounterflow.com

IAF0902.indd 21 adv 210x297 fc 08.indd 1

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March-april 09 | InternatIonal AquAFeed | 23

IAF0902.indd 23

IAF0902.indd 23

• Starch cook control • Bulk density control

production of the most demanding extrudates

www.andritzsprout.com [email protected]

www.extruder.nl

The solution behind the solution.

IAF0902.indd 4 Aqua_Feed-09.indd 1

Dry with 20-50% less energy

Extrusion features:

extruders provide the newest technology for

12/03/2009 10:02

12/03/2009 10:02

www.aquafeed.co.uk

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