Raw Materials and Their Impact on the Extrusion of Aqua Feeds Presented by: Brian Plattner, PE Wenger Manufacturing, Inc.

Fundamentals of Extrusion Processing Recipe Hardware Software Product Specifications

Raw Materials Raw materials and their characteristics are always the most important extrusion variable.

Particle Size Analysis of Typical Aquatic Feeds U.S. Standard Sieve Openings in Microns Percent on Sieve 20 30 40 50 60 80 Pan 850 600 425 300 250 180 1.00 3.00 28.0 29.0 21.0 14.0 4.0 Geometric Mean Diameter: 327 Microns Geometric Standard Deviation: 1.58

Benefits of Proper Particle Size Improved product appearance Reduced incidence of die orifices plugging Ease of cooking 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

Particle Size Analysis of Two Grinding Processes of Extruded Feed US Sieve Opening (microns) 1.5 mm grind (%)* 425 micron grind (%)** 20 840 0.50 30 590 3.51 40 420 37.75 50 297 40.16 36.75 60 250 10.44 34.31 70 210 5.12 13.60 80 177 3.15 100 149 3.55 140 105 4.37 Pan 2.51 4.26 *Mean Diameter = 316µm, 66,768 particles/g **Mean Diameter = 224µm, 519,365 particles/g

Effect of Grind Size on Extruded Feed Processing on X85 System Bulk Density (g/l) at Given Rate SME (kWh/t) at Given Rate and Bulk Density Rate (kg/h) at Given Bulk Density 1.5 mm 316 46.8 357 425 microns 232 42.3 513

Effect of Grind on Floating Aquatic Feed 200 400 600 800 1000 1200 1400 1600 1800 2000 Time (Seconds) Viscosity (cP) 20 40 60 80 100 120 Temperature (C) 3.5 g solids 25 ml water Temperature 3/64" Grind 2/64" Grind 40 Mesh Grind

Recipe Preparation Grind ingredients to proper particle size Weigh individual ingredients Particle size and density of each ingredient should be similar Premix by hand the micro-ingredients (anything less than 1% of total recipe) and add a carrier (part of a major ingredient) if necessary to bring premix size up to 3% of total recipe Add major ingredients, then premix (from #4) to mixer and mix 3-5 minutes. Add any liquids slowly and then mix another 3-5 minutes Final grind, if required Use sifter and/or magnet to detect and remove foreign material

PROTEIN Plant Sources Animal or Marine Sources Soy, Legumes, Wheat/corn glutens, cereal grains Good functional properties Lower cost Amino acid profile may require supplementation Animal or Marine Sources Meat, Fish, Poultry, Blood, Gelatin Poor functional properties unless fresh or spray dried Higher costs Good amino acid profile

Vegetable Proteins in Salmon, Trout, and Shrimp Diets Maximum Substitution for Fish Meal (%) Disadvantages Maize Gluten Meal 40 Yellow pigmentation of flesh Wheat Gluten 25 High Cost Soybean Meal 50 Palatability and Growth Inhibitors Soy Concentrate 75 Canola Meal 67 Low Protein Content Hardy (January 1999) Feed Management Magazine

Benefits of Vegetable Proteins in Aquatic Diets More expansion potential for floating diets More binding potential for improved durability Reduced ingredient costs Lower incidence of white mineral deposits in screw and die area Higher oil absorption levels possible in coating operations Reduce dependence on fish meal

Effect of Vegetable Protein Levels On Extrusion Moisture 15 17 19 21 23 25 27 29 31 10 20 30 35 40 Vegetable Proteins in Recipe (%) Extrusion Moisture (%)

Soybean Meal Nutrient Level Comparison Dehulled Solvent Extracted 49.0 3.3 1.2 Non-dehulled Solvent Extracted 44.0 7.0 1.2 Full Fat Soy 37.5 7.4 17.4 Crude Protein (%) Crude Fiber (%) Oil (%)

Addition of Slurries to Extrusion System Maximum particle size not to exceed 1.5 mm Fish ensilage slurries pumped into DDC Fat/oil slurries heated to 60°C Moisture is limiting factor for most slurry additions Enzyme treatments reduce viscosity

Wet slurries pumped into DDC preconditioner and extruder barrel (head #2)

Positive Displacement Wet Slurry Pump System slaved to Dry Recipe Rate

Maximum Wet Slurry Addition to Single Screw Extrusion Systems* % moisture in wet slurry Maximum slurry addition (% of total) Maximum slurry addition (% of dry) % slurry in final dried product 66.7 25.0 33.3 10.9 40.0 41.8 71.8 32.4 50.0 33.4 21.8 60.0 27.8 38.5 14.6 70.0 23.9 31.4 9.5 80.0 20.9 26.4 5.6 * Maximum moisture addition to Single Screw Systems is 16.7%

Maximum Meat Addition to Twin Screw Extrusion Systems* % moisture in wet slurry Maximum slurry addition (% of total) Maximum slurry addition (% of dry) % slurry in final dried product 66.7 30.0 43.0 13.7 40.0 50.0 100.0 26.3 60.0 33.3 18.1 70.0 28.6 40.1 11.8 80.0 25.0 6.9 * Maximum moisture addition to Twin Screw Systems is 20.0%

Protein denatures at 60 - 700C As protein denatures, it becomes insoluble (non-functional) Starch gelatinizes at 55 - 750C As starch gelatinizes it becomes soluble

STARCH Raw potato starch magnified 450 X Carbohydrate - energy source Assists expansion Improves binding and pellet durability Found in two forms Amylose Amylopectin 10 - 60 % levels in aquatic food Raw potato starch magnified 450 X

Effect of Extrusion on Starch Gelatinizes starch Improves digestibility in most species Forms starch-lipid complexes Increases binding characteristics Increases susceptibility to enzyme hydrolysis

Recommended Starch Levels in Aquatic Feeds Type Floating Sinking Minimum Starch (%) 20 10

Starch Content of Common Cereal Grains Corn Winter Wheat Sorghum Barley Oats Unpolished Rice % Starch (Dry Basis) 73 65 71 60 45 75

Heat of Gelatinization for Various Starches Heat of Gelatinization (cal / gram) Starch Source Size (microns) Amylose Content (%) High Amylose Corn Potato Tapioca Wheat Waxy Corn 7.6 6.6 5.5 4.7 55 20 22 28 5-25 15-121 5-35 1-35

Minimum Moisture Levels Necessary to Initiate Starch Gelatinization Starch Source % Moisture Wheat Corn Waxy Corn High Amylose Corn 31 28 34 Lower moistures during extrusion require higher extrusion temperatures to achieve same level of cook.

Rice as a Starch Source Small, tightly packed starch granules that hydrate slowly Becomes sticky when it gelatinizes Choose long grain varieties over medium and short grain varieties as they are much less sticky when cooked Rice is very digestible even when cook values are low Rice bran may contain up to 40% starch

Corn as a Starch Source Good expansion Excellent binding Sticky at high levels (>40%)

Wheat as a Starch Source Good binding Good expansion Can be sticky if overcooked Contains gluten (good binder) Most widely available starch source Often utilized as wheat flour which has most of the bran removed

Tubers as a Starch Source (Potato & Cassava) Excellent binding (at 5% levels) Requires less total starch in diet Good expansion Often precooked Smooth pellet surface Increased cost

Effect of Extrusion on Starch Process Raw Recipe Preconditioner Extruder Dryer % Cook 15.5 31.6 92.8 96.7

Purposes of Fat in Feeds Energy Source Increases Palatability Provides Essential fatty acids Carrier for Fat Soluble Vitamins

Fat Sources Animal Fat Poultry Fat Marine Oils Blended Animal and Vegetable Fats Feed Grade Vegetable Fats Must use FAH (fat acid hydrolysis) method for determining fat levels in extruded products.

Effect of Fat Levels on Product Quality (Single Screw Systems) Level of Fat in Extruded Mix Effect on Product Quality <7% 7-12% 12-17% Above 17% Little or no effect For each 1% of Fat Above 7%, the final bulk density will increase 16 g/l Product will have little or no expansion, but will retain some durability Final product durability may be poor Add 5% to above figures for twin screw systems

Effect of Internal Levels of Fat on Expansion of Extruded Feeds % Added Fat Bulk Density (g / l) 5 10 15 256 309 408 533

Internal Fat vs. Pellet Durability 75 ) 70 2 65 60 55 Maximum Compressive Stress (g / mm 50 45 40 35 30 6 8 10 12 14 16 18 20 22 24 26 28 30 Internal Fat (%)

To Maximize Fat Inclusion Levels Formulate with ingredients high in indigenous fats (example: flax meal) Heat fats to 40 - 600C prior to inclusion Add late in the process Maintain starch / function protein levels Increase thermal and/or mechanical energy inputs Increase moisture levels during extrusion

Ingredient Moisture (%) Protein Fat Starch Fish meal, Menhaden 8.0 62.0 9.8 0.0 Corn gluten meal 60.0 2.3 0.1 Soy Bean Meal 9.5 49.0 1.2 Broken rice 10.5 7.1 0.4 68.0 Wheat flour 11.5 12.0 3.0 65.0 Potato Starch 7.5 7.8 4.3 Fish Silage 75.5 20.6 2.6

Vitamin & Pigment Retention Vitamin/Pigment Retention Depends On: Raw material formulation Temperature Moistures Retention times An average of 10 to 15 percent of vitamins and pigments are lost during extrusion. Compensation is made by overages. Heat stable forms are preferred.

Preservation System Required for Soft Moist Aquatic Feeds (Final product moisture of 16-28%) Lower Aw (water activity) below 0.70 with humectants at 10-12% levels Reduce pH to 4.0 - 4.5 with acids at 1-2% levels or with fish silage/solubles Add mold inhibitors at 0.2-0.5% levels

Effect of Extrusion on Microbial Populations Microbe Raw Recipe After Extrusion TPC (CFU/g) Coli form Mold count Clostridium Listeria Salmonella 240,00 22,600 54,540 16,000 positive negative 9,300 <10 negative

Thermal Destruction Studies for Pathogenic Organisms 1 10 100 1000 10000 130 150 170 Time (Seconds) Thermal Plastic Spores E. Coli Salmonella Listeria 70 90 110 Temperature (C) 30 50

Effect of Extrusion Temperature on Fumonisin Toxin Levels (Katta, Jackson, Sumner, Hanna, Bullerman, Cereal Chem. 76(1):16-20, 1999) 20 25 30 35 40 45 50 55 60 65 70 140 150 160 170 180 190 200 Extrusion Temperature (C) Fumonisin B 1 Recovered (%)

Effects of Heat Processing on Insect Survival Temperature (°C) Effect >62 50-60 45-50 30-35 25-32 Death in less than 1 minute Death in less than 1 hour Death in less than 1 day Max temperature for reproduction Optimum for development Feed Management, January 2001, Vol. 52, No. 1, pg 27

After Ripening Factor Biochemical changes occurring after harvest are influenced by storage time.

By-Products Starch / Filler Sources Protein Sources Wheat Bran Wheat Midds (Pollards) Rice Bran Protein Sources Co-Products such as DDGS

By-Products By-Product Moisture (%) Protein Fat Fiber Sorghum DDG 9.5 30.3 12.5 10.7 Dried Brewers Grains (Barley) 24.0 5.0 15.5 Wheat DDG 7.5 38.5 8.2 6.2 Corn DDG 8.5 32.0 11.0 6.0

Effects of Adding Rework to Recipe (5 to 10 percent levels) Darker color Less expansion, higher bulk density Higher levels of cook More defined shape

Better Shape Definition Bulk Density Product Hardness Smooth Skin More Uniform RECIPE + Starch + Oil (Internal) + Fiber + Functional Protein + Non-Functional Protein + Rework - + ? + - + (1) (2) ? + ? + (1) Function of grind and particle size (2) Large cell structure