Presentation on theme: "Raw Materials and Their Impact on the Extrusion of Aqua Feeds"— Presentation transcript:
1Raw Materials and Their Impact on the Extrusion of Aqua Feeds Presented by:Brian Plattner, PEWenger Manufacturing, Inc.
2Fundamentals of Extrusion Processing RecipeHardwareSoftwareProduct Specifications
3Raw MaterialsRaw materials and their characteristics are always the most important extrusion variable.
4Particle Size Analysis of Typical Aquatic Feeds U.S. Standard SieveOpenings in MicronsPercent on Sieve203040506080Pan8506004253002501801.003.0028.029.021.014.04.0Geometric Mean Diameter: 327 MicronsGeometric Standard Deviation: 1.58
5Benefits of Proper Particle Size Improved product appearanceReduced incidence of die orifices pluggingEase of cookingReduced product breakage and finesIncreased water stabilityImproved retention of liquid coatings due to small cell structure
6Guidelines for Grind of Recipe Maximum particle size = 1/3 of die openingNot to exceed 1.5mm grind800 micron mm
7Particle Size Analysis of Two Grinding Processes of Extruded Feed US SieveOpening (microns)1.5 mm grind (%)*425 micron grind (%)**208400.50305903.514042037.755029740.1636.756025010.4434.31702105.1213.60801773.151001493.551401054.37Pan2.514.26*Mean Diameter = 316µm, 66,768 particles/g**Mean Diameter = 224µm, 519,365 particles/g
8Effect of Grind Size on Extruded Feed Processing on X85 System Bulk Density (g/l) at Given RateSME (kWh/t) at Given Rate and Bulk DensityRate (kg/h) at Given Bulk Density1.5 mm31646.8357425 microns23242.3513
9Effect of Grind on Floating Aquatic Feed 200400600800100012001400160018002000Time (Seconds)Viscosity (cP)20406080100120Temperature (C)3.5 g solids25 ml waterTemperature3/64" Grind2/64" Grind40 Mesh Grind
10Recipe Preparation Grind ingredients to proper particle size Weigh individual ingredientsParticle size and density of each ingredient should be similarPremix 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 recipeAdd major ingredients, then premix (from #4) to mixer and mix 3-5 minutes. Add any liquids slowly and then mix another 3-5 minutesFinal grind, if requiredUse sifter and/or magnet to detect and remove foreign material
11PROTEIN Plant Sources Animal or Marine Sources Soy, Legumes, Wheat/corn glutens, cereal grainsGood functional propertiesLower costAmino acid profile may require supplementationAnimal or Marine SourcesMeat, Fish, Poultry, Blood, GelatinPoor functional properties unless fresh or spray driedHigher costsGood amino acid profile
12Vegetable Proteins in Salmon, Trout, and Shrimp Diets Maximum Substitution for Fish Meal (%)DisadvantagesMaize Gluten Meal40Yellow pigmentation of fleshWheat Gluten25High CostSoybean Meal50Palatability and Growth InhibitorsSoy Concentrate75Canola Meal67Low Protein ContentHardy (January 1999) Feed Management Magazine
13Benefits of Vegetable Proteins in Aquatic Diets More expansion potential for floating dietsMore binding potential for improved durabilityReduced ingredient costsLower incidence of white mineral deposits in screw and die areaHigher oil absorption levels possible in coating operationsReduce dependence on fish meal
14Effect of Vegetable Protein Levels On Extrusion Moisture 1517192123252729311020303540Vegetable Proteins in Recipe (%)Extrusion Moisture (%)
16Addition of Slurries to Extrusion System Maximum particle size not to exceed 1.5 mmFish ensilage slurries pumped into DDCFat/oil slurries heated to 60°CMoisture is limiting factor for most slurry additionsEnzyme treatments reduce viscosity
17Wet slurries pumped into DDC preconditioner and extruder barrel (head #2)
18Positive Displacement Wet Slurry Pump System slaved to Dry Recipe Rate
19Maximum Wet Slurry Addition to Single Screw Extrusion Systems* % moisture in wet slurryMaximum slurry addition (% of total)Maximum slurry addition (% of dry)% slurry in final dried product66.725.033.310.940.041.871.832.450.033.421.860.027.838.514.670.023.931.49.580.020.926.45.6* Maximum moisture addition to Single Screw Systems is 16.7%
20Maximum Meat Addition to Twin Screw Extrusion Systems* % moisture in wet slurryMaximum slurry addition (% of total)Maximum slurry addition (% of dry)% slurry in final dried product66.730.043.013.740.050.0100.026.360.033.318.170.028.640.111.880.025.06.9* Maximum moisture addition to Twin Screw Systems is 20.0%
21Protein denatures at 60 - 700C As protein denatures, it becomes insoluble (non-functional)Starch gelatinizes at CAs starch gelatinizes it becomes soluble
22STARCH Raw potato starch magnified 450 X Carbohydrate - energy source Assists expansionImproves binding and pellet durabilityFound in two formsAmyloseAmylopectin% levels in aquatic foodRaw potato starch magnified 450 X
23Effect of Extrusion on Starch Gelatinizes starchImproves digestibility in most speciesForms starch-lipid complexesIncreases binding characteristicsIncreases susceptibility to enzyme hydrolysis
24Recommended Starch Levels in Aquatic Feeds TypeFloatingSinkingMinimum Starch (%)2010
25Starch Content of Common Cereal Grains CornWinter WheatSorghumBarleyOatsUnpolished Rice% Starch (Dry Basis)736571604575
26Heat of Gelatinization for Various Starches Heat of Gelatinization (cal / gram)Starch SourceSize (microns)Amylose Content (%)High Amylose CornPotatoTapiocaWheatWaxy Corn184.108.40.206.7552022285-2515-1215-351-35
27Minimum Moisture Levels Necessary to Initiate Starch Gelatinization Starch Source% MoistureWheatCornWaxy CornHigh Amylose Corn312834Lower moistures during extrusion require higher extrusion temperatures to achieve same level of cook.
28Rice as a Starch SourceSmall, tightly packed starch granules that hydrate slowlyBecomes sticky when it gelatinizesChoose long grain varieties over medium and short grain varieties as they are much less sticky when cookedRice is very digestible even when cook values are lowRice bran may contain up to 40% starch
29Corn as a Starch Source Good expansion Excellent binding Sticky at high levels (>40%)
30Wheat as a Starch Source Good bindingGood expansionCan be sticky if overcookedContains gluten (good binder)Most widely available starch sourceOften utilized as wheat flour which has most of the bran removed
31Tubers as a Starch Source (Potato & Cassava) Excellent binding (at 5% levels)Requires less total starch in dietGood expansionOften precookedSmooth pellet surfaceIncreased cost
32Effect of Extrusion on Starch ProcessRaw RecipePreconditionerExtruderDryer% Cook15.531.692.896.7
33Purposes of Fat in Feeds Energy SourceIncreases PalatabilityProvides Essential fatty acidsCarrier for Fat Soluble Vitamins
34Fat Sources Animal Fat Poultry Fat Marine Oils Blended Animal and Vegetable FatsFeed Grade Vegetable FatsMust use FAH (fat acid hydrolysis) method for determining fat levels in extruded products.
35Effect of Fat Levels on Product Quality (Single Screw Systems) Level of Fat in Extruded MixEffect on Product Quality<7%7-12%12-17%Above 17%Little or no effectFor each 1% of Fat Above 7%, the final bulk density will increase 16 g/lProduct will have little or no expansion, but will retain some durabilityFinal product durability may be poorAdd 5% to above figures for twin screw systems
36Effect of Internal Levels of Fat on Expansion of Extruded Feeds % AddedFatBulk Density(g / l)51015256309408533
38To Maximize Fat Inclusion Levels Formulate with ingredients high in indigenous fats (example: flax meal)Heat fats to C prior to inclusionAdd late in the processMaintain starch / function protein levelsIncrease thermal and/or mechanical energy inputsIncrease moisture levels during extrusion
40Vitamin & Pigment Retention Vitamin/Pigment Retention Depends On:Raw material formulationTemperatureMoisturesRetention timesAn average of 10 to 15 percent of vitamins and pigments are lost during extrusion. Compensation is made by overages. Heat stable forms are preferred.
41Preservation System Required for Soft Moist Aquatic Feeds (Final product moisture of 16-28%) Lower Aw (water activity) below with humectants at 10-12% levelsReduce pH to with acids at 1-2% levels or with fish silage/solublesAdd mold inhibitors at % levels
42Effect of Extrusion on Microbial Populations MicrobeRaw RecipeAfter ExtrusionTPC (CFU/g)Coli formMold countClostridiumListeriaSalmonella240,0022,60054,54016,000positivenegative9,300<10negative
44Effect of Extrusion Temperature on Fumonisin Toxin Levels (Katta, Jackson, Sumner, Hanna, Bullerman, Cereal Chem. 76(1):16-20, 1999)2025303540455055606570140150160170180190200Extrusion Temperature (C)Fumonisin B1Recovered (%)
45Effects of Heat Processing on Insect Survival Temperature (°C)Effect>6250-6045-5030-3525-32Death in less than 1 minuteDeath in less than 1 hourDeath in less than 1 dayMax temperature for reproductionOptimum for developmentFeed Management, January 2001, Vol. 52, No. 1, pg 27
46After Ripening FactorBiochemical changes occurring after harvest are influenced by storage time.
47By-Products Starch / Filler Sources Protein Sources Wheat Bran Wheat Midds (Pollards)Rice BranProtein SourcesCo-Products such as DDGS