Rendering Flashcards
definition of rendering
a cooking, drying and separating process that uses animal and poultry by-products including bone, fat, hide and feathers to produce purified fat and protein products
definition of a rendering plant
a place where animal by-products are prepared or treated for use in, or converted into, fertilizers, animal food, fats or oils, other than fats or oils used for human consumption; a place where these resulting substances are stored, packed or marked; a place where resulting substances are shipped.
animal by-product definition
includes blood or any of its components, bones, bristles, feathers, flesh, hair, hides, hoofs, horns, offal, skins and wool (and any things containing any of these things)
what are the primary determinants of the quality of the finished rendering product
temperature and length of time of cooking process
what do all rendering processes involve
the application of heat, extraction of moisture and separation of fat
what is the basic yield equation
raw material –> 67% water –> fats and tallow (15%) and protein (18%)
what are some benefits to rendering
materials are more resistant to spoiling after; fat and protein meals can be used in many processes; economical waste disposal of waste animal material
how can fat from the rendering process be used
in animal feed, soap-making, candles, as raw material for biodiesel production or in chemical industry
how can protein meal from rendering be used
in animal feed or fertilizer
what does the rendering process convert raw animal tissue into
protein products and fat products
percentage of live weight cattle that is not consumed by humans
49
percentage of live weight pigs that is not consumed by humans
44
percentage of live weight broilers not consumed by humans
37
percentage of live weight of most fish not consumed by humans
57
raw materials includes
abbatoir offal, dead stock, inedible animal tissues, blood, feathers, hair, meat trimmings from butcher shop, restaurant grease/fats, waste water treatment solids, recovered materials (spillage)
raw materials includes
abbatoir offal, dead stock, inedible animal tissues, blood, feathers, hair, meat trimmings from butcher shop, restaurant grease/fats, waste water treatment solids, recovered materials (spillage)
what are the first 4 steps in the basic rendering process
raw materials received, grinding raw materials for size reduction then cooking –> pressing
after cooking, raw material is pressed into what two substances
fat and protein
once fat is pressed, what happens to it next
storage and shipping
once protein is pressed what happens to it next
grinding then storage and shipping
what dictates the thermal efficiency of the rendering system
particle size
what dictates the thermal efficiency of the rendering system
particle size
what machine is used to cook raw material
an agitated vessel generally heated by a boiler system
how does the rotating shaft in a continuous cooker transfer heat
it is hollow and contains attached heat transfer surfaces through which pressurized steam is injected; steam provides the necessary heat transfer to facilitate moisture removal
how is protein separated from fat
free run fat drains off; material is pressed to separate the remaining solid fat from protein
what are protein solids called
crackling
objecting of storing final product
to handle in equipment that minimizes the risk of contamination
what type of equipment is the final product stored in
properly constructed bulk bins
why must bins, conveyors and elevators be properly ventilated
to minimize condensation and protect from potential contaminants
what are two requirements for storage facilities to maintain cleanliness
inspection points to permit examination; emptying/cleaning must be done regularly
what are two requirements for storage facilities to maintain cleanliness
inspection points to permit examination; emptying/cleaning must be done regularly
what are two requirements for delivery vehicles (for shipping final product
must be inspected to ensure cleanliness; must be dedicated to delivery of “prohibited” or “non-prohibited” material separately OR inspected and cleaned according to SOP between loads
what are possible air pollutants from the rendering process
odor (raw material, exhaust from cookers) and dust (from feathers, blood)
what equipment is used to control air pollution from rendering process
filters, cyclones, scrubbers (wet, dry)
what do wet scrubbers use in addition to water
scrubbing solutions, chemical oxidants such as sodium hypochlorite, caustic soda to control pH, sulphuric acid
what are hides used for
leather shoes, garments or upholstery
what are the 4 main constituents of tallow
oleic acid, stearic acid, glycerine, linoleic acid
what is oleic acid used for
cleansing creams, cosmetics, lubricants, textiles, foam, rubber, shampoo, cutting oils, emulsifiers
what is stearic acid used for
rubber, tires, lubricants, esters
what is glycerine used for
cosmetics, eprfumes, inks, glues, cements, solvents, antifreeze, medicine, gun power, explosives
what is linoleic acid used for
paints, lubricants, esters
uses of fat in feed
energy density, essential fatty acids, palatability, dust control, lubrication, reduce particle separation
inclusion rates of fat in feed
minimum (1%) and max (6-8%)
how are feed grade fats stablized
antioxidant is added
feed grade fats consist of blends of
animal and vegetable fats (ex. blended tallow, grease, poultry fat, restaurant cooking oils)
does color effect the nutritional value of fat
no but may be a consideration in consumer oriented products
the presence of high levels of FFA indicated what?
the fat was exposed to water, acids and/or enzymes
why is moisture undesirable in fat
it will encourage bacterial growth and fat-splitting enzymes
why is moisture undesirable in fat
it will encourage bacterial growth and fat-splitting enzymes
what is the ideal temperature to store fat at
slightly above melting point so it is still pumpable; excess heat will accelerate deteriotation
what are some of the types of protein meal
poultry by-product meal, feather meal, fish meal, blood meal, pure procine meal, lamb meat and bone meal (favored in pet food)
what does protein meal supply when used as feed
concentrated protein, bypass protein (dairy cattle), digestible phosphorous, minerals, palatability (swine)
inclusion rates of protein meal in diet
max 6-8%
definition of meat and bone meal
product obtained by rendering animal tissues with NO hair, hoof, horn, hide trimming, manure or stomach contents (except in the amounts that are unavoidable with good manufacturing practices)
definition of poultry by-product meal
product obtained by rendering parts of slaughtered poultry exclusive of feathers (except in amounts that are unavoidable with good practices)
feather meal definition
product obtained by hydrolyzing feathers from slaughtered poultry; free of additives or accelerators
definition of blood meal
product obtained from clean, fresh blood exclusive of all extraneous materials (hair, stomach contents or urine) – except in amounts that are unavoidable
definition of fish meal
clean dried ground tissues of undecomposed whole fish or fish cuttings or both
quality of rendering products are affected by
raw product consistency and freshness, processing and storage
specified risk material (SRM) includes
for cattle 30m and older – skull, brain, trigeminal ganglia, eyes, tonsils, spinal cord and dorsal root ganglia; distal ileum of cattle of all ages
when was the enhanced feed ban of SRM from animal feed and fertilizer put in place
2007
role of veterinarians with SRM management
facilitate clients, educate producers, remove SRM, train feedlots and abbatoirs, maintain records, become permitted salvage premise, use clinic/property to control SRM, facilitate transportation permits
role of veterinarians with SRM management
facilitate clients, educate producers, remove SRM, train feedlots and abbatoirs, maintain records, become permitted salvage premise, use clinic/property to control SRM, facilitate transportation permits
why is wool normally not put through the rendering process
lanolin messes up rendering equipment
why is rendering now used in CWD depopulations
used to remove protein (burn or bury) and can make use of fat because the prions don’t remain in it
what are some problems with rendering material used in animal feed
melamine in dog food; spray dried serum theory for spreading PED
when cracklings come out, why do they go through a shaker first
to remove ear tags and any metal (horse shoes should be taken off prior to rendering)
what do you flush delivery vehicles with between loads
flush with other protein
what is prohibited material
ruminant protein (can’t be fed to other ruminants)
what else is a product of rendering other than fat and protein
water
what dangerous fumes come from blood meal
hydrogen sulfide (can kill you)
at what points does the CFIA control SRM
from source to end point
