Seminar on Meat and meat processing

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Seminar on Meat and
meat processing
Submitted by Avinash sharma 4510
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contents

• Nutritional value of meat
• Composition of meat
• Pre slaughter changes
• Factors affecting pre slaughter changes
• Slaughter changes
• Post slaughter changes
• Cutting and deboning of meat
• Preservation and processing of meat
• Standards for meat products
• Gelatin production

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Nutritional value of meat

• Meat is very nutritious food
• Having abundance of proteins, fats, minerals,
  vitamin B complex

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Composition of meat

• Proteins15-20
• High biological value
• Rich in essential amino acids

Amino acid lamb pork beef
Lysine 7.6 7.8 8.4
Methionine 2.3 2.5 2.3
Cystine 1.3 1.3 1.4
Tryptophan 1.3 1.4 1.1
Essential amino acids as of crude protein in
fresh meats
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• 2. Meat fats 5-40
• Contains ample amount of essential fatty acids
  like linoleic acid, linolenic acid, arachidonic
  acid
• Most abundant fatty acid is oleic acid
• Some amount of cholesterol

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• 3. Minerals
• Good source of all minerals except calcium
• K is most abundant followed by P
• Good source of Fe
• Minerals provided by meat are in easily absorbed
  form

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• 4. Vitamins
• Lean meat excellent source of Vit B complex
• Thiamine, riboflavin and niacin are quite high
• Vitamin c is almost absent
• Contains traces of fat soluble vitamins

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Pre-slaughter changes

• Pre slaughter handling of animal is crucial for
  the meat quality
• Quality attribute of meat is its ease of chew
  ability i.e. tenderness of meat
• Unfavorable condition prior to slaughtering leads
  to loss in the quality of meat

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Factors affecting pre slaughter changes
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Slaughter changes

• Slaughtering involves mainly stunning and
  bleeding

• stunning
• projectile stunning
• use of electric current
• AC current of 50 volts is satisfactory

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Different stunning system

• High frequency stunning HD II-F
• Normal mains frequency can result in haemorrhages
  and bone fracture so frequency is converted in
  desired stunning frequency
• 50-400Hz

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• 2.Waterbath stunning N and HD II-1,5
• Use for poultry
• Chicken are hanged upside down and dipped into a
  water bath to which an electric current is
  applied

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Bleeding

• Bleeding can be done in these three ways-
• 1. Either the jugular vein is cut or
• 2. Carotid artery is cut
• 3. Anterior venacava-major blood vessel can be
  cut

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Slaughter changes
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• Failure of circulatory system
• Loss of homeostasis
• Decrease in blood pressure
• constriction of peripheral blood vessel
• Depletion of O2 leads to anaerobic pathways
• Accumulation of lactic acid

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• 2. pH decline
• Accumulation of lactic acid lowers down the pH
• Gradual decline continues from approx pH 7 in the
  living muscle during first few hours(5-6h) and
  then there is a little drop in the next
  15-20h,giving an ultimate pH in the range of
  5.5-5.7

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• 3. Rigor mortis
• Caused by chemical changes in the muscle after
  death, causing the limbs of the corpse to become
  stiff.
• ATP complexed with Mg2 is required for breaking
  the actomyosin bond,
• As the level drops, permanent actomyosin cross
  bridges begin to form,
• Muscle become less extensible
• If pH decline is very slow or fast, the onset and
  completion of rigor mortis is rapid

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• 4.Loss of protection from microorganisms
• Body defence mechanism stops and membrane
  properties are altered
• So meat is quite susceptible to invading
  microorganism
• 5.Degradation due to proteolytic enzymes
• Due to decline in pH autolytic lysosomal enzymes
  called cathepsins are activated
• Cathepsins causes the degradation of muscle
  protein

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Post slaughter changes

• Evisceration
• Discarding of viscera or inedible parts like
  alimentary canal, lungs, reproductive system
• Removal of feather, horns, skin etc

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• 2.Scalding
• Washing of carcasses with hot water (900C) to
  remove traces of blood
• Also lowers the chances of microbial attack
• Protein denaturation take place

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Cutting and deboning of meat

• Cutting
• Cutting of meat according the requirements.
• According to Meat and Meat Product Order (MMPO),
  cuts and size of the pieces should be defined.
• Basic requisites in meat cutting are
• Carcasses has to be essentially chilled,
• Cutting room should be maintained at 15-200C and
  RH of 80,
• Uniformity in cuts

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• 2. Deboning
• Removal of bone from meat
• Temp 150C,and perform quickly within 2-3h of
  slaughtering
• Deboning

mechanical
mannual
1.Genarally for muscle arround Neck, a screen
cuts meat into pieces nd it get
deboned. 2.Yield is 40-60
1.Chest and thigh Muscle are manually Deboned by
hand 2.Yield is high
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Flowchart of deboning of poultry
breeding
Diet of animal
Stunning using electicity
scalding
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evisceration
Chilling at refrigeration temperature
washing
Graded as per cuts
Pakaged and marketed
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Processing and preservation of meat
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• Chilling
• Storage at 2-50C
• Relative humidity is kept 90
• slows down the microbial growth and enzymatic
• as well as chemical reaction
• Shelf life of 5-7day

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• 2.Freezing
• Storage temperature- -180C to-200C
• Freezer burn occurs due to progressive surface
  dehydration resulting in the concentration of
  meat pigment on the surface,
• Freezing can be slow or rapid
• Rapid freezing is desierable

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• 3.Smoking
• provide bacteriostatic effect and a
  characteristic smoky flavor.
• Preservation is due to surface dehydration,
  lowering of surface pH and antioxidant property
  of smoke
• Aldehyde contributes most of the colour
• Phenol act as bacteriostatic, formaldehyde as
  bactericidal

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• 4.Irradiation
• EM radiation are used
• They destroy the microorganism by fragmenting
  their DNA and causing ionisation of inherent
  water.
• Gamma rays are commercially used
• 50-100k rad doseincreases shelf life of poultry
  by 19day
• Dose of 4-5M rad can sterilize poultry, pork.
• UV of 2650? are used for surface sterilization

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• 5.Cooking of meatthermal processing
• cooking

• Mild heating
• Below 1000C
• 58-750C is pasteurization

Heating beyond 1000c to achieve commercial
sterility

• Meat is then refrigerated

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• 6.Canning
• Process of preservation by thermal sterilization
  of a product held in a hermetically sealed
  container
• Shelf life of atleast 2 year at ambient
  temperature

meat
condiment
precooking
(700C for 15-30min)
Either manually or mechanically
filling
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Adjustment of headspace
It minimise the strain on the can seams due to
expansion of air during heating
Exhausting of air
Double seaming
retorting
High temperature and pressure
cooling
300C-400C
Labelled, storage and marketed
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• 7. Curing of meat
• Done for specific colour and flavour development
  and for preservaton
• Curing ingredientsNaCl, NaNo3,NaNo2 and sugar
• Nacl-preservative action
• Act by dehydration and alteration of osmotic
  pressure
• Chloride ions directly act on microbes
• Slows the action of photolytic enzyme

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• Role of sodium nitrate and sodium nitrite
• Served to stabilize the attractive colour and
  impart characteristic cured flavor
• Colour reaction of cured meat
• NO3 NO2
  NO
• NOMb NoMMb
  NoMb
• 
  
• 
  nitrosyl haemochrome

Absence of light and air
NRO
Nitric oxide myoglobin
Nitric oxide metmyoglobin
Heating or smoking
(pink colour pigment)
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• Permitted level of nitrate-500ppm and
  nitrite-200ppm.
• Nitrites are bactericidal to Clostridium
  botulinum.
• Nitrates and nitrites also retard the development
  of rancidity.
• Role of sugar
• Good food for nitrate reducing bacteria and
• flavor and preservation

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Meat microbiological standards

• A no of factors adds to he microbial load to
  meat-animal, production and post production
  process.
• Various microbiological standards
• 1. Total viable count
• Estimation of mesophiles and psychrophiles
• Handling and state of freshness or spoilage of
  meat
• 2. Enterococci
• Indicates poor hygienic quality of frozen meat
• Inadequate heat treatment of canned food

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• According to MMPO
• Total viable count in meat note more than
  105-107cfu/gm
• Total viable count in poultry not more than
  105cfu/gm
• Coliforms should be zero

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Gelatin production

• Gelatin a translucent, colourless, brittle,
  nearly tasteless solid substance extracted from
  the collagen inside animals connective tissue.
• It is having nine essential amino acid out of
  twelve.
• Bone and skin are good source of gelatin
• It is soluble in water and other polar solvents.

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• Production of gelatin
• Raw material is cleaned
• Defatting
• Demineralization to remove calcium and similar
  salts.
• Raw material is now called ossein.
• ossein

Alkali process
Acid process

• Bone is soaked in lime
• suspension for 60 days.
• Gelatin is known as type B.
• IEP-4.8-5.2

• Bone is treated with
• dil.acid for 8 weeks
• Gelatin is typeA.
• IEP-6-9.

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Extracting, purifying and drying gelatin

• Same extraction method for both types
• Carried out at controlled temperature using
  water.
• The dilute gelatin solution is then filtered,
  demineralized, concentrated in vaccum
  evaporators.(25-30concentrated)
• UHT-sterilised and cooled and extruded to form
  gelatine noodles.
• Dried by purifid air.
• Tested for gel strength, viscosity,and other
  parameters

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Uses of gelatin

1. As a gelling agent in cooking.
2. A a stabilizer, thickener n foods such as ice
   cream,jams, yogurt, cream,chese.
3. Gelatin constitute the shells of pharmaceutical
   capsules.
4. In photographic films and papers.
5. Used by swimmers to hold their hair in place.

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References

• Sharma B.D , Meat and meat product technology 1st
  edition ,Medical publisher (P) ltd,new Delhi
• www.egyankosh.com/meat
• www.wikipedia.com
• www.google.com/images/meat