Food hygiene - Part B (meat)

29. Chemical composition of meat and meat characteristics of individual animal species.

Meat = all body parts of animals suitable for human consumption, mainly striated muscles including connective tissue, fat, blood vessels, lymph nodes, nerves and bones.

🟨 CHEMICAL COMPOSITION OF MEAT

🔵 Water = ~75% (main component)

• Highest: Calf = 76.3%

• Lowest: Fat bull = 59.4%

• High thawing temperatures → water loss → ↓ meat quality

🔴 Protein = 20–25%

• Highest: Heifer = 23.5%

• Lowest: Fat bull = 16.6%

• More fat = less protein

• Limiting amino acids: Lysine & Methionine (except fish)

🟠 Fat = ~3%

• Triglycerides

• Phospholipids

• Cholesterol

• Essential fatty acids (linoleic acid etc.)

• Highest: Fat bull = 22.8%

• Lowest: Calf = 1.1%

🟢 Carbohydrates = ~1%

• Mainly glycogen

• Meat is poor in carbohydrates

🟣 Vitamins

• A, B1, B2, B3, B6, B12, C

• Cattle and pig liver are richest in vitamins

🟤 Minerals

• Na, K, Ca, Mg, Cl

• Beef and pork rich in minerals

⭐ Easy memory:

75 → 25 → 3 → 1
(Water → Protein → Fat → Carbohydrates)

🟨 MEAT CHARACTERISTICS OF INDIVIDUAL SPECIES

🔴 Beef

General:

• Red, Juicy, Marbled

Young cattle:

• Bright red

• Slightly fibrous

• Firm

• Little juice

Bull:

• Dark red

• Strongly fibrous

• Dry

• Little fat

Fattened ox/cow:

• Reddish (terracotta after storage)

• Thick fibrous

• High fat content

Old dairy cows:

• Bright when fresh

• Grey-brown after cooking

🩷 Veal

• Light red

• Delicate

• Soft consistency

• Wet and sticky

• Little fat

• Sweet taste

🐷 Pork

Young/fat pigs:

• Pale

• Slightly fibrous

• Soft consistency

Older pigs:

• Dark red

• Coarse fibres

• Overgrown with fat

• Heavily marbled

🟤 Mutton (>1 year old sheep)

• Bright red or terracotta

• Slightly fibrous

• Subcutaneous fat

• Not marbled

• Ammonia smell ⭐

🟢 Goat

• Lighter than mutton

• Little subcutaneous fat

• Highest fat around the kidney capsule ⭐

🟣 Horse

• Bright red → dark red (depends on age)

• Tender muscle fibres

• Not marbled

• Sweet taste ⭐ Why is horse meat so sweet? Higher glycogen levels than other species!

Stallion:

• Lighter meat

• Grey to bright tone

⭐ EXAM MEMORY LINE

75 Water → 25 Protein → 3 Fat → 1 Glycogen

Beef = red & marbled
Veal = pale & soft
Pork = marbled with age
Mutton = ammonia smell
Goat = kidney fat
Horse = sweet taste

30. The nutritional, biological and energy value of meat

🔵 Nutritional value

• Highly nutritious food

• High-value protein, easily absorbed by humans

• Provides energy

• Rich in protein, niacin (B3), thiamine (B1), vitamins B6 & B12, phosphorus, zinc and iron

• Protein: 20–25%

  • ~97% digestibility

  • Limiting AA: lysine & methionine

• Fat: ~3%

  • Triglycerides

  • Phospholipids

  • Cholesterol

  • Essential FA (linoleic, linolenic, arachidonic acid)

• Carbohydrates: ~1%

  • Mainly glycogen

  • Meat is poor in carbohydrates

🟢 Biological value (BV)

• Measure of how efficiently absorbed protein is used for protein synthesis

• Based on nitrogen balance

  • Proteins = major source of nitrogen

• Reflects:

  • Digestibility

  • Availability

  • Amino acid composition

• Higher BV = more protein retained and used by the body

🟣 Energy value

• Carbohydrates = 17 kJ (4 kcal)/g

• Protein = 17 kJ (4 kcal)/g

• Fat = 37 kJ (9 kcal)/g

• Alcohol = 29 kJ (7 kcal)/g

🟠 Nutritional labelling

• Energy expressed as kJ or kcal

• Protein, fat, carbohydrates = g

• Fibre, sodium, cholesterol = mg

• Values usually given per 100 g or 100 ml

• Allows calculation of energy intake and calorie tracking

⭐ Remember

• 20–25% protein → 3% fat → 1% glycogen

• Rich in Fe, Zn, P and B vitamins

• BV = protein quality

• 4–4–9–7 rule = carbs, protein, fat, alcohol

Questions from comittee:

Protein calculation: proteins contain 16% nitrogen, therefore protein = nitrogen × 6.25 (kjeldahls factor - nitrogen conversion factor)

Linoleic/arachidonic acid: essential omega-6 fatty acids that cannot be synthesized sufficiently and must come from the diet.

Additional nutritional information: salt and saturated fat.

Why nutritional labelling? Primarily because of EU Regulation 1169/2011, and secondarily to inform consumers.

31. Post-mortem changes in meat, ageing of meat, autolytic changes and their evaluation

Post-mortem changes

• Structural and biochemical changes occurring after death

• Affected by: nutrition, stress, trauma, temperature, pre-slaughter handling and housing

• Meat quality: composition (lean/fat), physical properties, eating quality

• Carcass quality: conformation, fatness and weight

🟢 1. Anaerobic glycolysis

• After death → no oxygen available

• ATP maintained by creatine phosphate and glycolysis

• Glycogen → lactic acid → ↓ pH

• High glycogen stores → more lactic acid → firmer meat

• Glycolysis rate measured by pH fall

• Stress before slaughter → ↓ glycogen → abnormal pH fall → PSE meat

🟣 2. Rigor mortis (muscle stiffening)

• ATP exhausted → myosin remains bound to actin

• Muscles become rigid

• Onset: 1 h to several hours

• Cattle: 3–6 h onset, ~20 h duration, ends after 24–48 h

• Muscle shortening may occur → tougher meat

• During rigor:

  • ↓ pH

  • ↓ water-holding capacity

• End of rigor:

  • Lactic acid → CO₂ + H₂O

  • ↑ pH

  • Meat softens and binds water better

• Factors affecting rigor:

  • Pre-slaughter stress → early rigor

  • Excessive chilling → cold shortening

  • Fast muscle fibres → more prone to PSE

Ageing of meat

• Ageing is a controlled process in which natural proteolytic enzymes break down muscle proteins, improving tenderness, flavour and water-holding capacity of meat

  

• Improves texture and flavour

• Beef: 10–14 days

• Pork: 5–7 days

• Usually wet ageing (vacuum-packed plastic)

• Changes during ageing:

  • Dissociation of actin-myosin complex

  • Myofibrillar proteins → peptides + amino acids

  • Lactic acid → CO₂ + H₂O → ↑ pH

  • ↑ tenderness, ↑ water-binding capacity

• Affected by:

  • Species

  • Temperature (0–5°C optimal)

Autolytic changes (spoilage)

• Release of autolytic enzymes after death

• Lactic acid → CO₂ + H₂O → ↑ pH (pH fresh meat = 6,4-6,6, Lactic acid = decrease pH)

• Protein degradation → ammonia, sulphides, mercaptans

• Fat hydrolysis and oxidation

• Meat becomes:

  • Softened

  • Discoloured

  • Foul-smelling

• Autolysis index = microbial contamination above 10⁷·⁵/cm², associated with visible spoilage of meat.

🟤 Microbial spoilage

• Psychrotrophic bacteria during chilling:

  • Pseudomonas

  • Listeria

  • Flavobacterium

  • Gram-positive bacteria

• Grow at 5–7°C

• Produce proteolytic and lipolytic enzymes

• Cause alkaline pH shift

• Pseudomonas aeruginosa

  • Fruity/fishy odour

  • Soapy taste

  • Colour changes and spoilage

• Regulation (EC) 2073/2005 sets limits for aerobic bacterial counts

⚫ Evaluation of autolytic changes

1. Conway test → ammonia content (indicator turns red)

2. Peroxide value & acid value → fat hydrolysis/oxidation

3. TBARS value → lipid oxidation

4. Sensory evaluation → freshness assessment

Qualitative derivations of meat – PSE, DFD, PSS (next Q)

⭐ Remember the sequence:
Anaerobic glycolysis → Rigor mortis → Ageing → Autolysis/spoilage

⭐ Key words:
Glycogen → Lactic acid → ↓ pH → Rigor → Tenderisation → Spoilage (ammonia, sulphides, bad odour).

questions form committee:

• Describe the convey’s method: Meat sample is mixed with alkali → Ammonia is released from the sample → Ammonia diffuses into the central chamber of a Conway dish containing an indicator or boric acid → The amount of ammonia is measured by colour change/titration.

↑ Ammonia = ↑ protein degradation

↑ Ammonia = more advanced spoilage/autolysis

⭐ Conway's method measures ammonia produced during protein degradation and is used to assess freshness and autolytic spoilage of meat.

• Describe the process of anaerobic glycogenolysis + rigor mortis: After death, absence of oxygen forces muscle cells to obtain ATP through anaerobic glycogenolysis. Glycogen is converted to lactic acid, causing pH to decrease until ATP reserves are depleted. Rigor mortis develops when ATP is depleted and actin-myosin cross bridges cannot dissociate, resulting in muscle stiffening.

• The aim of ageing is to allow natural enzymes to break down muscle proteins after rigor mortis, producing more tender, flavourful meat with improved water-holding capacity.

32. Meat quality deviations - PSE/DFD meat.

🔴 PSE (Pale Soft Exudative) meat

• Mainly affects pork

• Caused by accelerated glycolysis → rapid accumulation of lactic acid

• pH < 5.8 while meat temperature is still high (~35°C)

• If pH < 6 after 45 min, PSE is likely

• Rapid onset of rigor mortis!

• Causes:

  • Primary: mutation in RYR1 (ryanodine receptor) → uncontrolled Ca²⁺ release → rapid glycolysis

  • Secondary: short-term stress before slaughter

• Pathogenesis:

  • Pig is slaughtered while metabolism is still high (from stress response) → Lactic acid accumulates because circulation has stopped → ↓ pH damages muscle proteins → pale meat

• Meat characteristics:

  • Pale (lack of myoglobin), Soft, Watery (exudative, caused by low water-holding capacity)

  • Most evident in the thigh, back, and fillet muscles

🟤 DFD (Dark Firm Dry) meat

• Mainly affects pork

• Caused by incomplete acidification

• pH > 6 at 24 h

• Cause:

  • Long-term stress (24–48 h before slaughter)

  • Glycogen depletion

• Pathogenesis:

  • ↓ Glycogen → ↓ lactic acid production → ↑ Muscle pH → ↑ muscle activity → ↑ Oxygen consumption → ↓ Oxymyoglobin → dark meat

• Meat characteristics:

  • Dark, Firm, Dry appearance (High water-holding capacity)

  • More prone to microbial spoilage

🟢 Evaluation of PSE/DFD

1. pH measurement: electrode inserted directly into muscle

2. Colour: photometer

3. Hydraemia estimation: assessment of protein-water holding capacity

4. Compression test: meat placed on filter paper between glass plates with 1 kg weight for 5 min → evaluate compressed meat and moisture ring

extra:

🟣 PSS (Porcine Stress Syndrome)

• Autosomal recessive genetic disease

• Diagnosed by halothane test or PCR (~7 weeks)

• Causes malignant hyperthermia (rapid rise in body temperature)

• Triggered by:

  • Transport, Sudden movement, Vaccination

• Signs:

  • Extreme nervousness, PSE meat, Back muscle necrosis, Muscle tremors, Sudden death

⭐ Remember:

• PSE = Short stress → Rapid glycolysis → Low pH → Pale, Soft, Exudative

• DFD = Long stress → Glycogen depletion → High pH → Dark, Firm, Dry

• PSS = Genetic disease (RYR1 related) → Malignant hyperthermia + PSE meat

questions:

• pH of PSE meat at 45 min (5.8), pH of meat at slaughter (6.4-6.7) - I walked myself into this question…

• Can PSE meat be used for anything? Yes, fermented but DON’T say it’s good for it, it’s just usable so you dont HAVE to throw the carcass. (walked into these myself by mentioning it first)

• Can DFD meat be used for anything? apparently yes, but only as ingredient and not for direct sale

• When do we check the pH in PSE ? At 45 min and DFD ? 24h

• most obvious sign of PSE? exudation and liquid

• most common reason for DFD is lack of glycogen due to muscle activity

• you can talk about other meat deviations in this question, or maybe just mention them

33. Intravital effects on meat quality (genetics, species, breed, sex, age, breeding, nutrition, substances, diseases)

🔵 Genetics & Species

• Genetics influence productivity and meat quality within a breed

• Breed selection used to obtain desirable meat traits

• Meat quality differs between animal species (Q29)

• Examples:

  • Kobe → fattier meat

  • Texas Longhorn → leaner meat

🟢 Sex

• Affects fat deposition, growth rate, and carcass yield

• Females: mature earlier, meat is usually more tender and juicy

• Steers (castrated males): intermediate characteristics

🟣 Age

• Greater weight usually means greater age

• Young animals:

  • More muscle, Less internal fat, More tender meat

• Older/heavier animals:

  • More fat, Darker meat, Higher carcass yield

🟠 Way of breeding

• Social hierarchy can cause:

  • Stress, Bruises, Physical injuries

• Adequate space, shade, feeding areas, and resting areas improve welfare and meat quality

🟤 Nutrition

• Balanced nutrition affects meat:bone ratio, protein:fat ratio, fatty acids and energy content

Pasture feeding

• Slower growth, Leaner meat, Darker colour

• β-carotene → yellow fat

• Tocopherol (Vit E) → better colour & shelf life

High-concentrate diet

• Faster growth, Higher fat content, Juicier meat, Better palatability

High-fibre diet

• Less fattening, More developed skeleton, Higher water/protein content, Lower energy

High-fat diet

• Fatter carcass, Reduced length:circumference ratio

Supplements

• Dietary supplements → heavier carcass, higher dressing %, more muscle

• Niacin → improved ultimate pH and colour

• Vitamin E → better colour, freshness, tenderness and juiciness

• Se & Zn → reduce oxidative rancidity

• Excess iron → metallic taste

• Probiotics (Lactobacillus acidophilus) → improve intestinal microflora

🔴 Specific active substances & foreign substances

• Strictly forbidden in EU:

  • Hormones

  • β-adrenergic agonists

  • Growth-promoting antibiotics

⚫ Diseases & other factors

• Diseases alter muscle metabolism and physiology

• Transport and pre-slaughter handling → stress → poorer meat quality

• Cold season slaughter:

  • Higher pH after 24 h

  • Lower water-holding capacity

  • Tougher meat

• Imperfect stunning → blood spots in meat

• Ageing improves tenderness and odour through enzymatic myofibrillar degradation

⭐ Remember:
Genetics → Species → Breed → Sex → Age → Breeding → Nutrition → Substances → Diseases

questions:

• how do genetics effect meat quality? Genetics influence muscle development, fat deposition, marbling, tenderness and growth performance. Certain genetic defects such as PSS may predispose to PSE meat.

• 🥩 Who has darker meat and why? Age (Older animals → darker meat, More myoglobin)

• Species (Beef darker than pork, Horse darker than beef, Game animals often very dark)

• Sex (Males generally darker than females, Especially intact males. Why? Higher myoglobin concentration. Myoglobin stores oxygen in muscle. More age/activity → more myoglobin → darker red meat.

• Diseases mainly affect meat quality through emaciation, reduced carcass yield and altered muscle metabolism.

• Females generally have a higher fat content and more tender, juicier meat because they deposit fat earlier than males. Bulls are usually leaner and more muscular, while steers have intermediate characteristics

34. Classification of slaughter animals and grading of carcasses.

🔵 Classification of slaughter animals

• Carried out in slaughterhouse by legal persons certified by a competent authority

• All animals must be dressed before classification

🐷 Pigs (60–120 kg are classified)

• Weight: hot carcass weight after vet inspection, within 45 min after bleeding

  • With: head, feet, tail, ears, root, eyes

  • Without: all organs, nails

• Muscle proportion: determine lean content of meat

  • Two-point method: average weekly slaughter up to 100 pigs

  • Instrumentation: average weekly slaughter over 100 pigs

    • Optical probe (<100 pigs)

      • Measures back fat and rind thickness at P1, P2, P3

      • Inserted 4–5 cm (P1), 6.5 cm (P2), 8 cm (P3) from dorsal midline

    • HGP, FOM, UltraFOM

    • UltraFOM: non-invasive, automatic carcass grading system using 3D image

🐮 Cattle (calves <25 kg not classified)

• Weight: hot carcass weight after vet inspection within 60 min after bleeding

  • Whole kg (cattle), 0.5 kg (sheep)

  • Without: head, feet, hide, tail, all organs, spinal cord, major blood vessels

• Age and sex categories

  • T = calves >2 weeks and <150 kg

  • M = young cattle <12 months and >150 kg

  • A = young bulls (uncastrated male 1–2 years)

  • B = bulls

  • C = steers (castrated male)

  • D = cows

  • E = heifers (non-calved)

🐑 Sheep

• Slaughterhouses with >1000 sheep/year

• Based on weight and fatness

• Lean carcass preferred

• Assessed by palpation along spine and loin

🟢 Grading of carcasses

🐷 Pigs

• S = best, P = worst

• S = ≥60% lean meat ⭐

• E, U, R, O = decrease by 5% lean meat each grade

• P = ≤40% lean meat ⭐

Not classified pigs

• N = carcass <59.9 kg

• T = carcass >120 kg

• Z = fleshy sow

• H = poor sow

• K = boars and cryptorchids

• Marking: safe waterproof colour on hindfeet or front side of thigh of each half, at least 20 mm, plus identification stamp

🐮 Cattle

• Conformation grades (S–P) = amount of meat present

  • S = all profiles extremely convex, exceptional muscle development ⭐

  • R = straight profile, very good muscle development

  • P = all profiles concave to very concave, poor muscle development ⭐

• Fatness grades (1–5) = amount of fat present

  • 1 = very low fat, thoracic cavity without fat cover

  • 3 = moderate subcutaneous fat

  • 5 = very thick layer of subcutaneous fat ⭐

• Marking: safe waterproof colour on both forefeet or both shoulders and thighs, at least 20 mm, plus identification stamp

🐑 Sheep

• Marking: safe waterproof colour on inside of both thighs, at least 15 mm, plus identification stamp at least 20 mm

⭐ Exam memory:

• Pig = lean meat % (SEUROP)

• Cattle = Conformation (S–P) + Fatness (1–5)

• Sheep = Weight + Fatness

• what is the duty of official vet in this process? The OV performs ante-mortem and post-mortem inspection and determines whether the carcass is fit for human consumption. After the veterinary inspection, the carcass can be classified and graded by certified classifiers. The OV supervises the process and ensures compliance with legislation, food safety and animal welfare requirements

35. Hygiene and technology of processing and storage of animal by-products in the meat industry, including SRM.

🔵 Animal by-products

• Not intended for human consumption

• Potential risk to public and animal health

• Legislation:

  • Reg. (EC) 1069/2009 & 142/2011 → ABP health rules

  • Reg. (EC) 999/2001 → prevention, control and eradication of TSE

🟢 Hygiene and technology of processing

• Category 1 & 2: methods 2–5 (unless authority requires Method 1)

• Category 3: methods 1–5 or 7

• Records kept for 2 years to document CCP values

ABP Categories

🔴 Category 1 (highest risk)

• SRM, TSE animals, Zoo, circus and pet animals, Illegal treatment, Residues, Contact with wastewater treatment material

Use:

• Disposal only, Incineration 1300C, Fuel production after processing

🟠 Category 2 (high risk)

• Dead livestock, Digestive tract content, Unhatched poultry embryos, Material not suitable for animal consumption

Use:

• Landfill (after sterilisation), Technical purposes

🟢 Category 3 (lowest risk)

• By-products from healthy slaughtered animals fit for human consumption but not used

• Hides, feathers, blood, fish by-products, eggshells

Use:

• Organic fertiliser, Pet food, Animal feed, Biogas

• ⚠ Do NOT feed cattle-derived products back to cattle
  ⚠ Do NOT feed meat-and-bone meal because of TSE/BSE risk

🟣 Standard processing methods

Method 1 – Pressure sterilisation ⭐

• Particle size ≤ 50 mm

• 133°C / 20 min / 3 bar ⭐

Method 2

• Particle size ≤ 150 mm

• 100°C / 125 min

Method 3

• Particle size ≤ 30 mm

• 120°C / 13 min

Method 4

• Particle size ≤ 30 mm

• Fat added

• 130°C / 3 min

Method 5

• Particle size ≤ 20 mm

• 100°C / 60 min

• Fat and water removed by pressing

Method 6 (Category 3 aquatic animals/invertebrates only)

• Particle size 30–50 mm

• Formic acid → pH ≤4

• Stored 24 h

• 90°C / 60 min

Method 7

• Alternative validated method

• Must eliminate hazards:

  • Clostridium perfringens absent in 1 g after treatment

  • Salmonella absent in 25 g

  • Enterobacteriaceae controlled

🟠 Alternative processing methods

Alkaline hydrolysis

• NaOH and/or KOH

• 150°C / 3 h / 4 bar

High-pressure hydrolysis biogas process

• Method 1 sterilisation first

• 220°C / 20 min / 25 bar

• Anaerobic fermentation in biogas reactor

• Biogas combusted at 900°C

Biodiesel production

• Fat fraction separated

• Esterification: pH <1 with sulphuric acid, 72°C / 2 h

• Transesterification: pH 14 with KOH

• Vacuum distillation at 150°C

• Final product = biodiesel

🟤 Storage of by-products

• Must be stored appropriately to prevent risk to public and animal health

• Governed by Regulation (EC) 1069/2009

🔴 Specific Risk Material (SRM) ⭐

• Category 1 material

• Includes:

  • TSE-risk material

  • Illegal treatment

  • Residues

  • Contact with wastewater treatment material

• Must be stained immediately with:

  • Patent Blue V (0.5%) ⭐

Disposal routes

1. Incineration

2. Rendering + incineration

3. Rendering + landfill

⭐ High-yield exam facts

• Method 1 = 133°C, 20 min, 3 bar

• SRM = Category 1

• Patent Blue V (0.5%)

• 3 disposal routes: incineration, rendering + incineration, rendering + landfill

• ABP legislation = 1069/2009, 142/2011, 999/2001

Not interested in all the methods from 1-7 (committee 1), wanted to know about the categories 1-3 and how these were disposed of (as in question 36). By-products of category 3 can not be used for animal feed if from the same animal (cattle product for cattle feed). By-products of category 1 should be incinerated at 1300 degrees.

Committee 2 (2024): Only interested in methods 1, 6 and 7, wanted to know about category 3 by-products and their use. Not feed cattle to cattle and don't feed bone-meal because of TSE. 

36. Categorization, disposal and use of animal by-products not intended for human consumption.

🔵 Animal by-products not intended for human consumption

• Potential source of risk to public and animal health

• Regulation (EC) 1069/2009 & 142/2011 → health rules for by-products and derived products not intended for human consumption

• Regulation (EC) 999/2001 → prevention, control and eradication of TSE

⭐ If animal by-products of different categories are mixed → handled as the HIGHEST RISK category

🔴 Category 1 (highest level of hazard)

• Entire bodies and all body parts, including hides and skins from:

  • Animal suspected for TSE

  • Pet/zoo/circus animals

  • Experiment animals

  • Wild animals suspected with infection of transmissible disease

• Specified Risk Material (SRM) ⭐

  • Cattle: skull, brain, eyes, spinal cord, vertebral column (older cattle), tonsils, last 4m of small intestine, cecum, mesentery (all ages)

  • Small ruminants: skull, brain, eyes (older), spleen, ileum (all ages)

  • depending on species and age according to current EU legislation

• Animals submitted for illegal treatment

• Animals submitted with residues or environmental contaminants

• Animals collected during treatment of wastewater

Disposal and use

• Pressure sterilization: permanent marking and burial in authorized landfill (133°C, 20 min, 3 bar) ⭐

• Incineration: directly or after pressure sterilization (TSE) ⭐

• Transformed into biogas

🟠 Category 2

• Manure and GIT content

• Animal products collected during wastewater treatment

• Animals with authorized residues (NSAIDs, sedatives, antibiotics)

• Declared unfit for human consumption due to foreign bodies

• Products imported/introduced from third countries failing EU veterinary legislation

• Animals and parts of animals that died other than slaughter for human consumption:

  • Disease purpose, Foetus, Oocyte, Embryo, Semen, Dead-in-shell poultry

Disposal and use

• Same methods as Category 1 (incineration, pressure sterilization, biogas)

• After pressure sterilization and permanent marking it can be used as:

  • Organic fertilizers, Soil improvers, Compost, Biogas

• Some by-products can be applied to land without processing:

  • Manure, GIT content, Egg by-products

• Aquatic animals:

  • Ensiled, Composted, Transformed into biogas

• Technical uses: Fuel for combustion, Manufacture of derived products: Cosmetics and Medical products

🟢 Category 3 (everything else from animals with NO signs of disease) ⭐

• Carcass/parts fit for human consumption but not intended due to commercial reasons

• Head and feathers of poultry, hides and skins, horns and feet, pig bristles

• By-products from poultry and lagomorphs, day-old chicks, hatchery by-products, eggs and eggshells

• Pet food and feeding stuff of animal origin no longer intended for feeding

• Blood, placenta, wool, feathers, hair, horns, hoof cuts, raw milk

• Aquatic animals (except sea mammals)

• Catering waste

Disposal and use

• Same methods as Category 1 and 2

• Processed for the manufacturing of feed for:

  • Farm animals, Fur animals, Pet food (raw)

• Manufacturing of organic fertilizer or soil improvers

• Composted or transformed into biogas

• Applied to land without processing:

  • Raw milk, Colostrum

• Fuel for combustion

• Manufacture of derived products:

  • Cosmetics, Medical products

⚠ Committee note: Category 3 can be used for feed, BUT not species-to-species feeding (e.g. cattle products → cattle feed). Meat-and-bone meal restrictions are due to TSE/BSE risk.

⭐ Committee favourites

• Category 1 = highest risk = SRM = TSE

• Method 1 = 133°C, 20 min, 3 bar

• Category 1 → incineration (often mentioned as ~1300°C)

• Category 3 → feed, pet food, fertilizer, biogas

• Do NOT feed cattle-derived products back to cattle because of TSE/BSE risk.

Focus on how to destroy category 1 material and what you can use it all for

what is the colors associated with the risk category? 1 black, 2 yellow, 3 green.

37. Basic technological equipment and procedures in meat production

Basic technological equipment

🔪 Meat grinder (mincer)

• Forces meat or meat trimmings through a barrel with rotating knives

• Produces minced meat 1–13 mm thickness

🥣 Bowl cutter

• Horizontally revolving bowl + curved knives rotating vertically at high speed

• Produces finely comminuted lean meat and fat particles

🌭 Filling machine

• Fills meat batter into casings, glass jars, cans etc.

• Small/medium operations: piston type (manual) → piston forces meat through filling nozzle

• Large operations: continuous vacuum stuffers → remove more air ⭐

📎 Clipping machine

• Applies aluminium sealing clips on sausages

• Replaces manual tying

🧊 Ice flaker

• Produces ice flakes from potable water

• Keeps meat batter temperature low ⭐

🪓 Frozen meat cutter

• Cuts frozen meat blocks into smaller pieces

• Types:

  • Guillotine (vertical knives)

  • Rotating drum with knives

💉 Brine injector

• Injects brine (salt, nitrite, additives) into meat

• Used for ham, bacon etc.

• 2°C

🥁 Tumbler / Massager

• Rotating drum with steel paddles

• Ensures equal brine distribution

• Liberates muscular proteins from meat tissue

• 10°C tumble room (microbial prevention)

Procedures in meat production

1⃣ Cutting (size reduction)

• Forms meat batter

• Meat particles evenly distributed

• Lean meat method: prepared in two steps

• All-in method: meat and fat together from start

2⃣ Mixing / Tumbling / Tenderisation

• Mechanical rupture of muscle cells

• Releases proteins → forms colloids

• Enhances water-holding capacity ⭐

• Tumbling more effective due to higher forces

• Vacuum tumbling even more effective

• Tenderisation = small cuts with rollers or blades

3⃣ Salting / Curing

• Addressed separately in Q40

4⃣ Utilisation of spices / non-meat additives

• Addressed separately in Q38

5⃣ Stuffing / Filling

• Fillings placed into casings of different shapes and sizes

• Followed by heat treatment ASAP

• Vacuum prevents:

  • Air pockets, Poor firmness, Poor texture, Poor colour, Poor stability, Fat/water separation ⭐

6⃣ Smoking / Heat treatment

• Addressed separately in Q40

• Development of:

  • Colour, Flavour, Structure, Texture

• Microbiological stabilisation

• Limits overcooking effects

• Stabilises product structure

7⃣ Drying

• Addressed separately in Q40

⭐ High-yield exam points

• Meat grinder = 1–13 mm minced meat

• Vacuum stuffers remove air

• Ice flaker keeps meat batter cold

• Brine injector = salt + nitrite + additives

• Tumbler = equal brine distribution + protein release

• Mixing/tumbling increases water-holding capacity

• Vacuum stuffing prevents air pockets and fat/water separation.