32. Meat Deviations - PSE/DFD meat

Question 1

What is normal pH of meat?

Answer 1

6.4 - 6.6

Question 2

What does PSE stand for and why does it occur?

Answer 2

Pale Soft Exudative (most commonly in pork)

Due to accelerated glycolysis with rapid buildup of lactic acid -> decrease in pH. If meat has a pH below 6 within 45min = most likely PSE

Question 3

What is the consequence to the meat with PSE?

Answer 3

It leads to a
- rapid onset of rigor mortis
- excessive drip loss from cut surface (from protein denaturation and less water binding)
- paleness of muscle due to low myoglobin content

Question 4

Is PSE meat allowed to be used?

Answer 4

Yes, but ONLY for meat products after thermal or long lasting treatment

Question 5

What are factors that may lead to PSE?

Answer 5

Slaughter stress or genetics

Question 6

What does DFD stand for and why does it occur?

Answer 6

Dark, Firm, Dry

Pre-slaughter stress depletes the muscle glycogen reserves (more muscle activity) and increases oxygen consumption, less oxymyoglobin-> less lactic acid production PM = rapid onset of rigor mortis and pH higher than normal, after slaughtering.

pH above 6.2

Question 7

What is the pH in PSE meat?

Answer 7

Under 6

Question 8

What is the pH in DFD meat?

Answer 8

Above 6.2

Question 9

How can meat be evaluated for PSE/DFD?

Answer 9

• pH estimation - pH electrodes inserted into the muscle
• color estimation - photometer (pale vs dark)
• hydraemia estimation - testing the protein - water holding capacity;

Can use compression method; 1 kg meat on filtration paper between glass plate -> 5min, outline, soaked paper
- PSE (exudative) have bigger outline than DFD (dry)

Question 10

What are causes for DFD ?

Answer 10

Stress. 24-48h prior to slaughter, hypersensitivity, young animals with high temperament

Question 11

What is another word for Malignant hyperthermia?

Answer 11

Porcine Stress Syndrome

Question 12

Why does PSS occur?

Answer 12

Due to an autosomal recessive gene (should not be bred) .
Also possible from - environmental factors as during transport, overcrowding, sudden movements, vaccination and hot climate may trigger.

Question 13

What does PSS often lead to?

Answer 13

PSE

Question 14

What are clinical signs for PSS?

Answer 14

Nervous/stressed pigs, muscle tremors, tachypnea, skin irritation and rapid death. Rigor mortis develops within 5min

Question 15

How can PSS be diagnosed. How can it be prevented?

Answer 15

Can be diagnosed at 7w old by PCR

Prevention: in pigs that are carriers by good ventilation, better handling and not feed pigs within 12h before slaughtering