Rigor Mortis en la carne y carnes DFD Y PSE

Anomalies in Meat Transformation

Introduction to Meat and Its Nutritional Value

• The presentation discusses the transformation of muscle into meat, emphasizing that meat is the edible part of an animal's muscle when processed hygienically.

• Meat serves as a significant source of proteins, fats, and minerals in human diets, often valued highly in markets despite controversies surrounding its health implications.

Chemical Reactions Post-Sacrifice

• After an animal is sacrificed, its muscle remains soft and retains water at 38°C (the animal's body temperature), which facilitates certain chemical reactions.

• Rigor mortis occurs due to interrupted blood circulation, leading to a lack of oxygen for aerobic energy production; muscles then switch to anaerobic glycolysis for energy.

Anaerobic Metabolism and pH Changes

• During anaerobic glycolysis, lactate is produced as a byproduct, resulting in decreased pH levels in the meat which affects protein denaturation and water retention capacity.

• Factors influencing pH drop include intrinsic factors like species and age, as well as extrinsic factors such as substance administration and temperature.

Transition from Muscle to Rigid Meat

• The transition from soft muscle to rigid meat post-rigor mortis results in reduced elasticity and increased water exudation from the meat.

Anomalies: Dark Firm Dry (DFD) Condition

• DFD condition arises from accelerated glycogen degradation pre-slaughter leading to dark-colored, firm-textured meat with lower quality due to high pH levels (6.4 - 6.8). This indicates stress or illness prior to slaughter.

Anomalies: Pale Soft Exudative (PSE) Condition

• PSE condition primarily affects pigs under severe stress before slaughter; it results in pale meat with low acidity (pH 5.4 - 5.6) making it less desirable for consumers and difficult for butchers to utilize effectively.

Managing Stress Before Slaughter

• Allowing pigs adequate rest before slaughter can significantly reduce the risk of PSE conditions through better handling practices that minimize anxiety during transport and confinement.

Summary of pH Levels Across Conditions