Meat, Poultry, Fish and Egg Processing
Meat, poultry, fish and egg processing covers slaughter hygiene, post-mortem changes, chilling, curing, freezing, spoilage assessment and egg quality. The exam tests rigor mortis, cold chain control, curing and smoking, fish freshness indicators and egg candling.
Core rules
- After slaughter, muscle passes through pre-rigor, rigor mortis and resolution. Rigor affects tenderness and water-holding capacity.
- Rapid chilling controls microbial growth. Carcass hygiene depends on clean slaughter, evisceration and water quality.
- Curing uses salt, nitrite and sometimes nitrate; smoking adds flavour and surface preservation but does not sterilize.
- Fish spoilage produces volatile bases such as trimethylamine and total volatile basic nitrogen (TVB-N). Ice storage and low temperature slow spoilage.
- Egg quality is assessed by candling, albumen height and Haugh unit. Shell integrity and cold storage matter.
Worked example
100 kg meat at 35 °C is chilled to 4 °C. Using cp = 3.2 kJ/kg·K, heat removed = 100 × 3.2 × 31 = 9920 kJ. If removed over 12 h, average load = 9920 ÷ (12 × 3600) = 0.23 kW. The reasoning uses Q = m cp ΔT and converts time to seconds.
Traps
- Chilling before rigor is complete without considering cold shortening.
- Treating cured meat as sterile.
- Using appearance alone to judge fish freshness.
- Ignoring cross-contamination between raw and cooked meat.
- Storing eggs warm and losing quality.