Effect of processing plant on pork quality

The impact of processing plant on pork quality was studied by assessing pork quality in three commercial plants (A, B, C). Plants differed in the layout of the races, stunning systems (A and B: electrical, C: CO2 stunning) and chilling systems (A: rapid chilling, B and C: conventional). Factors not related to the processing plants (e.g. genetic background of animals, transport, lairage) were standardized. In total, nine batches of about 150 pigs each were processed. Each batch was purchased at a commercial farm and randomly divided into three groups for delivery to the three processing plants. Meat quality was evaluated by measuring early post-mortem muscle pH and temperature as well as ultimate pH, meat colour (Minolta Chroma Meter and Japanese colour scale), filter paper score (FPS), electrical conductivity (EC) and drip loss. Plant C produced an inferior quality compared to plants A and B: meat was paler (C: 2.8 vs. A: 2.9 and B: 3.0 on the Japanese colour scale) and had higher drip losses (C: 5.2 vs. A: 4.8 and B: 4.9%). Meat colour hardly differed between plants A and B but waterholding properties were best at plant A as indicated by FPS (A: 2.4 vs. B: 2.8 vs. C: 3.3) and EC (A: 5.4 vs. B: 6.4 vs. C: 7.4 mS). It is concluded that processing plant may influence meat quality. Correlations between early post-mortem measurements and meat quality traits were low. Nevertheless, high carcass temperatures and low pH values early post-mortem were shown to lead to inferior meat quality.