Shelf life of pork from five different quality classes

Area of Science:

• Food Science
• Microbiology
• Meat Science

Background:

• Meat quality is crucial for consumer acceptance and product shelf life.
• Five pork quality classes (PSE, PFN, RSE, RFN, DFD) were identified based on post-mortem characteristics.
• Understanding microbial dynamics in relation to pork quality is essential for the meat industry.

Purpose of the Study:

• To investigate the long-term shelf life of vacuum-packaged pork across different quality classes.
• To determine the microbial spoilage patterns in relation to pork quality over 35 days of refrigerated storage.
• To identify pork quality classes with significantly different shelf lives.

Main Methods:

• 117 pork loins from five quality classes were vacuum-packaged and stored at 4°C for 35 days.
• Microbial load (total aerobic mesophilic and lactic acid bacteria) was assessed at 0 and 35 days post-mortem.
• Statistical analysis (P>0.05, P<0.05) was used to compare microbial counts among quality classes.

Main Results:

• Initial microbial load at 0 days was not significantly different across pork quality classes.
• After 35 days, dark, firm, dry (DFD) pork exhibited higher microbial counts (P<0.05) due to elevated ultimate pH.
• Red, soft, exudative (RSE) pork was the second most susceptible to spoilage; PSE, PFN, and RFN classes showed similar microbial loads.

Conclusions:

• Pork quality significantly influences microbial spoilage and shelf life under vacuum packaging.
• DFD pork's higher pH contributes to accelerated microbial growth and spoilage.
• RSE pork's susceptibility to spoilage requires further investigation to understand underlying mechanisms.