LPT 321: Meat Science (1+1)

MICROBIAL COUNTS COMPUTED FOR ASSESSING QUALITY OF MEAT AND MEAT PRODUCTS

• Meat being a highly perishable commodity requires strict quality control right from slaughter operations till ultimate consumption.
• The basic objectives of quality control are:
  • Protection of public health
  • Extension of product shelf life
  • Provision of consumer satisfaction
  • Compliance of regulatory legislation
  • Competitive edge in the trade
• The general principles of meat product quality control involve:
  • Raw material control
  • Control of processing operations
  • Finished product inspection and control
• It is very difficult to examine meat and meat products for every pathogenic, toxigenic and spoilage microorganisms.
• However, a product cannot be improved unless some objective assessment of its quality is available.
• But the methods adopted should be simple with quick results.
• Hence, the following indicator organisms are relied upon to determine the sanitary and safety status of these items.

Total viable count (TVC)

• These are estimates of mesophiles and psychrophils and serve as useful indicators of handling history and state of freshness or spoilage of meat.
• TVC is also referred to as Aerobic Plate Count (APC) and Standard Plate Count (SPC)
• These counts provide meaningful guidance to streamline the processing operations.
• However, if these counts are less, most probable number (MPN) is enumerated.

Coliforms

• These consist of E. coli and Aerobactor aerogenes.
• Their presence indicates faecal contamination due to unhygienic handling during or after processing of meat products.
• Coliforms can be distinguished because of their property to produce gas from lactose at 44°C.
• However, out of two organisms in this category, E. coli is a better indicator of faecal contamination.

Enterococci

• These are members of faecal streptococci (group D), which consist of:
  • S. faecalis (and its varieties)
  • S. faecium (var durans)
  • S. bovis
  • S. equines
• These organisms indicate poor hygienic quality of frozen meats and inadequate heat treatment of canned meats.

Other indicators

• Besides above indicators, specific organisms like Staph. aureus, Salmonella, yeast and mould counts are also important.
• Heat-treated meats should also be screened for the presence or absence of B. cereus and Clostridia.
• Canned meat products are generally subjected to sterility test.
• For this purpose, cans are incubated at 30° C and 55° C for 15 days.
• Swollen or disfigured cans show the product spoilage.