Comparative Study of Fresh and Frozen Broiler Neck Skin Sampled for Process Hygiene Purposes

Abstract

The objective of the study was to determine the effect of freezing broiler neck skin samples before their microbial analysis, compared to freshly examined samples regarding total viable count (TVC) and Enterobacteriaceae count (EC). For this, 300 neck skin samples were taken at a German commercial broiler abattoir and each neck skin sample was cut into two parts. One randomly selected part underwent microbial examination after storage at 4 °C overnight; the other part was frozen at −30 °C for eight weeks before analysis in the same laboratory. Log cfu/g values of TVC and EC were separately compared between the fresh and frozen neck skin samples. A difference up to 0.5 log values was set as acceptable, i.e., fresh and frozen samples with counts that differed by this amount were considered as not different. The differences between the grouped samples of fresh and frozen broiler neck skin regarding both TVC and EC levels were less than 0.5 log values. Thus, it can be assumed that broiler neck skin samples, both fresh and frozen for eight weeks, are suitable for microbiological examination, as the TVC and EC results showed equivalence. Therefore, freezing broiler neck skin samples can be an option to maintain viable bacteria levels in broiler neck skin samples taken for microbiological examination in process control, when freezing and later examination is necessary due to insufficient laboratory capacity for the examination of fresh neck skin samples.

Keywords

• total viable count
• Enterobacteriaceae count
• equivalence test
• microbial comparison