Assessment of Microbial and Heavy Metal Contamination of Natural Sheep Casings from Different Geographic Regions

TL;DR

This study tested natural sheep casings from different countries for microbes and heavy metals, finding no significant health risks.

Contribution

The study provides a comparative assessment of microbial and heavy metal contamination in natural sheep casings from multiple geographic regions.

Findings

Microbial counts were low and did not include harmful pathogens like Salmonella or E. coli.

Lead was the most prevalent heavy metal, but all concentrations were within safe limits.

Contamination levels were not influenced by the geographic origin of the casings.

Abstract

Natural casings are integral components in the production of various meat products, including sausages, and their quality and safety have to be controlled to eliminate any risks to consumers’ health. A total of 35 samples of salted natural sheep casings from Turkey, Iran, China, Mongolia, Pakistan, New Zealand, the United Kingdom, and Belgium were tested for microbial contamination and the concentrations of potentially toxic heavy metals. The mean log values of microbial counts were determined at 3.45 ± 0.44 log CFU/g for aerobic mesophilic bacteria, 0.5 ± 0.43 log CFU/g for anaerobic sulfide-reducing bacteria, and 1.24 ± 0.63 log CFU/g for coagulase-positive staphylococci. Typical or suspected colonies of Salmonella spp., E. coli, and Listeria spp. were not identified on selective and differential agar. The examined casings were contaminated mainly with lead (0.077 ± 0.045 mg/kg), followed by arsenic (0.036 ± 0.029 mg/kg) and cadmium (0.009 ± 0.008 mg/kg). The concentrations of mercury in all samples were below the limit of quantification. The study demonstrated that the quality and safety of natural casings were not affected by their region of origin and that microbial contamination was not correlated with heavy metal concentrations.