Microbiological Changes in Meat and Minced Meat from Beavers (Castor fiber L.) during Refrigerated and Frozen Storage

Abstract

This study aims to evaluate the microbiological status, pH, and water activity of European beaver meat to establish its shelf-life and microbiological safety. In this study, the microbiological profiles of meat and minced meat obtained from the carcasses of beavers were investigated. Microbial evaluation of the chilled meat was performed within 24 h after hunting, on the 7th day and 14th day, and the evaluation of the frozen meat was made during the 11th week of storage. Meat samples were analysed for total viable count (TVC), psychrotrophic bacteria count (PBC), Enterobacteriaceae count (EBC), Escherichiacoli count (EC), total staphylococcal count (TSC), lactic acid bacteria count (LABC) and total yeast and mould counts (TYMC). Tests for the presence of pathogenic bacteria from the genus Salmonella and Listeria were also performed. Additionally, the pH and water activity were determined. The initial amount of TVC was 4.94 log CFU/g in meat samples and 4.80 log CFU/g in minced meat. After 14 days of storage, the TVC increased to 8.33 in meat samples and 8.08 log CFU/g in minced meat. Pathogenic bacteria such as Listeria and Salmonella were not found in the beaver meat tested. The microbiological state of meat stored frozen for 11 weeks was comparable to the state found in meat stored refrigerated for seven days regarding the number of microorganisms.

Staphylococcus aureus isolates from Eurasian Beavers (Castor fiber) carry a novel phage-borne bicomponent leukocidin related to the Panton-Valentine leukocidin

“…One paper, published in 1969, described the presence of S. aureus in several mammal species, including beavers, but results obtained by serological typing methods utilised then cannot be translated into CC affiliations 26 . A recent paper described a rare presence of S. aureus in minced beaver meat without providing further details 27 . While we are not aware of published S. aureus typing data from beavers (except for one MLST profile, see below), we observed CC8, CC12, CC49, CC398 and CC1956 in beavers from Germany and Austria.…”

“…A related issue is a potential infection risk for humans, given that human and beaver leukocidin genes are similar. Handling of dead or live beavers, for research or food 27 , should thus be performed under at least basic biosafety precautions, and the prevalence of BVL phages in beavers and related rodents should be investigated as well as possible SSTI in humans who handled beavers or beaver carcasses.…”

Effect of Edible Onion (Allium cepa L.) Film on Quality, Sensory Properties and Shelf Life of Beef Burger Patties

“…The beef burger patties were randomly distributed in a completely randomized design distributed in a factorial design 2 × 4 with two treatments and four beef burger patties storage times (0, 3, 6 and 9 days) and the replicates according to analyses realized. The following statistical model was used: Yijk = u + Oi + Tj + (OT)ij + Eijk (3) where: u is the overall mean, Oi is the effect of adding edible onion film, Tj is the effect of shelf life or storage, (OT)ij is the interaction between edible onion film and shelf life, and Eijk is random error. For sensory characteristics, the linear mixed model was used to analyze taste, odor, texture (tenderness), appearance and overall acceptance of each sample to identify the factors influencing the response.…”

“…Thus, beef becomes an excellent culture medium for microbial growth, whether due to favorable intrinsic factors, such as: chemical composition, high water activity, and pH decline rate; or by extrinsic factors, such as: humidity, temperature and chemical composition of the atmosphere [ 3 ]. These factors, together, can change the natural microbiota of meat and contribute to the development of pathogenic and deteriorating microorganisms, with environmental temperature being the most important extrinsic factor that determines microbial multiplication [ 4 ].…”

Staphylococcus Aureus Isolates From Eurasian Beavers (Castor Fiber) Carry a Novel Phage-borne Bicomponent Leukocidin Related to the Panton-valentine Leukocidin

“…One paper, published in 1969, described the presence of S. aureus in several mammal species, including beavers, but results obtained by serological typing methods utilised then cannot be translated into CC a liations 26 . A recent paper described a rare presence of S. aureus in minced beaver meat without providing further details 27 . While we are not aware of published S. aureus typing data from beavers (except for one MLST pro le, see below), we observed CC8, CC12, CC49, CC398 and CC1956 in beavers from Germany and Austria.…”