| Congresso Brasileiro de Microbiologia 2023 | Resumo: 689-1 | ||||
Resumo:Frog meat (Lithobates catesbeianus) is known for its high nutritional value and has been increasingly attracting the interest of consumers who seek food products which are not only nutritious, but also bring additional health benefits. Meat from the frog’s upper body (torso and forelimbs) is a by-product to hind legs processing, and can be used in the in the preparation of several products that add value to the aquaculture production chain, including mechanically deboned fish flesh. For this study, two batches of fresh meat from the frog’s upper body were evaluated for their microbiological quality according to the standards laid down by Brazilian Health Surveillance Agency (ANVISA). The batches were obtained on two different processing days, from a slaughterhouse certified by the Sanitary Inspection. Issues were found, while visiting the facility, as to the fasting period of the animals and their handling in the receiving area, especially during the lairage prior to thermal shock stunning. One day before the analysis, the frozen upper bodies of the frogs were removed from the freezer and kept under refrigeration (7°C) for twelve hours, for thawing. Samples were analysed in triplicate and were named B1 and B2, indicating their batch. Analyses were performed using conventional methods to detect Salmonella spp., and to identify and enumerate coagulase-positive staphylococcus and Escherichia coli. To carry out the analyses by MALDI-TOF mass spectrometry, bacterial cultures of Salmonella spp., Staphylococcus spp. and Escherichia coli obtained by conventional methods were incubated for 24 hours on nutrient agar, and used for application by direct transfer technique. The mass spectra were obtained using a MALDI-TOF mass spectrometer (Microflex LT, Bruker Daltonics) and were processed using FlexControl software (Germany). Results of the analyses using conventional methods were positive for E. coli, with a count of 240 MPN/g for B1 and 3 MPN/g for B2 – the B1 sample having a count higher than the limit set by Brazilian legislation, which is of 10 MPN/g. Results of the isolation and enumeration of coagulase-positive Staphylococcus showed the growth of typical colonies in both samples (B1 and B2), but the coagulase tests were negative. Salmonella spp. was detected in both samples (L1 and L2), and results of the analysis by MALDI-TOF mass spectrometry showed the presence of Salmonella spp. and E. coli in both samples as well. Identification of Staphylococcus spp. in samples B1 and B2 was not confirmed by this method, but other Gram-positive bacteria were detected: Enterococcus hirae and Enterococcus faecalis with a score higher than 2.3. These results indicate product contamination, which may be related to handling problems throughout different stages of the production chain. It is therefore necessary to improve the good hygiene practices in the slaughterhouse and during primary production. The different analytical methods used for this study were efficient in detecting the presence or absence of the studied bacteria, and a high degree of compatibility between results was also observed. Palavras-chave: Lithobates castebeianus, microbiological quality, Salmonella spp, Escherichia coli, Staphylococcus spp. Agência de fomento:Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro - FAPERJ | |||||