Academic literature on the topic 'Sensory and microbiological features of meat'

The aim of the research was an assessment of the effect of the Lactiplantibacillus plantarum SCH1 strain isolated from ecological raw fermented pork roast on pH, redox potential, nitrites, and nitrates content, L a* b* color parameters, total heme pigments content, nitrosyl myoglobin concentration, as well as the microbiological quality and sensory traits of cooked sausages produced from mechanically separated poultry meat (MSPM), cured with a lower sodium nitrite level (NaNO2 50 mg/kg) after production as well as after storage (1 and 3 weeks of storage). The biochemical identification of the Lactobacillus bacteria after storage was also performed. Tests were performed in two sausage treatments: C—control sausage made from MSPM and L—sausage made from MSPM inoculated with L. plantarum at approx. 107 cfu/g. No negative effect of using the L. plantarum SCH1 strain on the physical and chemical MSPM sausage features was found. The treatment with L. plantarum SCH1 was of better microbiological quality after 3 weeks of storage. The sausages with L. plantarum SCH1 kept good sensory quality while the control treatment was spoiled after storage.

Lactic acid bacteria (LAB) and coagulase negative cocci (CNC) were isolated from artisanal dry sausages sampled from the northeastern region of Chaco, Argentina. In order to evaluate their performancein situand considering technological features of the isolated strains, two mixed selected autochthonous starter cultures (SAS) were designed: (i) SAS-1 (Lactobacillus sakei487 +Staphylococcus vitulinusC2) and (ii) SAS-2 (L. sakei442 +S. xylosusC8). Cultures were introduced into dry sausage manufacturing process at a local small-scale facility. Microbiological and physicochemical parameters were monitored throughout fermentation and ripening periods, while sensory attributes of the final products were evaluated by a trained panel. Lactic acid bacteria revealed their ability to colonize and adapt properly to the meat matrix, inhibiting the growth of spontaneous microflora and enhancing safety and hygienic profile of the products. Both SAS showed a beneficial effect on lipid oxidation and texture of the final products.Staphylococcus vitulinusC2, from SAS-1, promoted a better redness of the final product. Sensory profile revealed that SAS addition preserved typical sensory attributes. Introduction of these cultures could provide an additional tool to standardize manufacturing processes aiming to enhance safety and quality while keeping typical sensory attributes of regional dry fermented sausages.

Sous vide, French means ‘‘under vacuum’’ the method; comprises pasteurizing foods in a vacuum package in a water bath at fully controllable temperatures (≤100°C). Sous vide is also an enclosure method. The product is consumed immediately after cooking or quickly re-heating between 0-3°C and can be stored for 3-5 weeks until consumption. With Sous vide technology, it is provided to prepare the product at the desired temperature and at the desired time without damaging the textures and quality features, without excessive drying of the outer surface. Meat, fish, chicken and vegetables can be cooked with this method. Meat and meat products prepared with sous vide technology are more delicious, juicy and crunchy and lose their nutrients at minimum level. Sous vide technology offers many advantages such as prolonging storage time, sensory quality and maintaining microbiological quality. Sous vide technology is reliable in many respects since the vegetative forms of bacteria in the food are inactivated by providing anaerobic environment with vacuum packaging and controlled temperature application.

AbstractThe effect of spraying lysozyme solutions of varying activity on microbiological stability and organoleptic features of chicken legs with skin was investigated. Lysozyme was applied at concentrations ranging from 3,000 to 48,000 U/mL. The effect of storage time at 4oC on the total aerobic bacterial count, coli titre, occurrence of enterococci, anaerobic spore forming bacilli, and pathogenic staphylococci was analysed along with the examination of sensory quality attributes. The investigations showed that the addition of lysozyme resulted in a considerable inhibition of growth of the initial aerobic bacterial counts and a limitation of disadvantageous organoleptic changes during cold storage of the legs. The lysozyme solution with the activity of 48,000 U/mL caused a 20-fold reduction in the initial aerobic bacterial count. Sensory examination showed that samples subjected to the action of lysozyme and stored for 120 h under cold storage conditions did not differ qualitatively from fresh legs. The obtained results revealed that lysozyme might be an effective agent extending shelf-life of portioned poultry meat.

PurposeTo study features, management and outcomes of cluster endophthalmitis following intravitreal bevacizumab (BCZ) injection in North India.MethodsIn this retrospective study, 28 patients (23 men) (mean age of 59.07±13 years) who received intravitreal injection of BCZ were included. Demographic details, best corrected visual acuity (BCVA), clinical features, microbiological findings and management of patients who developed endophthalmitis after injection of contaminated BCZ injections were reviewed. The organism isolated was Stenotrophomonas maltophilia.ResultsAll patients suffered from painful diminution of vision within 24–48 hours. Of the 28 eyes, 12 had lid and corneal oedema, raised intraocular pressure (IOP) (difference between mean preinjection and postinjection IOP: 4.42 mm Hg; p=0.005) and toxic anterior segment syndrome-like picture. 16 eyes presented with clear cornea, severe vitritis and poor media clarity. Among these, three eyes showed posterior hypopyon. Seventeen eyes underwent primary pars plana vitrectomy (PPV) and intravitreal vancomycin+ceftazidime based on severity of inflammation. Eleven eyes underwent primary tap and inject. Among these, four eyes required PPV due to persistent inflammation. Eleven eyes showed positive staining for Gram-negative bacilli. Seven eyes were culture positive for S. maltophilia. Mean preinjection BCVA was 0.77±0.48. The first recorded postinjection BCVA was 2.52±0.82. BCVA (at 1 month) improved to 0.88±0.66.ConclusionsS. maltophilia can be found contaminating hospital surfaces and water supply. Early PPV, prompt intravitreal antibiotics and close communication with microbiologists greatly aided in salvaging all eyes from our cohort. Majority of the patients recovered their preinjection BCVA and IOP and achieved quiescence of inflammation.

World rabbit meat production is estimated to be over 1 million tons, and Spain is the third largest producer. Although rabbit meat is marketed and consumed worldwide, information on microbiological quality is very scarce. Here, we report indicator organisms, spoilage flora, sensory quality, and some physicochemical traits of 24 h postmortem chilled rabbit carcasses and prepackaged rabbit meat stored chilled in air for 0 to 3 days at the retail level. The mean total bacterial count (4.01 ± 0.48 log CFU/g) for carcasses dressed at a small abattoir by a manual process was significantly lower (P < 0.05) than that (4.96 ± 0.90 log CFU/g) for carcasses dressed at a large abattoir in automated slaughter lines. Both groups of carcasses had mean pH values of 5.98. The dominant contaminants on carcasses from the small abattoir were Pseudomonas, lactic acid bacteria, and yeasts. These microorganisms and Brochothrix thermosphacta were dominant on carcasses from the large abattoir. On prepacked hind legs (pH 6.26 ± 0.18) stored at −1 to + 1° C (supermarket 1), mean aerobic mesophilic count was 5.87 ± 1.03 log CFU/g, and the major microbial groups were Pseudomonas, yeasts, lactic acid bacteria, and B. thermosphacta. On prepacked whole carcasses (pH 6.37 ± 0.18) displayed at −1 to + 5° C (supermarket 2), mean aerobic mesophilic count was 6.60 ± 1.18 and the same microbial groups were dominant. Relative Escherichia coli incidence was supermarket 2 > large abattoir > supermarket 1 > small abattoir. Overall, low numbers of coliforms, Enterobacteriaceae, psychrotrophic clostridia, coagulase-positive staphylococci, and molds were found. Sensory scores, pH values, and L-lactic acid content differentiated fresh carcasses from retail samples. Data obtained suggest that the microflora of chilled rabbit meat are different from those found on the meat of other animals.

One-centimeter cubes of the semimembranosus and adductor muscles of beef were inoculated with 5.2 × 106 of Salmonella typhimurium, Shigella sonnei, Yersinia enterocolitica, Escherichia coli, Pseudomonas aeruginosa or Streptococcus faecalis. Exposure of the meat by dipping in 1.2% acetic acid for 10 s reduced averge numbers recoverable of these bacteria by 65%. E. coli was the most resistant, losing 46% of its viable cells. One-half of the acetic acid was replaced with 0.046% formic acid without loss in effectiveness. The rate of increase in antimicrobial effects of the treatment declined with time. Discoloration of the meat occurred after dipping in both 1.2% acetic acid, and 0.6% acetic plus 0.046% formic acids for 10 s. In triangle tests of flavor, panelists failed to differentiate samples of baked ground beef treated (before grinding) with 0.6% acetic acid and 0.046% formic acid from controls dipped in water (P<0.05). However, the same type of test showed a significant flavor difference between meat dipped in 1.2% acetic acid or distilled water.

Orientador: Arnaldo Yoshiteru Kuaye
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-08-10T19:29:59Z (GMT). No. of bitstreams: 1 Miyagusku_Luciana_D.pdf: 3536658 bytes, checksum: 4556132ea7365aeee18aa4f6d36aaa0c (MD5) Previous issue date: 2008
Resumo: Lotes de amostras de cortes de coxa e de filé de peito de frango, previamente acondicionadas sob diferentes sistemas de embalagens (recobertas por filme de alta permeabilidade ao oxigênio (AR), em vácuo (VC) e em atmosfera modificada (AM) com CO2 e N2) foram submetidas à irradiação ionizante com uma fonte de 60Co. Com o objetivo de avaliar a influência do processo sobre a vida útil e manutenção da qualidade foram avaliados parâmetros físico-químicos, microbiológicos e sensoriais das amostras processadas e armazenadas sob refrigeração a temperatura de 7±1ºC por períodos de 42 dias (AR) e três meses (VC e AM). Os tratamentos das amostras de frango por irradiação não promoveram alteraçao de cor, determinada objetivamente, enquanto a oxidação lipídica, avaliada pelas determinações TBARS (substâncias reativas ao ácido tiobarbitúrico) como indicador, apresentaram tendência de valores crescentes, conforme incremento da dose. Os valores de pH das amostrascontrole coxa/AR,VC e AM e peito/AR,VC e AM não apresentaram diferenças significativas durante todo o período de armazenamento. A aplicação da irradiação às amostras de carne de frango acondicionadas em filme de alta permeabilidade ao oxigênio (coxa/AR e peito/AR) e em filme barreira (coxa/VC, peito/VC, coxa/AM e peito/AM) promoveu uma sensível redução de E.coli, Pseudomonas spp, e enterobacteriaceas totais, porém no sistema de embalagem AR as bactérias láticas e os bolores e leveduras apresentaram maior resistência. Nas amostras acondiciondas em filme com barreira (vácuo e atmosfera modificada) as bactérias láticas foram as mais resistentes. Não foi observado em nenhuma amostra o desenvolvimento de Brochothrix thermosphacta e Listeria monocytogenes durante todo o periodo de armazenamento. Os resultados das análises cromatográficas de substâncias oriundas da degradação lipídica revelaram perfis de compostos voláteis similares para amostras submetidas às três condições de atmosfera. O incremento nas doses de irradiação acima de 3kGy, independente do tipo de sistema de embalagem utilizada, promoveu alteração crescente do odor de queimado no produto revelando assim este valor como limite recomendável para a garantia de uma maior vida útil sem alteração sensorial perceptível. Observou-se uma sensível extensão da vida útil das amostras de coxa/AR em 2,8 vezes, peito/AR em 4,0 vezes e em amostras embaladas em filme barreira (coxa/VC, e peito/VC, coxa/AM e peito/AM) em 6,0 vezes superior ao das amostras-controle. O processo de irradiação demonstrou ser uma ferramenta potencial de utilização para extensão da vida útil e melhoria da qualidade de cortes de frango
Abstract: Samples of raw chicken thigh and chicken breast fillets previously packed in different packaging systems [wrapped in high oxygen-permeable film (AIR), vacuum packed (VC) and CO2 and N2 modified-atmosphere-packed (MA)] were submitted to ionizing radiation delivered by a 60Co unit. A series of physical-chemical, microbiological and sensory parameters were evaluated to assess the effect of the radiation process on the shelf-life and keeping quality of chicken cut samples exposed to radiation and subsequently cold-stored at 5±1ºC for 39 days (AIR) and 3 months (VC and MA). The results of instrumental color assessment trials showed that the radiation treatments investigated in this study did not cause any color changes in any of the radiation-treated chicken cuts. On the other hand, lipid oxidation - measured using the TBARS (thiobarbituric acid reactive substances) content as indicator ¿ exhibited a gradual increase proportional to the increase of the radiation dose. The pH values of the chicken thigh/AIR, VC and MA and chicken breast/AIR, VC and MA control samples did not exhibit any significant differences throughout the storage period investigated. Irradiation of the chicken meat samples packaged in high oxygen-permeable film (chicken thigh/AIR and chicken breast/AIR) and in barrier film (chicken thigh/VC, chicken breast/VC, chicken thigh/MA and chicken breast/MA) resulted in a considerable reduction of E.coli, Pseudomonas spp and total enterobacteria counts, however, lactic acid bacteria, yeasts and moulds demonstrated higher resistance in the AIR packaging system. In the samples packaged in barrier film (vacuum and modified atmospere) the lactic acid bacteria were identified as the most resistant to radiation. None of the samples showed growth of Brochothrix thermosphacta and Listeria monocytogenes throughout the storage period investigated. The results of chromatographic analyses of substances generated by lipid degradation showed similar compound profiles for the samples submitted to the three atmosphere conditions studied. In addition, no migration of substances from the packaging material to the meat samples was detected. Irrespective of the packaging system, increasing the radiation dose to levels above 3kGy resulted in the development of a burnt odor the intensity of which increased with increasing dose values, thereby indicating 3kGy to be a recommendable limit that ensures a product with a long shelf-life and without sensory perceptible changes. While the shelf-life of the control samples of chicken thigh/AIR and chicken breast/AIR was estimated at 5 days, irradiation with increasing doses of 1,5 to 7,0 kGy was found to result in a 1,8 to 7,4-fold increase in the shelf-life, respectively. The irradiation process demonstrated to be a potentially very useful tool to extend the shelf-life and improve the quality of chicken cuts
Doutorado
Doutor em Tecnologia de Alimentos

The diploma thesis processes system of evaluation applicable in processing plant Maso-Uzeniny-Brož (Meat-Sausages-Brož). It observes selected chemical, microbiological, technological and sensory features of suplied meat from various suppliers and its structure. Furthermore, it judges its relation to price.