If food is contaminated with pathogens such as Listeria monocytogenes, improper cooking during sous-vide preparation can lead to foodborne illnesses. In this study, it was found that L. monocytogenes were inactivated with both heat and the essential oil of Salvia officinalis (sage EO) in beef tenderloin of the musculus psoas major that had undergone sous-vide processing. To determine whether the enhancement of the efficacy of heat treatment is prospective, L. monocytogenes and sage EO were mixed. Groups with L. monocytogenes alone and sage essential oil combined with L. monocytogenes and test groups without EO were established. The samples were vacuum-packed, inoculated with L. monocytogenes, and then cooked sous-vide for the predetermined duration at 50, 55, 60, or 65 °C. In both groups with sous-vide beef tenderloin, the total bacterial count, the coliforms bacterial count, and the amount of L. monocytogenes were assessed on days 0, 3, 6, 9, and 12. Over these days, the amounts of L. monocytogenes, coliform bacteria, and overall bacteria increased. The identification of bacterial strains in various days and categories was performed by MALDI-TOF mass spectrometry. The test group that was exposed to a temperature of 50 °C for 5 min had a higher overall bacterial count for each day that was assessed. Pseudomonas fragi and L. monocytogenes were the most isolated organisms from the test group and the treated group. To ensure the safety for the consumption of sous-vide beef tenderloin, it was found that the addition of natural antimicrobials could produce effective outcomes.

• Klíčová slova
• Listeria monocytogenes, Salvia officinalis essential oil, antimicrobial effect, beef tenderloin (m. psoas major), sous-vide,
• Publikační typ
• časopisecké články MeSH

Sous-vide is a process comprising vacuum-sealing food, heating it to the desired temperature, and circulating it in a water bath in a sous vide machine. This cooking technique is increasingly common in homes and catering establishments due to its simplicity and affordability. However, manufacturers and chef's recommendations for low-temperature and long-term sous-vide cooking in media raise food safety concerns, particularly when preparing beef tenderloin. In this study, Salmonella enterica was found to be inactivated by heat and sage essential oil (EO) in beef samples from musculus psoas major that had been sous vide processed. To determine whether heat treatment was likely to increase the sous vide efficiency, S. enterica and sage EO were mixed. After being vacuum-packed and injected with S. enterica, the samples were cooked at 50-65 °C through the sous vide technique for the prescribed time. On days 1, 3, and 6, the amounts of S. enterica, total bacteria, and coliform bacteria were measured in the control and treated groups of beef processed sous vide. Mass spectrometry was used to identify bacterial isolates on different days. On each day that was measured, a higher number of all the microbiota was found in the samples exposed to 50 °C for 5 min. The most frequently isolated microorganisms from both groups of samples were Pseudomonas fragi (17%), Pseudomonas cedrina (8%), and Proteus vulgaris (8%); in the treated group, also S. enterica (21%), Pseudomonas fragi (13%), and Pseudomonas veronii (6%). After the heat treatment of samples at 65 °C for 20 min, the total count of bacteria and coliform bacteria was zero. It has been shown that adding sage essential oil (EO) in combination with sous vide processing technique leads to the stabilization and safety of beef tenderloin.

• Klíčová slova
• active substance, beef tenderloin, foodborne pathogen, novel application, safety, sage essential oil, stabilization, under vacuum,
• Publikační typ
• časopisecké články MeSH

Samples of steak tartare were artificially contaminated with a cocktail of Shiga toxin-producing Escherichia coli (STEC) O91, O146, O153, and O156 to the level of 3 log and 6 log CFU/g. Immediately after vacuum packing, high-pressure processing (HPP) was performed at 400 or 600 MPa/5 min. Some of the samples not treated with HPP were cooked under conditions of 55 °C for 1, 3, or 6 h. HPP of 400 MPa/5 min resulted in a 1-2 log reduction in the STEC count. In contrast, HPP of 600 MPa/5 min led to the elimination of STEC even when inoculated to 6 log CFU/g. Nevertheless, sub-lethally damaged cells were resuscitated after enrichment, and STEC was observed in all samples regardless of the pressure used. STEC was not detected in the samples cooked in a 55 °C water bath for 6 h, even after enrichment. Unfortunately, the temperature of 55 °C negatively affected the texture of the steak tartare. Further experiments are necessary to find an optimal treatment for steak tartare to assure its food safety while preserving the character and quality of this attractive product.

• Klíčová slova
• STEC, contamination, meat color, minced meat, sous vide treatment, vacuum packing,
• Publikační typ
• časopisecké články MeSH

Human foodborne botulism is an intoxication caused by ingestion of botulinum neurotoxins (BoNT) of serotypes A, B, E, and rarely also serotype F, produced in contaminated food by anaerobic bacteria Clostridium botulinum group I, group II, or by toxigenic strains of C. butyricum and C. baratii. BoNT-producing Clostridia are ubiquitously distributed in the environment and, under suitable conditions, they can enter the food chain, proliferate and produce BoNT in a variety of foods. In the past, the risk of foodborne botulism was primarily associated with homemade canned foods; however, the epidemiological importance of commercial and restaurant food is increasing nowadays. In this article, we review the public health aspects of foodborne botulism, including its clinical, epidemiological and laboratory diagnosis and discuss potential risks associated with minimally heated, vacuum or modified atmosphere-packed, ready-to-eat foods of extended durability.

• Klíčová slova
• BoNT/B, BoNT/E - food safety REPFED - sous-vide - botulism - geography., Clostridium botulinum - foodborne botulism - botulinum neurotoxins - botulinum toxin - BoNT/A,
• MeSH
• botulismus * epidemiologie   MeSH
• Clostridium botulinum MeSH
• lidé MeSH
• potravinářská mikrobiologie MeSH
• séroskupina MeSH
• veřejné zdravotnictví * statistika a číselné údaje   trendy   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Total phenolic content, phenolic profile and antioxidant activity were determined in free and bound phenolic fractions of thermally treated brown and white teff grains. RESULTS: Phenolic content in raw brown and white teff (1540 and 992 mg gallic acid equivalent kg-1 ) as well as antioxidant activity (6.3 and 5.5 mmol trolox equivalent kg-1 ) were higher in free phenolic fractions. The most significant decrease in total phenolics was observed after application of the sous-vide method (35% for brown teff and 11% for white teff). Main free phenolics of heat-treated teff were ferulic, protocatechuic, p-coumaric and ellagic acids, rutin and epigallocatechin. Main bound phenolics were ferulic, gallic, sinapic and ellagic acids, catechin and epigallocatechin. The detrimental effect on free and bound quercetin and bound cinnamic acid concentrations was also examined during heat treatment. Thermally treated brown teff showed a high level of in vitro organic matter digestibility if water cooking and rice cooker (both 99.5%) and sous-vide (96.5%) methods were applied. CONCLUSION: The sous-vide method may be recommended as the most suitable hydrothermal treatment for grains of teff when compared with water cooking and rice cooker methods. © 2017 Society of Chemical Industry.

• Klíčová slova
• Eragrostis tef L., HPLC, antioxidant activity, digestibility, phenolics,
• MeSH
• antioxidancia chemie   metabolismus   MeSH
• biologické modely MeSH
• Eragrostis chemie   MeSH
• fenoly chemie   metabolismus   MeSH
• lidé MeSH
• rostlinné extrakty chemie   metabolismus   MeSH
• trávení MeSH
• vaření MeSH
• vysoká teplota MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antioxidancia MeSH
• fenoly MeSH
• rostlinné extrakty MeSH