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1.
Food Microbiol ; 102: 103920, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809946

RESUMO

The aim of this study was to determine the biogenic amines (BAs) formed in chicken breast meat packaged using different techniques (AP, Hi-O2-MAP or VP) during the storage under different conditions (cold room or display case), to correlate the microbiological quality (TPC, LAB, Pseudomonas spp. and Enterobacteriaceae) of chicken meat with BAs formation and to assess the suitability of selected biogenic amines as indicators of chicken meat spoilage. The initial TPC of chicken fillets was 2.57-3.04 log cfu/g. Over time a systematic significant (p ≤ 0.05) increase in TPC was observed to >7.5 log cfu/g (AP and VP; display case) determined on day 9. It was found that cadaverine and tyramine dominated in quantitative terms in chicken fillets, regardless of packaging technique and storage conditions (166.00 mg/kg in AP meat in cold room on day 9 and 175.03 mg/kg on day 9 in MAP meat in display case, respectively). Taking into account the BAI, high and significant (p ≤ 0.05) correlation coefficients (from 0.51 to 0.95) were obtained with all analyzed indicators of microbiological quality. The concentration of cadaverine, putrescine contents or BAI can potentially serve as chemical quality indicator for freshness of chicken meat.


Assuntos
Aminas Biogênicas , Embalagem de Alimentos , Aves Domésticas/microbiologia , Animais , Aminas Biogênicas/análise , Cadaverina/análise , Galinhas , Microbiologia de Alimentos , Conservação de Alimentos , Carne/análise , Tiramina/análise
2.
Acta Sci Pol Technol Aliment ; 20(4): 473-484, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34724371

RESUMO

BACKGROUND: ood producers strive to meet the changing needs of consumers while maintaining the highest nutritional value of the products they supply. Physicochemical methods, which include modified atmosphere packaging, membrane techniques or ultrasounds, are the most frequently used to preserve food. Alternatively, biological methods can be applied, one of which is the use of bacteriophages (phages) to limit bacterial growth in the food environment. The purpose of our research was to verify the possibility of the use of bacteriophages as an antibacterial agent in minimally processed food environments of vegetable origin. The first stage of the research involved the isolation of phages against the dominant bacterial microflora in the analyzed products: broccoli sprouts, spinach leaves and freshly squeezed carrot-celery juice. Bacteriophages were isolated from municipal waste collected from sewage-treatment plants. Specific bacteriophages were isolated for twenty-nine out of thirty identified bacterial strains. The lytic activity of the phages was tested using a Bioscreen C automatic growth analyzer. Three methods for applying the phage cocktail were tested: direct addition of the cocktail, spraying it on, and placing the food product on a pad soaked with the phage mixture. The food products were packaged in a protective atmosphere and stored at 20°C. The total number of bacteria after adding the phage cocktail to the products was determined during the subsequent hours of incubation using classical microbial culturing. A significant decrease in the total number of bacteria was observed in the products containing phage suspensions. The obtained results suggest that application of the phage cocktail offers the possibility to extend the shelf life of the analyzed minimally processed food products by reducing the total number of saprophytic. METHODS: , food producers strive to meet the changing needs of consumers while maintaining the highest nutritional value of the products they supply. Physicochemical methods, which include modified atmosphere packaging, membrane techniques or ultrasounds, are the most frequently used to preserve food. Alternatively, biological methods can be applied, one of which is the use of bacteriophages (phages) to limit bacterial growth in the food environment. The purpose of our research was to verify the possibility of the use of bacteriophages as an antibacterial agent in minimally processed food environments of vegetable origin. The first stage of the research involved the isolation of phages against the dominant bacterial microflora in the analyzed products: broccoli sprouts, spinach leaves and freshly squeezed carrot-celery juice. Bacteriophages were isolated from municipal waste collected from sewage-treatment plants. Specific bacteriophages were isolated for twenty-nine out of thirty identified bacterial strains. The lytic activity of the phages was tested using a Bioscreen C automatic growth analyzer. Three methods for applying the phage cocktail were tested: direct addition of the cocktail, spraying it on, and placing the food product on a pad soaked with the phage mixture. The food products were packaged in a protective atmosphere and stored at 20°C. The total number of bacteria after adding the phage cocktail to the products was determined during the subsequent hours of incubation using classical microbial culturing. A significant decrease in the total number of bacteria was observed in the products containing phage suspensions. The obtained results suggest that application of the phage cocktail offers the possibility to extend the shelf life of the analyzed minimally processed food products by reducing the total number of saprophytic bac. RESULTS: , food producers strive to meet the changing needs of consumers while maintaining the highest nutritional value of the products they supply. Physicochemical methods, which include modified atmosphere packaging, membrane techniques or ultrasounds, are the most frequently used to preserve food. Alternatively, biological methods can be applied, one of which is the use of bacteriophages (phages) to limit bacterial growth in the food environment. The purpose of our research was to verify the possibility of the use of bacteriophages as an antibacterial agent in minimally processed food environments of vegetable origin. The first stage of the research involved the isolation of phages against the dominant bacterial microflora in the analyzed products: broccoli sprouts, spinach leaves and freshly squeezed carrot-celery juice. Bacteriophages were isolated from municipal waste collected from sewage-treatment plants. Specific bacteriophages were isolated for twenty-nine out of thirty identified bacterial strains. The lytic activity of the phages was tested using a Bioscreen C automatic growth analyzer. Three methods for applying the phage cocktail were tested: direct addition of the cocktail, spraying it on, and placing the food product on a pad soaked with the phage mixture. The food products were packaged in a protective atmosphere and stored at 20°C. The total number of bacteria after adding the phage cocktail to the products was determined during the subsequent hours of incubation using classical microbial culturing. A significant decrease in the total number of bacteria was observed in the products containing phage suspensions. The obtained results suggest that application of the phage cocktail offers the possibility to extend the shelf life of the analyzed minimally processed food products by reducing the total number of saprophytic bacteria.


Assuntos
Bacteriófagos , Bactérias , Verduras
3.
Int J Mol Sci ; 22(22)2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34830335

RESUMO

The food industry is still searching for novel solutions to effectively ensure the microbiological safety of food, especially fresh and minimally processed food products. Nowadays, the use of bacteriophages as potential biological control agents in microbiological food safety and preservation is a promising strategy. The aim of the study was the isolation and comprehensive characterization of novel bacteriophages with lytic activity against saprophytic bacterial microflora of minimally processed plant-based food products, such as mixed leaf salads. From 43 phages isolated from municipal sewage, four phages, namely Enterobacter phage KKP 3263, Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 have lytic activity against Enterobacter ludwigii KKP 3083, Citrobacter freundii KKP 3655, Enterobacter cloacae KKP 3082, and Serratia fonticola KKP 3084 bacterial strains, respectively. Transmission electron microscopy (TEM) and whole-genome sequencing (WGS) identified Enterobacter phage KKP 3263 as an Autographiviridae, and Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 as members of the Myoviridae family. Genome sequencing revealed that these phages have linear double-stranded DNA (dsDNA) with sizes of 39,418 bp (KKP 3263), 61,608 bp (KKP 3664), 84,075 bp (KKP 3262), and 148,182 bp (KKP 3264). No antibiotic resistance genes, virulence factors, integrase, recombinase, or repressors, which are the main markers of lysogenic viruses, were annotated in phage genomes. Serratia phage KKP 3264 showed the greatest growth inhibition of Serratia fonticola KKP 3084 strain. The use of MOI 1.0 caused an almost 5-fold decrease in the value of the specific growth rate coefficient. The phages retained their lytic activity in a wide range of temperatures (from -20 °C to 50 °C) and active acidity values (pH from 4 to 11). All phages retained at least 70% of lytic activity at 60 °C. At 80 °C, no lytic activity against tested bacterial strains was observed. Serratia phage KKP 3264 was the most resistant to chemical factors, by maintaining high lytic activity across a broader range of pH from 3 to 11. The results indicated that these phages could be a potential biological control agent against saprophytic bacterial microflora of minimally processed plant-based food products.


Assuntos
Bacteriófagos/genética , Citrobacter freundii/virologia , Enterobacter cloacae/virologia , Inocuidade dos Alimentos/métodos , Genoma Viral , Myoviridae/genética , Serratia/virologia , Bacteriólise/fisiologia , Bacteriófagos/classificação , Bacteriófagos/isolamento & purificação , Agentes de Controle Biológico/classificação , Agentes de Controle Biológico/isolamento & purificação , DNA Viral/genética , Microbiologia de Alimentos/métodos , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Humanos , Myoviridae/classificação , Myoviridae/isolamento & purificação , Filogenia , Esgotos/virologia , Verduras/microbiologia
4.
Molecules ; 26(19)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34641340

RESUMO

Salt concentrations in brine and temperature are the major environmental factors that affect activity of microorganisms and, thus may affect formation of biogenic amines (BAs) during the fermentation process. A model system to ferment cucumbers with low salt (0.5%, 1.5% or 5.0% NaCl) at two temperatures (11 or 23 °C) was used to study the ability of indigenous microbiota to produce biogenic amines and metabolize amino acid precursors. Colony counts for presumptive Enterococcus and Enterobacteriaceae increased by 4 and up to 2 log of CFU∙mL-1, respectively, and remained viable for more than 10 days. 16S rRNA sequencing showed that Lactobacillus and Enterobacter were dominant in fermented cucumbers with 0.5% and 1.5% salt concentrations after storage. The initial content of BAs in raw material of 25.44 ± 4.03 mg∙kg-1 fluctuated throughout experiment, but after 6 months there were no significant differences between tested variants. The most abundant BA was putrescine, that reached a maximum concentration of 158.02 ± 25.11 mg∙kg-1. The Biogenic Amines Index (BAI) calculated for all samples was significantly below that needed to induce undesirable effects upon consumption. The highest value was calculated for the 23 °C/5.0% NaCl brine variant after 192 h of fermentation (223.93 ± 54.40). Results presented in this work indicate that possibilities to control spontaneous fermentation by changing salt concentration and temperature to inhibit the formation of BAs are very limited.


Assuntos
Aminoácidos/análise , Bactérias/classificação , Aminas Biogênicas/análise , Cucumis sativus/microbiologia , Metabolômica/métodos , Sais/química , Bactérias/genética , Bactérias/isolamento & purificação , Cucumis sativus/química , DNA Ribossômico/genética , Fermentação , Microbiologia de Alimentos , Conservação de Alimentos , Concentração de Íons de Hidrogênio , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Cloreto de Sódio/química , Temperatura
5.
Pathogens ; 10(7)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202800

RESUMO

The widespread use of antibiotics, especially those with a broad spectrum of activity, has resulted in the development of multidrug resistance in many strains of bacteria, including Salmonella. Salmonella is among the most prevalent causes of intoxication due to the consumption of contaminated food and water. Salmonellosis caused by this pathogen is pharmacologically treated using antibiotics such as fluoroquinolones, ceftriaxone, and azithromycin. This foodborne pathogen developed several molecular mechanisms of resistance both on the level of global and local transcription modulators. The increasing rate of antibiotic resistance in Salmonella poses a significant global concern, and an improved understanding of the multidrug resistance mechanisms in Salmonella is essential for choosing the suitable antibiotic for the treatment of infections. In this review, we summarized the current knowledge of molecular mechanisms that control gene expression related to antibiotic resistance of Salmonella strains. We characterized regulators acting as transcription activators and repressors, as well as two-component signal transduction systems. We also discuss the background of the molecular mechanisms of the resistance to metals, regulators of multidrug resistance to antibiotics, global regulators of the LysR family, as well as regulators of histone-like proteins.

6.
Environ Monit Assess ; 192(2): 142, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31982958

RESUMO

Both polycyclic aromatic hydrocarbons (PAHs) and legacy organochlorine insecticides (OCPs), including DDT, are dangerous chemical contaminants. The aims of this study were to (i) determine background levels of PAHs and legacy OCPs for wheat samples collected in 2017 and 2018 in Poland, (ii) identify differences between levels in wheat harvested in various regions of Poland, (iii) evaluate differences in contamination sources manifested by the profiles of the identified chemicals, (iv) identify possible correlations between different classes of chemicals present in wheat, and (v) assess the health risks associated with the presence of PAHs and OCPs in Polish wheat. Average concentrations found in the samples were 0.09 ± 0.03 µg kg-1 for benzo[a]pyrene (BaP) (formerly used as a single PAH marker), 0.43 ± 0.16 for the more recently introduced collective PAH 4 marker (benzo[a]anthracene + benzo[a]pyrene + chrysene + benzo[b]fluoranthene), and 1.07 ± 0.68 µg kg-1 for DDT and its metabolites. The PAH profiles indicated contamination from combustion-related emission sources (liquid fossil fuels, coal, biomass). Health risks associated with the presence of PAHs and OCPs in cereals were assessed using the margin of exposure (MOE) approach. The MOE values calculated based on the highest concentrations found in this study exceeded 50,000 for both BaP and PAH 4. The calculated worst-case scenario value for DDT and metabolites was as low as 0.3% of the respective tolerable daily intake (TDI) value. Assessment of dietary risk has shown that the presence of the two contaminant classes in Polish wheat grains is of low concern.


Assuntos
Praguicidas , Hidrocarbonetos Policíclicos Aromáticos , Triticum , Monitoramento Ambiental , Praguicidas/análise , Polônia , Hidrocarbonetos Policíclicos Aromáticos/análise , Triticum/química
7.
J Agric Food Chem ; 68(3): 856-868, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31891502

RESUMO

Biogenic amines (BAs) are low molecular weight organic bases. BAs occurring naturally in living organisms are responsible for a number of vital functions, including (in humans) secretion of gastric acids, controlling body temperature, differentiation and growth of cells, immune reactions, and brain activity. However, if oversupplied with food, BAs may cause food poisoning and produce undesirable effects. Nine BAs and eight free amino acids (FAAs) were determined in 85 samples of 19 different varieties of fermented vegetables available on the Polish retail market. Both BA and FAA levels differed significantly among various varieties of the studied fermented vegetables. Averages for the sum of all tested BAs ranged from 30.29 ± 16.43 mg·kg-1 in fermented olives to 612.1 ± 359.33 mg·kg-1 in fermented Brussels sprout. BA profiles were dominated by putrescine (42%), tyramine (20%), cadaverine (18%), and histamine (8%); jointly, the four amines amounted to 88% of all nine studied BAs. The combined level of the latter four BAs was calculated for each vegetable variety as the so-called BA index (BAI). On that basis, the risk of BA-related adverse health effects has been assessed as high/medium/low in 6/3/10 of all 19 studied varieties of fermented vegetables. Brussels sprout and broccoli turned out to be the most risky vegetables from that point of view (BAI above 400 mg·kg-1). FAA levels ranged from 54.8 ± 12.76 (fermented olives) to 3917.42 ± 1528.73 mg·kg-1 (fermented garlic). The high content of FAAs may increase the risk of forming toxic amounts of BAs, depending on characteristics of the current and added microflora as well as on environmental and technological conditions the product is subjected to.


Assuntos
Aminoácidos/análise , Aminas Biogênicas/análise , Verduras/química , Aminas Biogênicas/toxicidade , Brassica/química , Fermentação , Contaminação de Alimentos/análise , Fatores de Risco
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