Peracetic acid application as an antimicrobial and its residual (HEDP): a holistic approach on the technological characteristics of chicken meat.

The most significant occurrence of food-borne diseases is due to Campylobacter and Salmonella contamination from chicken meat, and for this reason, strict regulations about strategies to improve the control of food pathogens are imposed by food safety authorities. Despite the efforts of poultry industry since the beginning of risk analysis and critical control point to reduce the burden of food-borne illness, technological barriers along the way are increasingly necessary to ensure safe food. The aim of this review was to carry out a scientific approach to the influence of peracetic acid (PAA) as an antimicrobial and its toxicological safety, in particular the stabilizer used in the formulation of PAA, 1-hydroxyethylidene 1,1-diphosphonic acid (HEDP), suggesting the possibility of researching the residual HEDP in meat, which would allow the approval of the PAA by the health authorities of several countries that still restrict it. This review also aims to ascertain the effectiveness of PAA, in different cuts and carcasses, by different application methods, comparing the effectiveness of this antimicrobial with other antimicrobials, and its exclusive or combined use, for the decontamination of poultry carcasses and raw parts. The literature results support the popularity of PAA as an effective intervention against pathogenic bacteria during poultry processing.

Development of active packaging film based on poly (lactic acid) incorporated with Piper betel leaf ethanolic extract and its application in the shelf-life extension of tuna meat.

Active packaging films based on poly (lactic acid) (PLA) were developed by adding different concentrations (5 wt% and 10 wt%) of betel leaf (Piper betel) ethanolic extract (BLEE). The extract showed excellent antioxidant (80.2 %) and antimicrobial properties (18.05 and 16.05 mm against S. aureus and E. coli respectively). The films' structural, functional, and mechanical attributes were studied, along with their potential for extending the shelf life of tuna meat. The water solubility and water permeability were reduced with the incorporation of BLEE; while the tensile strength showed an inverse relationship with the concentration, 214.5 kg/cm2 (5 wt%), and to 307.6 kg/cm2 (10 wt%). The lipid oxidation in PLA-BLEE-packed tuna meat stored under refrigeration (7 days) showed a significant reduction, which could be attributed to the phenolic migration from the films. The new PLA-BLEE films with significant antibacterial and film attributes could be used in food packaging and to extend the shelf life of commodities that have been packaged.

Microbiological stability and sensorial valorization of thyme and oregano essential oils alone or combined with ethanolic pomegranate extracts in wine marinated pork meat.

In the present study, wine-based marinades containing ethanolic extract from pomegranate (Punica granatum L.), alone or in combination with two Essential Oils (Thyme & Oregano), were used for pork fillets marination and their antimicrobial activity, as well as their sensorial impact were evaluated. Likewise, the marinades exhibited promising results concerning their recorded antimicrobial activity versus Enterobacteriaceae, Total Mesophilic Bacteria, Yeasts/molds, Staphylococcus spp., Pseudomonas spp. & Lactic Acid Bacteria (LAB). The outcome demonstrated that pork fillets marinated with wine containing ethanolic extract of pomegranate and Oregano Essential Oil were more resistant to spoilage compared to all other samples; thus, their shelf-life was significantly extended (4 days in some cases). Triterpenes (maslinic, oleanolic and betulinic acid), monoterpenes (p-cymene, carvacrol, thymol, limonene), organic acids (citric & malic acid) and phenols, were the main constituents found in the plant extract, the wine and Essential Oils applied, as determined through LC-QTOF/MS and HPLC analysis. Additionally, the sensorial properties (color, tenderness, flavor and juiciness) of the marinated meat samples were not negatively influenced. Consequently, marinades of this type could be used as natural preservatives in meat products, with satisfying antimicrobial and organoleptic results.

Inhibition of Listeria monocytogenes growth in turkey fillets by alginate edible coating with Trachyspermum ammi essential oil nano-emulsion.

The objective of this study was to determine the chemical composition and antibacterial activity of Trachyspermum ammi essential oil (TAEO). Moreover, the present study comparatively investigated TAEO in the forms of emulsion and Nano-emulsion in alginate-based edible coatings against inoculated Listeria monocytogenes in turkey fillets during 12 days in cold storage (at a temperature of 4 ± 1 °C). Alginate solutions with two levels of TAEO (in emulsion and Nano-emulsion forms) were prepared in this study. The bacterial count was performed on days 0, 1, 2, 4, 8, and 12. Based on the obtained results of the current study, a comparison of different treatments with the blank samples (without any coating) showed that the highest considerable result was observed in the samples with Nano-emulsion coating (P < 0.05). Nano-emulsion loaded alginate coating prevented the growth of listeria in turkey fillets even after 12 days of cold storage. According to the findings of this study, the application of alginate edible coatings containing TAEO, especially in Nano-form, can be very effective in controlling the growth of L. monocytogenes, as a foodborne pathogen, during storage; therefore, it is a good choice to be applied in the meat industry.

Effects of high-molecular-weight chitosan coating prepared in different solvents on quality of catfish fillets during 6-month frozen storage.

Effects of high-molecular-weight (800 kDa) chitosan coating on quality of catfish fillets were examined during 6-month frozen (-20 °C) storage. Coating solutions, included distilled water (Control), 800AC1% (1% w/v chitosan in 1% v/v acetic acid), AS3% (3% w/v aspartic acid), and 800AS3% (3% w/v chitosan in 3% w/v aspartic acid). Changes in physicochemical, microbial, and consumer perception of chitosan-coated catfish fillets during frozen storage were examined. The 800AS3% coating was found to be effective in inhibiting microbial growth, controlling lipid oxidation, reducing drip loss and cooking loss, and retaining color and texture of catfish fillet during frozen storage. After 6-month frozen storage, the aroma of thawed fillets coated with 800AS3% was accepted by 77.92% of consumers with 66% positive purchase intent. This study demonstrated that a nonpungent aspartic acid, instead of commonly used pungent acetic acid, can be used in preparation of preservative high-molecular-weight chitosan coating. PRACTICAL APPLICATION: The findings of this study indicated that high-molecular-weight chitosan coating showed preservative effects on quality of frozen raw catfish fillets. In our previous study, chitosan (800 kDa) at 1% and 3% concentrations showed antibacterial activity in vitro. The nonpungent aspartic acid can be used as a solvent to dissolve high-molecular-weight chitosan instead of the commonly used pungent acetic acid. The most effective coating treatment was 3% w/v chitosan in 3% w/v aspartic acid. This finding would be applicable to other seafood and fish products.

Effect of locust bean gum-sodium alginate coatings incorporated with daphnetin emulsions on the quality of Scophthalmus maximus at refrigerated condition.

In this study, the microbiological, physicochemical, and flavor changes of turbot (Scophthalmus maximus) coated with a composite active coating of locust bean gum (LBG) and sodium alginate (SA) supplemented with daphnetin emulsions (0.16, 0.32, 0.64 mg·mL-1) were determined during 18 days of refrigerated storage (4 ± 1 °C). Results showed that LBG-SA coatings containing 0.32 mg·mL-1 daphnetin emulsions could significantly lower the total viable count (TVC), psychrophiles, Pseudomonas spp. and H2S-producing bacteria counts, and inhibit the productions of off-flavor compounds including the total volatile basic nitrogen (TVB-N), trimethylamine (TMA) and ATP-related compounds. 32 volatile compounds were identified by solid phase microextraction combined with gas chromatography-mass spectrometer method (SPME-GC/MS) during refrigerated storage and the treated turbot samples significantly lowered the relative content of fishy flavor compounds. Further, the LBG-SA coatings containing daphnetin could also delay the myofibril degradation of the turbot samples. These results indicated that the LBG-SA coatings with 0.32 mg·mL-1 daphnetin were a potential alternative way to improve the quality of turbot during refrigerated storage.

Action mode of cranberry anthocyanin on physiological and morphological properties of Staphylococcus aureus and its application in cooked meat.

This study researched the action mode of cranberry anthocyanin (CA) against Staphylococcus aureus and the effect of CA on the counts of S. aureus and the quantity of cooked meat during storage. The antibacterial effect was assessed by minimum inhibitory concentration (MIC) and survival populations of S. aureus strains after CA treatments. The changes in intracellular adenosine 5'-triphosphate (ATP) concentration, cell membrane potential, content of bacterial protein and cell morphology were analyzed to reveal possible action mode. Application potentials of CA as antimicrobial agent were assessed during storage of cooked pork and beef. The result showed that the MIC of CA against S. aureus strains was 5 mg/mL. Approximately 8 log CFU/mL of S. aureus strains can be completely inhibited after treatment with 2.0 MIC of CA for 0.5 h. Treatments of CA resulted in lower intracellular ATP and soluble protein levels, damaged membrane structure and leakage of cytoplasmic. Application of CA on cooked pork and beef caused a significant decrease in S. aureus counts and pH values, and color-darkening compared with control samples. These findings demonstrated that CA played an effective antimicrobial against S. aureus and had a potential as natural preservative to inhibit the growth of food pathogens.

Application of essential oils as antimicrobial agents against spoilage and pathogenic microorganisms in meat products.

Meat and meat products are perishable products that require the use additives to prevent the spoilage by foodborne microorganisms and pathogenic bacteria. Current trends for products without synthetic preservatives have led to the search for new sources of antimicrobial compounds. Essential oils (EOs), which has been used since ancient times, meet these goals since their effectiveness as antimicrobial agents in meat and meat products have been demonstrated. Cinnamon, clove, coriander, oregano, rosemary, sage, thyme, among others, have shown a greater potential to control and inhibit the growth of microorganisms. Although EOs are natural products, their quality must be evaluated before being used, allowing to grant the Generally Recognized as Safe (GRAS) classification. The bioactive compounds (BAC) present in their composition are linked to their activity, being the concentration and the quality of these compounds very important characteristics. Therefore, a single mechanism of action cannot be attributed to them. Extraction technique plays an important role, which has led to improve conventional techniques in favour of green emerging technologies that allow to preserve better target bioactive components, operating at lower temperatures and avoiding as much as possible the use of solvents, with more sustainable processing and reduced energy use and environmental pollution. Once extracted, these compounds display greater inhibition of gram-positive than gram-negative bacteria. Membrane disruption is the main mechanism of action involved. Their intense characteristics and the possible interaction with meat components make that their application combined with other EOs, encapsulated and being part of active film, increase their bioactivity without modifying the quality of the final product.

Selenium-enriched Saccharomyces cerevisiae improves the meat quality of broiler chickens via activation of the glutathione and thioredoxin systems.

The aim of this study was to investigate the effects of selenium (Se)-enriched Saccharomyces cerevisiae (SSC) on meat quality and to elucidate the underlying mechanisms in broilers. A total of 200 one-day-old Arbor Acres broiler chickens were randomly allocated to one of four treatments with 5 replications of 10 chickens each. Group 1 served as a control and was fed a basal diet without Se supplementation, while groups 2, 3, and 4 were fed the basal diet supplemented with S. cerevisiae (SC), sodium selenite (SS), and SSC, respectively. Breast muscle samples were collected to evaluate meat quality, selenium concentration, oxidative stability, and the mRNA levels of antioxidant enzyme genes on day 42. As compared with groups 1 and 2, SS and SSC supplementation increased Se concentration, glutathione peroxidase (GPx) and thioredoxin reductase (TR) activities, total antioxidant capacity, and the mRNA levels of GPx-1, GPx-4, TR-1, and TR-3 (P < 0.05) and decreased drip loss and malondialdehyde (MDA) content (P < 0.05). As compared with group 3, SSC supplementation increased pH, lightness, yellowness, Se concentration, GPx and superoxide dismutase activities, and the mRNA levels of GPx-1 and GPx-4 (P < 0.05) but decreased drip loss and MDA content (P < 0.05). Thus, SSC improved meat quality and oxidative stability by activating the glutathione and thioredoxin systems, which should be attributed to the combined roles of Se and SC.

Biopolymer films based on chitosan/potato protein/linseed oil/ZnO NPs to maintain the storage quality of raw meat.

Biopolymer films based on chitosan/potato protein/linseed oil/ZnO NPs were developed to maintain the storage quality of raw meat. Results indicated that the incorporation of ZnO NPs could effectively improve the transparency and tensile strength of the films, while addition of linseed oil could make the composite film maintain good elastic property. Films blended with chitosan/potato protein/linseed oil/ZnO NPs (Fcpzl) exhibited an excellent moisture barrier capability. SEM showed that ZnO NPs could harmoniously exist in various polymers matrix. FTIR analysis demonstrated that different components were bound together by intramolecular and intermolecular interactions, among which hydrogen bonds were the main force. Raw meat samples were wrapped with different films to evaluate the preservative effect during 4 °C storage. Results indicated that Fcpzl possessed best protective effect of raw meat with excellent acceptable sensory properties during 7 days storage, which could reduce the speed of increasing pH and total bacterial counts.

Research Note: Microbial inactivation of raw chicken meat by supercritical carbon dioxide treatment alone and in combination with fresh culinary herbs.

The objective of the present study was to assess the potential synergistic effect between supercritical carbon dioxide (SC-CO2) and fresh culinary herbs (Coriandrum sativum and Rosmarinus officinalis) on the microbial inactivation of raw chicken meat. The microbiological inactivation was performed on Escherichia coli and natural flora (total mesophilic bacteria, yeasts, and molds). High pressure treatments were carried out at 40°C, 80 or 140 bar from 15 to 45 min. Microbial inactivation had a strong dependence on treatment time, achieving 1.4 log CFU/g reduction of E. coli after 15 min, and up to 5 log after 45 min, while a pressure increase from 80 up to 140 bar was not significant on the microbial inactivation. Mesophilic microorganisms were strongly reduced (>2.6 log CFU/g) after 45 min, and yeasts and molds were below the detection limits of the technique (<100 CFU/g) in most cases. The combination of fresh herbs together with SC-CO2 treatment did not significantly increase the inactivation of either E. coli or natural flora, which was similar to the SC-CO2 alone. The synergistic effect was obtained on the inactivation of E. coli using a proper concentration of coriander essential oil (EO) (0.5% v/w), while rosemary EO did not show a significant effect. Color analysis after the treatment showed an increment of lightness (L*), and a decrease of redness (a*) on the surface of the sample, making the product visually similar to cooked meat. Texture analysis demonstrated the modification of the texture parameters as a function of the process pressure making the meat more similar to the cooked one.

Inhibition of Enterococcus faecalis Growth and Cell Membrane Integrity by Perilla frutescens Essential Oil.

Some plant essential oils were reported to have antimicrobial activity and have the potential to replace chemical preservatives in food industry. In this study, the antibacterial activity and possible mechanism of Perilla frutescens essential oil (PEO) were evaluated using Enterococcus faecalis R612-Z1 as the target strain. The minimum inhibition concentration of PEO against E. faecalis was 0.5 µL/mL. The PEO solutions at the concentrations higher than minimum inhibition concentration had varying degrees of bactericidal effects against E. faecalis. With the addition of PEO, the cell membrane integrity was destroyed, the cell membrane potential was decreased, and the intracellular adenosine triphosphate loss was increased. By testing the bacterial counts and total volatile basic nitrogen contents in chicken breast meat, PEO can significantly inhibit the growth of E. faecalis. The results showed that PEO can be used as an effective natural food preservative during food storage.

Effect of natural extracts obtained from food industry by-products on nutritional quality and shelf life of chicken nuggets enriched with organic Zn and Se provided in broiler diet.

This study investigated the influence of an organic mineral-supplemented broiler diet on the quality of nuggets. The resulting chicken nuggets were enriched with inorganic and organic forms of Zn and Se. The nuggets were processed by incorporating extracts from food industry by-products (rosemary [RH and RL], hydroxytyrosol [HYT], pomegranate [P], grape [GS], and Harpagophytum [H]). The physiochemical, microbiological, and sensory characteristics of the chicken nuggets were evaluated over a 12-month period of frozen storage. The addition of natural extracts did not affect the pH, proximate composition, or color (CIELab) of the nuggets among samples. However, significative differences were found between month of analysis (range from pH 6.16 to 6.63; luminosity from 62.51 to 84.74; redness from 0.16 to 7.14; and yellowness from 10.80 to 33.77). In addition, the combination of phenolic compounds with Zn and Se retarded microbial growth and reduced protein and lipid oxidation, thus maintaining the sensory quality and extending the shelf life of this product. For instance, the combination of RL + GS reduced in 75% the microbiological growth regarding the control sample (C), while samples that incorporated RH + P or HYT + P + H presented 50% less than C. In addition, upon only incorporating organic minerals Zn and Se, microbiological deterioration is reduced in 15%. This mix was significantly effective at reducing the oxidative reactions of lipids and proteins by 40% and 50%, as measured after 9 and 12 mo of frozen storage, respectively. The addition of the natural extracts and Zn and Se did not adversely affect the acceptability of the meat product.

Macrolide-susceptible probiotic Enterococcus faecium ST296 exhibits faecal-environmental-oral microbial community cycling among beef cattle in feedlots.

Enterococci are included in the United States National Antimicrobial Resistance Monitoring System to track antibiotic resistance among commensal Gram-positive enteric bacteria, largely due to their high abundance in food animals and in retail meat. In the U.S. cattle industry, macrolides are used to prevent and control liver abscesses, which cause significant economic losses. Previous studies have suggested that feeding tylosin and the intensity of the pen environment, both expand and sustain respectively the prevalence of multidrug resistance among enterococci in feedlot cattle. This has led to research into alternative feed supplements and improved stewardship practices. In a randomized controlled trial, we measured the impact of a probiotic and an altered pen environment on antimicrobial resistance among faecal Enterococcus spp. in cattle fed tylosin. Supplementing cattle with an Enterococcus faecium and Saccharomyces cerevisiae-based probiotic yielded the isolation of E. faecium of the probiotic sequence type (ST296) from faecal and environmental samples in treatment groups, as well as from cattle and the manure pack in nearby pens. Of importance, the probiotic strain also was found in a desiccated and milled manure pack sample taken 120 days after the initial trial ended. Phylogenetic and SNP analyses revealed clonal survival and spread compatible with faecal-environmental-oral recycling of the probiotic strain within and among cattle and pens. The increase in prevalence of the ST296 strain occurred concomitant with a decrease in ST240, the dominant sequence type associated with ermB and tet(M) resistance genes in this trial. SIGNIFICANCE AND IMPACT OF THE STUDY: We demonstrate that a macrolide-susceptible probiotic Enterococcus faecium ST296 strain fed to beef cattle becomes fully embedded in the microbial community cycling of bacteria via faecal-environmental-oral transmission within and among feedlot pens. An initial investment in feeding the probiotic is thereby leveraged into expanding numbers of susceptible bacteria in cattle and their environment, even among those cattle fed tylosin.

Process risk model for Salmonella and ground chicken.

AIMS: To develop a process risk model (PRM) for evaluating the safety of individual lots of ground chicken (GC) contaminated with Salmonella (Salm). METHODS AND RESULTS: Data for prevalence, number and serotype of Salm were collected with 25 g samples of GC using a combination of methods (whole sample enrichment, quantitative polymerase chain reaction, cultural isolation and serotyping). These data were used to develop a predictive model for Salm contamination of GC as a function of serving size from 25 to 300 g. This model was combined with a model for thermal inactivation of Salm in GC and a dose-response model for Salm to develop a PRM in Excel that was simulated with NeuralTools and @Risk. Of 100, 25 g samples of GC examined, 19 tested positive for Salm. Three serotypes were isolated: Infantis (n = 13), Enteritidis (n = 5) and Typhimurium (n = 1). The number of Salm ranged from 0 to 2·56 log with a median of 0·93 log per 25 g of GC. The PRM predicted that Salm prevalence would increase (P < 0·05) from 19 to 57% to 82 to 93% as serving size increased from 25 to 100 g to 200 to 300 g. However, the total number of Salm in a 100-kg lot of GC and total severity of illness (TSI) were not affected (P> 0·05) by serving size. The PRM was also used to evaluate effects of serving size distribution, cooking, food consumption behaviour, consumer demographics and Salmonella virulence on TSI. CONCLUSIONS: How a lot of GC is partitioned and consumed does not affect TSI. Scenario analysis demonstrated that the PRM can integrate prevalence, number and serotype data for Salm with consumer handling, consumption and demographics data to identify safe and unsafe lots of GC for improved food safety and public health. SIGNIFICANCE AND IMPACT OF THE STUDY: Process-risk models like the one developed in this study represent a new, holistic approach to food safety that holds great promise for improving public health and reducing food recalls.

Peracetic acid reduces Campylobacter spp. on turkey skin: Effects of a spray treatment on microbial load, sensory and meat quality during storage.

Handling and consumption of Campylobacter-contaminated poultry meat is the most common cause of human campylobacteriosis. While many studies deal with interventions to reduce Campylobacter spp. on chicken carcasses, studies on other poultry species are rare. In the present study, a spray treatment with peracetic acid (PAA) on turkey carcasses was evaluated. For this, parts of breast fillets with skin and Campylobacter (C.) jejuni DSM 4688 (108 cfu/ml) inoculated drumsticks were sprayed for 30 s with PAA (1200 ppm) or water as control solution. Samples were packaged under modified atmosphere and stored at 4°C until analysis on day 1, 6 and 12. The breast fillets were used for determination of the total viable count, sensory and meat quality examination as well as myoglobin content and biogenic amines. The drumsticks were used for C. jejuni counts. PAA had a significant effect in reducing total viable counts on all days by up to 1.2 log10 compared to the untreated control. Treatment with water alone showed no effect. C. jejuni counts were significantly reduced by PAA (0.9-1.3 log10), while water achieved a 0.5 log10 reduction on C. jejuni counts on day 1. No differences in sensory, pH, electrical conductivity and myoglobin content could be found. The skin of the PAA treated fillets had lower redness values than the water control on day 1, whereas on day 12 parts of the water treated muscles were lighter than the untreated control. A lower putrescine content of the water sprayed fillets in comparison to the control sample on day 12 was the only significant difference concerning the biogenic amines. Results from this study indicate that a spray treatment with 1200 ppm PAA would be a useful measure to lower the Campylobacter spp. counts on turkey carcasses without having a negative influence on product quality.

Antimicrobial activity of cellulosic pads amended with emulsions of essential oils of oregano, thyme and cinnamon against microorganisms in minced beef meat.

Cellulosic pads, amended with emulsions containing essential oils of thyme and oregano, exhibited antimicrobial activity against the psychrophilic microbiota of minced beef. In addition, the pads were active against specific meat bacterial species (Pseudomonas putida, Pseudomonas fragi, Pseudomonas fluorescens, Enterococcus faecalis and Lactococcus lactis) and some common foodborne pathogens (Salmonella enterica, Campylobacter jejuni and Staphylococcus aureus). Three emulsions, IT131017, Mediterranean and Etnic, containing different percentages of carvacrol, thymol, linalool, and ɑ and ß-pinene, significantly reduced the growth of S. enterica and P. putida. Pads derived from emulsions Mediterranean and Etnic induced slight (0.3-0.8 Log10 CFUs/g) but reproducible reduction of the psychrophilic microbiota in minced meat and hamburger stored for 12 and 15 days at 4 °C.

Rapid Increase in Carbapenemase-Producing Enterobacteriaceae in Retail Meat Driven by the Spread of the blaNDM-5-Carrying IncX3 Plasmid in China from 2016 to 2018.

The presence and molecular characteristics of carbapenemase-producing Enterobacteriaceae (CPE) among meat products in China were investigated. A total of 110 carbapenem-resistant Enterobacteriaceae (CRE) isolates, including 94 Escherichia coli and 10 Klebsiella pneumoniae isolates, were identified from 105 of 794 (13.2%) samples. The positive rates markedly increased from 2016 (9.4%) to 2018 (22.2%). Only blaNDM genes were detected; 79.1% of blaNDM genes were carried by IncX3 plasmids. Routine monitoring of carbapenemase-producing Enterobacteriaceae in the animal food supply is highly recommended.

Inactivation effect of marination liquids prepared with koruk juice and dried koruk pomace on Salmonella Typhimurium, Escherichia coli O157:H7 and Listeria monocytogenes inoculated on meat.

The aim of this study was to determine the effects of marination liquids prepared with koruk juice and dried koruk pomace in terms of meat safety. In the study, marination liquids containing two different concentrations of koruk juice (25% and 50%) or dried koruk pomace (1% and 2%) were prepared separately with or without ingredients (1% salt and 0.1% thyme). Meat samples inoculated with two different levels (≅3 log and ≅6 log) of food-borne pathogens (S. Typhimurium, E. coli O157:H7 and L. monocytogenes) were marinated at 4 °C for different times (2, 24 and 48 h) and the effects of the treatment on target pathogens were determined. As a result of marinating process, the counts of S. Typhimurium, E. coli O157:H7 and L. monocytogenes inoculated at high levels (≅6 log) on meat samples were reduced in the range of 0.109-2.648 log CFU/g, 0.264-3.373 log CFU/g and 0.023-2.781 log CFU/g, respectively. The most effective treatment in reducing the counts of S. Typhimurium and E. coli O157:H7 was achieved by marination with ML1 (50% koruk juice + 50% water) for 48 h, while marination with ML2 (50% koruk juice + 50% water + 1% salt + 0.1% thyme) for 24 h was the most effective treatment for L. monocytogenes. When low inoculum levels were used (≅3 log), the counts of pathogens on meat samples were determined under detection limits after marination even for 2 h application. The results of sensory evaluation showed that the sample marinated with ML2 for 48 h was the most favored sample in terms of appearance, color, texture, taste and overall appreciation.

Enterocin BacFL31 from a Safety Enterococcus faecium FL31: Natural Preservative Agent Used Alone and in Combination with Aqueous Peel Onion (Allium cepa) Extract in Ground Beef Meat Storage.

Safety aspects and probiotic properties of Enterococcus faecium FL31 strain producing an enterocin, named BacFL31 were previously demonstrated. Taking into account its originality, the enterocin BacFL31 was added alone at 200 AU/g or in combination with the aqueous peel onion (Allium cepa) extract (APOE) at 1.56 ± 0.3 mg/mL to ground beef meat. Its biopreservative effect was evaluated by microbiological, physicochemical and sensory analyses during 14 days at 4°C. The APOE was characterized for its phytochemical content: total phenolic (TPC), flavonoids (TFC) and tannins contents (TAC), its antioxidant capacity using the in vitro 1,1-diphenyl-2-picrylhydrazyl (DPPH) and its antilisterial activity. APOE had a high TPC, TFC and TAC respectively with 140 ± 2.05 (mg GAE/g), 35 ± 0.5 (mg QE/g) and 20.6 ± 1.4 (mg CE/g). Equally, APOE showed a potential radical scavenging activity compared to the butylated hydroxytoluene (BHT), with an anti-radical power (ARP) of 46 ± 1.5. During 14 days of storage at 4°C, the combination between APOE and BacFL31 limited the microbial deterioration (P < 0.05), led to a decrease in thiobarbituric acid reactive substances (TBARS) values and slowed down the metmyoglobin (MetMb) and carbonyl group accumulation and delayed the disappearance of sulfphydryl proteins (P < 0.05). The combination was also efficient (P < 0.05) against microflora proliferation, decreased primary and secondary lipid oxidation (P < 0.05), reduced protein oxidation and enhanced significantly (P < 0.05) the sensory attributes. Thus, the enterocin BacFL31 use from a safe Enterococcus faecium combined with APOE as a potential natural preservative to biocontrol ground beef was promising as it was effective at low concentration. The data lay bases for new tests to be carried out in other food matrices.