ATHINA NTZIMANI - Academia.edu (original) (raw)
Papers by ATHINA NTZIMANI
Molecules/Molecules online/Molecules annual, May 14, 2024
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Applied Sciences
Convenient cuts of poultry products are of significant interest, but they are perishable products... more Convenient cuts of poultry products are of significant interest, but they are perishable products with a short shelf life. Modified atmosphere packaging (MAP) or the application of active packaging based on edible and biodegradable coatings could extend the shelf life of perishable foods. The aim of the present work was the kinetic modelling of the effect of MAP and active coatings with antimicrobial agents on the microbial growth and shelf life of chicken cuts. Broiler chicken thighs processed with pectin-based (2% w/w aqueous solution) edible coatings enriched with 1% extract of citrus bioflavonoids (flavomix) or 0.5% glucono-δ-lactone were stored under aerobic conditions at 0, 5 and 10 °C. Untreated thighs were also stored aerobically or in MAP (42.7% O2, 18.5% CO2). Quality evaluation was based on the growth of spoilage bacteria (TVC, Pseudomonas spp., Brochothrix thermosphacta), pH, colour, and sensory scoring. The tested quality indices were kinetically modelled and the Arrhen...
Foods
The contamination of ready-to-eat (RTE) and ready-to-cook (RTC) food products is a major global i... more The contamination of ready-to-eat (RTE) and ready-to-cook (RTC) food products is a major global issue raising worry to consumers. Therefore, the behavior of Listeria monocytogenes and Salmonella spp., inoculated on a traditional Middle Eastern (M.E.) ready-to-cook (RTC) chicken product (“Taouk”-style), using the Risk Ranger® tool and the necessary management options (to accomplish the hypothetical food safety objectives (FSO)), when unsuspecting consumers may taste such a product were the primary subjects of our study. The behavior of the aforementioned pathogens was studied in the presence and absence of a selected natural antimicrobial combination (chitosan [CH] and thyme oil [T]), and were added as a combined treatment (M-CH-T) to the RTs chicken samples, stored at 4 or 8 °C for a period of 8 d. In the product, wherein no antimicrobials were added (control treatment, M), the initial counts of L. monocytogenes increased by ca. 1.5 (4 °C) and 3.0 (8 °C) log colony-forming units (CF...
Sustainability
The efficacy of washing and the investigation of alternative sanitizing treatments for the reduct... more The efficacy of washing and the investigation of alternative sanitizing treatments for the reduction of microbial population are major issues for fresh fish and seafood. Limited work on the effect of alternative washing media on fish, particularly gilthead sea bream, one of the important popular fish species, has been published and no industrial scaling-up has been reported. The objective of this study was to systematically evaluate the effect of surface decontamination treatments on the microbial load of fish and the quality and shelf life during subsequent chilled storage. Citric acid (200 ppm for 0–10 min), lactic acid (200 ppm for 0–10 min), and peracetic acid (0–200 ppm for 0–4 min) were tested as alternative washing media by immersion of gutted gilthead sea bream by evaluating their effect on microbial growth and physicochemical and organoleptic degradation of fish. The results of the study indicated that washing with citric (200 ppm, 10 min) and peracetic acid (200 ppm, 4 min...
In the present study, the effect of natural antimicrobials- EDTA, lysozyme and the essential oils... more In the present study, the effect of natural antimicrobials- EDTA, lysozyme and the essential oils of rosemary and oregano- on the shelf-life, natural microflora, sensory and physicochemical characteristics of the semi-cooked coated chicken fillets stored at 4 °C, was examined. The organoleptic shelf-life, was determined 10, 11, 12 and 15 days for the A, AEL, AR/ AO και AELR/ AELO samples, respectively, whereas for the VP chicken fillets the shelf-life was 14 for the VPEL, 16 for the VP/ VPR/ VPO and 18 days for the VPELR/ VPELO chicken samples. Additionally, it was found that the most effective treatment against TVC, Brochothrix thermosphacta, Lactic acid bacteria and Yeasts/ Moulds was VPELR, whereas against Pseudomonas spp. and Enterobacteriaceae was the VPELO. These two treatments were also the most effective ones in preserving both sensory and physicochemical characteristics of the semi-cooked coated chicken fillets.Additionally, the survival/ growth of Listeria monocytogenes, S...
Journal of Marine Science and Engineering, 2022
The objective of the present study was the evaluation of the effect of slurry ice, as an alternat... more The objective of the present study was the evaluation of the effect of slurry ice, as an alternative cooling medium during harvesting and transportation, on the quality parameters (e.g., microbiological stability, sensory attributes, physicochemical changes) and shelf life of fish. The effect of seasonal variability of seawater temperature on fish preservation using the tested cooling media was also investigated. Gilthead sea bream (Sparus aurata) was slaughtered and transported in different mixtures of conventional flake ice and slurry ice for 24 h. Three mixtures of ice were tested as T: slaughtered in flake ice and transported in flake ice (control), TC: slaughtered in slurry ice and transported in flake ice, T50: slaughtered and transported in slurry ice 50%–flake ice 50%. Samples were subsequently stored isothermally at 0 °C for shelf-life evaluation. Three independent experiments were performed at three different periods, i.e., January, April, and September, referring to a sea...
The objective of the study was to investigate the efficiency of slurry ice during harvesting and ... more The objective of the study was to investigate the efficiency of slurry ice during harvesting and transportation of European sea bass (Dicentrarchus labrax) to retain flesh quality and extend shelf life, compared with conventional flake ice. Fish was slaughtered and transported in different mixtures of slurry ice and conventional flake ice (C: slaughtered and transported in 100% flake ice-Control samples, SC: slaughtered in 100% slurry ice and transported in 100% flake ice, S50: slaughtered and transported in 50% slurry ice-50% flake ice, S100: slaughtered and transported in 100% slurry ice) and subsequently stored under controlled isothermal conditions at 0 °C for shelf life modelling and flesh quality evaluation (proteolytic enzymes). The replacement of conventional flake ice with slurry ice as a slaughtering method led to improved quality stability during subsequent refrigerated storage and shelf life extension, in terms of microbial growth, flesh quality and sensory degradation o...
The antioxidant and antimicrobial properties of rosemary essential oil (EO) and extracts, entrapp... more The antioxidant and antimicrobial properties of rosemary essential oil (EO) and extracts, entrapped in carboxyl methyl cellulose (CMC) edible coating for smoked eel were investigated. Analysis of the EO indicated 1,8-cineole, L-camphor, a-pinene, and 1-borneol, as the main components. The solid residue generated by the EO distillation was extracted in an ultrasound bath with ethanol to give an extract rich in rosmarinic acid, diterpenes and flavonoids. The addition of the extract at 200–800 ppm (total phenol basis) in CMC coating provided antioxidant protection to smoked eel, which increased with concentration. Additionally, the combination of the extract (200 ppm) with EO (2000 ppm) retarded significantly the formation of both primary and secondary oxidation products, indicating possible synergistic effects. The antimicrobial activity of EO and extracts was moderate, with the extract at 800 ppm concentration showing the best results in decreasing the rate of total viable count, Pse...
Applied Sciences
The aim of the study was the evaluation and mathematical modeling of the effect of active modifie... more The aim of the study was the evaluation and mathematical modeling of the effect of active modified atmosphere packaging (MAP), by the incorporation of CO2 emitters in the package, on the microbial stability and shelf life of gutted sea bass during refrigerated storage. Gutted sea bass samples were packaged in modified atmosphere (50% CO2–40% N2–10% O2) with and without CO2 emitters (ACT-MAP, MAP) (gas/product volume ratio 3:1) and stored at isothermal conditions: 0 °C, 5 °C, and 10 °C. The gas concentration in the package headspace (%CO2, %O2) and microbial growth (total viable count, TVC, Pseudomonas spp., Enterobacteriaceae spp., lactic acid bacteria) were monitored during storage. The microbial growth was modeled using the Baranyi growth model, and the kinetic parameters (microbial growth rate, lag phase) were estimated at the tested temperature and packaging conditions. The results showed that the ACT-MAP samples presented significantly lower microbial growth compared to the MAP...
Journal of Food Protection
In the present study, natural antimicrobials chitosan and thyme, and their combination, were eval... more In the present study, natural antimicrobials chitosan and thyme, and their combination, were evaluated for their effect on the shelf life of a ready-to-cook (RTC) chicken-pepper kebab (skewer) stored under modified atmosphere packaging (MAP) conditions at 4 ± 0.5°C for 14 days. The following treatments were examined: control samples stored under aerobic packaging (A), samples stored under MAP (M), samples treated with 1.5% chitosan (vol/wt) and stored under MAP (M-CH), samples treated with 0.2% thyme essential oil (vol/wt) (M-T), and samples treated with 1.5% chitosan (vol/wt) and 0.2% thyme essential oil (vol/wt) and stored under MAP (M-CH-T). Treatment M-CH-T significantly affected aerobic plate counts and counts of lactic acid bacteria, Pseudomonas spp., Brochothrix thermosphacta, Enterobacteriaceae, and yeasts and molds during the entire storage period. Similarly, lipid oxidation of the RTC product was retarded (M-CH-T treatment) during storage, whereas redness was maintained in...
Journal of Food Science, Sep 1, 2010
The present study evaluated the effect of oregano essential oil (EO) on fresh salted, packaged (4... more The present study evaluated the effect of oregano essential oil (EO) on fresh salted, packaged (45%CO 2 /5%O 2 /50%N 2) rainbow trout fillets and stored for a period of 21 d at 4 • C. Treatments included the following: M1 (control without added EO), M2 (EO 0.2%, v/w), and M3 (0.4%, v/w). Populations of lactic acid bacteria (LAB), H 2 S-producing bacteria (including Shewanella putrefaciens), Enterobacteriaceae, and Pseudomonas spp. reached higher final numbers in control (M1) than for M2 and M3 samples. Under treatments M2 and M3, total volatile basic nitrogen (TVBN) and trimethylamine nitrogen (TMAN) values were lower than for M1 samples, whereas lipid oxidation, as judged by determination of thiobarbituric acid values (TBA), did not occur during the refrigerated storage period. Interestingly, treatment M2 resulted in a shelf-life extension of 7 to 8 d for the fresh trout fillets, whereas treatment M3 proved unsuitable (due to strong odor) for trout fillet preservation, as determined by sensory evaluation.
Food Microbiology, Feb 1, 2010
The present study examined the effect of natural antimicrobials: chitosan, thyme and their combin... more The present study examined the effect of natural antimicrobials: chitosan, thyme and their combination, on the shelf-life of a Ready to Cook (RTC) chicken-pepper kebab (skewer) stored under aerobic conditions at 4 AE 0.5 C for a period of 12 days. Treatments examined in the present study were the following: A (control samples, untreated), A-CH (chitosan; 1.5% v/w), AT (thyme essential oil; 0.2% v/w) and A-CH-T (chitosan; 1.5% v/w and thyme essential oil; 0.2% v/w). The shelf-life of the samples was determined using both microbiological and sensory analyses. Among the microorganisms examined, pseudomonads were the most resistant group towards the combined application of chitosan and thyme oil (ca. 1.5 log cycle reduction) while Lactic acid bacteria (LAB), Brochothrix thermosphacta and Enterobacteriaceae were the most sensitive to the combined action of these two agents (2-3 log cycle reduction). Yeasts-moulds were also part of the natural microbial association of the RTC product, with A-CH-T treatment suppressing effectively their growth during the entire period of storage. Treatments A-CH and A-CH-T resulted in lower pH values as compared to the control (A) samples. Of the treatments examined in the present study, A-CH-T, gave a ''spicy'', desirable and pleasant (organoleptically acceptable) RTC product. Based primarily on sensory data (taste attribute) A-CH, AT and A-CH-T treatments extended the product's shelf-life by ca. 4 and 6 days, respectively, as compared to the control sample.
Food Chemistry, Jun 1, 2009
The effect of nisin and EDTA treatments on the shelf-life of fresh chicken meat stored under modi... more The effect of nisin and EDTA treatments on the shelf-life of fresh chicken meat stored under modified atmosphere packaging at 4°C was evaluated. Chicken meat was subjected to the following antimicrobial treatment combinations: Nisin–EDTA treatments (added post-production to the chicken samples) included: N1 (no nisin–EDTA added; control sample), N2 (500IU/g; no EDTA added), N3 (1500IU/g; no EDTA added), N4 (500IU/g-10mM
Food Microbiology
The present study evaluated: (1) the formation of biogenic amines (BAs) in smoked turkey fillets ... more The present study evaluated: (1) the formation of biogenic amines (BAs) in smoked turkey fillets during storage under aerobic and modified atmosphere packaging (MAP) conditions at 4 degrees C, (2) the relation of BAs to microbial and sensory changes in turkey meat and (3) the possible role of BAs as indicators of poultry meat spoilage. Smoked sliced turkey fillets were stored in air and under vacuum, skin and two modified atmospheres (MAP), M1 (30% CO(2)/70% N(2)) and M2 (50% CO(2)/50% N(2)), at 4+/-0.5 degrees C, for a period of 30 days. The BAs determined were: tryptamine, tyramine, histamine, putrescine, cadaverine, spermidine and spermine. Low levels of BAs were observed throughout the entire storage period, with the exception of histamine, tyramine and tryptamine, for which higher concentrations were recorded. Values for these three BAs were the highest for air-packaged samples (32.9, 25.0 and 4.1mg/kg, respectively) and the lowest for skin-packaged samples (11.9, 4.3 and 2.8 m...
The present study examined the effect of natural antimicrobials: Ethylenediaminetetraacetate (EDT... more The present study examined the effect of natural antimicrobials: Ethylenediaminetetraacetate (EDTA), lysozyme, rosemary and oregano oil and their combinations, on the shelf-life of semi cooked coated chicken fillets stored under vacuum packaging (VP), at 4 ± 0.5°C for a period of 18 days. The treatments of semi cooked coated chicken fillets examined in the present study were the following: Air-packaged (A, control samples), vacuum-packaged (VP), VP with EDTA-lysozyme solution 1.50% w/w, (VP + EL), VP with rosemary oil 0.20% v/w, (VP + R), VP with oregano oil 0.20% v/w, (VP + O), VP with EDTA-lysozyme solution and rosemary oil (VP + EL + R) and finally VP with EDTA-lysozyme and oregano oil (VP + EL + O). The shelf-life of the samples was determined using both microbiological and sensory analyses. Among the antimicrobial combinations examined in the present study, the treatments VP + EL + R and VP + EL + O were the most effective against the growth of Gram-negative, Gram-positive bacteria, and to a lesser extent on yeasts. Based on both microbiological (TVC data) and sensory (taste attribute) analyses, treatments: VP and VP + O gave a shelf life extension of 6 days, whereas treatments VP + EL + R and VP + EL + O produced a shelf-life extension of 7-8 days, as compared to the control samples. Industrial Relevance: The present research has highlighted the use of natural antimicrobial treatment combinations, including: EDTA, lysozyme, rosemary and oregano oil and their combinations, in the extension of shelf-life of semi cooked coated chicken fillets stored under vacuum packaging at 4°C for a period of 18 days. Establishing, the determination of the shelf-life of fresh poultry and products represents a challenge for food companies as poultry meat has a short shelf-life, which causes substantial practical problems for its distribution. Therefore, knowledge of natural preservatives, that can be used as alternatives to chemical additives, that could extend the products' shelf life can have an important economic feedback by reducing losses attributed to spoilage and by allowing the products to reach distant and new markets. This study has shown that combinations of natural antimicrobials can extend the shelf-life of the product.
The aim of the present study was to evaluate the effect of natural antimicrobial agents EDTA, lys... more The aim of the present study was to evaluate the effect of natural antimicrobial agents EDTA, lysozyme, and 2 essential oils (rosemary and oregano) on the quality of a ready-to-eat poultry product (semicooked coated; SCC) stored under aerobic packaging conditions at 4°C (retail) and 8°C (abuse) for a period of 16 d. Treatments included the following: air-packaged chicken fillets (control, untreated); with EDTA (1.50% wt/wt); with lysozyme solution (1.50% wt/wt); with rosemary oil (0.20% vol/wt); with oregano oil (0.20% vol/wt); with a combination of EDTA and lysozyme solutions (1.50% wt/wt each); and with the combination of EDTA, lysozyme, and either rosemary or oregano essential oils (all added at concentrations previously mentioned). The shelf life of the SCC samples (untreated and treated) was determined using both microbiological and sensory analyses. Natural antimicrobial combinations consisting of EDTA, lysozyme, and rosemary or oregano essential oil affected the growth of Pseudomonas and yeasts and molds, whereas EDTA, lysozyme, and rosemary essential oil controlled Brochothrix thermosphacta population in the SCC chicken fillets stored at 4 and 8°C. The combination of EDTA, lysozyme, and either rosemary or oregano resulted in a shelf life extension of 5 d compared with the control samples at both 4 and 8°C, with the former combination producing a more sensorially acceptable product.
Molecules/Molecules online/Molecules annual, May 14, 2024
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Applied Sciences
Convenient cuts of poultry products are of significant interest, but they are perishable products... more Convenient cuts of poultry products are of significant interest, but they are perishable products with a short shelf life. Modified atmosphere packaging (MAP) or the application of active packaging based on edible and biodegradable coatings could extend the shelf life of perishable foods. The aim of the present work was the kinetic modelling of the effect of MAP and active coatings with antimicrobial agents on the microbial growth and shelf life of chicken cuts. Broiler chicken thighs processed with pectin-based (2% w/w aqueous solution) edible coatings enriched with 1% extract of citrus bioflavonoids (flavomix) or 0.5% glucono-δ-lactone were stored under aerobic conditions at 0, 5 and 10 °C. Untreated thighs were also stored aerobically or in MAP (42.7% O2, 18.5% CO2). Quality evaluation was based on the growth of spoilage bacteria (TVC, Pseudomonas spp., Brochothrix thermosphacta), pH, colour, and sensory scoring. The tested quality indices were kinetically modelled and the Arrhen...
Foods
The contamination of ready-to-eat (RTE) and ready-to-cook (RTC) food products is a major global i... more The contamination of ready-to-eat (RTE) and ready-to-cook (RTC) food products is a major global issue raising worry to consumers. Therefore, the behavior of Listeria monocytogenes and Salmonella spp., inoculated on a traditional Middle Eastern (M.E.) ready-to-cook (RTC) chicken product (“Taouk”-style), using the Risk Ranger® tool and the necessary management options (to accomplish the hypothetical food safety objectives (FSO)), when unsuspecting consumers may taste such a product were the primary subjects of our study. The behavior of the aforementioned pathogens was studied in the presence and absence of a selected natural antimicrobial combination (chitosan [CH] and thyme oil [T]), and were added as a combined treatment (M-CH-T) to the RTs chicken samples, stored at 4 or 8 °C for a period of 8 d. In the product, wherein no antimicrobials were added (control treatment, M), the initial counts of L. monocytogenes increased by ca. 1.5 (4 °C) and 3.0 (8 °C) log colony-forming units (CF...
Sustainability
The efficacy of washing and the investigation of alternative sanitizing treatments for the reduct... more The efficacy of washing and the investigation of alternative sanitizing treatments for the reduction of microbial population are major issues for fresh fish and seafood. Limited work on the effect of alternative washing media on fish, particularly gilthead sea bream, one of the important popular fish species, has been published and no industrial scaling-up has been reported. The objective of this study was to systematically evaluate the effect of surface decontamination treatments on the microbial load of fish and the quality and shelf life during subsequent chilled storage. Citric acid (200 ppm for 0–10 min), lactic acid (200 ppm for 0–10 min), and peracetic acid (0–200 ppm for 0–4 min) were tested as alternative washing media by immersion of gutted gilthead sea bream by evaluating their effect on microbial growth and physicochemical and organoleptic degradation of fish. The results of the study indicated that washing with citric (200 ppm, 10 min) and peracetic acid (200 ppm, 4 min...
In the present study, the effect of natural antimicrobials- EDTA, lysozyme and the essential oils... more In the present study, the effect of natural antimicrobials- EDTA, lysozyme and the essential oils of rosemary and oregano- on the shelf-life, natural microflora, sensory and physicochemical characteristics of the semi-cooked coated chicken fillets stored at 4 °C, was examined. The organoleptic shelf-life, was determined 10, 11, 12 and 15 days for the A, AEL, AR/ AO και AELR/ AELO samples, respectively, whereas for the VP chicken fillets the shelf-life was 14 for the VPEL, 16 for the VP/ VPR/ VPO and 18 days for the VPELR/ VPELO chicken samples. Additionally, it was found that the most effective treatment against TVC, Brochothrix thermosphacta, Lactic acid bacteria and Yeasts/ Moulds was VPELR, whereas against Pseudomonas spp. and Enterobacteriaceae was the VPELO. These two treatments were also the most effective ones in preserving both sensory and physicochemical characteristics of the semi-cooked coated chicken fillets.Additionally, the survival/ growth of Listeria monocytogenes, S...
Journal of Marine Science and Engineering, 2022
The objective of the present study was the evaluation of the effect of slurry ice, as an alternat... more The objective of the present study was the evaluation of the effect of slurry ice, as an alternative cooling medium during harvesting and transportation, on the quality parameters (e.g., microbiological stability, sensory attributes, physicochemical changes) and shelf life of fish. The effect of seasonal variability of seawater temperature on fish preservation using the tested cooling media was also investigated. Gilthead sea bream (Sparus aurata) was slaughtered and transported in different mixtures of conventional flake ice and slurry ice for 24 h. Three mixtures of ice were tested as T: slaughtered in flake ice and transported in flake ice (control), TC: slaughtered in slurry ice and transported in flake ice, T50: slaughtered and transported in slurry ice 50%–flake ice 50%. Samples were subsequently stored isothermally at 0 °C for shelf-life evaluation. Three independent experiments were performed at three different periods, i.e., January, April, and September, referring to a sea...
The objective of the study was to investigate the efficiency of slurry ice during harvesting and ... more The objective of the study was to investigate the efficiency of slurry ice during harvesting and transportation of European sea bass (Dicentrarchus labrax) to retain flesh quality and extend shelf life, compared with conventional flake ice. Fish was slaughtered and transported in different mixtures of slurry ice and conventional flake ice (C: slaughtered and transported in 100% flake ice-Control samples, SC: slaughtered in 100% slurry ice and transported in 100% flake ice, S50: slaughtered and transported in 50% slurry ice-50% flake ice, S100: slaughtered and transported in 100% slurry ice) and subsequently stored under controlled isothermal conditions at 0 °C for shelf life modelling and flesh quality evaluation (proteolytic enzymes). The replacement of conventional flake ice with slurry ice as a slaughtering method led to improved quality stability during subsequent refrigerated storage and shelf life extension, in terms of microbial growth, flesh quality and sensory degradation o...
The antioxidant and antimicrobial properties of rosemary essential oil (EO) and extracts, entrapp... more The antioxidant and antimicrobial properties of rosemary essential oil (EO) and extracts, entrapped in carboxyl methyl cellulose (CMC) edible coating for smoked eel were investigated. Analysis of the EO indicated 1,8-cineole, L-camphor, a-pinene, and 1-borneol, as the main components. The solid residue generated by the EO distillation was extracted in an ultrasound bath with ethanol to give an extract rich in rosmarinic acid, diterpenes and flavonoids. The addition of the extract at 200–800 ppm (total phenol basis) in CMC coating provided antioxidant protection to smoked eel, which increased with concentration. Additionally, the combination of the extract (200 ppm) with EO (2000 ppm) retarded significantly the formation of both primary and secondary oxidation products, indicating possible synergistic effects. The antimicrobial activity of EO and extracts was moderate, with the extract at 800 ppm concentration showing the best results in decreasing the rate of total viable count, Pse...
Applied Sciences
The aim of the study was the evaluation and mathematical modeling of the effect of active modifie... more The aim of the study was the evaluation and mathematical modeling of the effect of active modified atmosphere packaging (MAP), by the incorporation of CO2 emitters in the package, on the microbial stability and shelf life of gutted sea bass during refrigerated storage. Gutted sea bass samples were packaged in modified atmosphere (50% CO2–40% N2–10% O2) with and without CO2 emitters (ACT-MAP, MAP) (gas/product volume ratio 3:1) and stored at isothermal conditions: 0 °C, 5 °C, and 10 °C. The gas concentration in the package headspace (%CO2, %O2) and microbial growth (total viable count, TVC, Pseudomonas spp., Enterobacteriaceae spp., lactic acid bacteria) were monitored during storage. The microbial growth was modeled using the Baranyi growth model, and the kinetic parameters (microbial growth rate, lag phase) were estimated at the tested temperature and packaging conditions. The results showed that the ACT-MAP samples presented significantly lower microbial growth compared to the MAP...
Journal of Food Protection
In the present study, natural antimicrobials chitosan and thyme, and their combination, were eval... more In the present study, natural antimicrobials chitosan and thyme, and their combination, were evaluated for their effect on the shelf life of a ready-to-cook (RTC) chicken-pepper kebab (skewer) stored under modified atmosphere packaging (MAP) conditions at 4 ± 0.5°C for 14 days. The following treatments were examined: control samples stored under aerobic packaging (A), samples stored under MAP (M), samples treated with 1.5% chitosan (vol/wt) and stored under MAP (M-CH), samples treated with 0.2% thyme essential oil (vol/wt) (M-T), and samples treated with 1.5% chitosan (vol/wt) and 0.2% thyme essential oil (vol/wt) and stored under MAP (M-CH-T). Treatment M-CH-T significantly affected aerobic plate counts and counts of lactic acid bacteria, Pseudomonas spp., Brochothrix thermosphacta, Enterobacteriaceae, and yeasts and molds during the entire storage period. Similarly, lipid oxidation of the RTC product was retarded (M-CH-T treatment) during storage, whereas redness was maintained in...
Journal of Food Science, Sep 1, 2010
The present study evaluated the effect of oregano essential oil (EO) on fresh salted, packaged (4... more The present study evaluated the effect of oregano essential oil (EO) on fresh salted, packaged (45%CO 2 /5%O 2 /50%N 2) rainbow trout fillets and stored for a period of 21 d at 4 • C. Treatments included the following: M1 (control without added EO), M2 (EO 0.2%, v/w), and M3 (0.4%, v/w). Populations of lactic acid bacteria (LAB), H 2 S-producing bacteria (including Shewanella putrefaciens), Enterobacteriaceae, and Pseudomonas spp. reached higher final numbers in control (M1) than for M2 and M3 samples. Under treatments M2 and M3, total volatile basic nitrogen (TVBN) and trimethylamine nitrogen (TMAN) values were lower than for M1 samples, whereas lipid oxidation, as judged by determination of thiobarbituric acid values (TBA), did not occur during the refrigerated storage period. Interestingly, treatment M2 resulted in a shelf-life extension of 7 to 8 d for the fresh trout fillets, whereas treatment M3 proved unsuitable (due to strong odor) for trout fillet preservation, as determined by sensory evaluation.
Food Microbiology, Feb 1, 2010
The present study examined the effect of natural antimicrobials: chitosan, thyme and their combin... more The present study examined the effect of natural antimicrobials: chitosan, thyme and their combination, on the shelf-life of a Ready to Cook (RTC) chicken-pepper kebab (skewer) stored under aerobic conditions at 4 AE 0.5 C for a period of 12 days. Treatments examined in the present study were the following: A (control samples, untreated), A-CH (chitosan; 1.5% v/w), AT (thyme essential oil; 0.2% v/w) and A-CH-T (chitosan; 1.5% v/w and thyme essential oil; 0.2% v/w). The shelf-life of the samples was determined using both microbiological and sensory analyses. Among the microorganisms examined, pseudomonads were the most resistant group towards the combined application of chitosan and thyme oil (ca. 1.5 log cycle reduction) while Lactic acid bacteria (LAB), Brochothrix thermosphacta and Enterobacteriaceae were the most sensitive to the combined action of these two agents (2-3 log cycle reduction). Yeasts-moulds were also part of the natural microbial association of the RTC product, with A-CH-T treatment suppressing effectively their growth during the entire period of storage. Treatments A-CH and A-CH-T resulted in lower pH values as compared to the control (A) samples. Of the treatments examined in the present study, A-CH-T, gave a ''spicy'', desirable and pleasant (organoleptically acceptable) RTC product. Based primarily on sensory data (taste attribute) A-CH, AT and A-CH-T treatments extended the product's shelf-life by ca. 4 and 6 days, respectively, as compared to the control sample.
Food Chemistry, Jun 1, 2009
The effect of nisin and EDTA treatments on the shelf-life of fresh chicken meat stored under modi... more The effect of nisin and EDTA treatments on the shelf-life of fresh chicken meat stored under modified atmosphere packaging at 4°C was evaluated. Chicken meat was subjected to the following antimicrobial treatment combinations: Nisin–EDTA treatments (added post-production to the chicken samples) included: N1 (no nisin–EDTA added; control sample), N2 (500IU/g; no EDTA added), N3 (1500IU/g; no EDTA added), N4 (500IU/g-10mM
Food Microbiology
The present study evaluated: (1) the formation of biogenic amines (BAs) in smoked turkey fillets ... more The present study evaluated: (1) the formation of biogenic amines (BAs) in smoked turkey fillets during storage under aerobic and modified atmosphere packaging (MAP) conditions at 4 degrees C, (2) the relation of BAs to microbial and sensory changes in turkey meat and (3) the possible role of BAs as indicators of poultry meat spoilage. Smoked sliced turkey fillets were stored in air and under vacuum, skin and two modified atmospheres (MAP), M1 (30% CO(2)/70% N(2)) and M2 (50% CO(2)/50% N(2)), at 4+/-0.5 degrees C, for a period of 30 days. The BAs determined were: tryptamine, tyramine, histamine, putrescine, cadaverine, spermidine and spermine. Low levels of BAs were observed throughout the entire storage period, with the exception of histamine, tyramine and tryptamine, for which higher concentrations were recorded. Values for these three BAs were the highest for air-packaged samples (32.9, 25.0 and 4.1mg/kg, respectively) and the lowest for skin-packaged samples (11.9, 4.3 and 2.8 m...
The present study examined the effect of natural antimicrobials: Ethylenediaminetetraacetate (EDT... more The present study examined the effect of natural antimicrobials: Ethylenediaminetetraacetate (EDTA), lysozyme, rosemary and oregano oil and their combinations, on the shelf-life of semi cooked coated chicken fillets stored under vacuum packaging (VP), at 4 ± 0.5°C for a period of 18 days. The treatments of semi cooked coated chicken fillets examined in the present study were the following: Air-packaged (A, control samples), vacuum-packaged (VP), VP with EDTA-lysozyme solution 1.50% w/w, (VP + EL), VP with rosemary oil 0.20% v/w, (VP + R), VP with oregano oil 0.20% v/w, (VP + O), VP with EDTA-lysozyme solution and rosemary oil (VP + EL + R) and finally VP with EDTA-lysozyme and oregano oil (VP + EL + O). The shelf-life of the samples was determined using both microbiological and sensory analyses. Among the antimicrobial combinations examined in the present study, the treatments VP + EL + R and VP + EL + O were the most effective against the growth of Gram-negative, Gram-positive bacteria, and to a lesser extent on yeasts. Based on both microbiological (TVC data) and sensory (taste attribute) analyses, treatments: VP and VP + O gave a shelf life extension of 6 days, whereas treatments VP + EL + R and VP + EL + O produced a shelf-life extension of 7-8 days, as compared to the control samples. Industrial Relevance: The present research has highlighted the use of natural antimicrobial treatment combinations, including: EDTA, lysozyme, rosemary and oregano oil and their combinations, in the extension of shelf-life of semi cooked coated chicken fillets stored under vacuum packaging at 4°C for a period of 18 days. Establishing, the determination of the shelf-life of fresh poultry and products represents a challenge for food companies as poultry meat has a short shelf-life, which causes substantial practical problems for its distribution. Therefore, knowledge of natural preservatives, that can be used as alternatives to chemical additives, that could extend the products' shelf life can have an important economic feedback by reducing losses attributed to spoilage and by allowing the products to reach distant and new markets. This study has shown that combinations of natural antimicrobials can extend the shelf-life of the product.
The aim of the present study was to evaluate the effect of natural antimicrobial agents EDTA, lys... more The aim of the present study was to evaluate the effect of natural antimicrobial agents EDTA, lysozyme, and 2 essential oils (rosemary and oregano) on the quality of a ready-to-eat poultry product (semicooked coated; SCC) stored under aerobic packaging conditions at 4°C (retail) and 8°C (abuse) for a period of 16 d. Treatments included the following: air-packaged chicken fillets (control, untreated); with EDTA (1.50% wt/wt); with lysozyme solution (1.50% wt/wt); with rosemary oil (0.20% vol/wt); with oregano oil (0.20% vol/wt); with a combination of EDTA and lysozyme solutions (1.50% wt/wt each); and with the combination of EDTA, lysozyme, and either rosemary or oregano essential oils (all added at concentrations previously mentioned). The shelf life of the SCC samples (untreated and treated) was determined using both microbiological and sensory analyses. Natural antimicrobial combinations consisting of EDTA, lysozyme, and rosemary or oregano essential oil affected the growth of Pseudomonas and yeasts and molds, whereas EDTA, lysozyme, and rosemary essential oil controlled Brochothrix thermosphacta population in the SCC chicken fillets stored at 4 and 8°C. The combination of EDTA, lysozyme, and either rosemary or oregano resulted in a shelf life extension of 5 d compared with the control samples at both 4 and 8°C, with the former combination producing a more sensorially acceptable product.