Search

"Chicken tawook" is a marinated boneless chicken entrée consumed in the Middle East. The aim of this study was to determine whether bioactive essential oil (EO) components carvacrol (CA), cinnamaldehyde (CI), and thymol (TH) would delay the growth of microorganisms causing tawook spoilage during aerobic (AP) or vacuum (VP) packed storage. The EOs at 1% and 2% were mixed individually with the marinade. The samples (10 g of chicken cubes with 1.2 g of marinade - with or without EOs) were stored in bags under AP and VP (Geryon

Studies have indicated shortcomings in food safety knowledge and practices among pregnant women in the Arab region. A high-risk group for having severe outcomes from foodborne illnesses. This study aimed to assess self-reported food safety knowledge and practices among pregnant women in the UAE during the COVID-19 pandemic. A total of 354 pregnant women residing in the UAE completed an online survey between October 2021 and January 2022. The questionnaire included socio-demographic information, food safety knowledge, and food practices during the COVID-19 pandemic. Correct answers for food safety knowledge were scored out of 50 and the total score was compared by sociodemographic characteristics. The total mean score for the study population was 26.7 ± 4.6 out of 50. Participants had good knowledge about foodborne diseases (81.3%) and personal hygiene practices (61.8%). While they were least knowledgeable about cross-contamination (43.3%) and temperature control practices (35.8%). Significantly higher knowledge scores were observed with higher levels of education and primigravida women (p

The study aimed to evaluate the antimicrobial activity of 0.5 or 1% (w/w) chitosan and 1% (w/w) garlic against Salmonella spp., Escherichia coli O157:H7 and Listeria monocytogenes in hummus dip stored at 4, 10, or 25°C for 28, 21, or 7 days, respectively. In hummus without garlic, at all storage temperatures and storage periods, 0.5% chitosan decreased Salmonella spp., E. coli O157:H7, and L. monocytogenes by 0.9-2.3, 0.6-2.3, and 0.9-1.3 log CFU/g, respectively. In comparison, 1% chitosan decreased the numbers by 1.6-2.9, 1.4-2.7, and 1.3-1.8 log CFU/g, respectively. In hummus with 1% garlic, 0.5% chitosan decreased Salmonella spp., E. coli O157:H7, and L. monocytogenes by 0.7-2.5, 0.6-2.2, and 1.0-1.5 log CFU/g, respectively. Furthermore, 1% chitosan decreased the numbers by 1.6-2.8, 1.2-2.7, and 1.5-1.6 log CFU/g, respectively. With few exceptions, adding 1% garlic to hummus did not result in any significant reduction (at p 0.05) in microbial numbers. The greatest decreases of Salmonella spp., E. coli O157:H7, and L. monocytogenes were 3.1, 3.6, and 2.9 log CFU/g with 1% chitosan held at 4°C for 28 days. The highest overall acceptability was for hummus with 0.5% chitosan + 1% garlic. Commercial use of chitosan is expected to help producers improve hummus safety. PRACTICAL APPLICATION: Hummus is consumed worldwide as a dip due to its taste and health benefits. Microbial safety of hummus can be enhanced by incorporating chitosan, derived from the natural polymer chitin, into the formulation. This enhanced recipe would be a bonus for producers and consumers alike.

This special issue compiled 13 research articles and one review analyzing natural antimicrobial agents applied in real food systems. The accepted submissions were received from 14 countries, including Spain, Brazil, Lebanon, United Arab Emirates, Jordan, Greece, Thailand, Turkey, Saudi Arabia, Italy, Argentina, Canada, Iran, and China. The studied antimicrobial substances included phenolic compounds from plant tissues, terpenes from plant essential oils, bacteriocins, and chitosan. The treated food matrices were fresh fruit, fruit juices, beef, chicken products, camel meat, cheese, fish, and yogurt. Most of the published papers directly applied the natural substances in the food matrices, and others use edible coatings, marinades, micro and nanocarriers. Also, hurdle technologies were used to increase the antimicrobial effect of the studied natural substances, including temperature, vacuum packaging, ultraviolet, and edible coatings. In conclusion, promising results were obtained to impulse the transitions of natural antimicrobials as effective agents in the food industry; some contributions to the mode of actions of natural antimicrobials in real food systems were also included.

We investigated the impact of chitosan and oregano essential oil (EO) individually or in combination on the quality of eel fillets in vacuum packaging (VP) and stored under refrigeration (...

The present study evaluated the effect of yogurt-based marinade combined with active essential oil components (EOs) namely: thymol (TH), carvacrol (CA), and cinnamaldehyde (CI) on Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella spp. in camel meat (CM) chunks during storage at 4 and 10 °C. Fresh cocktail mixtures of L. monocytogenes, E. coli O157:H7 and Salmonella spp. strains were inoculated on CM samples. Subsequently, a yogurt-based marinade, with or without 1% or 2% of the added EOs, was mixed with the CM chunks. After treatment, marinated camel samples were stored at 4 and 10 °C for 0, 1, 4 and 7 days. Adding yogurt-based marinade to the CM samples did not cause any significant changes in L. monocytogenes, E. coli O157:H7 and Salmonella spp. numbers at 4 °C, but at 10 °C resulted in a significant decrease in numbers on day 4 and 7 of storage by 1.4–1.5; 2.7–2.1 and 2.5–2.8 log CFU/g, respectively, compared to untreated CM samples. The incorporation of EOs into the CM with marination (CMM) further enhanced the microbial reduction of E. coli O157:H7 and Salmonella. At 10 °C, the synergistic effect of EOs with marinade was greater than at 4 °C. Increasing the concentration of the EOs used in this study from 1% to 2%, enhanced E. coli O157:H7 and Salmonella spp. reduction during storage at 4 and 10 °C while L. monocytogenes numbers were not affected. Increasing active EO component concentrations to 2% caused further significant reductions in Salmonella spp. in the CMM samples during storage by 1.0–2.7 log CFU/g (P ˂ 0.05) at 4 and 10 °C. At 10 °C, increasing the concentration of CI and TH to 2% caused a further reduction (P ˂ 0.05) of E. coli O157:H7 numbers by days 4 and 7 in the range of 3.6–4.4 log CFU/g. Among all tested EOs, 2% TH and 2% CI had the greatest effect against E. coli O157:H7 and Salmonella spp. in CMM during storage at 4 and 10 °C. In comparison to CMM, the highest scores of all examined sensory attributes were found in CMM samples with 1% and 2% CI added. Results indicate that the EO component CI can be used as an effective tool to decrease populations of E. coli O157:H7 and Salmonella spp. in CM with minor sensory changes.

The objective of the study was to assess the antimicrobial effect of active essential oil components (EOs) namely (carvacrol (CA), cinnamaldehyde (CI) and thymol (TH)) on Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7 in chicken tawook during storage at 4 and 10 °C. A marinade consisting of ingredients commonly used in the chicken tawook recipe was prepared and mixed with 1% and 2% v/v CA, CI or TH. The marinade with or without EOs was added to fresh chicken breast cubes inoculated with the foodborne pathogens. Afterward, marinated chicken “tawook” was stored at 4 and 10 °C covered with cling wrap to mimic chill and mild abuse storage conditions for up to 7 days. At 10 °C, the marinade decreased L. monocytogenes numbers on day 4 and 7 by about 2.4 log10 CFU/g as compared to unmarinated samples. Adding EOs to chicken tawook did not change L. monocytogenes numbers during storage at 4 and 10 °C. For Salmonella spp., the marinade decreased the numbers during 10 °C storage on day 4 and 7 by about 4.9 log10 CFU/g as compared to unmarinated samples. At 4 °C, EOs at 2% decreased Salmonella spp. on day 7 by 0.5 log10 CFU/g. One percent CI significantly decreased Salmonella by 1.5 log10 CFU/g, at day 4 of storage. At 10 °C, 1% CA, 2% CI, 1% and 2% TH decreased Salmonella spp. in the samples by 0.5 log10 CFU/g on day 7. The marinade decreased E. coli O157:H7 numbers on the chicken samples during 10 °C storage on day 4 and 7 by about 3.3 log10 CFU/g as compared to unmarinated samples. Regardless of storage day at 4 °C, EOs decreased E. coli O157:H7 populations in chicken tawook by ≤2.4 log10 CFU/g compared to samples without EOs, where the decrease was ≤1.4 log10 CFU/g. Moreover, no significant decrease in E. coli O157:H7 populations could be attributed to the addition of EOs in samples which were stored at 10 °C. Increasing the concentration of EOs from 1 to 2% seemed to have no significant effect in reducing the tested foodborne pathogen populations.

The present study examined the effect of natural antimicrobials: Chitosan, thyme oil and their combination, on the shelf- life of smoked eel fillets stored under vacuum packaging (VP) at 4°C. Based on sensory odor data smoked eel fillets had a shelf- life of 35 (control), 42 (thyme treated and >49 (thyme, chitosan-thyme treated) days. The thiobarbituric acid value (TBA) value of the control eel sample was significantly higher than the chitosan-thyme-treated eel samples. The use of chitosan singly, or in combination with thyme oil reduced lipid oxidation (TBA) of the smoked eel samples. A trimethylamine nitrogen (TMA-N) value of 10 mg N/100 g, could be suggested as an indication of smoked eel spoilage initiation. Control and treated eel reached total volatile basic nitrogen (TVB-N) values of 13.1-31.5 mg N/100 g below the maximum permissible level of TVB-N in fish and fishery products. Eel samples reached the value of 7.0 log cfu/g (Total Plate Count,TPC) on days 35 (smoked) and 42 (thyme treated), whereas both chitosan and chitosan-thyme treated eel samples never reached this limit value. Results of our study show thyme or chitosan (singly, or in combination) inhibit the growth of mesophilic bacteria and extend the shelf- life of smoked eel. Deanship of Scientific Research at King Saud University

Recently, increasing attention has been paid on Leuconostoc lactis as a promising bioactive organism against food-borne and spoilage bacteria. A total of nine strains, including six different species of the genus Lactobacillus and three species of the genus Leuconostoc, were isolated from chicken carcasses (n=60) collected from wholesale poultry markets located at Al-Riyadh city, Saudi Arabia in 2016 and identified by API 50 CHL assays. L. lactis isolates were resistant to bile salts and vancomycin. The autolytic phenotype of L. lactis was evaluated under starvation conditions in the presence of potassium phosphate buffer. The strains tested showed partial autolysis of approximately 18% after 7 h of starvation at 37°C at the end of the exponential phase. The inhibitory activity of whole-protein extracts of L. lactis against the foodborne bacteria, Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus and Micrococcus luteus was evaluated by renaturing sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The major activity of the total protein appeared as two clear bands on the SDS-PAGE, of approximately 57 and 42 kDa against L. monocytogenes, B. cereus and B. subtilis. No active band was shown against S. aureus and M. luteus. Key words: Bacteriocins, biopreservation, lactic acid bacteria, pathogens, poultry.

We investigated the impact of chitosan and oregano essential oil (EO) individually or in combination on the quality of eel fillets in vacuum packaging (VP) and stored under refrigeration (4°C). Treatments studied were (i) control eel fillets stored in VP (E), (ii) eel fillets treated with 0.3% (v/w) oregano EO and stored in VP (E-OR), (iii) eel fillets treated with 2.0% (w/v) chitosan and stored in VP (E-CH), and (iv) eel fillets treated with 2.0% (w/v) chitosan and 0.3% (v/w) oregano EO and stored in VP (E-CH-OR). Treatments E-CH-OR and E-CH significantly reduced counts of mesophilic bacteria

Purpose In many developing countries, the main source of food related illness is the fast foods restaurants. Health inspections of fast-food restaurants may not be sufficient to ensure and enforce the food safety regulations. The purpose of this paper is to investigate the food safety knowledge, attitudes and practices (KAP) of fast food handlers in Qatar. Design/methodology/approach Data were collected from 102 fast-food handlers through a structured survey. The questionnaire comprised questions on food safety KAP. The association between scores for KAP among the food handlers was measured with Spearman’s rank correlation. Findings A significant direct association was found throughout the different criteria of food safety KAP. In total, 90 percent of fast food handlers had undergone formal training on food safety. Although fast food handlers thought they had overall good knowledge on food safety (93.9 percent), results showed that they had a poor knowledge on proper cleaning of equipment, cross-contamination, foodborne diseases, food danger zone and correct procedures for thawing of frozen food. Only (34.7 percent) of the food handlers correctly identified Salmonella as a food pathogen. Originality/value Based on the current findings, the authors believe that continuous food safety and hygiene training should be implemented in all food service operations especially in fast-food restaurants in Qatar to ensure that all food handlers have the knowledge and the skill to provide safe food.

In this study, we examined the antimicrobial effects of citrus extract (Citrox(®)) and chitosan on lactic acid bacteria (LAB) and the pathogens Escherichia coli O157:H7 and Salmonella enterica on turkey meat during storage under vacuum packaging (VP) at 4 and 10 °C. We also examined the effects of Citrox and chitosan on pathogen contamination in tryptic soy broth (TSB). Chitosan alone or in combination with Citrox inhibited the growth of endogenous LAB in turkey meat, whereas citrus extract did not cause a major reduction in bacterial density. Citrus extract combined with chitosan yielded the lowest mesophilic total viable counts (TVCs), irrespective of temperature, showing major declines in all treated turkey samples from days 0-21 of storage. The shelf-lives of untreated, Citrox-treated, and chitosan and Citrox/chitosan-treated samples (as determined by TVC and sensory data) were 13, 17, and >21 days, respectively, at 4 °C for VP turkey. The addition of Citrox was more effective against S. enterica than E. coli in turkey, causing reductions of >0.5 and 2 log cfu/g at 4 and 10 °C, respectively, after 21 days of storage. Interestingly, the addition of chitosan had a significant inhibitory effect on E. coli at 4 °C and S. enterica at 10 °C as compared with the control (inoculated samples) resulting in dramatic reductions in E. coli (2 log) and S. enterica (5 log) cell counts on day 21. Of all the treatments examined, citrus extract in combination with chitosan showed an additive inhibitory effect against both pathogens, reducing E. coli and S. enterica populations, by approximately 2.7 or 4.5 and 2.2 or 5.6 log cfu/g, respectively, at 4 and 10 °C on day 21 of storage.

Controlling spoilage of the popular ethnic marinated beef “Shawarma” is crucial to achieve high quality, extend shelf-life, reduce food waste and meet the need of the globalized supply chain. Active essential oil (EO) components (thymol and carvacrol) were added at 0.4% and 0.8% (w/w) to preserve marinated beef, stored under aerobic or vacuum packaging. Microbiological and sensory (odor) parameters were assessed during 21 days at 4 °C. The treatments with higher EO concentration achieved higher antimicrobial activity than the lower ones and significantly reduced the mesophilic total viable count (TVC), lactic acid bacteria (LAB), Brochothrix thermosphacta, Pseudomonas spp., total coliforms, Escherichia coli, yeasts and molds. The higher EO concentration extended the microbiological shelf-life by 6 days, as judged by TVC and compared to the controls (aerobic and vacuum packaging) but was unacceptable sensorially. The lower EO concentration increased the microbiological shelf-life by 3 days and the sensorial shelf-life by 9 and > 12 days, under aerobic and vacuum conditions, respectively.

The study aimed to determine D and z-values of Escherichia coli O157:H7 strains and Salmonella spp. in camel lean meat burger (CM) and camel meat burger with hump fat (CMF). Two E. coli O157:H7 strains, S. Typhimurium and S. Copenhagen were mixed individually with CM and CMF samples, placed in sterile pouches and exposed to water bath heat treatment at 55, 57.5, 60, 62.5, 65, 67.5 °C for different time intervals. The D-values of E. coli O157:H7 161-84 in CM burgers at 60, 62.5, 65, 67.5 °C were 53.5, 20.1, 8.3, and 3.0 s, respectively, while the values in CMF samples were 76.0, 25.9, 9.9 and 4.1 s, respectively. The D-values of S. Typhimurium in CM burgers at 55, 57.5, 60, 62.5 °C were 349.2, 70.5, 18.4 and 6.7 s, respectively, while the values in CMF were 512.1, 77.1, 21.1 and 8.4 s, respectively. There was a significant (P

The effects of vacuum packaging, chitosan (1.5%, w/v), and natamycin (10 mg/L, w/v) on phyllo pastry quality were studied by monitoring microbiological, chemical, and sensory changes. Five lots were prepared with or without vacuum packaging, chitosan, and natamycin: A, air packaged (control); V, vacuum packaged; VC, vacuum packaged with chitosan; VN, vacuum packaged with natamycin; and VCN, vacuum packaged with both chitosan and natamycin. Based on the sensory acceptability data, a shelf life of 6 (A), 12 (V), 14 (VN), 16 (VC), and 17 (VCN) days was obtained at 4°C. VCN treatment resulted in a shelf life extension of 11 days compared with the shelf life of the control. Microbiological data revealed that the combination of chitosan and natamycin resulted in significant reductions of microbial species (mesophilic total viable counts, yeasts and molds, psychrotrophic bacteria, lactic acid bacteria, Enterobacteriaceae, and enterococci) of 1 to 3 log CFU/g on the final day (day 18) of storage. Results suggest that the combination of chitosan and natamycin, which is an effective antifungal agent, can delay the spoilage of phyllo pastry while maintaining acceptable sensorial characteristics and the original freshness and appearance of the product.

The demand for marinated chicken worldwide, is continuously growing. To date, limited data on addition of active components of Essential Oils (EOs) to marinades for chicken preservation are available. The antimicrobial effect of carvacrol and thymol, added at 0.4 and 0.8% v/w to marinated fresh chicken, stored in air and under vacuum packaging (VP), for 21 days at 4 °C, was examined. The samples were monitored for microbiological (total viable count (TVC), lactic acid bacteria (LAB), Brochothrix thermosphacta, Pseudomonas spp., total coliforms, Escherichia coli, yeasts and molds) and sensory attributes (odor characteristics). Our data supports that among the tested microorganisms, Pseudomonas spp., LAB and B. thermosphacta were the most dominant microbiota in the marinated chicken samples. Additionally, the use of active EOs components, especially the higher concentration (0.8% v/w) in combination with VP, retarded the growth of spoilage microbiota and resulted in a significant reduction of about 2.9–3.1 log cfu/g and a microbiological shelf-life extension of marinated chicken by>6 days, as judged by TVC data. Interestingly, the combination of active components of EOs at the lower concentration (0.4% v/w) and packaging (air or vacuum) resulted in a significant sensorial shelf-life extension of 15 and>21 days, as compared to the controls' shelf-life of 9 days. The results of our study demonstrated the potential of the active components, carvacrol and thymol, as natural effective antimicrobial hurdles to control the growth of spoilage microorganisms in marinated chicken meat. Faculty of Agricultural and Food Sciences, American University of Beirut

The antimicrobial effect of citrus extract (at 1 mL/kg [C1] and 2 mL/kg [C2]) on naturally occurring microbiota and inoculated pathogens (E. coli O157:H7 and L. monocytogenes at ca. 6 log cfu/g) in the traditional Greek yogurt-based salad Tzatziki stored at 4, 10, or 21 °C, was examined. Lactic acid bacteria (LAB) were high (8.0–8.5 log cfu/g) and varied only minimally for both the control (untreated) and the citrus extract-treated salad samples, whereas the higher citrus extract concentration yielded the lowest yeast populations, irrespective of temperature, during the entire storage period. Populations of inoculated E. coli (6 log cfu/g) declined in both untreated and citrus extract-treated samples from day 0–70, 35, and 15 at 4, 10, and 21 °C, respectively. Citrus extract had a significant effect on the survival of the inoculated E. coli O157:H7, with reductions of 2.8–4.8 log cfu/g in the citrus extract-treated samples at the end of the storage period. Our data show that L. monocytogenes survived in both untreated and citrus extract-treated samples during the entire storage period, irrespective of the storage temperature. The higher concentration of citrus extract had a significant effect on the survival of L. monocytogenes in the treated samples, and reductions of 1.5–3.0 logs were noted on final day 70, 35 and 15 at 4, 10 and 21 °C, respectively. The results of our study demonstrated the potential of citrus extract as a natural compound that can control the growth of food-borne pathogenic bacteria, such as E. coli O157:H7 and L. monocytogenes in Tzatziki, a yogurt-based salad. Deanship of Scientific Research at King Saud University for funding this research through Research Group Project No. RG-1435-016.

The antimicrobial effect of citrus extract (at 1 mL/kg [C1] and 2 mL/kg [C2]) on naturally occurring microbiota and inoculated pathogens (E. coli O157:H7 and L. monocytogenes at ca. 6 log cfu/g) in the traditional Greek yogurt-based salad Tzatziki stored at 4, 10, or 21 °C, was examined. Lactic acid bacteria (LAB) were high (8.0-8.5 log cfu/g) and varied only minimally for both the control (untreated) and the citrus extract-treated salad samples, whereas the higher citrus extract concentration yielded the lowest yeast populations, irrespective of temperature, during the entire storage period. Populations of inoculated E. coli (6 log cfu/g) declined in both untreated and citrus extract-treated samples from day 0-70, 35, and 15 at 4, 10, and 21 °C, respectively. Citrus extract had a significant effect on the survival of the inoculated E. coli O157:H7, with reductions of 2.8-4.8 log cfu/g in the citrus extract-treated samples at the end of the storage period. Our data show that L. monocytogenes survived in both untreated and citrus extract-treated samples during the entire storage period, irrespective of the storage temperature. The higher concentration of citrus extract had a significant effect on the survival of L. monocytogenes in the treated samples, and reductions of 1.5-3.0 logs were noted on final day 70, 35 and 15 at 4, 10 and 21 °C, respectively. The results of our study demonstrated the potential of citrus extract as a natural compound that can control the growth of food-borne pathogenic bacteria, such as E. coli O157:H7 and L. monocytogenes in Tzatziki, a yogurt-based salad.

The present study evaluated the use of nisin, natamycin and/or their combination as antimicrobial treatments to improve the shelf-life of Galotyri cheese. Samples were treated with nisin [N1 (100 IU/g), N2 (200 IU/g)], natamycin [NA1 (0.01% w/w), NA2 (0.02% w/w)] and their combinations N1-NA1, N1-NA2, N2-NA1 and N2-NA2. A Galotyri control (N0) cheese sample was also tested (absence of nisin or natamycin). Single N1, N2 treatments reduced lactobacilli and lactococci populations, but their effect was less pronounced, as compared to the combined nisin-natamycin treatments between days 14 and 28 of storage. Yeast populations in natamycin-treated Galotyri cheese samples or those additionally treated with nisin were significantly suppressed throughout the entire period of storage. Control N0 or N1, N2 treated samples received significantly lower acceptability scores, as compared to either natamycin or natamycin-nisin treated samples. Natamycin, added either singly or in combination with nisin, efficiently suppressed fungal growth in the Galotyri cheese. The observed shelf life of Galotyri, based on overall acceptability data, was the longest for N1-NA1, N1-NA2, N2-NA1 and N2-NA2 cheese samples (>28 days) followed by the N1, N2 treated samples (18-19 days) whereas for the control N0 a shelf-life of 14-15 days was attained.

In this study fresh turkey meat was packaged under vacuum and stored at 2 °C. The following lots were used: T (control); stored under vacuum packaging (VP), T-RO; stored under VP, treated with rosemary oil 0.25% v/w, T-CH; stored under VP, treated with chitosan 1.5% w/v, and T-CH-RO; stored under VP, treated with chitosan 1.5% w/v and rosemary oil 0.25% v/w. Of the microbial microflora species examined, irrespective of treatment, lactic acid bacteria (LAB) constituted the most abundant group. Interestingly, total plate counts (TPCs) and LAB counts, exceeding the limit value of 7 log cfu/g, in T and T-RO turkey samples coincided with low taste scores (5 and 6, respectively) on days 12 and 18 of storage. The shelf-life was approximately 10, 17–18 and > 21 days for the control (T), T-RO, T-CH and T-CH-RO turkey samples, respectively. Thus, a shelf-life extension of 7–8 and > 11 days was obtained for T-RO and T-CH, and T-CH-RO turkey samples, respectively. The presence of chitosan in T-CH and T-CH-RO samples did not negatively influence the taste of cooked turkey meat.

The qualitative and quantitative profile of biogenic amines (BA) in 50 samples of dry fermented sausages sold in Greek retail markets were determined by HPLC. Putrescine, cadaverine, tryptamine, β-phenylethylamine spermidine, spermine were analysed by UV detection after pre-column derivatization with benzoyl chloride, whereas tyramine and histamine were analysed by fluorescence detection after post-column derivatization with o-phthaldialdehyde (OPA). With the exception of spermidine and spermine a wide variation of BA levels was observed among the samples. Of the BA examined, tyramine, putrescine, histamine and cadaverine showed high concentrations ranging from: 0 to 510 mg/kg (median: 197.7 mg/kg), 0 to 505 mg/kg (median: 96.5mg/kg), 0 to 515 mg/kg (median: 7.0mg/kg) and 0 to 690 mg/kg (median: 3.6 mg/kg), respectively. The histamine content of 28% of the samples exceeded the toxicity limit of 100mg/kg set for histamine in some fish species. Levels of tryptamine and β-phenyl-ethylamine never exceeded 50 and 29 mg/kg, respectively. Results of the present study suggest that the amounts of BA in dry fermented sausages, sold in Greek retail markets, may pose a potential health risk for sensitive individuals or for those undergoing classical monoamine oxidase inhibiting (MAOI) drug therapy.

This study explores the effects of chitosan and natamycin on the quality of fresh “Phyllo” – a dough-based wheat product, by monitoring the microbiological, physicochemical and sensory parameters. Four different lots of phyllo samples stored under aerobic packaging conditions, in the absence or presence of the aforementioned antimicrobials, were prepared and stored at 4 °C. Microbiological data suggested that, the combination of chitosan and natamycin resulted in significant reductions (1–3 log cfu/g) of the microbial species examined (mesophilic total viable counts; TVC), yeasts/molds, psychrotrophic and lactic acid bacteria (LAB), Enterobacteriaceae and coliforms) by day 10. The pH values of treated phyllo samples were lower on final day 10, as compared to the untreated phyllo, and of the Hunter color parameters (L*, b* and a*) that were evaluated, mostly the combined treatment of chitosan and natamycin maintained the original lightness (L*) and color (yellowness) stability (b*) of phyllo product during the storage period. Sensory data, based on overall acceptability (mean values of appearance and odor) scores confirmed the superiority of combined treatment of chitosan and natamycin, resulting in almost a doubling of the shelf-life of fresh phyllo, while retaining excellent sensorial characteristics (appearance and odor) even on final storage day (10).

The present study examined the effect of chitosan (1.0% w/v) in combination with packaging on the shelf-life of fresh swordfish steaks. Treatments included the following: A (untreated, control samples stored in air), A-CH (treated with chitosan 1.0% w/v, stored in air), VP (untreated, stored under vacuum packaging) and VP-CH (treated with chitosan, stored under vacuum packaging). VP-CH significantly affected Total Viable Counts (TVC), Pseudomonas spp., H2S-producing bacteria (including Shewanella putrefaciens), lactic acid bacteria and Enterobacteriaceae. Production of TMA-N and TVB-N for A-CH, VP and VP-CH swordfish samples was significantly lower than for control (A) samples at day 8 of storage. Histamine formation for all treatments was low. A-CH and VP-CH resulted in significantly lower levels of putrescine, cadaverine and tyramine (day 8) as compared to A and VP swordfish samples. Results of this study indicate that the shelf-life of swordfish steaks can be extended using, either aerobic or vacuum packaging and in combination with chitosan, by approximately 4 (A-CH), 8 (VP) and 12 (VP-CH) days. Swordfish steaks treated with chitosan and stored under VP were sensorially acceptable up to 17 days. The presence of chitosan (A-CH and VP-CH) did not negatively influence the taste of cooked swordfish.

In this study fresh chicken liver meat was stored under vacuum packaging (VP) and under refrigeration (4 °C). The following treatments were used: V (control samples, stored under VP), VT1 (thyme oil; 0.1% v/w, stored under VP) and VT2 (thyme oil; 0.3% v/w, stored under VP). Lipid oxidation was low, as judged by determination of malondialdehyde (MDA) values, in vacuum-packaged chicken liver meat, both in the absence or presence of thyme essential oil (EO) during the entire storage period. Of the color parameters (L*, a*, b*) monitored during storage time, L* (lightness) values for vacuum-packaged chicken liver, irrespective of treatment, showed a varying trend, whereas a* (redness) values for V, VT1, and VT2 liver samples decreased, showing no significant differences. As determined by sensory analysis the observed shelf life of chicken liver samples was longest for VT2 (>12 d) followed by VT1 (12 d) and control (V) samples (7 d). Our results suggest that a Brochothrix thermosphact count (7 log CFU/g) and appearance of visible colonies can be used as indicators of chicken liver spoilage.

In this study, we compared the effect of basil essential oil (EO) and various packaging conditions on “Anthotyros,” a Greek whey cheese. This cheese was stored at 4 °C under aerobic (A), vacuum (V), and modified atmosphere (M, 40%/60%; CO2/N2,) conditions, without or with (AB, VB, and VM) basil EO added to the cheese samples to a final concentration of 0.4% (v/w). The quality characteristics and the shelf life of both untreated and basil EO-treated cheese were assessed using microbiological, physicochemical, and sensory parameters. Microbiological results revealed that either modified atmosphere/vacuum packaging (MAP/VP) singly or in combination with basil EO delayed microbial growth as compared to the control (A) samples. The sensory and microbiological data showed that the combined use of MAP and VP with added basil EO extended the shelf life of fresh Anthotyros (4 °C) by approximately 10–12 days (treatment MB) and 6 days (treatment VB) as compared to aerobic packaging (A). Under these treatments, whey cheese samples maintained good sensory characteristics. This study has shown that the combined use of either VP or MAP, and basil EO, can extend the shelf life of whey cheese and maintain the freshness and the sensorial characteristics of the product.

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 degrees 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 M-T. M-CH, and M-CH-T samples. Based primarily on sensory data (taste attribute), M-CH and M-T treatments extended RTC product shelf life by 6 clays, whereas M-CH-T treatment resulted in a product with a shelf life of 14 days that maintained acceptable sensory characteristics (shelf life of the control was 6 days). Journal of Food Protection

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 +/- 0.5 degrees 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), A-T (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, A-T and A-CH-T treatments extended the product's shelf-life by ca. 4 and 6 days, respectively, as compared to the control sample. (C) 2009 Elsevier Ltd. All rights reserved. Food Microbiology

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 present study evaluated the effect of thyme essential oil and packaging on fresh Mediterranean swordfish fillets during storage at 4 °C. Treatments in the present study included the following: air (A), modified atmosphere packaging (M), air with thyme oil (AT) and MAP with thyme oil (MT). Of the physicochemical parameters examined, TBA values for A and M swordfish samples were variable, indicative of no specific oxidative rancidity trend, whereas MT treatment inhibited lipid oxidation in swordfish samples during storage. On the basis of microbiological and sensory data, TMA-N and TVB-N limit values of acceptability for Mediterranean swordfish, of ca. 3.72 and 24.5 mg N/100 g, for the initiation of fresh Mediterranean swordfish spoilage, may be proposed. Of the treatments used in the present study, MT and M were the most effective for the inhibition of pseudomonads and H 2 S-producing bacteria in swordfish. Lactic acid bacteria and Enterobacteriaceae (to a lesser extent) were also found to be part of the natural microbial flora of swordfish, irrespective of packaging treatment. Based primarily on sensory data, the shelf-lives of fresh refrigerated Mediterranean swordfish were 8 and 13 days under aerobic and MAP conditions, respectively. Addition of 0.1% thyme essential oil extended the product’s shelf-life under aerobic conditions by 5 days, whereas the combination of MAP and thyme oil resulted in a significant shelf-life extension of the swordfish fillets, i.e. by approximately 7½ days, according to sensory data, as compared to the control sample.

Summary The spoilage potential of fresh musky octopus (Eledone moschata) was determined by evaluating the changes in biochemical and physical properties, microbial growth and sensory quality of the mantle and tentacles, over a period of 18 days. Whole musky octopus, stored in melting ice from the time of harvest, had a storage life of 10 days. Early deterioration in the sensory quality resulted primarily from autolytic reactions. Pseudomonas spp. dominated the spoilage flora, reaching an average count of 108 CFU g−1 at the end of the trial. The bacterial metabolic end products (trimethylamine, total volatile bases) were not useful as objective indicators of freshness, and measurements of pH would only provide an indicator of decomposition. Changes in the dielectric properties of the mantle were reflective of quality deterioration, but could not yield precise information on the storage history of the cephalopod. The common sulphide producer, Shewanella putrefaciens, was not a major spoiler of ice-stored musky octopus.

The present work evaluated the effect of modified atmosphere packaging (MAP) on quality characteristics and shelf-life extension of the whey cheese ''Myzithra Kalathaki'' using microbiological, chemical and sensory analyses. Myzithra cheese was packaged in four different atmospheres: vacuum, 20% CO2/80% N-2 (M-1), 40% CO2/60% N-2 (M-2) and 60% CO2/40% N-2 (M-3); identical cheese samples were packaged in air, taken as controls. All cheese samples were kept under refrigeration (4 +/- 0.5 degrees C) for 45 days. Of the four atmospheres, the M-2 and M-3 gas mixtures were the most effective for inhibiting growth of aerobic microflora and psychrotrophs in cheese samples until days 40 and 33 of refrigerated storage, respectively. Lactic acid bacteria (LAB) were part of the cheese microflora becoming dominant toward the end of the storage period regardless of packaging conditions. Enterobacteriaeceae were also part of the cheese microflora being effectively inhibited after day 35 of storage. Molds and yeasts were also totally inhibited by MAP (M-2 and M-3) gas mixtures throughout the entire storage period. Of the chemical quality indices determined, lipid oxidation varied below 0.005 absorbance at 532 nm for all treatments, except control samples for which absorbance values of 0.02 were recorded after 35 days of storage. Lipolysis did not vary significantly with type of packaging treatment while proteolysis values showed and increasing trend up to day 25 of storage and then decreased toward the end of the storage period. Sensory evaluation (odour and taste) showed that Myzithra cheese packaged under MAP (M-2 and M-3) retained good sensory characteristics for 30 days of storage while control samples were sensorily unacceptable after 10-12 days of storage. (C) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved. Lwt-Food Science and Technology

The present work evaluated the effect of air, vacuum and modified atmosphere packaging (MAP) on the shelf-life of chilled Mediterranean swordfish (Xiphias gladius). Fresh swordfish slices were stored in air, under vacuum and MAP (40%/30%/30%, CO(2)/N(2)/O(2)) under refrigeration (4 degrees C) for a period of 16 days. Of the three treatments used (vacuum, MAP and air), both MAP and vacuum packaging (VP) were the most effective for inhibiting growth of aerobic microflora in swordfish samples until days 9-10 of refrigerated storage. Of the microbial species determined, both Pseudomonas spp. and H(2)S-producing bacteria (including Shewanella putrefaciens) were dominant in swordfish samples stored in air, whereas growth of these species was partly inhibited under VP and MAP conditions. Lactic acid bacteria (LAB) and Enterobacteriaceae were also found to be members of the final swordfish microbial flora, irrespective of packaging conditions throughout the entire storage period. Of the chemical freshness indices determined, thiobarbituric acid (TBA) values were variable in swordfish samples, indicative of no specific oxidative rancidity trend. Trimethylamine nitrogen (TMA-N) values of swordfish samples stored in air, under VP and MAP exceeded the limit value of 5mgN/100g fish muscle after days 7, 8-9 and 11 days of storage, respectively. In a similar trend, total volatile basic nitrogen (TVB-N) for swordfish samples stored in air, under VP and MAP exceeded the limit value of 25mgN/100g fish muscle after 7-8, 10 and 12 days of storage, respectively. Sensory analyses (odor and taste attributes) indicated a shelf-life of ca. 7 days for air, 9 days for VP and 11-12 days for the MA-packaged swordfish samples.