Radiosensitization of Bacillus cereus spores in minced meat treated with cinnamaldehyde (original) (raw)
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Food Science and Quality Management, 2013
Spores of Bacillus cereus, like other bacterial spores, are heat and radiation resistance causing problem in food processing because of the high temperature or irradiation dose needed to inactivate them. In this work, combination treatments of heat and irradiation were tested for their potential to reduce heat-resistance of B. cereus spores in raw milk, carrot juice and water. D T and Z-values were used to characterize heat resistance of these spores, whereas D 10-values were used to characterize radiation resistance. The results obtained indicated that D 85-values ranged from 24.9 to 35.2 min, D 90-values ranged from 7.6 to 11.6 min and D 95-values ranged from 2.4 to 4.7 min. The Z-values of B. cereus spores in the used media ranged from 9.81 to 11.24 o C. The D 10values ranged from 1.9 to 2.6 kGy. Pre-irradiation treatment at 4 kGy followed by heating reduced D 90-values 2.8 to 3.4 times. The obtained findings indicated the effectiveness of irradiation at 4 kGy followed by heating in a same process to ensure safety of raw milk or carrot juice contaminated with Bacillus cereus.
Innovative Romanian Food Biotechnology, 2013
This study investigated the microbial, chemical and sensorial properties of chicken sausage exposed to gamma irradiation and stored at 0-4 o C. Chicken sausage was treated with 0, 2, 4 or 6 kGy doses of gamma irradiation. Microbial, chemical, and sensory analyses of chicken sausage were evaluated at 0, 4, 8, 12, 16 and 20 weeks of storage. Irradiation at 2, 4 and 6 kGy significantly reduced the counts of total viable (mesophilic aerobic) plate counts (TPCs), fecal coliform and yeast load and prolonged the refrigerated shelf-life of chicken sausage. Irradiation significantly decreased their amount of total acidity, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances (TBARS), while storage increased the total acidity, VBN and TBARS for irradiated and non-irradiated samples. The percentage of protein slightly increased in irradiated samples with higher doses, while the percentage of fat significantly decreased. Gamma irradiation showed no significant effect on th...
Journal of food science, 2017
This study was performed to evaluate the effect of different doses (0, 1.5, 3, and 4.5 kGy) of e-beam irradiation on the quality parameters (pH, Hunter's parameter, and heme pigment) and stability qualifiers (peroxide value [POV], thiobarbituric acid reactive substances [TBARSs], and total volatile basic nitrogen [TVBN]) of smoked duck meat during 40 d of storage under vacuum packaging at 4 °C. The initial populations of total bacteria (7.81 log CFU/g) and coliforms (5.68 log CFU/g) were reduced by approximately 2 to 5 log cycles with respect to irradiation doses. The results showed that pH, myoglobin, met-myoglobin, L(*) , a(*) , and b(*) showed significant differences with respect to different doses and storage intervals; a(*) and b(*) did not vary significantly because of storage. Higher pH was found in samples treated with 4.5 kGy at 40 d, while the minimum was observed in nonirradiated samples at day 0 of storage. Higher POV (2.31 ± 0.03 meq peroxide/kg) and TBARS (5.24 ± 0...
Journal of food protection
The effect of gamma-radiation (0.5, 1, and 2 kGy) on the shelf life of fresh skinless chicken breast fillets stored aerobically at 4 degrees C was evaluated. Microbiological, chemical, and sensorial changes occurring in chicken samples were monitored for 21 days. Irradiation reduced populations of bacteria, i.e., total viable bacteria, Brochothrix thermosphacta, lactic acid bacteria (LAB), and the effect was more pronounced at the highest dose (2 kGy). Pseudomonads, yeasts and molds, and Enterobacteriaceae were highly sensitive to gamma-radiation and were completely eliminated at all doses. Of the chemical indicators of spoilage, thiobarbituric values for nonirradiated and irradiated aerobically packaged chicken samples were in general low (<1 mg of malonaldehyde per kg of muscle) during refrigerated storage for 21 days. With regard to volatile amines, both trimethylamine nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) values for nonirradiated aerobically packaged chic...
Using gamma irradiation and low temperature on microbial decontamination of red meat in Iran
Indian Journal of Microbiology, 2007
Gamma irradiation can be used as one of the most efficient methods to reduce microorganisms in food. The irradiation of food is used for a number of purposes, including microbiological control, insects control and inhibition of sprouting and delay of senescence of living food. The aim of this study was to study effects of gamma irradiation, refrigeration and frozen storage as the combination process for improvement of red meat shelf-life. The bovine meat samples were treated with 0, 0.5, 1, 2 and 3 kGy of gamma irradiation and kept in refrigerator for 3 weeks and in freezer for 8 months. The control and irradiated samples were stored at 4–7°C and at −18°C for refrigeration and frozen storage, respectively; and microbial and chemical analyze was done at 1 week and 2 months intervals. In this study the optimum dose of gamma radiation in order to decrease the total count of Mesophilic bacteria, Coliforms, Staphylococcus aureus and especially for elimination of Salmonella was obtained at 3 kGy. Microbial analysis indicated that irradiation and storage at low temperature had a significant effect on the reduction of microbial loads. There was no significant difference in chemical characteristics during freezing storage in bovine meat. Also, irradiated meat samples (3 kGy) were stored in 4–7°C for 14 days, compared to 3 days for non irradiated samples.
Innovative Food Science & Emerging Technologies, 2010
The thermal stability of heat-shocked and non-heat-shocked spores of the virulence-attenuated Sterne strain of Bacillus anthracis was evaluated at select temperatures in irradiated, raw ground beef (25% fat) heated in a water bath or cooked using two different commercial grills. For the former, 3-g portions of inoculated ground beef were packaged in bags that were completely immersed in a temperature-controlled circulating water bath held at 65°C (149°F), 70°C (158°F), 75°(167°F), and 80°C (176°F) for a predetermined length of time. For the latter, formed ground beef patties (95-g each) were inoculated with spore stock A or B of the Sterne strain and then cooked on a commercial open-flame gas grill or on a commercial clamshell electric grill to achieve target internal temperatures of either 71.1°C (160°F), 82.2°C (180°F), or 93.3°C (200°F). Cooking ground beef patties on commercial grills, resulted in reductions of ca. 0.8 to 3.5 log 10 CFU/g for spore stocks A and B of B. anthracis Sterne after heating to 71.1°C (160°F), 82.2°C (180°F), or 93.3°C (200°F) on either the open-flame gas grill which required ca. 9.6 min to reach the target internal temperatures or on the clamshell electric grill which required ca. 4.0 min to reach the target internal temperatures. In comparison, our data using a water bath system and heating at 65°to 80°C predict nearly 4 log reductions in spore levels for short times,~½ min, depending possibly on the temperature. Thus, our data suggest that models based on heating ground beef in a water bath is not a good predictor of reductions of levels of spores of B. anthracis Sterne strain that would be obtained when cooking ground beef patties on commercial grills under conditions that may be typically used by consumers and/or retail establishments. Nevertheless, our data validated that cooking ground beef patties on a commercial grill at a temperature considered to be "welldone" and a temperature (71.1°C;160°F) recommended by the USDA/FSIS, is effective at killing spores of B. anthracis Sterne. Industrial relevance: Heating ground beef in a water bath or cooking ground beef patties on commercial grills under conditions simulating those that are used by consumers and/or that occur in retail food service establishments is effective at killing spores of B. anthracis Sterne.
and Implications Four of the bacterial pathogens that are of major concern to the meat industry, Listeria monocytogenes, Campylobacter jejuni, Salmonella enterica Typhimurium and Escherichia coli O157:H7 were studied for their susceptibility to high carbon dioxide atmospheres during irradiation and storage by utilizing high-carbon-dioxide modified atmosphere packages (MAP) compared to vacuum packaging. Frankfurters and cooked pork chops (L. monocytogenes), chicken breasts (C. jejuni and S. enterica) and ground beef (E. coli O157:H7) were inoculated with the respective pathogens, packaged in vacuum or MAP and irradiated with doses appropriate to each pathogen. Surviving bacteria were monitored during refrigerated and temperature-abused storage. While irradiation was very effective for reducing the number of pathogens on each product, the use of high carbon dioxide atmosphere in MAP did not increase the effectiveness of irradiation as an antimicrobial treatment. The MAP treatment resulted in less recovery of L. monocytogenes than vacuum for cooked pork chops during refrigerated storage, and for E. coli O157:H7 on ground beef when exposed to room temperature, but not for the other pathogens or products. Consequently, while irradiation is a very effective means of reducing or eliminating bacterial pathogens on meat products, the addition of a high-carbon dioxide MAP system during storage of the products did not greatly improve the control of these pathogens.
The effect of ␥-radiation (0.5, 1, and 2 kGy) on the shelf life of fresh skinless chicken breast fillets stored aerobically at 4ЊC was evaluated. Microbiological, chemical, and sensorial changes occurring in chicken samples were monitored for 21 days. Irradiation reduced populations of bacteria, i.e., total viable bacteria, Brochothrix thermosphacta, lactic acid bacteria (LAB), and the effect was more pronounced at the highest dose (2 kGy). Pseudomonads, yeasts and molds, and Enterobacteriaceae were highly sensitive to ␥-radiation and were completely eliminated at all doses. Of the chemical indicators of spoilage, thiobarbituric values for nonirradiated and irradiated aerobically packaged chicken samples were in general low (Ͻ1 mg of malonaldehyde per kg of muscle) during refrigerated storage for 21 days. With regard to volatile amines, both trimethylamine nitrogen (TMA-N) and total volatile basic nitrogen (TVB-N) values for nonirradiated aerobically packaged chicken increased steeply, with final values of ca. 20.3 and 58.5 mg N/100 g of muscle, respectively. Irradiated aerobically packaged chicken samples had significantly lower TMA-N and TVB-N values (P Ͻ 0.05) of ca. 2.2 to 3.6 and 30.5 to 37.1 mg N/100 g of muscle, respectively, during refrigerated storage for 21 days. Of the biogenic amines monitored, only putrescine and cadaverine were detected in significant concentrations in both nonirradiated and irradiated chicken samples, whereas histamine formation was noted only in nonirradiated samples throughout storage. On the basis of sensorial evaluation, low-dose irradiation (0.5 and 1.0 kGy) in combination with aerobic packaging extended the shelf life of fresh chicken fillets by ca. 4 to 5 days, whereas irradiation at 2.0 kGy extended the shelf life by more than 15 days compared with that of nonirradiated chicken.
Radiation Physics and Chemistry, 2010
Ready-to-cook Iranian barbecued chicken consists of cubed chicken breast, lemon juice, salt, red pepper, onion, saffron and vegetable oil with an overall pH value of about 5.5. This product is sometimes consumed under-cooked, hence it may pose health hazards to consumers when contaminated with food-borne pathogens. In this study, the effect of gamma irradiation (0, 1.5, 3 and 4.5 kGy) on the microbial quality of ready-to-cook (RTC) barbecued chicken samples stored at 4 1C for 15 days was investigated. Moreover, the effectiveness of irradiation for inactivating Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella typhimurium inoculated into the samples was also studied. Irradiation of the samples resulted in dose dependent reduction in counts of aerobic mesophilic bacteria, yeasts and molds, Enterobacteriaceae and lactic acid bacteria. Among the microbial flora, yeasts and molds and Enterobacteriaceae were more sensitive to irradiation and got completely eliminated at dose of 3 kGy. D 10 values of L. monocytogenes, E. coli O157:H7 and S. typhimurium inoculated into the samples were 0.680, 0.397 and 0.601 kGy, respectively. An irradiation dose of 3 kGy reduced the counts of E. coli O157:H7 to an undetectable level in RTC barbecued chicken but was ineffective on elimination of L. monocytogenes and S. typhimurium. However, none of the food-borne pathogens were detected in the samples irradiated at 4.5 kGy. This study showed that irradiation had no undesirable effects on the initial sensory attributes of barbecued chicken. At the end of the storage period, irradiated samples were more acceptable compared to non-irradiated ones.
Meat Science, 2014
The objectives of the present work were to assess the use of moderate doses of gamma irradiation (2 to 5 kGy) and to reduce the risk of pathogen presence without altering the quality attributes of bovine trimmings and of patties made of irradiated trimmings. Microbiological indicators (coliforms, Pseudomonas spp and mesophilic aerobic counts), physicochemical indicators (pH, color and tiobarbituric acid) and sensory changes were evaluated during storage. 5 kGy irradiation doses slightly increased off flavors in patties. Two pathogenic markers (Listeria monocytogenes and Escherichia coli O157:H7) were inoculated at high or low loads to trimming samples which were subsequently irradiated and lethality curves were obtained. Provided that using irradiation doses ≤2.5 kGy are used, reductions of 2 log CFU/g of L. monocytogenes and 5 log CFU/g of E. coli O157:H7 are expected. It seems reasonable to suppose that irradiation can be successfully employed to improve the safety of frozen trimmings when initial pathogenic bacteria burdens are not extremely high.