Effect of Pre-Cure Freezing and Thawing on the Microflora, Fat Characteristics and Palatability of Dry-Cured Ham1

1982 ◽  
Vol 45 (3) ◽  
pp. 244-248 ◽  
Author(s):  
J. D. KEMP ◽  
B. E. LANGLOIS ◽  
A. E. JOHNSON
Keyword(s):  
Escherichia Coli ◽  
Weight Loss ◽  
Bacillus Cereus ◽  
Clostridium Perfringens ◽  
The Other ◽  
Freezing And Thawing ◽  
Fourth Group ◽  
Microbial Counts ◽  
Peroxide Values ◽  
Lower Peroxide

Hams were placed in cure after thawing by 3 methods: at 2C, at 16C, and in water at 37C. A fourth group was placed in cure while still frozen. Microbiological populations and fat rancidity tests were determined at various intervals during processing. Sensory scores and tenderness values were determined after 3 months of aging. Clostridium perfringens, Bacillus cereus, Escherichia coli, coliforms and enterococci were not detected after salt equalization. Hams cured without thawing had lower initial bacterial, yeast and mold counts but no differences among thaw groups were observed in counts during aging. Hams thawed in water had lower flavor and overall satisfaction scores than the other groups. Fat breakdown as noted by FFA, TBA and peroxide values increased with aging but were erratic although ham cured without thawing had lower peroxide values. Satisfactory dry-cured aged hams were produced regardless of method of thawing. However, since hams cured without thawing had less weight loss, lower peroxide numbers, lower initial microbial counts and similar final microbial counts and sensory scores, it appears that hams do not need to be thawed to produce dry-cured aged hams.

Fate of Pathogens Inoculated onto Vacuum-Packaged Sliced Hams to Simulate Contamination During Packaging1

1979 ◽  
Vol 42 (6) ◽  
pp. 464-469 ◽  
Author(s):  
M. E. STILES ◽  
L.-K. NG
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Bacillus Cereus ◽  
Clostridium Perfringens ◽  
Subsequent Treatment ◽  
Vacuum Packaging ◽  
E Coli ◽  
Survival And Growth ◽  
And Staphylococcus Aureus

Ham and chopped ham from two manufacturers were contaminated with five enteropathogens: Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, at time of slicing and vacuum-packaging, to simulate contamination by manufacturer. Subsequent treatment of the samples, representing sound and undesirable retail handling and consumer use conditions, indicated marked differences in the fate of the pathogens between these products and within product type between the two manufacturers. Greatest differences were observed between the chopped ham products. All pathogens, except C. perfringens, grew actively in fresh ham and chopped ham with abusive holding at 30 and 21 C. After storage at 4 or 10 C for 30 days, B. cereus and C. perfringens were no longer detected, even after subsequent holding at 30 or 21 C for 24 h. E. coli survival and growth was variable, S. typhimurium survived well and grew under some conditions and S. aureus was generally inhibited at high levels of competition.

Clostridium perfringens as an Indicator of Hygienic Quality of Depurated Shellfish

1986 ◽  
Vol 49 (1) ◽  
pp. 33-36 ◽  
Author(s):  
ROBERT H. MADDEN ◽  
H. BULLER ◽  
D. W. McDOWELL
Keyword(s):  
Escherichia Coli ◽  
Clostridium Perfringens ◽  
Fecal Pollution ◽  
The Other ◽  
Acceptable Level ◽  
Laboratory Studies ◽  
E Coli ◽  
Commercial Practice ◽  
Considerable Period

A comparison of the recoveries of Clostridium perfringens, Escherichia coli and Streptococcus faecalis from naturally and artificially contaminated mussels and oysters was made. Only C. perfringens was regularly recovered from naturally contaminated shellfish. Laboratory studies showed that this was due to C. perfringens spores retaining viability significantly longer than vegetative cells of the other organisms tested, under marine conditions. Over 97% of presumptive C. perfringens colonies were confirmed as positive. A survey of mussels at 24 sites, over ca. 60 km of coastline, found C. perfringens at 23 but E. coli at only two of the sites. Therefore, enumeration of C. perfringens can indicate fecal pollution where enumeration of E. coli shows none. Also, confirmation of presumptive colonies may not be required, rendering enumeration more rapid. Despite the greater persistence of C. perfringens spores, studies in a commercial depuration tank showed that oysters were cleansed to an acceptable level using a standard 48-h immersion. Depuration was found to be essential because all three organisms tested survived for a considerable period of time in oysters stored dry at 4°C, which is normal commercial practice.

Characterization of Bacillus cereus Isolates from Raw Soybean Sprouts

2004 ◽  
Vol 67 (5) ◽  
pp. 1031-1035 ◽  
Author(s):  
HYE-JUNG KIM ◽  
DONG SUN LEE ◽  
HYUN-DONG PAIK
Keyword(s):  
Bacillus Cereus ◽  
Clostridium Perfringens ◽  
Clostridium Botulinum ◽  
The Other ◽  
Starch Hydrolysis ◽  
Anaerobic Microorganisms ◽  
Soybean Sprouts ◽  
Large Populations ◽  
Mesophilic Microorganism

Raw soybean sprouts, which are used as ingredients in cook-chilled products, were analyzed to evaluate the incidence of mesophilic aerobic microorganisms, psychrotrophic microorganisms, anaerobic microorganisms, coliforms, and spore-forming microorganisms Bacillus cereus, Clostridium botulinum, and Clostridium perfringens. Mesophilic microorganisms on raw soybean sprouts were present in large populations, 5.5 × 106 to 1.4 × 108 CFU/g, and psychrotrophic microorganisms were found to be more numerous than the other groups. Coliforms accounted for 15% of mesophilic microorganism counts on average, and the average for spore-forming microorganisms was 5.2 × 102 CFU/g. B. cereus was isolated from 12 of 17 soybean sprout samples, whereas C. botulinum and C. perfringens were not isolated. B. cereus was isolated in greater numbers at 30° C compared with other temperatures and was not isolated at 4° C. Of the 55 strains isolated from soybean sprouts, 52 were positive for starch hydrolysis, and only 3 strains did not hydrolyze starch. Among the 55 strains of B. cereus isolates, 53 showed the ability to produce diarrheal enterotoxin by CRET-RPLA.

scholarly journals COMPARISON OF ANTIBACTERIAL ACTIVITY OF HONEY AGAINST AEROBIC AND ANAEROBIC BACTERIA

2021 ◽  
pp. 41-43
Author(s):  
S. DHANARAJ ◽  
S. S. M. UMAMAGESWARI ◽  
M. MALAVIKA ◽  
G. BHUVANESHWARI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Clostridium Perfringens ◽  
Anaerobic Bacteria ◽  
The Other ◽  
E Coli ◽  
Diffusion Technique ◽  
Aerobic And Anaerobic

Objective: To compare the antibacterial activity of honey against aerobic and anaerobic bacteria. Methods: Honey is extracted from the honey comb by trained persons. Antimicrobial activity of honey is performed by Agar Cup Diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and Clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to honey whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to honey. Conclusion: Due to its vast antibacterial activity of honey, it can be used along with other antibiotics to increase its efficiency.

scholarly journals COMPARISON OF ANTIBACTERIAL ACTIVITY OF GARLIC AGAINST AEROBIC AND ANAEROBIC BACTERIA

2021 ◽  
pp. 44-46
Author(s):  
K. G. DHANUSH ◽  
S. S. M. UMAMAGESWARI ◽  
M. MALAVIKA ◽  
G. BHUVANESHWARI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Clostridium Perfringens ◽  
Anaerobic Bacteria ◽  
The Other ◽  
E Coli ◽  
Diffusion Technique ◽  
Aerobic And Anaerobic

Objective: To compare the antibacterial activity of garlic against aerobic and anaerobic bacteria. Methods: Antimicrobial activity of garlic is performed by Agar cup diffusion technique for 3 bacteria Staphylococcus aureus, E. coli and clostridium perfringens. Results: By performing the technique with proper guidance, it is observed that the Staphylococcus aureus specimen shows sensitivity to garlic whereas the other two specimens Escherichia coli and clostridium perfringens doesn’t show any sensitivity to garlic. Conclusion: Due to its vast antibacterial activity of garlic, it can be used along with other antibiotics to increase its efficiency.

Microflora Isolated from Imported Frozen Lean Beef Pieces1

1978 ◽  
Vol 41 (4) ◽  
pp. 251-253 ◽  
Author(s):  
J. L. OBLINGER ◽  
J. E. KENNEDY
Keyword(s):  
Escherichia Coli ◽  
Clostridium Perfringens ◽  
Microbial Flora ◽  
Fecal Coliforms ◽  
Meat Processing ◽  
Microbial Counts ◽  
Lean Beef ◽  
Fecal Streptococci ◽  
Yeasts And Molds

Forty samples of frozen imported lean beef pieces from six countries were obtained from two centralized meat processing operations. The samples were analyzed for total aerobic counts (35, 20, 7 C), yeasts and molds, fecal streptococci, Staphylococcus aureus, Clostridium perfringens, total coliforms, fecal coliforms, Escherichia coli, and Salmonella. Characterization of the microbial flora from 20 of the samples was also done. Microbial counts were consistently low in all analyses; no Clostridium perfringens or Salmonella was recovered from any samples. The microbial flora was predominantly Pseudomonas, Flavobacterium, Moraxella, Acinetobacter, Corynebacterium, Micrococcus, Staphylococcus and Lactobacillus; the remaining isolates included Alcaligenes, Erwinia, Citrobacter, Klebsiella, Streptococcus, Bacillus and Arthrobacter.

Donairs (Gyros) - Potential Hazards and Control

1986 ◽  
Vol 49 (5) ◽  
pp. 369-377 ◽  
Author(s):  
EWEN C. D. TODD ◽  
R. SZABO ◽  
F. SPIRING
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Heat Source ◽  
Bacillus Cereus ◽  
Clostridium Perfringens ◽  
Temperature Measurements ◽  
Microbiological Analysis ◽  
Short Period ◽  
And Control

Because of concerns that meat in donairs could allow growth of pathogens during cooking and overnight cooling of leftovers, 34 donairs from eleven establishments had temperatures taken and were examined microbiologically. Temperatures varied depending on depth of measurement and stage from the raw product to reheated leftovers. These were frequently >4 or <60°C and could be considered at temperatures favorable for growth of pathogens. Although aerobic colony counts were high (mean of 105 to 107 CFU/g), counts tended to decrease the longer the donair remained cooking on the spit. Staphylococcus aureus, Bacillus cereus, Clostridium perfringens and Escherichia coli were never more than 104/g despite some abusive practices, such as leaving donairs on the spit with the heat source turned off because the demand was low. Salmonella was found only in raw chicken slices to be used in donairs. It is recommended that good hygienic practices be encouraged at donair establishments and temperature measurements of donairs taken to verify these. Only if meat is <50°C at 1 cm below the surface during cooking or >5°C for the raw product or cooled leftovers, should samples be considered for microbiological analysis unless abusive practices have been observed. Because temperatures may vary over a short period of time during cooking, at least five measurements are recommended for each stage of the donair life (raw product, cooking donair, cooled leftovers and reheating donairs).

scholarly journals IDENTIFICATION OF FOOD PATHOGENS AND DETERMINATION OF THEIR DISTRIBUTION LEVEL IN UKRAINIAN FOOD PRODUCTS OF ANIMAL AND PLANT ORIGIN BY PCR METHOD

2019 ◽  
Vol 13 (4) ◽  
Author(s):  
O. Berhilevych ◽  
L. Pylypenko ◽  
V. Kasianchuk ◽  
A. Ilyeva ◽  
P. Shubin
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Clostridium Perfringens ◽  
Foodborne Pathogens ◽  
Shiga Toxin ◽  
Raw Materials ◽  
Cow Milk ◽  
Plant Origin ◽  
Pcr Method

The foodborne pathogens cause serious public health problems in each country. In this regard, microbiological investigation is included in food safety management of the food chain. Molecular methods and mostly polymerase chain reaction (PCR) are considered highly sensitive, specific and rapid methods for pathogens detection from raw material and food. This study describes the using of specially designed and highly specific primers for PCR to identify 5 common and especially dangerous causeve agents of food poisoning and disease and to determine their level of distribution in food of animal and plant origin. The studies included the identification of methicillin-resistant Staphylococcus aureus (MRSA) and Cronobacter spp. (E. sakazakii) from raw milk, Shiga toxin-producing strains of Escherichia coli (STEC) from beef and swine carcasses, Bacillus cereus and Clostridium perfringens from various types of plant and animal raw materials and products of its processing - fruits, vegetables, berries, dried and preserved products, food concentrates, half-canned food. A total of 397 food samples were investigated to detect these pathogens using classical bacteriological methods and PCR. It was found that the distribution of foodborne pathogens in the studied products of animal and plant origin was as follows: Staphylococcus aureus (MRSA) and Cronobacterspp. (E. sakazakii) in raw cow milk in 6.5% and 19.4% of cases, respectively; shiga-toxin-producing Escherichia coli (STEC) from beef and pork carcasses in 8.1% and 5.7%; Bacillus cereus and Clostridium perfringens from different types of plant and animal raw materials and their processing products averages 27.5 % and 7.7 %, respectively. The advantages of molecular biological methods to which the PCR method relates, include their speed, as well as the specificity of identification of microorganisms by the features of genetic regions of genes that carry information about their pathogenicity factors. It has been found that the rate of detection of these pathogens when using the PCR method in comparison with classical methods increases at least 5-9 times. This data will be useful for assessing microbiological risk and will help authorities develop strategies to reduce consumer health risks.

scholarly journals Zn, Cu, and Fe Concentrations in Dehydrated Herbs (Thyme, Rosemary, Cloves, Oregano, and Basil) and the Correlation with the Microbial Counts of Listeria monocytogenes and Other Foodborne Pathogens

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1658
Author(s):  
José María García-Galdeano ◽  
Marina Villalón-Mir ◽  
José Medina-Martínez ◽  
Lydia María Vázquez-Foronda ◽  
Jessandra Gabriela Zamora-Bustillos ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Polyethylene Terephthalate ◽  
Clostridium Perfringens ◽  
Foodborne Pathogens ◽  
Microbial Growth ◽  
Microbial Count ◽  
Natural Preservative ◽  
Microbial Counts ◽  
Aromatic Herbs

Zn, Cu, and Fe concentrations were measured in dehydrated herbs (thyme, rosemary, cloves, oregano, and basil) marketed in bulk or packaged in glass or polyethylene terephthalate (PET). Microbial counts of Listeria monocytogenes and other five foodborne pathogens were also checked when herbs were previously added to the growing media. The highest mean concentrations were found in basil for Zn and Cu, and in thyme and basil for Fe; the lowest ones for these minerals were in cloves (p < 0.05). Basil had significantly higher microbial counts in five of the six foodborne pathogens studied (p < 0.05). Cloves have the best hygienic quality as there is no microbial growth of L. monocytogenes, Clostridium perfringens, and Bacillus cereus; they therefore could be used as a natural preservative in food. Aromatic herbs marketed in bulk showed a significantly higher microbial count (p < 0.05). Zn, Cu, and Fe concentrations were positively correlated with microbial growth for L. monocytogenes, C. perfringens, B. cereus, and psychrophilic microorganisms (p < 0.05), so they could act as a growing factor for the foodborne pathogens.

scholarly journals Dry-Aging: How Freezing Can Affect the Yield and the Quality of Beef?

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
A. P. S. Bernardo ◽  
A. Caroline ◽  
F. A. Ribeiro ◽  
C. R. Calkins ◽  
M. D. S. do Nascimento ◽  
...  
Keyword(s):  
Weight Loss ◽  
Water Activity ◽  
Bacterial Count ◽  
Cooking Loss ◽  
Raw Material ◽  
Total Bacterial Count ◽  
Freezing And Thawing ◽  
Microbial Counts ◽  
Physical Chemical ◽  
Left And Right

ObjectivesDry-aged beef is in high demand in the Brazilian market. The raw material used for dry-aged normally comes from high quality beef, and the production of this raw material can vary during the year. The viability of dry aging a previously frozen beef is very important to this market. So, the present study aimed to evaluate the effects of freezing and thawing, before and after dry-aging on losses, physical-chemical and microbial characteristics of beef.Materials and MethodsTwelve pairs of striploins (left and right-side) from Nellore cattle were collected at 3 d postmortem in a commercial beef plant and sent to the Meat Laboratory at the University of Campinas. Both left and right strip loins were divided in half, and each of the four sections per animal were randomly assigned to one of four treatments: never frozen dry-aging (Dry); dry-aging followed by steak fabrication and freezing/thawing (4°C/24 h) (Dry+F); freezing before aging, fast thawing (20°C/15 h) followed by dry-aging (FT+Dry); freezing before aging, slow thawing (4°C/48 h) followed by dry-aging (ST+Dry). The aging process was performed at 2°C and 70% relative humidity for 28 d. Weight losses (thawing, evaporation and trimming) and physical-chemical analyses (pH, water activity, moisture, TBARS, cooking loss and Warner-Bratzler shear force) were evaluated for all treatments, while microbial analyses were evaluated only for the Dry, FT+Dry and ST+Dry treatments. The data was analyzed using the software Statistica for ANOVA one-way and means (± SEM) were tested by Tukey test at 5% significance.ResultsSamples from the Dry+F treatment had lower (P < 0.05) thaw loss (1.1 ± 0.1%), followed by FT+Dry (3.7 ± 0.4%) and ST+Dry samples (5.4 ± 0.3). Freezing samples before dry-aging resulted in (28.5 ± 0.8%) greater weight loss during aging (P < 0.05) compared to never-frozen and frozen after dry-aging samples (24.2 ± 0.7%), with no differences in trimming loss (P > 0.05). Freezing had no effect on pH, TBARS and WBSF (P > 0.05). FT+Dry and ST+Dry samples had lower water activity, moisture and cooking loss values compared to Dry and Dry+F (P < 0.05). In this study, microbial counts were not affected by freezing/thawing methods (P > 0.05). The highest counts, found at the end of aging, were 3.54 log CFU/g of total bacterial count (FT+Dry), 5.05 log CFU/g of psychrotrophic microorganisms (ST+Dry), 2.56 log CFU/g of lactic acid bacteria (ST+Dry), 1.8 log CFU/g of Enterobacteriaceae (FT+Dry) and 3.02 log CFU/g of yeasts and molds (Dry). The mold genus isolated were Aspergillus sp. and Cladosporium sp.ConclusionResults indicate that freezing loins before dry-aging increases losses without affecting the microbiological counts. Conversely, freezing steaks after dry-aging maintains the physical-chemical characteristics when compared to never-frozen dry-aged steaks. Thus, despite no impact on microbial counts, freezing samples before dry-aging is not recommended due to the higher levels of weight loss, while freezing steaks after dry-aging can be an alternative to extend the shelf-life.

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