Effect of Salt and Sodium Nitrite on Growth and Enterotoxin Production of Staphylococcus aureus during the Production of Air-Dried Fresh Pork Sausage†‡

2008 ◽  
Vol 71 (1) ◽  
pp. 191-195 ◽  
Author(s):  
W. BANG ◽  
D. J. HANSON ◽  
M. A. DRAKE
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Nitrite ◽  
Growth Characteristics ◽  
Coliform Bacteria ◽  
Safety Hazard ◽  
Pork Sausage ◽  
Enterotoxin Production ◽  
Plate Counts ◽  
Pork Sausages ◽  
Potential Food

Staphylococcus aureus contamination and enterotoxin production is a potential food safety hazard during the drying step of production of air-dried fresh country sausage. The growth characteristics and enterotoxin production of S. aureus during the drying step of this product with and without added sodium nitrite were evaluated. Three strains of S. aureus were grown to stationary phase and inoculated (104 CFU/g) into sausage ingredients. Fresh pork sausages were stuffed into natural casings and allowed to dry for 10 days at 21°C with 60% relative humidity (RH). In control sausage (1.76% [wt/wt] salt) with no S. aureus, aerobic plate counts increased by 5.5 log/g during the 10-day drying period, and coliforms increased by 4.8 log/g. The addition of sodium nitrite (154 ppm of nitrite, 2.24% [wt/wt] salt) or increased salt (3.64%, wt/wt) to sausage limited the growth of coliform bacteria (P < 0.05). S. aureus numbers increased approximately 2 log units during the drying step, regardless of additional salt or nitrite. Additional salt or nitrite had no effect on S. aureus growth (P > 0.05). Staphylococcal enterotoxin (SE) was not detected in air-dried fresh sausages at any time. Our results suggest that drying of fresh pork sausage under similar parameters listed in this study does not support SE production.

Effects of Potassium Sorbate on Normal Flora and on Staphylococcus aureus Added to Minced Cod

1982 ◽  
Vol 45 (9) ◽  
pp. 824-828 ◽  
Author(s):  
DONALD J. LYNCH ◽  
NORMAN N. POTTER
Keyword(s):  
Staphylococcus Aureus ◽  
Storage Period ◽  
Inhibitory Effect ◽  
Potassium Sorbate ◽  
Normal Flora ◽  
Ph Changes ◽  
Normal Microflora ◽  
Enterotoxin Production ◽  
Plate Counts ◽  
Storage Temperatures

Minced cod and pasteurized minced cod, with and without 0.5% potassium sorbate, were subjected to abusive storage temperatures of 7 and 15°C. Staphylococcus aureus FRI 100 was inoculated into the cod before storage. Total aerobic plate counts (20 and 35°C), pH changes, S. aureus counts and the presence of thermonuclease were monitored throughout the studies. With the unpasteurized minced cod, potassium sorbate caused slightly lower aerobic plate counts (at 20 and 35°C) in the 7°C study over an 11-day storage period. Psychrotrophic organisms were inhibited to a slightly greater extent than were mesophilic organisms. Inoculated S. aureus was quickly outgrown by the normal microflora without or with sorbate. Similar results were obtained at the still more abusive temperature of 15°C over a storage period of 5 d, but the inhibitory effect of sorbate was less evident. Pasteurized minced cod, inoculated with S. aureus and stored at 15°C, showed a considerable difference in growth of S. aureus with and without sorbate. Potassium sorbate resulted in a markedly slower rate of growth of the pathogen and a substantial delay of several days in production of detectable levels of thermonuclease. This delay in nuclease production is indicative of a similar delay in enterotoxin production.

scholarly journals Effects of Chitosan on Clostridium perfringens and Application in the Preservation of Pork Sausage

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 70 ◽  
Author(s):  
Shun-Hsien Chang ◽  
Ching-Hung Chen ◽  
Guo-Jane Tsai
Keyword(s):  
Heat Resistance ◽  
Clostridium Perfringens ◽  
Sodium Nitrite ◽  
Nitrite Reduction ◽  
Pork Sausage ◽  
Bacterial Proliferation ◽  
Color Retention ◽  
A Value ◽  
Deacetylation Degree ◽  
Pork Sausages

The effects of chitosan with 95% deacetylation degree (DD95) on the spore germination, cell proliferation, and heat resistance of Clostridium perfringens CCRC 10,648 and CCRC 13,019 were investigated, and its application on pork sausage with sodium nitrite reduction was also evaluated. DD95 chitosan can strongly reduce the heat resistance of both strains. The D80 and D100 values for strain CCRC 13,019 decreased from 40.98 and 4.64 min to 39.21 and 3.26 min, respectively, as a result of adding 250 ppm DD95; meanwhile, addition of chitosan decreased the D80 and D100 values for CCRC 10,648 from 41.15 and 6.46 min to 39.52 and 3.78 min, respectively. In pork sausage, addition of 3000 ppm DD95 chitosan considerably slowed down the bacterial proliferation and volatile basic nitrogen production. There were no significant differences in color (L* and b* values), shearing force, and hardness in the pork sausages with or without DD95 chitosan during storage at 4 and 25 °C. However, the addition of DD95 chitosan in pork sausage significantly retarded the decrease of the a* value. Therefore, DD95 chitosan could reduce the concentration of sodium nitrite required in pork sausages for color retention.

Effect of Chloride Salts and Nitrite on Survival of Trichina Larvae and Other Properties of Pork Sausages

1982 ◽  
Vol 45 (3) ◽  
pp. 281-284 ◽  
Author(s):  
R. N. TERRELL ◽  
A. B. CHILDERS ◽  
T. J. KAYFUS ◽  
C. G. MING ◽  
G. C. SMITH ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Potassium Chloride ◽  
Calcium Chloride ◽  
Sodium Nitrite ◽  
Magnesium Chloride ◽  
Plate Count ◽  
Pork Sausage ◽  
Ground Pork ◽  
Plate Counts ◽  
Chloride Salts

Two experiments were conducted using trichinae-infected pork shoulders. In the first experiment, samples of ground pork shoulder were allocated to the following treatments: (a) sodium nitrite levels of 0, 75 or 150 ppm, and (b) chloride salt levels of 2.5% sodium chloride, 3.18% potassium chloride, 1.35% magnesium chloride and 1.58% calcium chloride (for the latter three chloride salts, ionic strengths equivalent to that of 2.5% sodium chloride were used). In the second experiment, samples of ground pork shoulder were allocated to treatments in which 0, 25, 50, 75 or 100% of the sodium chloride was replaced with a 70:30 mixture of magnesium chloride: potassium chloride. Pork sausage links were made and stored for 12 d in a refrigerated display case. All chloride salts numerically reduced total plate counts compared to controls (no added salts) and calcium chloride or magnesium chloride significantly reduced total plate counts (P<.05). However, addition of sodium nitrite (75 or 150 ppm) did not affect total plate counts. Percentages of dead trichina larvae (visually determined) were greater (P<.05) for potassium chloride and sodium chloride than for magnesium or calcium chloride. However, in the second study when salts of equivalent ionic strengths were not used, replacement of sodium chloride with a 70:30 mixture of magnesium chloride: potassium chloride did not affect (increase or decrease) pH, total plate count or juice-loss during cooking. Percentages of dead trichina larvae increased for the 75 and 100% replacement levels when compared to controls.

scholarly journals Characterisation of classical enterotoxins, virulence activity, and antibiotic susceptibility of Staphylococcus aureus isolated from Thai fermented pork sausages, clinical samples, and healthy carriers in northeastern Thailand

2020 ◽  
Vol 64 (2) ◽  
pp. 289-297
Author(s):  
Wanwisa Sankomkai ◽  
Wongwarut Boonyanugomol ◽  
Kairin Kraisriwattana ◽  
Julalak Nutchanon ◽  
Kraisorn Boonsam ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
Extracellular Enzymes ◽  
Clinical Samples ◽  
Pork Sausage ◽  
Hospitalised Patients ◽  
Pork Sausages ◽  
Healthy Carriers ◽  
Northeastern Thailand

AbstractIntroductionContamination by Staphylococcus aureus of food produced from animal sources may have diverse and multifactorial causes that depend on geographical distribution. The goal of this study was to isolate and characterise S. aureus strains from contaminated fermented pork sausage, which is a local food of northeastern Thailand.Material and MethodsS. aureus strains were isolated from local pork sausage, and the presence of classical enterotoxins was determined by PCR and reversed passive latex agglutination. These results were compared with strains derived from hospitalised patients and healthy carriers. Additionally, production of extracellular enzymes and haemolysin, biofilm formation, and antibiotic susceptibility were assessed.ResultsS. aureus was identified in 36 sausage isolates (60%). The strains positive for staphylococcal enterotoxin A were more frequently found in isolates from sausage and healthy carriers than in those from patients. All tested S. aureus strains were positive for DNase, lipase, proteinase, haemolysin, and biofilm formation; notably, strains isolated from food and healthy carriers displayed similar values. Most isolates were resistant to penicillin and ampicillin, while none were to methicillin.ConclusionsThai fermented pork sausages are associated with a high risk of staphylococcal food poisoning, which may be linked to contamination caused by carriers. Dissemination of knowledge regarding best practices in sanitation and hygiene is important in local communities.

Effect of Storage Temperature on the Outgrowth and Toxin Production of Staphylococcus aureus in Freeze-Thawed Precooked Tuna Meat

2016 ◽  
Vol 79 (4) ◽  
pp. 620-627 ◽  
Author(s):  
AI KATAOKA ◽  
ELENA ENACHE ◽  
CARLA NAPIER ◽  
MELINDA HAYMAN ◽  
LISA WEDDIG
Keyword(s):  
Staphylococcus Aureus ◽  
Storage Temperature ◽  
Salt Content ◽  
Frozen Storage ◽  
Toxin Production ◽  
Sensory Profile ◽  
Katsuwonus Pelamis ◽  
Enterotoxin Production ◽  
Sample Composition ◽  
Plate Counts

ABSTRACT The aim of this study was to determine the time for a 3-log CFU/g outgrowth of Staphylococcus aureus and its toxin production in previously frozen precooked tuna meat (albacore [Thunnus alalunga] prepared as loin, chunk, and flake or skipjack [Katsuwonus pelamis] prepared as chunk and flake) held either at 21 or 27°C. A five-strain cocktail of enterotoxin-producing S. aureus was surface inoculated with ~103 CFU/g onto tuna samples. The experimental time–temperature conditions were designed to mimic common industry holding conditions. After a 3-h incubation at 37°C, inoculated samples were individually vacuum sealed and stored at −20°C for 4 weeks. Following frozen storage, samples were thawed to the target temperature (21 or 27°C) and then incubated aerobically. Growth of S. aureus in tuna was then monitored using Baird Parker agar; simultaneously, aerobic plate counts, enterotoxin production, and sensory profile (color and odor) were determined. The results showed that the time for a 3-log CFU/g increase was >20 h at 21°C and 8 to 12 h at 27°C for albacore, with toxin production observed at 14 to 16 h at 21°C and at 8 h at 27°C. A 3-log CFU/g increase for skipjack occurred at 22 to 24 h at 21°C and at 10 to 14 h at 27°C. The toxin production in skipjack started at 20 to 22 h at 21°C and at 8 to 10 h at 27°C. Toxin production was observed before a 3-log increase was achieved in albacore samples at 21°C. Under all conditions, toxins were detected when the cell density of S. aureus was 6 log CFU/g. Overall, significantly faster S. aureus growth was observed in albacore compared with skipjack (P < 0.05), possibly owing to differences in sample composition (e.g., pH and salt content). The data developed from this study can be used by the tuna industry to model the growth and enterotoxin production of S. aureus and to design manufacturing controls that ensure food safety.

Microbiological Quality of Fresh Blue Crabmeat, Clams and Oysters

1983 ◽  
Vol 46 (11) ◽  
pp. 978-981 ◽  
Author(s):  
B. A. WENTZ ◽  
A. P. DURAN ◽  
A. SWARTZENTRUBER ◽  
A. H. SCHWAB ◽  
R. B. READ
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Microbiological Quality ◽  
Fecal Coliforms ◽  
Geometric Means ◽  
Colony Forming Units ◽  
Plate Counts ◽  
The Mean ◽  
Eastern Oysters

The microbiological quality of fresh blue crabmeat, soft- and hardshell clams and shucked Eastern oysters was determined at the retail (crabmeat, oysters) and wholesale (clams) levels. Geometric means of aerobic plate counts incubated at 35°C were: blue crabmeat 140,000 colony-forming units (CFU)/g, hardshell clams, 950 CFU/g, softshell clams 680 CFU/g and shucked Eastern oysters 390,000 CFU/g. Coliform geometric means ranged from 3,6/100 g for hardshell clams to 21/g for blue crabmeat. Means for fecal coliforms or Escherichia coli ranged from <3/100 g for clams to 27/100 g for oysters, The mean Staphylococcus aureus count in blue crabmeat was 10/g.

Effect of tea tree oil on Staphylococcus aureus growth and enterotoxin production

Food Control ◽  
2016 ◽  
Vol 62 ◽  
pp. 257-263 ◽  
Author(s):  
Ce Shi ◽  
Xingchen Zhao ◽  
Haiyang Yan ◽  
Rizeng Meng ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Tea Tree Oil ◽  
Tea Tree ◽  
Enterotoxin Production

scholarly journals Effects of Different Dietary Levels of Whey Lactose as a Prebiotic Disaccharide on the Productive Performances and Selected Indices of the Caecal Micro-Environment in Broiler Chickens

2017 ◽  
Vol 17 (4) ◽  
pp. 1107-1122 ◽  
Author(s):  
Mohamed Nabil Alloui ◽  
Witold Szczurek
Keyword(s):  
Broiler Chickens ◽  
Volatile Fatty Acids ◽  
Body Weight Gain ◽  
Control Diet ◽  
Coliform Bacteria ◽  
Control Group ◽  
Breast Meat ◽  
Plate Counts ◽  
Acid Producing Bacteria ◽  
The Impact

AbstractThe primary aim of this study was to investigate the impact of three dietary levels of lactose (LAC) originating from conventional dried whey (DW) and the duration of these treatments (from 8 to 21 or to 42 days of age) on growth performance, basic post-slaughter traits and excreta quality of broiler chickens kept in cages. A secondary purpose was to investigate the effect of LAC level on some parameters of the caecal micro-environment and gross morphology in these birds. A total of 560 Ross 308 chickens (sex ratio 1:1) were assigned to 7 dietary combinations with 10 replicate cages of 8 birds per cage. The control group was fed basal diets consisting of maize, wheat and soybean meal. The other 6 groups received the same basal diets with DW added in amounts equivalent to a LAC dietary levels of 1, 2 or 3%. Only continuous feeding (day 8 to 42) with 1% and 2% levels of LAC was found to yield the overall body weight gain (BWG) during the whole 42-day rearing period, which was significantly higher than that on the control diet, with a larger share of breast meat in carcass at a 2% LAC. However, these effects were associated with greater faecal score values indicating more watery excreta compared with the control. Increasing levels of LAC augmented the relative caecal weight and length. A reduction in the caecal pH was confirmed at day 21 for birds fed 1% and 2% of dietary LAC. The lower pH values were correlated to an increased sum of total volatile fatty acids (VFA), causing large increases in the concentration of undissociated forms of individual VFA. The decline in plate counts of coliform bacteria was observed with 2% and 3% LAC, whereas the counts of lactic acid-producing bacteria (LAB) were higher at these two LAC levels. The present findings lead to the conclusion that the dietary level of 2% LAC originated from DW is the most effective in enhancing the productivity of broilers, with moderate occurrence of undesirable side effects.

Comparison of the Petrifilm™ Yeast and Mold Culture Film Method to Conventional Methods for Enumerating Yeasts and Molds in Foods

1991 ◽  
Vol 54 (6) ◽  
pp. 443-447 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
R.E. BRACKETT ◽  
T. L. FOX
Keyword(s):  
Correlation Coefficients ◽  
Food Group ◽  
Black Pepper ◽  
Plate Count ◽  
Food Groups ◽  
Plate Count Agar ◽  
Plate Counts ◽  
Yeasts And Molds ◽  
Potential Food ◽  
Film Method

Petrifilm™ Yeast and Mold (YM) plates were compared to acidified potato dextrose agar (APDA) and chloramphenicol-supplemented plate count agar (CPCA) for its suitability to enumerate yeasts and molds in 13 groups of food products. These products consisted of beans (dry and frozen, green), corn meal, flour (wheat), fruit (apple), a meat/vegetable entree (chicken pot pie), a precooked meat (beef), milk (dehydrated, nonfat), nuts (pecans), pasta, potatoes (dehydrated), precooked sausage, and a spice (black pepper). Correlation coefficients of Petrifilm™ YM plates versus APDA and CPCA pour plates for recovering total yeasts and molds from a composite of the thirteen test foods were, respectively, 0.961 and 0.974. Individually, Petrifilm™ YM plate counts were equivalent or higher than APDA and CPCA for some food groups and lower for other food groups. Because food particle interference can make enumeration of yeast and mold colonies on Petrifilm™ YM plates difficult for some food groups, potential food interference will need to be evaluated for each food group tested.

Sign in / Sign up

Export Citation Format

Share Document