Growth of Salmonella enterica and Staphylococcus aureus in No-Knead Bread Dough during Prolonged Yeast Fermentation†

2011 ◽  
Vol 74 (2) ◽  
pp. 285-288
Author(s):  
STEVEN PAO ◽  
CHYER KIM ◽  
LARRY JORDAN ◽  
WILBERT LONG ◽  
PAULA INSERRA ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Foodborne Pathogens ◽  
Salmonella Enterica ◽  
Weight Ratio ◽  
Yeast Fermentation ◽  
Bread Making ◽  
Substantial Growth ◽  
Water Salt ◽  
Slow Rise ◽  
And Staphylococcus Aureus

A convenient bread making method involving prolonged fermentation of no-knead (nonkneaded) dough has become popular in recent years. In the present study, the microbial safety of no-knead dough made with a 375:325:5:1 weight ratio of flour, water, salt, and bread yeast was investigated. Three brands of dehydrated yeast were used for this study. The growth of inoculated Salmonella enterica and Staphylococcus aureus in no-knead dough during fermentation was significant (P < 0.05), regardless of yeast brand. The multiplication rates of S. enterica in the initial 12 h and S. aureus over the entire 24 h of fermentation were positively correlated with fermentation temperatures of 21 to 38°C (P < 0.005; r ≥ 0.996). Mean counts of S. enterica increased by 0.5, 1.5, 1.9, and 2.4 log CFU/g, respectively, after 6, 12, 18, and 24 h of fermentation at 21°C. The level of S. aureus increased by 0.4, 1.1, 1.7, and 2.2 CFU/g, respectively, after 18 h of fermentation at 21, 27, 32, and 38°C. Because prolonged fermentation permits substantial growth of infectious and/or toxin-producing foodborne pathogens, the making of slow-rise, no-knead bread may compromise consumer kitchen sanitation and food safety.

Inactivation of Salmonella enterica serovar Typhimurium and Staphylococcus aureus in rice by radio-frequency heating

2021 ◽  
Author(s):  
Ki-Ok Jeong ◽  
Sang-Soon Kim ◽  
Sang-Hyun Park ◽  
Dong-Hyun Kang
Keyword(s):  
Staphylococcus Aureus ◽  
Radio Frequency ◽  
Heating Rate ◽  
Foodborne Pathogens ◽  
Color Change ◽  
Oryza Sativa L ◽  
Rf Heating ◽  
Pathogen Inactivation ◽  
Treatment Conditions ◽  
And Staphylococcus Aureus

The objectives of this study were to determine the effect of the milling degree (MD) of Oryza sativa L. (Korean rice) on the heating rate, pathogen inactivation (Salmonella Typhimurium and Staphylococcus aureus), and color change resulting from radio-frequency (RF) heating. Rice samples inoculated with pathogens were placed in a polypropylene jar and subjected to RF heating for 0-75 s. The heating rate of rice with a 2% MD was the highest during RF heating, followed by those with a 0, 8, and 10% MD, and the reduction of pathogens showed the same trend. The reduction of the levels of pathogens in rice with a MD 0 and 2% was significantly higher than that observed for rice with a MD of 8 and 10% under the same treatment conditions. For example, log reductions of S. Typhimurium in rice by 55 s RF heating were 3.64, 5.19, 2.18, and 1.80 for milling degree of 0, 2, 8, and 10%, respectively. At the same treatment conditions, log reduction of S. aureus were 2.77, 5.08, 1.15, and 0.90 for milling degree of 0, 2, 8, and 10%, respectively. The color of rice measured according to L*, a*, and b* was not significantly altered after RF heating, regardless of the MD. Therefore, the MD of rice should be considered before RF heating is applied to inactivate foodborne pathogens.

Growth Inhibitory Effects of Kimchi (Korean Traditional Fermented Vegetable Product) against Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus

2008 ◽  
Vol 71 (2) ◽  
pp. 325-332 ◽  
Author(s):  
YONG-SUK KIM ◽  
ZIAN-BIN ZHENG ◽  
DONG-HWA SHIN
Keyword(s):  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Control Group ◽  
Growth Inhibitory ◽  
Side Dish ◽  
Pepper Powder ◽  
And Staphylococcus Aureus ◽  
Vegetable Product

Kimchi is a unique Korean traditional vegetable product that is fermented by lactic acid bacteria (LAB) and is mainly consumed as a side dish with boiled rice. Its main ingredients are brined Chinese cabbage, red pepper powder, and fermented fish sauce, and these are combined with many spices such as garlic, green onion, ginger, and some seaweed. The relationship between the concentration of LAB or the pH and the growth of three gram-positive foodborne pathogens (Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus) was evaluated. Heat treatment (HT; 85°C for 15 min) or neutralization treatment (NT; pH 7.0) was conducted on day 0 (0-D group) and day 3 (3-D group) of incubation. The pH in the control group and the NT group dropped sharply to 4.12 to 4.30 after 2 days of incubation and slightly decreased thereafter, whereas the pH in the control group and HT group stayed at 7.0 during incubation. LAB were not detected in the HT kimchi during incubation. B. cereus in the NT-0-D, NT-3-D, and HT-3-D groups was reduced by 1.5 to 3.1 log CFU/ml but increased slightly in the HT-0-D group. L. monocytogenes in HT-3-D and NT-3-D groups disappeared after 5 days of incubation, and S. aureus in the NT-0-D group disappeared after 4 days. These findings indicate that growth of all the foodborne pathogens was inhibited by NT-0-D, HT-3-D, and NT-3-D, but B. cereus was not inhibited by HT-0-D. Thus, growth of LAB in kimchi is an important factor in the control of foodborne pathogens.

Bacteriocin Production by Lactic Acid Bacteria Isolated from Regional Cheeses: Inhibition of Foodborne Pathogens

1994 ◽  
Vol 57 (11) ◽  
pp. 1013-1015 ◽  
Author(s):  
MARIA E. FARIAS ◽  
AIDA A. P. DE RUIZ HOLGADO ◽  
FERNANDO SESMA
Keyword(s):  
Heat Treatment ◽  
Staphylococcus Aureus ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Foodborne Pathogens ◽  
Bacteriocin Production ◽  
Antimicrobial Compounds ◽  
Heat Stable ◽  
And Storage ◽  
And Staphylococcus Aureus

Four strains of enterococci isolated from Argentina regional cheeses were found to produce bacteriocins that were active against several lactic acid bacteria. Among them, enterocin CRL35 produced by Enterococcus faecium CRL35 was also inhibitory to foodborne pathogens like Listeria monocytogenes and Staphylococcus aureus. These antimicrobial compounds were sensitive to proteases and heat stable; inhibitory activity of enterocin CRL35 showed also to be stable at extreme pHs, heat treatment, and storage in different conditions.

Removal of pathogenic bacterial biofilms by combinations of oxidizing compounds

2015 ◽  
Vol 61 (5) ◽  
pp. 351-356 ◽  
Author(s):  
Gabriela María Olmedo ◽  
Mariana Grillo-Puertas ◽  
Luciana Cerioni ◽  
Viviana Andrea Rapisarda ◽  
Sabrina Inés Volentini
Keyword(s):  
Staphylococcus Aureus ◽  
Salmonella Enterica ◽  
Klebsiella Oxytoca ◽  
Fold Increase ◽  
Clinical Isolates ◽  
Bacterial Biofilms ◽  
Simultaneous Application ◽  
E Coli ◽  
Serovar Typhimurium ◽  
And Staphylococcus Aureus

Bacterial biofilms are commonly formed on medical devices and food processing surfaces. The antimicrobials used have limited efficacy against the biofilms; therefore, new strategies to prevent and remove these structures are needed. Here, the effectiveness of brief oxidative treatments, based on the combination of sodium hypochlorite (NaClO) and hydrogen peroxide (H2O2) in the presence of copper sulfate (CuSO4),were evaluated against bacterial laboratory strains and clinical isolates, both in planktonic and biofilm states. Simultaneous application of oxidants synergistically inactivated planktonic cells and prevented biofilm formation of laboratory Escherichia coli, Salmonella enterica serovar Typhimurium, Klebsiella pneumoniae, and Staphylococcus aureus strains, as well as clinical isolates of Salmonella enterica subsp. enterica, Klebsiella oxytoca, and uropathogenic E. coli. In addition, preformed biofilms of E. coli C, Salmonella Typhimurium, K. pneumoniae, and Salmonella enterica exposed to treatments were removed by applying 12 mg/L NaClO, 0.1 mmol/L CuSO4, and 350 mmol/L H2O2for 5 min. Klebsiella oxytoca and Staphylococcus aureus required a 5-fold increase in NaClO concentration, and the E. coli clinical isolate remained unremovable unless treatments were applied on biofilms formed within 24 h instead of 48 h. The application of treatments that last a few minutes using oxidizing compounds at low concentrations represents an interesting disinfection strategy against pathogens associated with medical and industrial settings.

scholarly journals Synthesis, characterization and antimicrobial activity of novel benzofuran- and thiophene-containing diketoxime derivatives

2017 ◽  
Vol 82 (4) ◽  
pp. 367-377 ◽  
Author(s):  
Demet Coskun ◽  
Seher Gur ◽  
Mehmet Coskun
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Salmonella Enterica ◽  
Good Activity ◽  
E Coli ◽  
Minimum Inhibitory Concentrations ◽  
Serovar Typhimurium ◽  
And Staphylococcus Aureus

The aim of this study was the preparation of 1,1?-(2,5-thiophenediyl) bis[1-(2-benzofuranyl)methanone] (2), the corresponding diketoxime (3), and the ether and ester derivatives (4a?e) of the diketoxime. These compounds were prepared in good yields. Minimum inhibitory concentrations (MIC) of the synthesized compounds 1?4 were determined against Salmonella enterica subsp. enterica serovar Typhimurium, Escherichia coli and Staphylococcus aureus. Among the synthesized compounds, 1 and 4e showed good activity against E. coli, S. enterica and S. aureus.

Inhibitory Effects of Combinations of Chemicals on Escherichia coli, Bacillus cereus, and Staphylococcus aureus Biofilms during the Clean-in-Place Process at an Experimental Dairy Plant

2020 ◽  
Vol 83 (8) ◽  
pp. 1302-1306
Author(s):  
EUN-SEON LEE ◽  
JONG-HUI KIM ◽  
MI-HWA OH
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Citric Acid ◽  
Bacillus Cereus ◽  
Foodborne Pathogens ◽  
Combined Treatment ◽  
Food Additives ◽  
Inhibitory Effects ◽  
E Coli ◽  
And Staphylococcus Aureus

ABSTRACT In dairy plants, clean-in-place (CIP) equipment cannot be disassembled, making it difficult to clean the inner surface of pipes. In this study, the inhibitory effects of chemical agents on biofilms formed by three foodborne pathogens, Bacillus cereus, Escherichia coli, and Staphylococcus aureus, was evaluated in a dairy CIP system. The experiment was conducted on a laboratory scale. Each of the three bacteria (200 μL) was inoculated onto stainless steel (SS) chips (25 by 25 mm), and the effect of single cleaning agents was evaluated. Individual treatments with NaClO (30, 50, 100, and 200 ppm), NaOH (0.005, 0.01, 0.05, and 0.1%), citric acid (1, 3, 5, and 7%), and nisin (5, 10, 25, 50, 100, and 200 ppm) were used to clean the SS chip for 10 min. The most effective concentration of each solution was selected for further testing in a commercial plant. Simultaneous cleaning with 200 ppm of NaClO (10 min) and 7% citric acid (10 min) reduced the biofilms of B. cereus, E. coli, and S. aureus by 6.9, 7.0, and 8.0 log CFU/cm2, respectively. Both 7% citric acid and 0.1% NaOH were optimal treatments for E. coli. NaClO and citric acid are approved for use as food additives in the Republic of Korea. Our results revealed that a combined treatment with NaClO and citric acid is the most effective approach for reducing biofilms formed by common foodborne pathogens on CIP equipment. These findings can contribute to the production of safe dairy products. HIGHLIGHTS

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