Hygienic Shortcomings of Frozen Dessert Freezing Equipment and Fate of Listeria monocytogenes on Ice Cream–Soiled Stainless Steel

2017 ◽  
Vol 80 (11) ◽  
pp. 1897-1902
Author(s):  
A. Inuwa ◽  
A. Lunt ◽  
C. Czuprynski ◽  
G. Miller ◽  
S. A. Rankin
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Contact Time ◽  
Pathogenic Bacteria ◽  
Steel Surface ◽  
Ice Cream ◽  
Small Scale ◽  
Stainless Steel Surface ◽  
Frozen Dessert ◽  
Complementary Study

ABSTRACT Although frozen dairy desserts have a strong record of safety, recent outbreaks of foodborne disease linked to ice creams have brought new attention to this industry. There is concern that small-scale frozen dessert equipment may not comply with or be reviewed against published comprehensive design and construction sanitation specifications (National Sanitation Foundation or 3-A sanitary standards). Equipment sanitary design issues may result in reduced efficacy of cleaning and sanitation, thus increasing the likelihood of postprocess contamination with pathogenic bacteria. In this context, and given that Listeria monocytogenes outbreaks are of great concern for the frozen dessert industry, a complementary study was conducted to evaluate the fate of L. monocytogenes in ice cream mix on a stainless steel surface. Our results showed that L. monocytogenes survived for up to 6 weeks at room temperature and 9 weeks at 4°C in contaminated ice cream on a stainless steel surface. Furthermore, chlorine- and acid-based surface sanitizers had no detrimental effect on the L. monocytogenes when used at a concentration and contact time (1 min) recommended by the manufacturer; significant reduction in CFU required 5 to 20 min of contact time.

Effects of Inoculation Level, Material Hydration, and Stainless Steel Surface Roughness on the Transfer of Listeria monocytogenes from Inoculated Bologna to Stainless Steel and High-Density Polyethylene

2007 ◽  
Vol 70 (6) ◽  
pp. 1423-1428 ◽  
Author(s):  
ANDRÉS RODRÍGUEZ ◽  
WESLEY R. AUTIO ◽  
LYNNE A. McLANDSBOROUGH
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
High Density Polyethylene ◽  
Steel Surface ◽  
Testing Machine ◽  
High Density ◽  
Stainless Steel Surface ◽  
Material Type ◽  
The Absolute

The influence of inoculation level, material hydration, and stainless steel surface roughness on the transfer of Listeria monocytogenes from inoculated bologna to processing surfaces (stainless steel and polyethylene) was assessed. Slices of bologna (14 g) were inoculated with Listeria at different levels, from 105 to 109 CFU/cm2. Transfer experiments were done at a constant contact time (30 s) and pressure (45 kPa) with a universal testing machine. After transfer, cells that had been transferred to sterile stainless steel and polyethylene were removed and counted, and the efficiency of transfer (EOT) was calculated. As the inoculation level increased from 105 to 109 CFU/cm2, the absolute level of transfer increased in a similar fashion. By calculating EOTs, the data were normalized, and the initial inoculation level had no effect on the transfer (P > 0.05). The influence of hydration level on stainless steel, high-density polyethylene, and material type was investigated, and the EOTs ranged from 0.1 to 1 under all the conditions tested. Our results show that transfers to wetted processing surfaces (mean EOT = 0.43) were no different from dried processing surfaces (mean EOT = 0.35) (P > 0.05). Material type was shown to be a significant factor, with greater numbers of Listeria transferring from bologna to stainless steel (mean EOT = 0.49) than from bologna to polyethylene (mean EOT = 0.28) (P < 0.01). Stainless steel with three different surface roughness (Ra) values of <0.8 μm (target Ra = 0.25, 0.50, and 0.75 μm) and two different finishes (mechanically polished versus mechanically polished and further electropolished) was used to evaluate its effect on the transfer. The surface roughness and finish on the stainless steel did not have any effect on the transfer of Listeria (P > 0.05). Our results showed that when evaluating the transfer of Listeria, the use of EOTs rather than the absolute transfer values is essential to allow comparisons of transfer conditions or comparisons between research groups.

scholarly journals Disinfectant action of Cymbopogon sp. essential oils in different phases of biofilm formation by Listeria monocytogenes on stainless steel surface

Food Control ◽  
2010 ◽  
Vol 21 (4) ◽  
pp. 549-553 ◽  
Author(s):  
Maíra Maciel Mattos de Oliveira ◽  
Danilo Florisvaldo Brugnera ◽  
Maria das Graças Cardoso ◽  
Eduardo Alves ◽  
Roberta Hilsdorf Piccoli
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Essential Oils ◽  
Biofilm Formation ◽  
Steel Surface ◽  
Stainless Steel Surface

Atlas® Listeria monocytogenes LmG2 Detection Assay Using Transcription Mediated Amplification to Detect Listeria monocytogenes in Selected Foods and Stainless Steel Surface

2014 ◽  
Vol 97 (5) ◽  
pp. 1343-1358 ◽  
Author(s):  
Vanessa Bres ◽  
Hua Yang ◽  
Ernie Hsu ◽  
Yan Ren ◽  
Ying Cheng ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Ice Cream ◽  
Food Samples ◽  
Steel Grade ◽  
Stainless Steel Surface ◽  
Dilution Ratio ◽  
Reference Methods ◽  
Detection Assay ◽  
The U.S

Abstract The Atlas Listeria monocytogenes LmG2 Detection Assay, developed by Roka Bioscience Inc., was compared to a reference culture method for seven food types (hot dogs, cured ham, deli turkey, chicken salad, vanilla ice cream, frozen chocolate cream pie, and frozen cheese pizza) and one surface (stainless steel, grade 316). A 125 g portion of deli turkey was tested using a 1:4 food:media dilution ratio, and a 25 g portion for all other foods was tested using 1:9 food:media dilution ratio. The enrichment time and media for Roka's method was 24 to 28 h for 25 g food samples and environmental surfaces, and 44 to 48 h for 125 g at 35 ± 2°C in PALCAM broth containing 0.02 g/L nalidixic acid. Comparison of the Atlas Listeria monocytogenes LmG2 Detection Assay to the reference method required an unpaired approach. For each matrix, 20 samples inoculated at a fractional level and five samples inoculated at a high level with a different strain of Listeria monocytogenes were tested by each method. The Atlas Listeria monocytogenes LmG2 Detection Assay was compared to the Official Methods of Analysis of AOAC INTERNATIONAL 993.12 method for dairy products, the U.S. Department of Agriculture, Food Safety and Inspection Service, Microbiology Laboratory Guidebook 8.08 method for ready-to-eat meat and environmental samples, and the U.S. Food and Drug Administration Bacteriological Analytical Manual, Chapter 10 method for frozen foods. In the method developer studies, Roka's method, at 24 h (or 44 h for 125 g food samples), had 126 positives out of 200 total inoculated samples, compared to 102 positives for the reference methods at 48 h. In the independent laboratory studies, vanilla ice cream, deli turkey and stainless steel grade 316 were evaluated. Roka's method, at 24 h (or 44 h for 125 g food samples), had 64 positives out of 75 total inoculated samples compared to 54 positives for the reference methods at 48 h. The Atlas Listeria monocytogenes LmG2 Detection Assay detected all 50 L. monocytogenes strains that encompassed 13 serotypes across the various lineages and none of the 30 exclusive organisms, including seven other Listeria species. The product consistency and kit stability studies revealed no statistical differences between the three lots tested or to the term of the shelf life. Finally, the robustness study demonstrated no statistical differences when samples were incubated at 33 ± 2°C or 37 ± 2°C, when enrichment aliquots were 1.3 mL or 1.7 mL, or when the samples were analyzed the same day or five days later. Overall the Atlas Listeria monocytogenes LmG2 Detection Assay is statistically equivalent to or better than the reference methods and is robust to the tested variations.

Growth and Biofilm Formation by Listeria monocytogenes in Catfish Mucus Extract on Four Food Contact Surfaces at 22 and 10°C and Their Reduction by Commercial Disinfectants

2017 ◽  
Vol 81 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Nitin Dhowlaghar ◽  
Piumi De Abrew Abeysundara ◽  
Ramakrishna Nannapaneni ◽  
Mark W. Schilling ◽  
Sam Chang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Biofilm Formation ◽  
Steel Surface ◽  
Stainless Steel Surface ◽  
Food Contact Surfaces ◽  
Contact Surfaces ◽  
Ammonium Compounds

ABSTRACTThe objective of this study was to determine the effect of strain and temperature on growth and biofilm formation by Listeria monocytogenes in high and low concentrations of catfish mucus extract on various food contact surfaces at 10 and 22°C. The second objective of this study was to evaluate the efficacy of disinfectants at recommended concentrations and contact times for removing L. monocytogenes biofilm cells from a stainless steel surface covered with catfish mucus extract. Growth and biofilm formation of all L. monocytogenes strains increased with higher concentrations of catfish mucus extract at both 10 and 22°C. When 15 μg/mL catfish mucus extract was added to 3 log CFU/mL L. monocytogenes, the biofilm levels of L. monocytogenes on stainless steel reached 4 to 5 log CFU per coupon at 10°C and 5 to 6 log CFU per coupon at 22°C in 7 days. With 375 μg/mL catfish mucus extract, the biofilm levels of L. monocytogenes on stainless steel reached 5 to 6 log CFU per coupon at 10°C and 6 to 7.5 log CFU per coupon at 22°C in 7 days. No differences (P > 0.05) were observed between L. monocytogenes strains tested for biofilm formation in catfish mucus extract on the stainless steel surface. The biofilm formation by L. monocytogenes catfish isolate HCC23 was lower on Buna-N rubber than on stainless steel, polyethylene, and polyurethane surfaces in the presence of catfish mucus extract (P < 0.05). Contact angle analysis and atomic force microscopy confirmed that Buna-N rubber was highly hydrophobic, with lower surface energy and less roughness than the other three surfaces. The complete reduction of L. monocytogenes biofilm cells was achieved on the stainless steel coupons with a mixture of disinfectants, such as quaternary ammonium compounds with hydrogen peroxide or peracetic acid with hydrogen peroxide and octanoic acid at 25 or 50% of the recommended concentration, in 1 or 3 min compared with use of the quaternary ammonium compounds, chlorine, or acid disinfectants alone, which were ineffective for removing all the L. monocytogenes biofilm cells.

scholarly journals Lactobacillus sakei 1 and its bacteriocin influence adhesion of Listeria monocytogenes on stainless steel surface

Food Control ◽  
2011 ◽  
Vol 22 (8) ◽  
pp. 1404-1407 ◽  
Author(s):  
Lizziane K. Winkelströter ◽  
Bruna C. Gomes ◽  
Marta R.S. Thomaz ◽  
Vanessa M. Souza ◽  
Elaine C.P. De Martinis
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Steel Surface ◽  
Stainless Steel Surface ◽  
Lactobacillus Sakei

scholarly journals Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential

2010 ◽  
Vol 41 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Maíra Maciel Mattos de Oliveira ◽  
Danilo Florisvaldo Brugnera ◽  
Eduardo Alves ◽  
Roberta Hilsdorf Piccoli
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Steel Surface ◽  
Stainless Steel Surface

Efficacy of aerosolized hydrogen peroxide-based sanitizer on the reduction of pathogenic bacteria on a stainless steel surface

Food Control ◽  
2012 ◽  
Vol 27 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Na-Young Choi ◽  
Seung-Youb Baek ◽  
Jae-Hyun Yoon ◽  
Mi-Ran Choi ◽  
Dong-Hyun Kang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Stainless Steel ◽  
Pathogenic Bacteria ◽  
Steel Surface ◽  
Stainless Steel Surface

Persistent Listeria monocytogenes Strains Show Enhanced Adherence to Food Contact Surface after Short Contact Times

2000 ◽  
Vol 63 (9) ◽  
pp. 1204-1207 ◽  
Author(s):  
JANNE M. LUNDÉN ◽  
MARIA K. MIETTINEN ◽  
TIINA J. AUTIO ◽  
HANNU J. KORKEALA
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Contact Surface ◽  
Food Processing ◽  
Contact Time ◽  
Ice Cream ◽  
Short Contact ◽  
Steel Surfaces ◽  
Food Contact Surface ◽  
Epifluorescence Microscope

Adherence of 3 persistent and 14 nonpersistent Listeria monocytogenes strains to stainless steel surfaces after short and long contact times was investigated. L. monocytogenes strains were obtained from poultry plants and an ice cream plant throughout several years. Adherence tests were performed in tryptic soy broth at 25°C for 1, 2, and 72 h. Test surfaces were rinsed after the contact time, and attached cells were stained with acridine orange and enumerated with an epifluorescence microscope. The persistent poultry plant strains showed adherence 2- to 11-fold higher than the nonpersistent strains following 1- and 2-h contact times. The adherence of the persistent ice cream plant strain after 1- and 2-h contact times was higher than most of the nonpersistent strains. Seven of 12 nonpersistent ice cream strains showed an adherence of less than half that of the persistent strain. After 72 h, the differences in adherence were not as marked, since half the nonpersistent strains had reached adherence levels comparable with the persistent strains. In fact, three nonpersistent strains showed even higher adherence than the persistent strains. Thus, results of this study reveal that persistent L. monocytogenes strains show enhanced adherence at short contact times, promoting their survival in food processing facilities and possibly having an effect on initiation of persistent plant contamination.

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