Destruction of Alicyclobacillus acidoterrestris Spores in Apple Juice on Stainless Steel Surfaces by Chemical Disinfectants

2009 ◽  
Vol 72 (3) ◽  
pp. 510-514 ◽  
Author(s):  
RICHARD PODOLAK ◽  
PHILIP H. ELLIOTT ◽  
BRADLEY J. TAYLOR ◽  
AAKASH KHURANA ◽  
DARRYL G. BLACK
Keyword(s):  
Stainless Steel ◽  
Chlorine Dioxide ◽  
Apple Juice ◽  
Octanoic Acid ◽  
Stainless Steel Surface ◽  
Peroxyacetic Acid ◽  
Alicyclobacillus Acidoterrestris ◽  
Practical Applications ◽  
Maximum Reduction ◽  
Steel Surfaces

A study was conducted to determine the effects of three commercially available disinfectants on the reduction of Alicyclobacillus acidoterrestris spores in single-strength apple juice applied to stainless steel surfaces. Apple juice was inoculated with A. acidoterrestris spores, spread onto the surface of stainless steel chips (SSC), dried to obtain spore concentrations of approximately 104 CFU/cm2, and treated with disinfectants at temperatures ranging from 40 to 90°C. The concentrations of disinfectants were 200, 500, 1,000, and 2,000 ppm of total chlorine for Clorox (CL) (sodium hypochlorite); 50, 100, and 200 ppm of total chlorine for Carnebon 200 (stabilized chlorine dioxide); and 1,500, 2,000, and 2,600 ppm for Vortexx (VOR) (hydrogen peroxide, peroxyacetic acid, and octanoic acid). For all temperatures tested, VOR at 2,600 ppm (90°C) and CL at 2,000 ppm (90°C) were the most inhibitory against A. acidoterrestris spores, resulting in 2.55- and 2.32-log CFU/cm2 reductions, respectively, after 2 min. All disinfectants and conditions tested resulted in the inactivation of A. acidoterrestris spores, with a maximum reduction of >2 log CFU/cm2. Results from this study indicate that A. acidoterrestris spores, in single-strength apple juice, may be effectively reduced on stainless steel surface by VOR and CL, which may have practical applications in the juice industry.

Biofilm Formation and Sporulation by Bacillus cereus on a Stainless Steel Surface and Subsequent Resistance of Vegetative Cells and Spores to Chlorine, Chlorine Dioxide, and a Peroxyacetic Acid–Based Sanitizer

2005 ◽  
Vol 68 (12) ◽  
pp. 2614-2622 ◽  
Author(s):  
JEE-HOON RYU ◽  
LARRY R. BEUCHAT
Keyword(s):  
Stainless Steel ◽  
Relative Humidity ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Biofilm Formation ◽  
Total Cell ◽  
Stainless Steel Surface ◽  
Peroxyacetic Acid ◽  
Vegetative Cells ◽  
Cell Counts

Biofilm formation by Bacillus cereus 038-2 on stainless steel coupons, sporulation in the biofilm as affected by nutrient availability, temperature, and relative humidity, and the resistance of vegetative cells and spores in biofilm to sanitizers were investigated. Total counts in biofilm formed on coupons immersed in tryptic soy broth (TSB) at 12 and 22°C consisted of 99.94% of vegetative cells and 0.06% of spores. Coupons on which biofilm had formed were immersed in TSB or exposed to air with 100, 97, 93, or 85% relative humidity. Biofilm on coupons immersed in TSB at 12°C for an additional 6 days or 22°C for an additional 4 days contained 0.30 and 0.02% of spores, respectively, whereas biofilm exposed to air with 100 or 97% relative humidity at 22°C for 4 days contained 10 and 2.5% of spores, respectively. Sporulation did not occur in biofilm exposed to 93 or 85% relative humidity at 22°C. Treatment of biofilm on coupons that had been immersed in TSB at 22°C with chlorine (50 μg/ml), chlorine dioxide (50 μg/ml), and a peroxyacetic acid–based sanitizer (Tsunami 200, 40 μg/ml) for 5 min reduced total cell counts (vegetative cells plus spores) by 4.7, 3.0, and 3.8 log CFU per coupon, respectively; total cell counts in biofilm exposed to air with 100% relative humidity were reduced by 1.5, 2.4, and 1.1 log CFU per coupon, respectively, reflecting the presence of lower numbers of vegetative cells. Spores that survived treatment with chlorine dioxide had reduced resistance to heat. It is concluded that exposure of biofilm formed by B. cereus exposed to air at high relative humidity (≥97%) promotes the production of spores. Spores and, to a lesser extent, vegetative cells embedded in biofilm are protected against inactivation by sanitizers. Results provide new insights to developing strategies to achieve more effective sanitation programs to minimize risks associated with B. cereus in biofilm formed on food contact surfaces and on foods.

Evaluation of Chlorine, Chlorine Dioxide, and a Peroxyacetic Acid–Based Sanitizer for Effectiveness in Killing Bacillus cereus and Bacillus thuringiensis Spores in Suspensions, on the Surface of Stainless Steel, and on Apples

2006 ◽  
Vol 69 (8) ◽  
pp. 1892-1903 ◽  
Author(s):  
AUDREY C. KRESKE ◽  
JEE-HOON RYU ◽  
LARRY R. BEUCHAT
Keyword(s):  
Stainless Steel ◽  
Bacillus Thuringiensis ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Food Processing ◽  
Horse Serum ◽  
Peroxyacetic Acid ◽  
Food Processing Industry ◽  
Bacillus Spores ◽  
Food Contact Surface

Chlorine (10 to 200 μg/ml), chlorine dioxide (10 to 200 μg/ml), and a peroxyacetic acid–based sanitizer (40 and 80 μg/ml) were evaluated for effectiveness in killing spores of Bacillus cereus and Bacillus thuringiensis in suspensions and on the surface of stainless steel and apples. Water and 5% horse serum were used as carriers for spore inoculum applied to the surface of stainless steel coupons, and 5% horse serum was used as a carrier for inoculum applied to apples. Inocula were dried on stainless steel for 5 h and on apples for 22 to 24 h before treating with sanitizers. At the concentrations of sanitizers tested, sensitivities of planktonic B. cereus and B. thuringiensis spores were similar. A portion of the spores surviving treatment with chlorine and, more markedly, chlorine dioxide had decreased tolerance to heat. Planktonic spores of both species were more sensitive to sanitizers than were spores on the surface of stainless steel or apples. At the same concentrations, chlorine was more effective than chlorine dioxide in killing spores in suspension and on stainless steel. The lethality of chlorine dioxide was markedly reduced when inoculum on stainless steel coupons was suspended in 5% horse serum as a carrier rather than water. Chlorine and chlorine dioxide at concentrations of 10 to 100 μg/ml were equally effective in killing spores on apples. Significant reductions of ≥3.8 to 4.5 log CFU per apple were achieved by treatment with 100 μg/ml of either of the two sanitizers. The peroxyacetic acid sanitizer (40 and 80 μg/ml) was ineffective in killing Bacillus spores in the test systems investigated. Results provide information on the effectiveness of sanitizers commonly used in the food processing industry in killing Bacillus spores in suspension, on a food-contact surface, and on a ready-to-eat food.

scholarly journals EFFECT OF SOLUTE CONCENTRATION AND PRE-SOIL INTERACTION ON THE MICROFLORA OF DAIRY ORIGIN ON STAINLESS STEEL SURFACES1

1970 ◽  
Vol 33 (12) ◽  
pp. 541-544 ◽  
Author(s):  
H. M. Barnhart ◽  
R. B. Maxcy ◽  
C. E. Georgi
Keyword(s):  
Stainless Steel ◽  
Water Loss ◽  
Food Processing ◽  
Solute Concentration ◽  
Moisture Loss ◽  
Stainless Steel Surface ◽  
Dairy Food ◽  
Temperature And Humidity ◽  
Closed Systems ◽  
Steel Surfaces

Use of modern dairy food processing equipment creates a complex microenvironment. Closed systems reduce air drying. The rate and extent of drying are dependent on temperature and humidity of the environment. These factors were studied to determine their impact on the microflora of films of milk on stainless steel surfaces. An ecosystem was established to simulate dairy food equipment by using 1cm2 pieces of stainless steel in controlled humidity chambers. Presoiling water loss from a film of milk, and solute concentration were studied to determine their influence on the fate of the microflora. Temperature and humidity of the atmosphere influenced the rate of moisture loss from films. Pre-soiling reduced the rate of water loss from films of milk sufficiently to allow bacterial growth at 12–80% relative humidity (RH). Results indicate bacteria can grow in a film placed in humidities well below the 95% RH limit previously projected. Apparently the substrate is influenced by interaction of the milk film and the stainless steel surface.

scholarly journals Contribution of environmental factors in the formation of biofilms by Alicyclobacillus acidoterrestris on surfaces of the orange juice industry

2020 ◽  
Vol 50 (3) ◽  
Author(s):  
Tatiane Viana Dutra ◽  
Daniela Biral do Prado ◽  
Márcia Maria dos Anjos ◽  
Miguel Machinski Junior ◽  
Jane Martha Graton Mikcha ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Orange Juice ◽  
Biofilm Formation ◽  
Microbial Load ◽  
Natural Food ◽  
Stainless Steel Surface ◽  
Alicyclobacillus Acidoterrestris ◽  
Food Grade ◽  
Rubber Surface ◽  
Initial Load

ABSTRACT: The objective of this study was to evaluate the effect of the initial microbial load, temperature and contact time on the biofilm formation of Alicyclobacillus acidoterrestris on stainless steel and natural food-grade rubber using orange juice as culture medium. The low initial load of A. acidoterrestris (2 log CFU/mL) led to biofilm formation on the stainless steel surface after 48 h of contact at 28 ºC and after 24 h at 45 ºC, and on natural food-grade rubber surface after 48 h of contact at both temperatures. The high initial microbial load (5 log CFU/mL) led to biofilm formation on stainless steel after 4 h of contact at 28 °C and 45 °C, while biofilm was formed on natural food-grade rubber after 8 h of contact at 28 °C and 4 h at 45 °C. The microbial load also affected the presence of spores in biofilm, which was observed on both surfaces only at high initial loads of A. acidoterrestris.

Scanning Electron Microscopic Examination of Yersinia enterocolitica Attached to Stainless Steel at Selected Temperatures and pH values1

1988 ◽  
Vol 51 (6) ◽  
pp. 445-448 ◽  
Author(s):  
PAULA J. HERALD ◽  
EDMUND A. ZOTTOLA
Keyword(s):  
Stainless Steel ◽  
Yersinia Enterocolitica ◽  
Steel Surface ◽  
Electron Microscopic Examination ◽  
Growth Conditions ◽  
Stainless Steel Surface ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Steel Surfaces ◽  
Scanning Electron

Attachment of Yersinia enterocolitica to stainless steel surfaces at 35, 21, and 10°C was investigated using scanning electron microscopy (SEM). Cells adhered at all three temperatures, but, in general, the greatest number of adhered cells were observed at pH 8 and 21°C. Multi-flagellated cells were noted under these growth conditions. When grown at pH 9.5 and 21°C, fibrils were observed between cells and extending to the stainless steel surface. Fewer cells with flagella were seen at this pH. Adherence may be related to the flagella and any exopolymer surrounding the cells.

Comparison of Nucleation Site Density for Pool Boiling and Gas Nucleation

2005 ◽  
Vol 128 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Yusen Qi ◽  
James F. Klausner
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Pool Boiling ◽  
Nucleation Site ◽  
Stainless Steel Surface ◽  
Distilled Water ◽  
Site Density ◽  
Significant Difference ◽  
Steel Surfaces ◽  
Nucleation Site Density

It has been well established that the rate of heat transfer associated with boiling systems is strongly dependent on the nucleation site density. Over many years attempts have been made to predict nucleation site density in boiling systems using a variety of techniques. With the exception of specially prepared surfaces, these attempts have met with little success. This paper presents an experimental investigation of nucleation site density measured on roughly polished brass and stainless steel surfaces for gas nucleation and pool boiling over a large parameter space. A statistical model used to predict the nucleation site density in saturated pool boiling is also investigated. The fluids used for this study, distilled water and ethanol, are moderately wetting and highly wetting, respectively. Using distilled water it has been observed that the trends of nucleation site density versus the inverse of the critical radius are similar for pool boiling and gas nucleation. The nucleation site density is higher for gas nucleation than for pool boiling. An unexpected result has been observed with ethanol as the heat transfer fluid, which casts doubt on the general assumption that heterogeneous nucleation in boiling systems is exclusively seeded by vapor trapping cavities. Due to flooding, few sites are active on the brass surface and at most two are active on the stainless steel surface during gas nucleation experiments. However, nucleation sites readily form in large concentration on both the brass and stainless steel surfaces during pool boiling. The pool boiling nucleation site densities for ethanol on rough and mirror polished brass surfaces are also compared. It shows that there is not a significant difference between the measured nucleation site densities on the smooth and rough surfaces. These results suggest that, in addition to vapor trapping cavities, another mechanism must exist to seed vapor bubble growth in boiling systems.

A model heat-exchange apparatus for the investigation of fouling of stainless steel surfaces by milk I. Deposit formation at 100 °C

1989 ◽  
Vol 56 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Carole L. Foster ◽  
Michel Britten ◽  
Margaret L. Green
Keyword(s):  
Stainless Steel ◽  
Heat Exchange ◽  
Time Course ◽  
Small Scale ◽  
Lag Phase ◽  
Stainless Steel Surface ◽  
Deposit Formation ◽  
Factors Affecting ◽  
Steel Surfaces ◽  
Exchange Apparatus

SummaryA model heat-exchange apparatus was used to investigate the factors affecting deposit formation from milk on a stainless steel surface at 100 °C. The structure and composition of the deposits were determined by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and chemical analysis after solution in alkali. The effects of changing the pH, preheating and skimming of the milk were similar to those observed in a small-scale continuous ultra high temperature plant. The time course of deposit formation showed that a lag phase did not occur, but the deposit which formed after more than 45 min was more porous than that formed after shorter times. Most (50–90%) of the fresh deposit was readily removed by sonication, leaving a sublayer richer in minerais than the original. The results provide evidence for the two-layer model for deposit formation proposed by Tissier & Lalande (1986).

Improved Quantitative Recovery of Listeria monocytogenes from Stainless Steel Surfaces Using a One-Ply Composite Tissue

2004 ◽  
Vol 67 (10) ◽  
pp. 2212-2217 ◽  
Author(s):  
KEITH L. VORST ◽  
EWEN C. D. TODD ◽  
ELLIOT T. RYSER
Keyword(s):  
Stainless Steel ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Steel Plates ◽  
Stainless Steel Surface ◽  
Disc Diffusion ◽  
Buffer Solution ◽  
Composite Tissue ◽  
Steel Surfaces ◽  
Diffusion Assay

Four sampling devices, a sterile environmental sponge (ES), a sterile cotton-tipped swab (CS), a sterile calcium alginate fiber-tipped swab (CAS), and a one-ply composite tissue (CT), were evaluated for quantitative recovery of Listeria monocytogenes from a food-grade stainless steel surface. Sterile 304-grade stainless steel plates (6 by 6 cm) were inoculated with approximately 106 CFU/cm2 L. monocytogenes strain Scott A and dried for 1 h. The ES and CT sampling devices were rehydrated in phosphate buffer solution. After plate swabbing, ES and CT were placed in 40 ml of phosphate buffer solution, stomached for 1 min and hand massaged for 30 s. Each CS and CAS device was rehydrated in 0.1% peptone before swabbing. After swabbing, CS and CAS were vortexed in 0.1% peptone for 1 min. Samples were spiral plated on modified Oxford agar with modified Oxford agar Rodac Contact plates used to recover any remaining cells from the stainless steel surface. Potential inhibition from CT was examined in both phosphate buffer solution and in a modified disc-diffusion assay. Recovery was 2.70, 1.34, and 0.62 log greater using CT compared with ES, CS, and CAS, respectively, with these differences statistically significant (P < 0.001) for ES and CT and for CAS, CS, and CT (P < 0.05). Rodac plates were typically overgrown following ES, positive after CS and CAS, and negative after CT sampling. CT was noninhibitory in both phosphate buffer solution and the modified disc-diffusion assay. Using scanning electron microscopy, Listeria cells were observed on stainless steel plates sampled with each sampling device except CT. The CT device, which is inexpensive and easy to use, represents a major improvement over other methods in quantifying L. monocytogenes on stainless steel surfaces and is likely applicable to enrichment of environmental samples.

The influence of chemical cleaning methods on pitting morphology attributed to microbially influenced corrosion of stainless steels

CORROSION ◽  
10.5006/3707 ◽  
2020 ◽  
Author(s):  
Muhammad Awais Javed ◽  
Nathaniel Rieders ◽  
Iwona Beech ◽  
Recep Avci ◽  
Wayne Neil ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Stainless Steel Surface ◽  
Metallic Materials ◽  
Chemical Cleaning ◽  
Microbially Influenced Corrosion ◽  
Quantitative Measurements ◽  
Treatment Type ◽  
Steel Surfaces ◽  
Potential Impact ◽  
Cleaning Methods

Chemical cleaning methods are frequently employed for the removal of biofilm/corrosion products from metallic materials to evaluate the type and severity of microbially influenced corrosion (MIC) damage. The study described here investigates the effect of commonly applied cleaning treatments on the dissolution of stainless steel surface inclusions and emphasizes the potential impact of such treatments on MIC diagnostics. Polished 304 grade stainless steel coupons were ultrasonicated for 1, 3 and 7 min in each of the three commonly applied agents, i.e. Clarke’s, nitric acid and hydrofluoric acid-based solutions. Post-treatment analyses of steel surfaces revealed pitting attack. For each treatment type and duration, the morphology and quantitative measurements of pits were recorded. Shape, size and depth of examined pits closely resembled damage that, in many laboratory-based studies, have been attributed to MIC. The investigation herein demonstrates that caution ought to be exerted when implicating MIC as the cause of stainless steel pitting damage.

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