Abrishami, S.H., Tall, B.D., Bruursema, T., Epstein, P.,
and Shah, D. 1994. Bacterial adherence and viability on cutting board surfaces.
J. Food Safety. 14:153-172.
KEYWORDS: Sanitizer, cutting board, wood, plastic, E. coli, adherence, attachment, xylem, viability
ABSTRACT: Evaluation of the adherence and viability of Escherichia coli inoculated onto the surfaces of plastic cutting boards and new and used wood cutting boards. Objectives were to evaluate bacterial attachment and viability to plastic and wooden cutting board surfaces, to determine if either material exhibited bacterial growth-promoting or inhibiting properties, and to examine the retention of bacteria on surfaces after a low temperature, non-detergent wash in a modified commercial dishwasher. Results corroborated the anecdotal concept that bacteria are better retained on wooden than plastic cutting board surfaces. When exposure time was extended to 2 h, > 90% of the cells placed on new and used dry wood surfaces were not recovered after vigorous rinsing. Studies demonstrated that bacteria adhering to wood surfaces resided within the structural and vegetative elements of the wood's xylem tissues and were viable; wood was more retentive than plastic; penetration of the inoculum liquid promoted cell adherence to the wood matrix; and conditioning of wood with water before inoculation interfered with bacterial adherence.
Ak, N.O., Cliver, D.O., and Kaspar, C.W. 1994. Cutting
boards of plastic and wood contaminated experimentally with bacteria. J.
Food Prot. 57(1):16-22.
KEYWORDS: Sanitizer, cutting board, wood, plastic, comparison, cross-contamination, E. coli, L. monocytogenes, S. typhimurium, recovery, survival
ABSTRACT: Study of the microbiology of plastic and wooden cutting boards and comparison of their potential to promote cross-contamination of foods in home kitchens. New and used plastic (four polymers plus hard rubber) and wood (nine hardwoods) cutting boards were cut into 5-cm squares ("blocks"). Escherichia coli (3 strains, including O157:H7), Listeria innocua, L. monocytogenes, or Salmonella typhimurium was applied to the block surface in nutrient broth or chicken juice and recovered by soaking the surface in nutrient broth or pressing the block onto nutrient agar, within 3-10 min or up to ca. 12 h later. Bacteria inoculated onto plastic blocks were readily recovered for minutes to hours and would multiply if held overnight. Recoveries from wooden blocks were generally less than those from plastic blocks, regardless of new or used status; differences increased with holding time. Clean wood blocks usually absorbed the inoculum completely within 3-10 min. If these fluids contained 103-104 CFU of bacteria likely to come from raw meat or poultry, the bacteria generally could not be recovered after entering the wood. If > or = 106 CFU were applied, bacteria might be recovered from wood after 12 h at room temperature and high humidity, but numbers were reduced by at least 98%, and often more than 99.9%. Mineral oil treatment of the wood surface had little effect on the microbiological findings. These results do not support the often-heard assertion that plastic cutting boards are more sanitary than wood.
Ak, N.O., Cliver, D.O., and Kaspar, C.W. 1994. Decontamination
of plastic and wooden cutting boards for kitchen use. J. Food Prot. 57(1):23-30.
KEYWORDS: Sanitizer, cutting board, wood, plastic, comparison, cross-contamination, recovery, survival, chicken fat, humidity
ABSTRACT: Study with objective to compare the cleaning and decontamination of plastic and wooden cutting boards so as to prevent cross-contamination under conditions pertinent to home kitchens. Persistence and overnight multiplication of bacteria on plastic surfaces depended on maintenance of humidity so as to prevent drying of the contaminant. New plastic cutting surfaces were relatively easy to clean and were microbiologically neutral, but plastic boards with extensive knife scars were difficult to clean manually, especially if they had deposits of chicken fat on them. Fewer bacteria were generally recovered from wooden blocks than from plastic blocks. Clean wood blocks rapidly absorbed all of the inoculum, after which the bacteria could not be recovered within 3 to 10 min. If the board surface was coated with chicken fat, some bacteria might be recovered even after 12 h at room temperature and high humidity. Cleaning with hot water and detergent generally removed these bacteria, regardless of bacterial species, wood species, and whether the wood was new or used.
Anderson, M.E., Marshall, R.T., Stringer, W., and Naumann,
H. 1977. Efficacies of three sanitizers under six conditions of application
to surfaces of beef. J. Food Sci. 42(2):326-329.
KEYWORDS: Sanitizer, chlorine, acetic acid, quaternary ammonium, application, efficacy, selective, bacteria
ABSTRACT: Determination of the efficacies of three sanitizers (chlorine, acetic acid, and quaternary ammonium), optimum conditions for applying them, and whether they selectively eliminated portions of the microflora. Acetic acid gave a high initial average decrease in counts (-1.47 log), and counts decreased (-1.79 log) up to 48 hr after sanitization. Chlorinated solution caused an initial mean difference of -0.31 log and a difference after 48 hr of 0.53. The quaternary ammonium compound produced differences of -0.79 and -0.03 log in immediate and 48-hr counts. Acetic acid and hypochlorite were nonselective, but the quaternary sanitizer allowed more oxidase positive, nonfermentative bacteria to survive.
Anon. 1994. Microbial pathogens readily trapped in wood
of cutting boards. Am. Soc. Microbiol. News. 60(8):408.
KEYWORDS: Sanitizer, cutting board, wood, survival, adherence, photo, electron photomicrograph, E. coli, Salmonella spp., Campylobacter spp.
ABSTRACT: Quotes findings of D. Shah and B. Tall (FDA) and S. Abrishami (NSF International), which indicate that microbial pathogens (e.g. Escherichia coli O157, Salmonella spp., and Campylobacter spp.) are readily trapped in the porous surfaces of wooden cutting boards, and can survive for prolonged periods if the wood remains damp, but remain viable for at least 2 h even after the surface has been dried. Also included is a photo (scanning electron photomicrograph) showing enterohemorrhagic E. coli cells adhering to wood.
FROM: Banks, A.L. TO: Letter to O.P. Snyder. September
28, 1994. RE: Response to 8/17/94 letter to FDA Commissioner David Kessler.
KEYWORDS: Sanitizer, cutting board, study, FDA, NSF, bacteria, retention, absorbent
ABSTRACT: Response to referenced letter, which raises a question about the accuracy of retail food safety information as provided by FDA personnel and the methods being used to convey the information. Regarding the question of validity of a recent study on cutting boards, the author defends the study jointly published by FDA and NSF in which wood cutting board surfaces are said to retain more bacteria than plastic cutting board surfaces (with claim that bacteria reside in the inner structural and nutrient-conducting elements of wood tissues), that the bacteria are metabolically active and viable after resident times of at least 2 hrs, that wood has greater retentive properties than plastic even after cold water rinsing, and so forth. No intention of redoing the study is indicated, and disagreement is expressed at the claim that the study was biased and flawed. Despite the findings of the study, however, there is no indication that FDA intends to further prohibit use of wooden cutting boards (beyond the statement in 1993 food code that wood may not be used as a food-contact surface except in some well defined circumstances, and the specification that hard maple or an equivalently hard, close grained, and [relatively] nonabsorbent wood be used in those cutting boards constructed of wood).
Bauer, J.M., Beronio, C.A., and Rubino, J. 1995. Antibacterial
activity of environmentally "green" alternative products tested in standard
antimicrobial tests and a simulated in-use assay. J. Environ. Health. 57(7):13-18.
KEYWORDS: Sanitizer, alternative, "green", comparison, assessment, antimicrobial, antibacterial, AOAC, EPA, S. aureus, S. choleraesuis, K. pneumoniae, E. coli, transfer, contamination, efficacy
ABSTRACT: Examination of the ability of "green" products to kill or eliminate representative Gram positive and Gram negative bacteria from nonporous surfaces. Assessment of the antimicrobial activity of the products using tests required for EPA registration as antibacterial. None of the alternative products met the required levels against S. aureus or S. choleraesuis (using AOAC Use Dilution Method). None of the "green" products achieved required levels of sanitizing activity against S. aureus and K. pneumoniae (using EPA Non-Food Contact Sanitizer Test). In a test simulating in-use conditions (inoculation of Formica surface with E. coli or S. aureus, surface then dried and treated with a "green" product or an EPA registered disinfectant or water alone), the "green" products showed no significant reduction in bacterial levels on the surface and showed a high level of contamination transferred to the sponge. The EPA registered disinfectant reduced counts on both the surface and the sponge to minimal or nondetectable levels for both types of bacteria.
Brody, J. 1993. Wood found to be safer choice than plastic
for cutting board. Star Tribune. Minneapolis, MN. March 2, 1993.
KEYWORDS: Sanitizer, cutting board, plastic, wood, comparison, antibacterial
ABSTRACT: Article by New York Times reporter which appeared in Variety section of Star Tribune. Reports on the observations of D. Cliver and N. Ak of the Food Research Institute, University of Wisconsin-Madison, that bacteria were killed on wood cutting boards but increased in numbers on plastic cutting boards. [Reference appears to be to the unpublished data of Cliver and Ak entitled "Microbiology of cutting boards for food safety."] The observation was made during research which had been intended to find ways to decontaminate wooden cutting boards and make them as safe as plastic. Plastic boards were assumed to be safer because the surface is non-porous and contaminating organisms could be readily washed off. Wood boards, on the other hand, were believed to provide a place into which bacteria could soak, making removal difficult, but also allowing cross-contamination on a subsequent use of the board.
Buckalew, J.J., Schaffner, D.W., and Solberg, M. 1996.
Surface sanitation and microbiological food quality of a university foodservice
operation. J. Foodservice Systems. 9:25-39.
KEYWORDS: Sanitizer, data, analysis, foodservice, safety, contact, surface, meat, coliform, aerobic, E. coli, S. aureus
ABSTRACT: Analysis of data collected over a 2-year period as part of a food safety surveillance program designed and implemented by the Rutgers Food Science Department. The microbiological testing and surveillance program monitored the sanitary state of food contact surfaces and performed food audits of the Rutgers Dining Services facilities. The analysis of data revealed that unacceptable surface sanitation was correlated with the physical presence of food debris, water, or both. Follow up testing revealed that the program was able to consistently reduce the probability of surface failure recurrence. Poor equipment design was often contributory to especially problematic surfaces. Lunchmeat and raw meat were found to be the most problematic types of food according to university guidelines. Food failures were most frequently due to unacceptable levels of indicator bacteria including total coliforms, total aerobic counts, and Escherichia coli. The most common type of failure due to an unacceptable level of a foodborne pathogen was due to unacceptable levels of Staphylococcus aureus.
Carpentier, B. 1997. Sanitary quality of meat chopping
board surfaces: a bibliographical study. Food Microbiol. 14:31-37.
KEYWORDS: Sanitizer, cutting board, wood, plastic, bibliographic, literature, household, butcher, bacteria, France
ABSTRACT: A bibliographic study on cutting board hygiene based on 12 scientific publication indicating that little work has been done on the subject. The focus of some studies has been limited to household cutting boards and others discussed only those surfaces used by butchers. Differences in experimental factors from one study to another could explain the different survival rates of bacteria after inoculation onto wooden surfaces. This comparative study was undertaken in part to answer the question of whether scientific work on this subject has been sufficient to justify the ban on wooden meat cutting surfaces [in France]. Points of comparison are experimental conditions employed in laboratory studies (including method of surface contamination, origin and condition of microorganisms used to contaminate surfaces, residence time between artificial contamination of surface and evaluation of contamination, type of wood used, orientation of wood fibers in cutting board surfaces, humidity level of wood prior to contamination, surface state of wood, fouling of wood prior to contamination, and method of sampling prior to microorganism count), impact of various factors on contamination of meat cutting board surfaces (including influence of residence time between artificial contamination of surface and microorganism count, influence of origin and environment of bacteria, influence of microorganism sampling method, and influence of surface state of wood), and comparison of wood and plastic meat cutting board surfaces (including laboratory studies and field studies). In very brief conclusion, no real demonstration of the superiority of plastic is said to be found in the existing literature.
Cliver, D.O., and Ak, N.O. 1993. Microbiology of cutting
boards for food safety. Food Research Inst., University of Wisconsin-Madison.
Madison, WI. February 7, 1993.
KEYWORDS: Sanitizer, cutting board, wood, plastic, comparison, bacteria, survival, recovery, inhibition, fat
ABSTRACT: Study with objectives to investigate bacterial contamination of wood cutting boards and to find convenient means of decontaminating the wood to the level of safety found in plastic cutting boards. Results, however, indicated that no bacteria were recovered from wood blocks, suggesting that the bacteria were somehow injured and unable to express themselves by the spread plating method that was used in enumeration. On further examination, no injured bacteria were detected in broth medium by the Most Probable Number technique. Attempts were made to find an inhibitory compound in wood that prevented bacterial growth, but if such a substance exists, it could not be extracted from the wood for analysis. It is suggested that bacteria remain alive for periods of time in wood pores, but cannot emerge from the surface to contaminate anything else. Further tests were performed, this time with application of chicken fat to the cutting surfaces before contamination. This time, the presence of a visible amount of contaminant on the surface after overnight holding coincided with high recovery of bacteria. Results of this second part of the study showed the importance of not letting fatty food residues accumulate on cutting boards. This report appears to have been the basis for subsequent work published in 1994 [J. Food Prot. 57(1):16-22] entitled "Cutting boards of plastic and wood contaminated experimentally with bacteria" by N.O. Ak, D.O. Cliver, and C.W. Kaspar.
Daley, D., Kereluk, K., and Lloyd, R. 1971. Microbiological
aspects of the hospital environment: bacteriological effectiveness of a
utensil washer-sanitizer. Health Lab. Sci. 8(1):21-28.
KEYWORDS: Sanitizer, hospital, utensil, bedpan, machine, efficiency, effective
ABSTRACT: Description of a study in which a recently developed patient utensil washer-sanitizer was tested and evaluated for its washing and sanitizing efficiency. Artificially soiled and contaminated utensils of various types and sizes were processed through the unit and tested for cleanliness and levels of contamination. The unit tested is steam-heated and has a total washing-sanitizing cycle of 22.5 minutes, including a detergent wash period of 5.25 min. and a sanitizing period of 8.25 min. The maximum temperatures achieved during the washing and sanitizing phases were 94°C and 94.5°C, respectively. The results demonstrated that the utensil washer-sanitizer, when properly operated, was highly effective in cleaning soiled bedside utensils and was capable of effectively reducing the microbial levels of contamination to those suggested by the U.S. Public Health Service in their standards for sanitized surfaces.
de Beer, D., Srinivasan, R., and Stewart, P. 1994. Direct
measurement of chlorine penetration into biofilms during disinfection.
Appl. Environ. Microbiol. 60(12):4339-4344.
KEYWORDS: Sanitizer, biofilm, P. aeruginosa, K. pneumoniae, chlorine, biocide, efficacy, planktonic cell
ABSTRACT: Study with objective to determine biocide penetration into a microbial biofilm during biocide treatment. Direct concentration measurements in biofilms were achieved by using microelectrodes, which are needle-shaped sensors with a tip diameter of 1 to 10 µm, which prevents disruption of the biofilms during measurements. The biofilms tested contained Pseudomonas aeruginosa and Klebsiella pneumoniae. The penetration depth of chlorine into the biofilm and rate of penetration varied depending on the measurement location, reflecting heterogeneity in the distribution of biomass and in local hydrodynamics. The shape of the chlorine profiles, the long equilibrium times, and the dependence on the bulk chlorine concentration showed that the penetration was a function of simultaneous reaction and diffusion of chlorine in the biofilm matrix. Frozen cross sections of biofilms, stained with a redox dye and a DNA stain, showed that the area of chlorine penetration overlapped with nonrespiring zones near the biofilm-bulk fluid interface. It is thus indicated that the limited penetration of chlorine into the biofilm matrix is likely to be an important factor influencing the reduced efficacy of chlorine against biofilms as compared with its action against planktonic cells.
Dhaliwal, D.S., Cordier, J.L., and Cox, L. 1992. Impedimetric
evaluation of the efficiency of disinfectants against biofilms. Letters
in Appl. Microbiol. 15:217-221.
KEYWORDS: Sanitizer, evaluation, impedimetric, efficacy, biofilm, attachment, suspension, surface, resistance, S. aureus, E. coli, S. enteritidis, L. monocytogenes, PVC, Teflon, Plexiglas, wood, rubber, stainless steel
ABSTRACT: Study to determine whether disinfectants behave differently towards bacteria attached to surfaces compared with those bacteria in suspension, and to see if surface-types have an influential role in biofilm resistance towards disinfectants. An impedimetric evaluation of disinfectant efficacy has shown that biofilms of S. aureus, E. coli, S. enteritidis, and L. monocytogenes attached to polyvinyl chloride, Teflon, Plexiglas, wood, rubber, and stainless steel are more resistant than the same bacteria in suspension. Based on the activity against the test-organisms after 1, 3, and 5 min with exposures to 0.5, 1, and 2% of each disinfectant, the resistance towards disinfection was related to the type of hard-surface to which biofilms were attached.
Eilers, J.R. 1991. Sanitation auditing. Food Processing.
KEYWORDS: Sanitizer, sanitation audit, inspection, suggestion, improvement
ABSTRACT: Begins by stating that FDA considers a violation of the Food, Drug, and Cosmetics Act to have occurred when conditions exist where food could become unsafe, unwholesome, or adulterated [even if the food does not actually become so]. In light of this, food processors have often found it in their best interests to have sanitation audits performed by outside services. In these audits, there is an evaluation of the adequacy of and adherence to the sanitation program, including such items as cleaning practices, maintenance, pest control, and personnel practices. Inspection findings are used to prepare a final report and rating. This process differs from regulatory inspections in that regulatory inspectors generally list deficiencies without suggestions for correcting them, leaving it to the processor to find methods and materials to eliminate the deficiencies. An audit can also identify problems unrelated to safety and wholesomeness (such as defects in package appearance, overfilling, and so forth).
Favero, M.S., McDade, J.J., Robertsen, J., Hoffman, R.,
and Edwards, R. 1968. Microbiological sampling of surfaces. J. Appl. Bacteriol.
KEYWORDS: Sanitizer, sampling, method, swab-rinse, rinse, agar contact, direct surface agar plating, enumeration, viable, particulate, assay
ABSTRACT: Report with objective to describe techniques for assessing the level of microbial contamination on surfaces and their application. Discussion of experimental systems used to evaluate surface sampling techniques. Whereas no single assay procedure can characterize completely the microbial elements on a surface, the rinse technique is probably the most accurate for enumerating viable microorganisms, and the direct surface agar plating technique is the best for enumerating particulates containing viable microorganisms. However, the convenience of other methods, such as the agar contact method, will often be the dominant factor in the selection of a sampling method.
FDA. 1988. Recommended guidelines for controlling environmental
contamination in dairy plants. Dairy Food Sanitation. 8(2):52-56.
KEYWORDS: Sanitizer, FDA, recommendation, guideline, dairy, pasteurization, chlorine, anionic, quaternary ammonium compound, iodophor, Ice Cream Association, Milk Industry Foundation International, Listeria spp., Yersinia spp.
ABSTRACT: Provides update of recommended guidelines to assist state milk agencies and the dairy industry in controlling environmental contamination in dairy plants. Guidelines were first issued in September, 1986, and new information derived from Dairy Safety Initiatives is added. Guidelines are primarily directed at controlling environmental, post-pasteurization contamination of product by such organisms as Listeria and Yersinia, but are applicable for all other contaminants. Topics include minimum time/temperature combinations for pasteurization, problems with vat pasteurization systems, post-pasteurization contamination, cross-connections, use of returned product and reclaiming operations, airborne contamination, plant environment (general), plant traffic, personnel cleanliness, sampling and testing. In the area of personnel cleanliness, it is advised that handwashing facilities be properly designed and conveniently located near work stations, and that employees be encouraged to use them frequently. Minimum levels of sanitizers are recommended as follows: chlorine based sanitizers at 100 ppm, acid anionics at 200 ppm, quaternary ammonium compounds at 100 ppm, and iodophors at 25 ppm, with further caution that sanitizers are not effective unless product surfaces are clean. Publication indicates joint authorship by FDA and Milk Industry Foundation International Ice Cream Association.
Frank, J.F., Gillett, R.A., and Ware, G. 1990. Association
of Listeria spp. contamination in the dairy processing plant environment
with the presence of Staphylococci. J. Food Prot. 53(11):928-932.
KEYWORDS: Sanitizer, Listeria spp, indicator, staphylococci
ABSTRACT: Research with objective to select a suitable indicator for the presence of Listeria spp. in the dairy processing plant and to develop criteria to guide its use. The study included the following microbial groups: total aerobes, anaerobes, acid producers, salt tolerant aerobes, Enterobacteriaceae, lactobacilli, staphylococci, enterococci, gram-negative bacteria, and yeast and mold. Staphylococci were determined to be the best indicator group by using discriminate analysis selection.
Frank, J.F., and Koffi, R.A. 1990. Surface-adherent growth
of Listeria monocytogenes is associated with increased resistance
to surfactant sanitizers and heat. J. Food Prot. 53(7):550-554.
KEYWORDS: Sanitizer, L. monocytogenes, inoculum, adherence, planktonic, survival, resistance, develop, inactivation, environment, simulation, heat
ABSTRACT: Study with objective to prepare an inoculum for antimicrobial testing (viz. L. monocytogenes) which would include adherent growth on an inert surface, depleted nutrient levels with periodic exposure to fresh nutrients, and below optimum growth temperature. Such an inoculum would provide better representation of the food processing plant environment than typical laboratory culture. Additional objective to test the ability of commonly used surface active sanitizers to inactivate these cells. Adherent microcolony cells decreased by 2 to 3 log cycles immediately after exposure to the sanitizers. The remaining population of microcolony cells survived 20 min of exposure demonstrating resistance to both tested sanitizers at all concentrations. Removing adherent cells from the surface increased their sanitizer susceptibility to near that of planktonic cells. Heating adherent microcolonies at 70°C for 5 min resulted in a less than 5-log decrease in population with a surviving population of over 10 CFU/sq. cm. These results demonstrate the ability of L. monocytogenes to develop resistance to inactivating agents when exposed to specific growth environments.
FROM: Frank, J. TO: Letter to O.P. Snyder. August 24.
KEYWORDS: Sanitizer, biofilm, L. monocytogenes, retail, deli, control, limit
ABSTRACT: Notification of pending sending of publications relating to Listeria and biofilms, per recipient's request. Acknowledges lack of published information on L. monocytogenes in retail food establishments, and, consequently, lack of critical limits pertaining to Listeria control.
Fukayama, M.Y., Tan, H., Wheeler, W., and Wei, C. 1986.
Reactions of aqueous chlorine and chlorine dioxide with model food compounds.
Environ. Health Perspectives. 69:267-274.
KEYWORDS: Sanitizer, chlorine, aqueous, dioxide, chlorination, food, toxicity, reaction, lipid, amino acid, fatty acid, methyl ester, flour, shrimp, incorporation, risk, mutagenic
ABSTRACT: Presentation of information to help in evaluating the possible health risks associated with chlorination in food processing, while acknowledging the need for more information on the level and reactivity of chlorine used in various processes, the identity and toxicity of the reaction products, and the levels of these compounds to which consumers are exposed. The presentation reviews published information concerning the reactions of chlorine gas, aqueous chlorine, and ClO2 with model food compounds, the fate of chlorine during the chlorination of specific food products, and the potential toxicity of the reaction products. Fatty acids and their methyl esters react with chlorine with the degree of incorporation corresponding to their degree of unsaturation. Aqueous chlorine oxidizes and chlorinates lipids and amino acids much more readily than chlorine dioxide. Several amino acids are highly susceptible to oxidation and chlorination by chlorine compounds. Reactions of chlorine and chlorine dioxide with several food products, including flour and shrimp, have also been characterized. In one model system, 99% of the chlorine gas either reacted with components of flour or was consumed by oxidation/chlorination reactions. The lipids extracted from the chlorinated flour contained significant amounts of chlorine. Exposure of shrimp to hypochlorous acid solution resulted in significant incorporation of chlorine into the edible portion. Although significant quantities of chlorine can be incorporated into specific model compounds and food products, the health risks associated with exposure to chlorinated organic products are unknown. Preliminary studies using the Ames Salmonella/microsome mutagenicity assay indicate that the reaction products from mixtures of aqueous chlorine and various lipids or tryptophan are nonmutagenic.
Gabis, D., and Faust, R.E. 1988. Controlling microbial
growth in food processing environments. Food Technol. December):81-82,
KEYWORDS: Sanitizer, processing, microbe, bacteria, contamination, niche, survival, inactivation, growth, design, construction, maintenance, clean, monitor
ABSTRACT: Discussion of several of the environmental factors contributing to microbial contamination in the food plant, and suggestion of measures to prevent contamination. Recommends preventing niches (which cannot be effectively cleaned and disinfected in a reasonable time with normal cleaning tools and supplies) from becoming sources of microbiological contamination of products. This begins with the design of the processing environment and continues with its maintenance and sanitization. Identifies variables which contribute to probability of contamination (mostly involving niches) and which determine microbial growth (including availability of water, nutrients, pH, oxidation-reduction potential, temperature, presence or absence of inhibitors, and interactions among the different microorganisms in the population). Offers recommendations for prevention of microbial growth, such as design and construction of plants and equipment, maintenance practices, cleaning and sanitation practices, and environmental monitoring.
Gilbert, R.J. 1970. Comparison of materials used for cleaning
equipment in retail food premises, and of two methods for the enumeration
of bacteria on cleaned equipment and work surfaces. J. Hyg. (Camb.). 68:221-232.
KEYWORDS: Sanitizer, comparison, efficacy, antibacterial, procedure, anionic detergent, hypochlorite, enumeration, recovery, calcium alginate, swab-rinse, agar sausage, Agaroid
ABSTRACT: Provides results of field trials, carried out in a large self-service store, from an attempt to compare disinfectants and detergent-disinfectants for use in the retail food trade, and also in an attempt to determine recommended procedures for cleaning equipment with these agents. Comparisons were made of the various cleaning efficiencies, as determined by bacterial plate counts, of detergent and disinfectant solutions and machine cleaning oils applied with either clean cloths or disposable paper towels to items of equipment. The most satisfactory results were always obtained when anionic detergent and hypochlorite solutions were applied in a two step procedure. Tests were made to compare the calcium alginate swab-rinse and the agar sausage (Agaroid) techniques for the enumeration of bacteria on stainless steel, plastic, Formica and wooden surfaces before and after a cleaning process. Although recovery rates were always greater by the swab-rinse technique, the agar sausage technique was considered to be a useful routine control method for surface sampling.
Gunther, W. 1993. Wood cutting board paradox answered.
University of Minnesota. St. Paul, MN. June 18, 1993.
KEYWORDS: Sanitizer, cutting board, wood, plastic, antibacterial, wetting agent, oil
ABSTRACT: Description of the findings of a study done at the University of Wisconsin-Madison, in which it was observed that wood cutting boards appeared to kill bacteria while plastic cutting boards allowed bacteria to increase in numbers. No mechanism or causal agents for this phenomenon were found. Dr. Edmund Zottola from the University of Minnesota examined the study and concluded that the study was flawed in that the tests were performed using new wood cutting boards. As part of the manufacturing process, the new boards are treated with wetting agents so that oil applied at the factory can penetrate the wood more completely; the wetting agents have antibacterial properties. The wetting agents and oils are soon washed out when the new board is put into use, and the antibacterial properties are thus eliminated. Bacteria are thus said to penetrate the wood and grow down below the surface, thus confirming the 'common knowledge' of the environmental health community. Plastic cutting boards are also said to be readily able to be cleaned in the average kitchen, unlike wood cutting boards.
Helke, D.M., and Wong, A.C.L. 1994. Survival and growth
characteristics of Listeria monocytogenes and Salmonella typhimurium
on stainless steel and buna-n rubber. J. Food Prot. 57(11):963-968.
KEYWORDS: Sanitizer, dairy, milk, L. monocytogenes, S. typhimurium, stainless steel, buna-n rubber, temperature, relative humidity, bacteriostatic, bacteriostasis
ABSTRACT: Study with objective to examine the survival and growth of L. monocytogenes and S. typhimurium under various environmental conditions on stainless steel and buna-n, two materials commonly used in the dairy industry. The interactions of temperature, relative humidity, soil and surface were examined. The effect of cleaning and sanitizing on the bacteriostatic nature of buna-n rubber was also studied. Survival in phosphate-buffered saline and dilute pasteurized whole milk on both stainless steel and buna-n was highest at 6°C and 75.5% relative humidity. Survival of both microorganisms at 25°C and 75.5% humidity was increased in dilute pasteurized whole milk on stainless steel, but not on buna-n. The survival and growth of both organisms in raw milk soils was similar to that in pasteurized whole milk soil. Buna-n was not bacteriostatic towards all organisms, as the total viable count in raw milk increased by more than a factor of 10 after 1 day storage at 25°C and 75.5% humidity. Unlike other soils tested, survival of S. typhimurium at [all tested] conditions and L. monocytogenes at 25°C and both humidities in whey was higher on buna-n than on stainless steel. At 6°C and both humidities, L. monocytogenes levels remained constant on both surfaces in whey. The bacteriostatic effect of buna-n was not affected significantly by exposure to 20 cycles of a simulated clean-in-place process.
HITM. 1994. Cutting boards and other food contact equipment
and utensils: immersion cleaning and sanitizing process in a 3-compartment
KEYWORDS: Sanitizer, sink, utensil, cutting board, process, standard, procedure, detergent, brush.
ABSTRACT: Identifies process and output specifications: to wash and sanitize cutting boards and other food contact equipment and utensils in a 3-compartment sink to prevent cross-contamination of foods and maintain a safe level of microorganisms. Identifies the hazard: to prevent cross-contamination, cutting boards, large bowls, pans, kettles and knives must be washed and sanitized between preparation of different food items, particularly raw and cooked foods and any time after these items have been used or emptied. Provides sequence of eight steps: get ready (checking listed supplies, cleaning and rinsing sink); fill sinks (with wash compartment receiving detergent, second compartment for rinse water, and third compartment receiving sanitizer); remove gross soil (to be done before putting item into wash sink); wash and scrub surface (with brush to loosen and remove all soil, with recommendation when to change wash water); rinse (by immersion, again with recommendation as to when to change water); sanitize surface (with options of immersion for 1 min in sink with sanitizer, flooding surface with squirt bottle and wiping with paper towel, or immersion in hot [170-180°F] for 30 sec); air dry (thoroughly); and clean sink (drain the liquid, clean with brush and hot detergent solution, rinse, drain again and allow to air dry, with further recommendation on supplies).
Jeong, D.K., and Frank, J.F. 1994. Growth of Listeria
monocytogenes at 10°C in biofilms with microorganisms isolated
from meat and dairy processing environments. J. Food Prot. 57(7):576-586.
KEYWORDS: Sanitizer, L. monocytogenes, biofilm, competition, bacteria, plant environment, survival, growth
ABSTRACT: Research with objective to determine the ability of L. monocytogenes to grow in a biofilm with competing bacteria isolated from meat and dairy plants. Determination also of biofilm growth at two nutrient levels. L. monocytogenes was able to grow in multispecies biofilms formed on stainless steel at 10°C in the presence of bacteria isolated from dairy and meat plant environments. Biofilm L. monocytogenes increased more slowly in the presence of competing microflora than in monoculture, but none of the 8 competing isolates studied were able to completely exclude L. monocytogenes from the biofilm within 25 days of incubation. Once a population of L. monocytogenes was established on the surface, it invariably increased in numbers. In biofilms containing a mixture of 4 competitive cultures, L. monocytogenes maintained itself at about 1% of the total population.
Kotula, K.L., Kotula, A.W., Rose, B., Pierson, C., and
Camp, M. 1997. Reduction of aqueous chlorine by organic material. J. Food
KEYWORDS: Sanitizer, chlorine, aqueous, residual, depletion, organic, albumin, serum, lean, muscle, adipose,
ABSTRACT: Study with purpose to determine chlorine depletion due to the presence of serum albumin, Trypticase soy agar, adipose tissue, and lean muscle tissue and to characterize the bactericidal effect of aqueous chlorine using the Chambers method. Aqueous chlorine is used to reduce surface bacteria populations on carcasses of slaughter animals after evisceration, during chilling, and after transport; however, it dissipates in the presence of organic matter. The study characterized the amount of residual chlorine present when aqueous HOCl was exposed to bovine serum albumin, bovine lean muscle, porcine adipose tissue, or Trypticase soy agar surfaces. Chlorine depletion by albumin was almost instantaneous, but was influenced by the amount of albumin present and the initial chlorine concentration. Chlorine exposed to organic surfaces was reduced most readily by lean muscle, then by Trypticase soy agar, and least by adipose tissue. Thirteen pure bacterial cultures and two mixed cultures associated with meat were exposed to aqueous chlorine to characterize the effectiveness of the chlorine. All cultures except B. cereus and E. faecalis were destroyed within 15 s by 3 ppm chlorine. Based on the data, it is concluded that available chlorine reduction is dependent on exposure time, chlorine concentration, and amounts/source of organic material, and that bacterial inactivation by aqueous chlorine is species specific. Estimation of chlorine dose for carcass decontamination during washing and chilling can be facilitated using the data from this study.
Krysinski, E.P., Brown, L.J., and Marchisello, T. 1992.
Effect of cleaners and sanitizers on Listeria monocytogenes attached
to product contact surfaces. J. Food Prot. 55(4):246-251.
KEYWORDS: Sanitizer, cleaner, biofilm, L. monocytogenes, polyester, polyurethane, stainless steel, inactivation, HACCP
ABSTRACT: Evaluation of a variety of chemical cleaning and sanitizing compounds for their ability to remove and/or inactivate surface adherent L. monocytogenes. Resistance of adherent cells to sanitizers was dependent upon the surface studied, being greatest on polyester/polyurethane followed by polyester and stainless steel. Biofilm removal with cleaners followed the same pattern as sanitizers with the polyester/polyurethane surface being most difficult to clean. Complete biofilm removal and/or inactivation was obtained in many cases where the surface was first cleaned prior to exposure to sanitizer. This supports conventional wisdom in that cleaning must precede sanitizing in order to remove and inactivate microorganisms. Listeria biofilms should be controllable by combining good manufacturing practices with the discipline of a Hazard Analysis Critical Control Point program.
Kupfer, G.A. 1993. Tests conducted by NSF International
indicate no difference in safety between wood and plastic cutting boards.
NSF International. Ann Arbor, MI. August 20, 1993.
KEYWORDS: Sanitizer, cutting board, wood, plastic, comparison, bacteria, survival, viability, E. coli
ABSTRACT: Announcement, following completion of a series of tests to determine differences in bacterial viability potential between wood and plastic cutting boards and the effects of these on a common bacteria that may cause food poisoning. Results of NSF study indicate no difference between the two materials. This contradicts results of a study at the University of Wisconsin, in which wooden cutting boards were found to kill bacteria that survive well on plastic boards. In the NSF study, wood and plastic surfaces were compared for viability of E. coli, and the effects of wood dust and wood and plastic chips on cultures of E. coli were tested. No difference in growth support potential of either surface was demonstrated for the E. coli.
Lee, S.-H., and Frank, J.F. 1991. Inactivation of surface-adherent
Listeria monocytogenes [by] hypochlorite and heat. J. Food Prot.
KEYWORDS: Sanitizer, L. monocytogenes, adherence, stainless steel, resistance, thermal, heat, hypochlorite, inactivation
ABSTRACT: Research with objective to determine the resistance to hypochlorite and heat of adherent cells of L. monocytogenes attached to stainless steel. Although the 4 h and 8 d adherent populations were at similar levels, 8 d adherent cells were over 100 times more resistant than the 4 h adherent cell population when exposed to 200 ppm hypochlorite for 30 s. When stainless steel slides containing adherent cells were heated at 72°C both adherent cell populations were inactivated after 1 min. Detectable numbers of L. monocytogenes remained on stainless steel slides after treatment at 65°C for 3 min when adherent 8 d cells were tested but not when adherent 4 h cells were used.
Marshall, KC 1992. Biofilms: an overview of bacterial
adhesion, activity, and control at surfaces. Am. Soc. Microbiol. News.
KEYWORDS: Sanitizer, biofilm, overview, adhesion, adsorption, surface, response, growth, development, control
ABSTRACT: Provides definition for what is otherwise described as the visibly slimy layer on solid surfaces. Describes biofilm as ubiquitous in flowing aqueous environments, developing on virtually all surfaces immersed in natural aqueous environments, without respect for whether that surface is biological (aquatic plants and animals) or otherwise (stones, particles, metal, concrete, etc.). Examples of biofilms include those fouling ship hulls and water conduits, those forming on heat exchanger surfaces (rendering the unit almost inoperative), those in the human and in animal gastrointestinal tracts (colonies of bacteria that provide a degree of protection from pathogenic species), those forming on the surface of prosthetic devices inserted into the human body (S. epidermidis), those in water reticulation systems (which may protect potentially pathogenic bacteria [e.g., Legionella spp.] from the effects of chlorination), those in dental plaque which can lead to tooth decay, those forming on contact lenses, and so forth. Topics discussed include why biofilms form, molecular adsorption to surfaces, bacterial adhesion to surfaces, physiological responses in bacteria at surfaces, bacterial growth and biofilm development, ecophysiology of biofilms, and control of biofilm development.
Miller, A.J., Brown, T., and Call, J. 1994. Comparison
of bacterial adherence to wooden and plastic cutting boards. U.S. Department
of Agriculture, Agricultural Research Service, Eastern Regional Research
Center. Philadelphia, PA. November 21, 1994.
KEYWORDS: Sanitizer, cutting board, polyethylene, plastic, hardwood, wood, ground beef, E. coli, adherence, removal, bacteria, inhibition
ABSTRACT: Comparison of adherence and removal potential of beef bacterial microflora to polyethylene and hardwood cutting boards. Ground beef was placed for 0-90 min onto cutting boards at room temperature, removed, then surface swabs were performed and enumerated. Boards were cleaned with various cleaning agents, then analyzed for bacterial removal potential. Aqueous extracts from 8 hardwoods were then incubated with Escherichia coli O157:H7 for 0-30 h at 37°C to determine their inhibitory potential. Differences were not significant between bacterial levels on wooden and plastic boards regardless of contact time. Washing with any cleaner, including water, removed most bacteria from either board type. White ash extracts reduced E. coli levels to undetectable within 24 h; black cherry and red oak exhibited low inhibitory activity. Slight growth was observed in extracts from all other hardwoods, including hard maple, suggesting that aqueous extractable agents that are active against E. coli O157:H7 are generally not present in hardwoods. The study demonstrates the need to control cutting board sanitation regardless of composition.
Mosley, E.B., Elliker, P.R., and Hays, H. 1976. Destruction
of food spoilage, indicator and pathogenic organisms by various germicides
in solution and on a stainless steel surface. J. Milk Food Technol. 39(12):830-836.
KEYWORDS: Sanitizer, comparison, antibacterial, efficacy, iodophor, sodium hypochlorite, quaternary ammonium compound, QAC, stainless steel, S. derby, E. coli, Candida, P. aeruginosa, S. aureus, S. lactis, B. licheniformis, dairy processing, meat processing
ABSTRACT: Study to compare several newly developed imported iodophors with five widely used domestic preparations, including two iodophors, sodium hypochlorite, and two quaternary ammonium compounds. Further objective to develop a procedure that simulates actual use of germicides in food and dairy industries. As most dairy industry pipelines, vats and processing equipment, and most meat and poultry plant surface areas are of stainless steel, special polished stainless steel strips were inoculated with organisms and exposed to different concentrations of germicides for various time periods. Representative food spoilage, indicator, and pathogenic organisms were used in the study, including S. derby, E. coli, yeast of the genus Candida, P. aeruginosa, S. aureus, S. lactis, and spore of B. licheniformis. Results of the germicide experiments showed generally similar effectiveness by iodophor and hypochlorite. Both were superior to the quaternary ammonium compounds when used at much lower concentrations. The iodophors exhibited a consistently greater rate of destruction of yeast cells than the hypochlorite when low concentrations of germicide were used. As for tests using the polished stainless steel strips, the halogen compounds were again superior to the QAC in destroying the bacterial cells, especially against gram-negative species including Salmonella.
Mossel, D.A.A., Kampelmacher, E.H., and van Noorle Jansen,
L. 1966. Verification of adequate sanitation of wooden surfaces used in
meat and poultry processing. Zbl. Bakt I Orig. 201:91-104.
KEYWORDS: Sanitizer, cutting board, wood, quantitative, cross-contamination, Salmonella, meat processing
ABSTRACT: Study of the quantitative aspects of the contamination of initially pathogen-free proteinaceous staple foods by such wooden surfaces as chopping blocks after these have been sanitized by the use of some current agents, especially abrasive ones. The ultimate intent of the study was to break the chain of contamination, by which Salmonella has been shown to spread from clinically healthy carriers to previously Salmonella-free red meat and poultry by means of contact with surface contamination. Either of the three tests (calcium alginate swab, agar "sausages" [Ten Cate], and mending tape or sticky film [Thomas]) was quite useful to establish proper sanitation immediately after such a treatment had been carried out. However, when checking on the adequacy of decontamination some twelve hours afterwards, a more involved procedure was required to differentiate between proper sanitation and the apparent "spontaneous dying off" of Enterobacteriaceae. It was found that by moistening the wooden surface area with a nontoxic resuscitation fluid of reduced surface tension prior to examination, a more real effect could be observed (or, in the words of the article, the "non-real-effect" was eliminated).
Mosteller, T.M., and Bishop, J.R. 1993. Sanitizer efficacy
against attached bacteria in a milk biofilm. J. Food Prot. 56(1):34-41.
KEYWORDS: Sanitizer, gasket, rubber, Teflon, enumeration, efficacy, biofilm, attached, suspended, iodophor, hypochlorite, acid anionic, peroxyacetic acid, fatty acid, quaternary ammonium, bacteria, Y. enterocolitica, P. fluorescens
ABSTRACT: Study with objectives to evaluate the efficacy of in-use concentrations of sanitizers on bacteria attached to gasket materials, to compare bacterial attachment to rubber and Teflon gaskets, to examine different methods of enumeration, and to compare sanitizer efficacy on attached and suspended bacteria. The goal reduction for all of the sanitizers tested was > or = 3 log cycles or 99.9%. Results indicated that iodophor, hypochlorite, acid anionic, peroxyacetic acid, fatty acid, and quaternary ammonium sanitizers failed to provide an adequate reduction in the numbers of attached bacteria at levels of 104 to 105/mm2 in most cases. The test organisms attached in slightly higher numbers to the rubber surface versus Teflon. Plate counts, impedance microbiology, and the direct epifluorescent filter technique were tested as methods of enumeration. Impedance microbiology was the best method of enumeration, since it allowed the estimation of both reversibly and irreversibly attached bacteria. The goal reduction (for attached and suspended bacteria) was reached on the Teflon surface with the iodophor, hypochlorite, and fatty acid sanitizers with a log-cycle reduction in the number of Yersinia enterocolitica of 3.09, 3.19, and 3.31, respectively. Pseudomonas fluorescens was reduced by 3.16 on both the rubber and Teflon surfaces when exposed to the hypochlorite sanitizer.
Mullerat, J., Klapes, N.A., and Sheldon, B. 1994. Efficacy
of Salmide, a sodium chlorite-based oxy-halogen disinfectant, to inactivate
bacterial pathogens and extend shelf-life of broiler carcasses. J. Food
KEYWORDS: Sanitizer, Salmide, sodium chlorite, oxyhalogen, broiler, chicken, skin, S. typhimurium, bacteriocide, inactivation, shelf life, extension
ABSTRACT: Evaluation of the bacteriocidal efficacy of various Salmide applications against an antibiotic-resistant S. typhimurium strain inoculated onto fresh broiler drumstick skin. The biocidal activity of Salmide (sodium chlorite-based oxyhalogen disinfectant) was tested alone and in combination with either l.34 mM disodium ethylenediaminetetraacetic acid (EDTA), 0.347 mM sodium lauryl sulfate or 210 mM trisodium phosphate against a nalidixic acid-resistant strain of S. typhimurium inoculated onto fresh broiler drumstick skin. Each Salmide test concentration applied in combination with 1.34 mM EDTA produced S. typhimurium population reductions in excess of 97%. A similar trend was observed for treatments containing 27, 54, or 81 mM Salmide and 0.347 mM sodium lauryl sulfate. However, when S. typhimurium was exposed to 210 mM trisodium phosphate alone, a 99.5% population reduction was observed. This value was not significantly different from those obtained for treatments containing 210 mM trisodium phosphate and any of the three levels of Salmide. Based on the enumeration of mesophilic and psychotropic populations, the combined Salmide and EDTA treatment was shown to produce a slight extension in broiler drumstick shelf life compared with an untreated control.
Oh, D.H., and Marshall, D.L. 1995. Destruction of Listeria
monocytogenes biofilms on stainless steel using monolaurin and heat.
J. Food Prot. 57(3):251-255.
KEYWORDS: Sanitizer, antimicrobial, monolaurin, heat, adherent, planktonic, stainless steel, biofilm, L. monocytogenes
ABSTRACT: Determination of individual and combined antimicrobial effects of monolaurin and heat on planktonic, 1-day adherent, or 7-day adherent cells of L. monocytogenes in order to evaluate biofilm removal from stainless steel. Planktonic cells were more sensitive to heat and monolaurin than were cells attached to stainless steel; and 1-day adherent biofilm cells were more sensitive to each treatment than were 7-day adherent cells. Adherent cells were destroyed by 50 µg/ml monolaurin combined with heating at 65°C for 5 min. Cells in a rich nutrient environment were more resistant to treatment than were cells in a depleted nutrient environment. Results demonstrate the usefulness of combining chemical and physical treatments to control L. monocytogenes biofilm problems in the food industry.
Olson, W., Vesley, D., Bode, M., Dubbel, P., and Bauer,
T. 1994. Hard surface cleaning performance of six alternative household
cleaners under laboratory conditions. J. Environ. Health. 56(6):27-31.
KEYWORDS: Sanitizer, disinfectant, commercial, alternative, lemon juice, vinegar, ammonia, baking soda, borax, antimicrobial, antibacterial, cleaner
ABSTRACT: Comparison of several commercially available household bathroom and kitchen cleaning products (with and without EPA registered disinfectant properties) with several "alternative" products, including lemon juice, vinegar, ammonia, baking soda and borax. Test criteria included microbial reduction, based on remaining colony forming units of a tracer organism (Serratia marcescens), and soil reduction (of simulated bathroom and kitchen soil formulations) based on subjective grading by a panel of individuals. Among bathroom cleaners, the commercial cleaners and vinegar gave the most effective microbial reduction while a commercial cleaner without disinfectant was most effective at soil removal. Among kitchen cleaners, again the commercial products and vinegar were most effective at microbial reduction while the commercial cleaners and ammonia were most effective at soil removal.
Parnes, C.A. 1997. Efficacy of sodium hypochlorite bleach
and "alternative" products in preventing transfer of bacteria to and from
inanimate surfaces. Environ. Health. January/February):14-20.
KEYWORDS: Sanitizer, sodium hypochlorite, bleach, alternative, ammonia, baking soda, borax, vinegar, detergent, efficacy, comparison, bacteria, inactivation, S. aureus, S. typhi, E. coli
ABSTRACT: Investigation of the ability of sodium hypochlorite bleach at the dilution recommended for disinfection of nonporous surfaces, and several "alternatives" (ammonia, baking soda, borax, vinegar, and a liquid dishwashing detergent) at concentrations in excess of normal recommendations for use, to kill and/or remove bacteria from surfaces. Exploration of the ability of these products to prevent the transfer of bacteria from one surface to another. Results of initial tests using a procedure required by the EPA for the determination of disinfectant efficacy of dilutable products, indicated that only bleach was effective against S. aureus, S. typhi, and E. coli. These organisms represent the wide array of Gram positive and negative bacteria found on various surfaces. Although undiluted ammonia and vinegar also showed antimicrobial activity against the Gram negative organisms S. typhi and E. coli, none of the "alternatives" were effective against the Gram positive bacteria, S. aureus. As the identity of bacteria on any surface is unknown by the consumer, the use of a disinfectant proven to have a broad spectrum of antimicrobial activity is suggested by the author to be more prudent than using a substance having limited or no efficacy.
Prescott, L.M., Harley, J.P., and Klein, D. 1996. Wooden
versus plastic cutting boards. Microbiology. 3rd Ed. Wm. C. Brown. Dubuque,
KEYWORDS: Sanitizer, cutting board, wood, plastic, comparison, antimicrobial, antibacterial, phenolic, lignin, enzyme
ABSTRACT: Mentions the controversy concerning wooden cutting boards and those made of plastic, specifically which material is better at minimizing survival and cross contamination from microorganisms associated with uncooked foods. It is stated that wooden cutting boards have been found to be antimicrobial, unlike plastic cutting boards. It is suggested that this effect may be due to water-soluble phenolics from the lignin, which makes up approximately one-third of wood. The sensitivity of enzymes to water-soluble wood constituents is also discussed, as in the use of wooden toothpicks to transfer microbial isolates for use in the polymerase chain reaction.
Raloff, J. 1993. Wood wins, plastic trashed for cutting
meat. Science News. 143(February 6):84-85.
KEYWORDS: Sanitizer, cutting board, wood, plastic, comparison, recovery, survival, bacteria, impermeability
ABSTRACT: Provides some of the benefits of wooden cutting boards, including less damage to knife blades than plastic or glass, but cites recommendation from many sources including kitchen suppliers and USDA to use plastic, supposedly because the less porous material gives bacteria less chance of escaping rigorous cleaning, therefore reducing the chance of bacteria surviving to contaminate other foods. Continues by providing results of research by D.O. Cliver and N.O. Ak. This study was intended to identify decontamination techniques to render wood as safe as plastic, but instead demonstrated no recoverable bacteria following inoculation onto wooden cutting boards. This apparent bacteriocidal effect of wood was also demonstrated at high humidity and room temperature, while the bacteria grew on plastic under the same conditions. Treatment of wooden boards with mineral oil made the wood more impermeable, and thus allowed the bacteria to survive longer. A USDA microbiologist admitted knowing of no scientific study demonstrating the advantages of one surface material over another in inhibiting bacterial contamination. But, according to O.P. Snyder, this federal agency, like state and local inspectors, have "bought the myth" that plastic is safer than wood, and even if others confirm the data by Cliver and Ak, it may be some time before any requirements for plastic cutting boards are eliminated.
Restaino, L., Frampton, E.W., Bluestein, R., Hemphill,
J., and Regutti, R. 1994. Antimicrobial efficacy of a new organic acid
anionic surfactant against various bacterial strains. J. Food Prot. 57(6):496-501.
KEYWORDS: Sanitizer, buffered organic acid anionic surfactant, antimicrobial, efficacy, S. aureus, S. typhimurium, P. aeruginosa, L. monocytogenes
ABSTRACT: Study with objectives to compare the antimicrobial properties of various concentrations (0.6 to 1.75%) of a new buffered organic acid anionic surfactant with six traditional sanitizers at recommended concentrations when applied to a Formica surface previously inoculated with S. aureus, and to ascertain its effectiveness at 0.6% concentration against four bacterial strains important in the food industry. In the absence of organic material, the traditional sanitizers were not significantly different from water in reducing S. aureus at time 0, whereas > or = 1.2% buffered organic acid anionic surfactant reduced a significantly greater number of bacteria. When compared with water over 60 min, only the acid anionic surfactant significantly reduced S. aureus cells. Sixty minutes after exposure, a 1.75% concentration of the acid anionic surfactant was 100 times more effective than organic chlorine. Overall, the organic material reduced the effectiveness of the traditional sanitizers and the acid anionic surfactant. In the presence of 0.5% protein, the acid anionic surfactant levels > or = 0.6% significantly reduced more S. aureus cells than the quaternary ammonium sanitizer immediately after application. The acid anionic surfactant at levels > or = 0.6% were significantly more effective in reducing S. aureus during a 60 min exposure than the organic chlorine sanitizer. In a separate efficacy study, a concentration of 0.6% killed > 5 logs of S. aureus, Salmonella typhimurium, Pseudomonas aeruginosa and Listeria monocytogenes cells after 30 s exposure.
Roy, B., Ackermann, H.-W., Pandian, S., Picard, G., and
Goulet, J. 1993. Biological inactivation of adhering Listeria monocytogenes
by listeriaphages and a quaternary ammonium compound. Appl. Environ. Microbiol.
KEYWORDS: Sanitizer, L. monocytogenes, inactivation, adhesion, phage, listeriaphage, QAC, efficacy, stainless steel, polypropylene, plant, environment,
ABSTRACT: Study intended to evaluate the efficacy of listeriaphages in sanitizing stainless steel and polypropylene surfaces contaminated with L. monocytogenes. Overall objective was to develop a biodisinfectant formulation specifically active against L. monocytogenes and capable of preventing its development in food and food-processing plants. Phage suspensions at concentrations of up to 3.5 x 108 PFU/ml were at least as efficient as a 20 ppm solution of a quaternary ammonium compound in reducing L. monocytogenes populations. A synergistic activity was observed when two or more phages were used in combination and when phages were suspended in quaternary ammonium compound. The biological activity of the three phages was not affected by quaternary ammonium compound concentrations of 50 ppm and a contact time of 4 h.
Scalzo, A.M., Dickerson, R.W., and Read, R. 1969. A method
for measuring dish temperature in commercial dishwashers. J. Milk Food
KEYWORDS: Sanitizer, dishwasher (commercial), thermometer (paper), evaluation
ABSTRACT: Evaluation for measuring maximum surface temperature of dishes during commercial dishwashing in a single-tank, conveyor-type unit using paper thermometers that change, irreversibly, from white to black at a critical temperature. A thermocouple, taped to a dish, was used to determine the maximum temperature attained at the surface of the dishes; this result was compared with the measurement obtained from a paper thermometer affixed to the dish. Measurements of temperature by the two methods were within the 10°F span of the paper thermometer. Paper thermometers were found satisfactory for measuring the maximum temperature of the dish surface during dishwashing and also appear useful for routine checking of dishwasher performance.
Scheusner, D.L. 1982. Methods to evaluate cleaners and
sanitizers. J. Food Prot. 45(13):1257-1260.
KEYWORDS: Sanitizer, antibacterial, cleaning, evaluation, method, standard, laboratory, reproducibility, AOAC, in-use, swab, sponge, tube sampler, contact plate, recovery, simulated-use, tray test
ABSTRACT: Divides methods to evaluate germicides into three categories: standard laboratory tests (such as the Available Chlorine Germicidal Equivalent test, which are specifically defined for reproducibility in any laboratory by any operator, but the test results often lack relevance to actual product use conditions), in-use tests (which are relevant to product use, but the procedures for which do not permit proper controls to be included in the organism recovery methods) and simulated-use tests (which are relevant to actual product use). An additional example of a standard laboratory test is the Germicidal and Detergent Sanitizers test (also an AOAC test); in-use testing recovery methods discussed include cotton swab, cellulose sponge, tube sampler, and contact plate. For simulated-use testing, the example given is the tray test, in which a cafeteria tray is soiled, inoculated and cleaned in a manner to simulate actual product use. This test method permits the necessary controls to be used. Tray test reproducibility is as good as that of the other recovery methods tested and organism recovery is quantitative. The tray test provides a means for determining biological cleaning where the effect of both cleaning and germicidal activity are measured together.
Scott, E., Bloomfield, S.F., and Barlow, C. 1984. Evaluation
of disinfectants in the domestic environment under 'in use' conditions.
J. Hyg. (Camb.). 92:193-203.
KEYWORDS: Sanitizer, evaluation, effectiveness, efficacy, domestic, kitchen, bathroom, hypochlorite, phenolic
ABSTRACT: Study with objective to develop an 'in use' test to investigate effectiveness of disinfectant application and of detergent and hot water cleaning of kitchen, bathroom, and toilet to represent the domestic environment. Detergent and hot water cleaning produced no observable reduction in microbial contamination. Single and daily application tests demonstrated that hypochlorite and phenolic disinfectants can be used to produce substantial reductions in bacterial contamination in the home. Results indicate that maximum protection afforded by disinfection is relatively brief; 3-6 h after disinfection, contamination levels were only marginally less than those observed at pretreatment. Some suggestions are made for improvements in home hygiene.
Stewart, P.S., Griebe, T., Srinivasan, R., Chen, C., Yu,
F., deBeer, D., and McFeters, G. 1994. Comparison of respiratory activity
and culturability during monochloramine disinfection of binary population
biofilms. Appl. Environ. Microbiol. 60(5):1690-1692.
KEYWORDS: Sanitizer, respiration, culturable, monochloramine, biofilm, efficacy, evaluation, oxygen, glucose, redox
ABSTRACT: Report comparing various measures of respiratory activity with colony-forming activity as indicators of the efficacy of biofilm disinfection. Bacterial biofilms were exposed to monochloramine and biocidal efficacy was evaluated by plate counts, microelectrode-measured oxygen concentration profiles across the biofilms, overall glucose consumption rates, and ability of individual bacteria to reduce a redox stain. Biofilm bacteria challenged with monochloramine retained significant respiratory activity, even though they could not be cultured on agar plates. Microbial colony counts on agar media declined by approximately 99.9% after 1 hr of disinfection, whereas the number of bacteria stained by a fluorescent redox dye experienced a 93% reduction. Integrated measures of biofilm respiratory activity, including net oxygen and glucose utilization rates, showed only a 10 to 15% reduction. In this biofilm system, measures of microbial respiratory activity and culturability yielded widely differing estimates of biocide efficacy.
Tarquin, A.J., and Rittmann, D.D. 1992. Can chlorine dioxide
and activated carbon control THM? Water Eng. Mgmt. June):16-17.
KEYWORDS: Sanitizer, water supply, trihalomethane, chlorine dioxide, activated carbon (granulated)
ABSTRACT: Comparison of the effectiveness of chlorine dioxide relative to powdered activated carbon and granular activated carbon for reduction of trihalomethanes in water produced at the city of El Paso's surface water treatment plants in Texas. Conclusions were made from the results as follows: 1) Chlorine dioxide appears to be very effective for reducing trihalomethane concentration in drinking water, but a mechanism for removing residual chlorites and chlorates must be included in the process; 2) Powdered activated carbon does not appear to be an acceptable treatment method for achieving a significant reduction of trihalomethane in drinking water. 3) Granulated activated carbon is very effective at reducing trihalomethane concentration to a very low level, even at empty bed contact times as low as five minutes.
Tebbutt, G.M. 1991. An assessment of cleaning and sampling
methods for food-contact surfaces in premises preparing and selling high-risk
foods. Epidemiol. Inf. 106:319-327.
KEYWORDS: Sanitizer, method, assessment, effectiveness, contact, agar, swab, alginate, sample, surface, brush, nylon, wood, polypropylene, paper, detergent, hypochlorite
ABSTRACT: Study comparing the performance of alginate swabs and agar-contact plates for sampling different types of food surfaces before and after cleaning. Examination of the effectiveness of a variety of surface cleaning methods, and assessment of the acceptability of the different techniques. Contact plates were more convenient, and were at least as sensitive as the swabbing method. To assess cleaning efficacy, repeated sampling was carried out in selected premises and several cleaning methods were introduced for trial periods. Some surfaces, notably wood and polypropylene, were particularly difficult to clean. For these, scrubbing with a nylon brush was the best method. Other surfaces were more easily cleaned, and generally the methods introduced as part of this study were better than the original method used in the premises. Paper proved to be unpopular, and cleaning solutions applied with it did no better than those cleaned with a multiuse cloth kept soaking in a detergent and hypochlorite solution.
Welker, C., Faiola, N., Davis, S., Maffatore, I., and
Batt, C. 1997. Bacterial retention and cleanability of plastic and wood
cutting boards with commercial food service maintenance practices. J. Food
KEYWORDS: Sanitizer, cutting board, wood, plastic, comparison, bacteria, retention, cleaning, E. coli, adenosine triphosphate
ABSTRACT: Study with objective to compare the bacterial retention and cleanability of plastic and wooden cutting boards under conditions commonly found in commercial food service operations. Plastic and wood boards were subjected to repeated hand and machine washing to simulate wear that would occur during commercial usage. Electron microscopy revealed a more pronounced wearing of the wood surface as compared with the plastic, with cracks on the wood that were sufficiently wide to entrap bacteria. New and previously washed wood and plastic surfaces were inoculated with E. coli and then washed using standard food service washing and sanitizing procedures. The plastic surfaces were consistently cleaner than wood surfaces by measurement of residual adenosine triphosphate; wood surfaces that had been hand washed five times prior to inoculation were significantly less clean than any other surfaces or treatments. Even after standard food service washing and sanitizing, colonies of the inoculated bacteria were observed sporadically, but only on wood surfaces and not on plastic. Results suggest that wood surfaces can absorb moisture and in effect can absorb contaminating bacteria, and the difficulty in removing these bacteria may made this material less desirable from a food safety perspective.
Worsfold, D., and Griffith, C.J. 1996. An assessment of
cleanliness in domestic kitchens. Hygiene & Nutrition in Foodservice
& Catering. 1:163-173.
KEYWORDS: Sanitizer, assessment, luminometer, ATP, bioluminescence, assay, kitchen, surface, cleanliness, standard, guideline
ABSTRACT: An investigation, using a luminometer, undertaken to determine the extent of soiling and the effectiveness of routine cleaning in domestic kitchens. The cleanliness of 5 hand or food contact surfaces in 47 domestic kitchens was determined by meats of ATP bioluminescence assay. There was a wide range of ATP levels on the surfaces but overall the levels exceeded those found on surfaces which had been cleaned according to recommended sanitation practice. The difficulties of establishing and maintaining realistic standards of cleanliness in the domestic kitchen are reviewed and recommendations for improvements are given.
Yu, F.P., and McFeters, G.A. 1994. Physiological responses
of bacteria in biofilms to disinfection. Appl. Environ. Microbiol. 60(7):2462-2466.
KEYWORDS: Sanitizer, response, physiological, biofilm, enumeration, chlorine, monochloramine, disinfection, bacteria, viability, survival, respiration
ABSTRACT: Study observing changes in the physiological activities of attached bacteria with exposure to disinfectants without disrupting biofilm integrity by using 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), rhodamine 123, and tritiated uridine incorporation. Enumeration results obtained by these methods were compared with those from the plate count and direct viable count methods. CTC is an indicator of bacterial respiratory activity, rhodamine 123 is incorporated into bacteria in response to transmembrane potential, and the incorporation of uridine represents the global RNA turnover rate. The results acquired by these methods following disinfection exposure showed a range of responses and suggested different physiological reactions in biofilms exposed to chlorine and monochloramine. The direct viable count response and respiratory activity were affected more by disinfection than were the transmembrane potential and RNA turnover rate on the basis of comparable efficiency as evaluated by plate count enumeration. Information revealed by these approaches can provide different physiological insights that may be used in evaluating the efficacy of biofilm disinfection.
Zottola, E.A. 1994. Microbial attachment and biofilm formation:
a new problem for the food industry? Food Technol. 48(7):107-114.
KEYWORDS: Sanitizer, biofilm, attachment, overview, bacteria, control
ABSTRACT: A science status summary which focuses on undesirable bacterial attachment and biofilm formation in food systems. Cites major contributors to the study of bacterial attachment, beginning with Zobell (1943). Topics discussed include attachment in aquatic systems, the 5-stage process theory of biofilm formation, attachment on meat and poultry surfaces, biofilm in food processing systems, and implications in food processing systems. Suggests over 10 topics of future research needs, and adds that the list is by no means complete. Concludes by emphasizing the importance of correct cleaning and sanitizing procedures in food processing systems, since microorganisms in a biofilm can apparently be controlled in the same way as microorganisms elsewhere in food processing systems.
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