scholarly journals Bacteriological investigation of the washing and sterilization of food containers

1947 ◽  
Vol 45 (2) ◽  
pp. 151-158 ◽  
Author(s):  
R. Knox ◽  
Jacqueline Walker
Keyword(s):  
Great Improvement ◽  
Hot Water ◽  
Routine Method ◽  
Steam Sterilization ◽  
Education Department ◽  
Large Numbers ◽  
Before And After ◽  
Plate Counts ◽  
Bacteriological Investigation ◽  
Washing Water

1. We have investigated bacteriologically the conditions in a central meals kitchen from which about 3000 meals were issued daily to some 65 departments.2. Plate counts showed that the containers in which the meals were sent out contained large numbers of organisms, from several thousand to several hundred thousand per container.3. Counts of this order were obtained both before and after the routine method of washing.4. These counts were reduced to the order of a few hundred or less per container by steam sterilization.5. Exposure for 2–3 min. to steam from a simple jet sterilizer was effective for all except large insulated lids which required at least 5 min.6. Treatment for 5 min. in a chamber filled with steam from a boiler was effective with all types of containers and lids tested.7. If containers are to be sterilized at all they must be sterilized each time they are to be used.8. A great improvement in the bacteriological counts can be achieved by attention to the hygiene of washing, e.g. by the use of plenty of hot water with soap and soda or perhaps preferably with detergents, with a second sink of very hot water for rinsing, and by using fresh sterilized dish-cloths each time the washing water is changed.9. Counts almost as good as those given by steam sterilization were obtained by washing with soap and water at 48–50° C., wiping with a sterilized dish-cloth and then rinsing in a second sink of water at 75–80° C.10. The arguments for and against steam sterilization are discussed.This investigation was greatly helped by the co-operation of the Leicester Education Department.

Decontamination of Knives Used in the Meat Industry: Effect of Different Water Temperature and Treatment Time Combinations on the Reduction of Bacterial Numbers on Knife Surfaces

2008 ◽  
Vol 71 (7) ◽  
pp. 1338-1342 ◽  
Author(s):  
REBECCA M. GOULTER ◽  
GARY A. DYKES ◽  
ALISON SMALL
Keyword(s):  
Treatment Time ◽  
Hot Water ◽  
Meat Industry ◽  
Bacterial Reduction ◽  
Industry Effect ◽  
Before And After ◽  
International Regulations ◽  
Plate Counts ◽  
Alternative Procedures ◽  
Knife Blade

Previous regulations in Australia and internationally required that knives used during the slaughter and dressing of carcasses be sanitized by brief submersion in water at 82°C. Many current international regulations allow science-based equivalent alternative procedures to be used. However, limited time-temperature data are available on the response of bacteria to hot-water treatment on knives. The present study was undertaken to determine the effect of combinations of time and temperature ranging from 1 to 60 s and 60 to 82°C on the disinfection of knives artificially contaminated with Escherichia coli and Listeria monocytogenes. In addition, the effect of a prerinse at 40°C on the disinfection of artificially contaminated knives treated under the same controlled conditions as above was established. The experiments, which were carried out with knives in a meat matrix at each of 42 time and temperature combinations, with and without the prerinse, were performed in a laboratory water bath. Bacterial reductions were established by plate counts from the knife blade before and after immersion. Mean log reductions were subjected to statistical analysis, and basic models were generated from the results. The results demonstrated that dipping knives in water for shorter times at higher temperatures, for example, 82°C for 1 s, or longer times at lower temperatures can produce equivalent inactivation of bacteria. Prerinsing knives at 40°C increases the performance of the subsequent dipping step. Models produced from the data in this study can be used to predict suitable combinations of time and temperature to achieve a desired bacterial reduction.

scholarly journals 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

1970 ◽  
Vol 68 (2) ◽  
pp. 221-232 ◽  
Author(s):  
R. J. Gilbert
Keyword(s):  
Control Method ◽  
Field Trials ◽  
Surface Sampling ◽  
Step Procedure ◽  
Cleaning Equipment ◽  
Before And After ◽  
Plate Counts ◽  
Self Service ◽  
Materials Used ◽  
Retail Food

SUMMARYThere is no official scheme for testing disinfectants and detergent/disinfectants for use in the retail food trade and few recommended procedures have been given for the cleaning of equipment with these agents. Therefore, field trials were carried out in a large self-service store. 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 (0·75 % w/v) and hypochlorite (200 p.p.m. available chlorine) 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.

scholarly journals Endotoxin contamination in the dental surgery

2007 ◽  
Vol 56 (9) ◽  
pp. 1230-1234 ◽  
Author(s):  
M. K. Huntington ◽  
J. F. Williams ◽  
C. D. Mackenzie
Keyword(s):  
Bacterial Load ◽  
Dental Surgery ◽  
Paired Samples ◽  
Dental Procedures ◽  
Large Numbers ◽  
Endotoxin Exposure ◽  
Endotoxin Contamination ◽  
Plate Counts ◽  
High Concentrations ◽  
Heterotrophic Plate Counts

Dental waterlines contain large numbers of Gram-negative bacteria. Endotoxin, a component of such organisms, has significant health implications. Paired samples of dental unit water and the aerosols generated during dental procedures were collected, and assayed for bacteria and endotoxin levels, using heterotrophic plate counts and the Limulus amoebocyte lysate test. Consistent with published studies, the extent of bacterial contamination in the dental waters sampled for this investigation surpassed the levels associated with potable water, with counts in excess of 2.0×106 c.f.u. ml−1 in some samples. Correspondingly high concentrations of endotoxin [up to 15 000 endotoxin units (EU) ml−1] were present in the water. A statistically significant Spearman correlation coefficient of ρ=0.94 between endotoxin (EU ml−1) and bacterial load (c.f.u. ml−1) was demonstrated. All of the aerosol samples contained detectable endotoxin. Further studies of the consequences of dental endotoxin exposure, and evaluation of means to prevent exposure, are warranted.

scholarly journals Hot-Water Treatment of Mango Fruits to Reduce Anthracnose Decay

1969 ◽  
Vol 46 (4) ◽  
pp. 272-283
Author(s):  
William Pennock ◽  
Gilberto Maldonado
Keyword(s):  
Water Treatment ◽  
Water Temperature ◽  
Safety Margin ◽  
Hot Water ◽  
Hot Water Treatment ◽  
Mango Fruit ◽  
Commercial Practice ◽  
Before And After

1. Anthracnose damage was greatly reduced in mango fruit picked at shipping maturity and immersed in hot water before storage and subsequent ripening. 2. The equipment and method of treating the fruits are described and discussed. 3. A precise technique which was devised for measuring anthracnose damage before and after storage is also described. 4. Immersion of the fruit for 15 minutes in water held at temperatures between 51° C. and 51.5° C., with a safety margin of 0.5° C., is recommended for commercial practice before packing and shipment. Water temperature must be kept below 52° C. to prevent possible scalding of the fruit.

Parameters predictive of Legionella contamination in hot water systems: Association with trace elements and heterotrophic plate counts

2011 ◽  
Vol 45 (6) ◽  
pp. 2315-2321 ◽  
Author(s):  
Annalisa Bargellini ◽  
Isabella Marchesi ◽  
Elena Righi ◽  
Angela Ferrari ◽  
Stefano Cencetti ◽  
...  
Keyword(s):  
Trace Elements ◽  
Water Systems ◽  
Hot Water ◽  
Plate Counts ◽  
Heterotrophic Plate Counts

Control Points To Reduce Movement of Central Nervous System Tissue during Beef Slaughter

2017 ◽  
Vol 80 (2) ◽  
pp. 355-360
Author(s):  
J. L. Aalhus ◽  
R. D. Thacker ◽  
I. L. Larsen ◽  
J. C. Roberts ◽  
M. A. Price ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cold Water ◽  
Effective Means ◽  
Hot Water ◽  
Spongiform Encephalopathy ◽  
Cross Contamination ◽  
Central Nervous System Tissue ◽  
Before And After ◽  
Disease Variant

ABSTRACT Consumption of central nervous system tissue (CNST) from cattle with bovine spongiform encephalopathy (BSE) is thought to cause the human neurological disease, variant Creutzfeldt-Jacob disease. To identify points of cross-contamination of beef carcasses with CNST, 55 young beef cattle were slaughtered and processed through a federally inspected multispecies abattoir. The objectives of this study were to evaluate CNST spread following the placement of a plug in the penetration site of the skull after captive bolt stunning, to evaluate cross-contamination of carcasses before and after splitting, to compare the effects of hot water pasteurization (84°C for 10 s) versus cold water wash (10°C for 30 s) for reducing CNST on the carcass, and to examine other possible sources of cross-contamination in the abattoir. Results indicated that the use of a plastic plug reduced CNST contamination near the bolt penetration site. This study also confirmed that carcass splitting resulted in an increase in CNST contamination at various areas of the carcass. Hot water pasteurization appeared to be an effective means of removing CNST contamination from carcasses in most of the areas sampled.

Effect of heat flushing on the concentrations of Legionella pneumophila and other heterotrophic microbes in hot water systems of apartment buildings

1996 ◽  
Vol 42 (8) ◽  
pp. 811-818 ◽  
Author(s):  
Outi M. Zacheus ◽  
Pertti J. Martikainen
Keyword(s):  
Water Temperature ◽  
Legionella Pneumophila ◽  
Heterotrophic Bacteria ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Circulating Water ◽  
Heterotrophic Microbes ◽  
Before And After ◽  
Circulating Water System

The decontamination of Legionella pneumophila and other heterotrophic microbes by heat flushing in four legionellae-positive hot water systems was studied. Before the decontamination procedure, the concentration of legionellae varied from 3.0 × 10−3 to 3.5 × 10−5 cfu/L and the hot water temperature from 43.6 to 51.5 °C. During the contamination the temperature was raised to 60–70 °C. All taps and showers were cleaned from sediments and flushed with hot water twice a day for several minutes. The decontamination lasted for 2–4 weeks. In a few weeks the heat-flushing method reduced the concentration of legionellae below the detection limit (50 cfu/L) in the hot circulating water system just before and after the heat exchanger. The high hot water temperature also decreased the viable counts of heterotrophic bacteria, fungi, and total microbial cells determined by the epifluorescent microscopy. However, the eradication of legionellae failed in a water system where the water temperature remained below 60 °C in some parts of the system. After the decontamination, the temperature of hot water was lowered to 55 °C. Thereafter, all the studied hot water systems were recolonized by legionellae within a few months, showing that the decontamination by heat flushing was temporary. Also, the contamination of other bacteria increased in a few months to the level before decontamination.Key words: legionellae, hot water system, decontamination, water temperature, heterotrophic bacteria.

A STUDY OF CROSS-CONTAMINATION OF FOODBORNE PATHOGENS ON THE KITCHEN SURFACES

2015 ◽  
Vol 77 (31) ◽  
Author(s):  
Murni Noor Al Amin ◽  
Wan Rosmiza Zana Wan Dagang
Keyword(s):  
Foodborne Pathogens ◽  
Cross Contamination ◽  
Salmonella Spp ◽  
Isolation And Identification ◽  
E Coli ◽  
Meal Preparation ◽  
Before And After ◽  
Change In The Mean ◽  
Plate Counts ◽  
Raw Poultry

Cross-contamination provides the opportunity for various of bacteria to be deposited on each of the surface contact during meal preparation. Raw poultry especially raw chicken was the main reservoir of foodborne pathogens that can cause foodborne diseases. Therefore, a study on the potential of cross-contamination contribute to spread E. coli, Salmonella spp. and S. aureus on the kitchen surfaces during chicken preparation was conducted. A total of 36 isolates were collected from six sampling sites before and after the chicken preparation. The enumeration of the bacteria from the sampling sites showed a significant change in the mean total plate counts (TPC) of the isolates before and after the chicken preparation. These results emphasized that cross-contamination occurred around the sampling sites during the preparation of the chicken. Isolation and identification of the three foodborne pathogens, E. coli, Salmonella spp. and S. aureus were carried out on its respectively selective and differential media. The presumptive identified foodborne pathogens were confirmed as E. coli, Salmonella spp. and S. aureus according to their microscopic and biochemical characteristics.

Insemination before and after the onset of heat in sows

1962 ◽  
Vol 4 (1) ◽  
pp. 91-96 ◽  
Author(s):  
J. L. Hancock ◽  
G. J. R. Hovell
Keyword(s):  
Zona Pellucida ◽  
Low Fertility ◽  
The Third ◽  
Large Numbers ◽  
Before And After

Counts were made before and after fixation of the numbers of fertilised and unfertilised ova recovered from 3 mated sows, 7 unmated sows and from 34 sows inseminated at varying times before and after the onset of heat.The percentages of fertilised ova for sows inseminated the day before heat (day — 1) on the first day of heat (day 0) the second day of heat (day 1) and the third day of heat (day 2) are respectively for unfixed and fixed ova: 7·1 and 9·8, day – 1 ; 55·9 and 68·8, day 0; 63·4 and 98·2, day 1; 20·1 and 15·2, day 2. No fertilised ova were recorded from unmated sows; the percentages for mated sows were 94·3 and 95·5.It is concluded that failure of fertilisation is likely to be the greatest source of loss of fertility in inseminations made before heat and late in heat.Most ova from sows inseminated on day — 1 and from sows inseminated in day 2 had no spermatozoa on the zona pellucida. A few ova from sows inseminated on day 2 had very large numbers of spermatozoa present.It is suggested that failure of the spermatozoa to reach the site of fertilisation rather than their loss of fertilising capacity is likely to be the cause of the low fertility of early inseminations.

South Africa and Land Ownership: What's in a Deed?

1995 ◽  
Vol 22 ◽  
pp. 439-443
Author(s):  
H. M. Feinberg
Keyword(s):  
South Africa ◽  
South African ◽  
Land Ownership ◽  
Land Claims ◽  
Legal Documents ◽  
Large Numbers ◽  
Black Spots ◽  
Before And After ◽  
The Subject ◽  
Emotional Issue

The subject of African land ownership is and will continue to be a highly emotional issue of great importance in the new South Africa. Africans and Afrikaners alike have strong historical ties to the land. Thousands of Africans owned land outside the Reserves before 1948. These landowners included large numbers of Africans who purchased over 3,000 farms and lots between 1913 and 1936 in the Transvaal, Natal, and even the Orange Free State (plus uncounted African buyers in the Cape Province). Individuals, tribal groups, or people organized into partnerships owned land. In the 1990s Africans complain bitterly about land losses, especially after 1948 as a result of the apartheid policy of forced removals which aimed to eliminate the so-called “black spots” from white areas. In addition, some Africans point to the problem of land losses between 1913 and 1948, and others resent the severe restrictions resulting from the Natives Land Act, Act No. 27 of 1913, which prevented Africans from freely buying land in three of the four provinces of South Africa after 1913.On 8 November 1994 the South African Parliament passed the Restitution of Land Rights Act, a law which is intended to allow Africans to reclaim their lost land. Claims by former owners or their descendants will be buttressed by legal documents of one type or another. Some of these legal documents have an interesting and unintended use, however: historians can take advantage of them to build an understanding of African land ownership before and after apartheid began in 1948.

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