Molecular Subtyping and Characterization of Psychrotolerant Endospore-Forming Bacteria in Two New York State Fluid Milk Processing Systems

2007 ◽  
Vol 70 (10) ◽  
pp. 2354-2364 ◽  
Author(s):  
JASON R. HUCK ◽  
NICOLE H. WOODCOCK ◽  
ROBERT D. RALYEA ◽  
KATHRYN J. BOOR
Keyword(s):  
Control Strategies ◽  
New York State ◽  
Raw Milk ◽  
Effective Control ◽  
Processing Plant ◽  
Milk Processing ◽  
High Temperature Short Time ◽  
Processing Plants ◽  
Processing Continuum ◽  
Fluid Milk

Psychrotolerant endospore-forming bacteria Bacillus and Paenibacillus spp. are important spoilage organisms in fluid milk. A recently developed rpoB subtyping method was applied to characterize the diversity and phylogenetic relationships among Bacillus and related sporeformers associated with milk processing systems. Milk samples representing the processing continuum from raw milk to pasteurized products were collected from two fluid milk processing plants, held at 6°C uptothe code date that had been established by each processing plant (i.e., either 18 or 21 days), and plated for bacterial enumeration throughout storage. Bacterial colonies selected to represent the visible diversity in colony morphology on enumeration plates were examined further. Among 385 bacterial isolates characterized, 35% were Bacillus spp., and 65% were Paenibacillus spp. A total of 92 rpoB allelic types were identified among these isolates, indicating considerable diversity among endospore-forming spoilage organisms present in fluid milk systems. Of the 92 allelic types identified, 19 were isolated from samples collected from both processing plants. The same rpoB allelic types were frequently identified in paired raw milk and packaged product samples, indicating that Bacillus and Paenibacillus spp. can enter dairy processing systems through raw milk. Certain subtypes were found exclusively in pasteurized samples, including those that were temporally independent, suggesting the possibility of in-plant sources for these spoilage organisms, including through the persistence of selected subtypes in processing plants. Development of effective control strategies for the diverse array of psychrotolerant endospore-forming organisms that currently limit the shelf lives of high-temperature short-time fluid milk products will require comprehensive, integrated efforts along the entire milk processing continuum.

scholarly journals Quality of raw milks in three milk processing plants in Cordoba

2014 ◽  
Vol 6 (1) ◽  
pp. 103 ◽  
Author(s):  
VIRGINIA RODRÍGUEZ, R. ◽  
ALFONSO CALDERÓN R. ◽  
OSCAR VERGARA G.
Keyword(s):  
Physicochemical Parameters ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Fecal Coliforms ◽  
Processing Plant ◽  
Normal Range ◽  
Dual Purpose ◽  
Milk Processing ◽  
Processing Plants

An important condition in dairy processing plant is to obtain materials of excellent physicochemical and microbiological quality to reduce public health risks. High counts of mesophilic show contamination and lack of good manipulation in milking and milk conservation. Coliforms are a demonstration of contamination with fecal material. The norms in Colombia establish the mesophilic count as standard of microbiological quality. The purpose of this study was to determine the physicochemical and microbiological quality and health of the udders, in raw milk from dual purpose farms, supplying three milk processing plants in Cordoba (Colombia). 149 raw milk samples were collected of tree processing plants in Cordoba department. Physicochemical parameters set out in Decree 616 of 2006 were determined and aerobic mesophilic, total coliforms, fecal coliforms, and somatic cell count were established too. The variables obtained were analyzed by descriptive statistics using SAS. The physicochemical parameters were within the normal range but averages of mesophilic and somatic cells counts were high, which allows conclude that the physicochemical quality is good, but there are shortcomings in the microbiological quality and in the udder health, and is on the farms devoted to milk production where must be implemented and certified excellent management and prevention practices.

A Survey of Four Fluid Milk Processing Plants for Airborne Contamination Using Various Sampling Methods

1992 ◽  
Vol 55 (1) ◽  
pp. 38-42 ◽  
Author(s):  
TYH-JENQ REN ◽  
JOSEPH F. FRANK
Keyword(s):  
Sampling Methods ◽  
Raw Milk ◽  
Particle Counter ◽  
Milk Processing ◽  
Airborne Contamination ◽  
Processing Plants ◽  
Particle Counts ◽  
Milk Storage ◽  
Andersen Sampler ◽  
Fluid Milk

Air in four commercial fluid milk plants was sampled for microbiological and nonmicrobiological particles over a 4-month period. An Andersen two-stage and Ross-Microban sieve samplers, a Biotest RCS sampler, and a Met-one laser particle counter were used to sample air. Air was sampled two to three times per day in raw milk storage, processing, and filling areas. Viable particle counts per 100 L air obtained with the Andersen sampler were 2.03 ± 0.41 (log10 Mean ± SD), 2.26 ± 0.57, and 2.41 ± 0.70 in raw milk storage, processing, and filling areas, respectively. These levels were significantly (p<0.05) greater than those obtained using the RCS and Ross-Microban samplers. Overall correlations of the Ross-Microban and RCS samplers with the Andersen sampler were r2 = 0.71 and 0.62, respectively. Correlations between Andersen sampler results and number of total particles greater than 0.5 μm were r2 = 0.36 in raw milk storage, 0.15 in the processing area, and 0.18 in the filling area.

SANITARY CONDITIONS IN TWELVE FLUID MILK PROCESSING PLANTS AS DETERMINED BY USE OF THE RINSE FILTER METHOD1

1973 ◽  
Vol 36 (4) ◽  
pp. 237-241 ◽  
Author(s):  
R. T. Marshall ◽  
R. Appel
Keyword(s):  
Membrane Filtration ◽  
Tap Water ◽  
Sodium Thiosulfate ◽  
Milk Processing ◽  
Sanitary Condition ◽  
Processing Plants ◽  
Rinse Water ◽  
Sanitary Conditions ◽  
Milk Storage ◽  
Fluid Milk

Experiments were done in 12 fluid milk processing plants to determine their sanitary condition. Tap water was sterilized by membrane filtration and sodium thiosulfate was added to inactivate residual sanitizer. This water was used to rinse the pasteurized milk storage tank, filler bowls and filled containers. Samples of rinse water were filtered through membrane filters which were incubated on media to produce colonies. Total and coliform counts were made. Storage tanks contributed fewer bacteria to the water than other equipment. About 60% of the first cartons taken from fillers were contaminated with at least 1 bacterium per 100 ml of rinse water and 37% contained at least 1 coliform per 100 ml. The method appears useful to evaluate the sanitary conditions of equipment.

Evaluation of Air Samplers for Recovery of Biological Aerosols in Dairy Processing Plants

1989 ◽  
Vol 52 (9) ◽  
pp. 655-659 ◽  
Author(s):  
YOUNG-JAE KANG ◽  
JOSEPH F. FRANK
Keyword(s):  
Membrane Filter ◽  
Ice Cream ◽  
Processing Plant ◽  
Milk Processing ◽  
Air Sampler ◽  
Biological Aerosols ◽  
Dairy Processing ◽  
Processing Plants ◽  
Stage 1 ◽  
Number Of Particles

An All Glass Impinger-30 (AGI-30), Andersen 6-stage Sieve Air Sampler (Andersen impactor), Reuter centrifugal air sampler (RCS sampler), and the Millipore open type membrane filter sampler (Filter sampler) were evaluated for viable particle recovery in three dairy processing plant environments. There were two size distribution peaks for viable particles, at stage 1 (>7.0 μm) and stage 3 (3.3–4.7 μm). About 10–12% of the particles were smaller than 2.1 μm in size and were mostly non-molds. During milk processing, the highest number of particles were >7.0 μm in size. But, during ice cream processing and in the idle ice cream room, the highest number of particles were 3.3–4.7 μm in size and were mostly molds. Mean viable particle recovery decreased in the order of AGI-30, Andersen impactor, RCS sampler, and Filter sampler for each of the three sampling environments. These results contrast to those obtained using laboratory-generated aerosols where both the AGI-30 and RCS sampler exhibited low recovery. The increased aerosol recovery by AGI-30 in processing plant compared to laboratory-generated aerosols indicates the presence of carrier and passenger type aerosol particles which disintegrate upon impingement. A comparison of the percent of non-mold cfu recovered by the RCS sampler vs. Andersen impactor indicates that the RCS sampler has a bias toward the detection of non-mold containing particles at all three of the locations tested. The Andersen impactor proved to be the most reliable sampler for recovering biological aerosols from dairy processing plant air.

Hygienic features of working conditions at milk processing plants and their impact on the health of workers

2020 ◽  
pp. 611-611 ◽  
Author(s):  
A. N. Danilov ◽  
T. A. Novikova ◽  
J. A. Aleshina
Keyword(s):  
Working Conditions ◽  
Processing Plant ◽  
Milk Processing ◽  
Processing Plants ◽  
Health Disorders

The results of complex hygienic studies of working conditions at the milk processing plant are presented. The influence of harmful working conditions (classe s 3.2-3.3) on the formation of workers ‘ health disorders is shown. Priority measures to preserve the health of employees of milk processing enterprises are defined.

Hygienic Conditions and Microbial Contamination in Six Ewe's-Milk-Processing Plants in Sardinia, Italy

1997 ◽  
Vol 60 (3) ◽  
pp. 283-287 ◽  
Author(s):  
SOFIA COSENTINO ◽  
FRANCESCA PALMAS
Keyword(s):  
Microbial Contamination ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Raw Material ◽  
Processing Conditions ◽  
Technological Parameters ◽  
Milk Processing ◽  
Processing Plants ◽  
Ewe's Milk

In Sardinia, ewe's milk is almost exclusively used for cheese manufacture, and it is usually processed in small dairies which do not have sufficient technical and scientific knowledge for largescale controlled production. This study was carried out to identify the sources of contamination and the kinds of contaminating microorganisms present in six ewe's milk processing plants in Sardinia. Samples were collected during production hours three times over a period of 6 months. Raw milk, heat-treated milk, curd, 30-day-old cheese, lactic culture, rennet, and water used in processing lines were analyzed and the microbial contamination of air and surfaces was evaluated. Total mesophilic aerobic counts, coliforms, Escherichia coli, gram-negative psychrotrophs, Staphylococcus aureus, Salmonella spp., Listeria spp., yeasts, and molds were determined. Our survey confirmed that the production offood of high microbiological quality is strictly dependent on the microbiological quality of the raw material, optimization of the parameters for the heat treatment, water of potable quality, well-defined cleaning and disinfection procedures, and properly hygienic processing conditions. In fact, only plants characterized by raw milk and rennet of acceptable quality, generally clean work surfaces, and low microbial counts in the air of working areas made finished products of high microbiological quality. Standardization of technological parameters and achievement of properly hygienic processing conditions will help minimize the risk of developing food-safety problems, in compliance with public health regulatory requirements. These actions would help guarantee an adequate quality of Sardinian ewe's milk cheeses and might also lead to access to the international market.

Environmental Survey for Listeria Species in California Milk Processing Plants

1990 ◽  
Vol 53 (3) ◽  
pp. 198-201 ◽  
Author(s):  
BRUCE R. CHARLTON ◽  
HAILU KINDE ◽  
LEON H. JENSEN
Keyword(s):  
Listeria Monocytogenes ◽  
Environmental Samples ◽  
Raw Milk ◽  
Plant Location ◽  
Milk Product ◽  
Isolation Rate ◽  
Milk Processing ◽  
Processing Plants ◽  
Manufacturing Activity ◽  
Positive Results

This survey was undertaken to determine the prevalence of Listeria monocytogenes and Listeria spp. in environmental samples obtained from milk processing plants located throughout California. Identification of Listeria spp. other than L. monocytogenes was not made. Milk processing plants were categorized as to type of product produced and subdivided into areas based on manufacturing activity occurring in that area. A total of 597 environmental samples from 156 plants were analyzed in the six month period of January through July 1987. Listeria spp. were isolated from 75 (12.6%) of the samples. Thirty-eight of the Listeria spp. (50.7%) were identified as L. monocytogenes. Forty-six plants (29.5%) yielded positive results for Listeria spp., of which, 31 plants (19.9%) were positive for L. monocytogenes. Listeria was recovered more frequently from fluid milk product plants and frozen milk product plants. Likewise, Listeria was isolated most frequently from the packaging-filling room location within a plant and least frequently from the raw milk receiving room. Although Listeria spp. was isolated most frequently from the conveyor site, the drain site within a plant location gave a Listeria isolation rate similar to the total number of Listeria positive sites within that plant location.

Significance of Psychrotrophic Strains of Serratia liquefaciens in Milk1

1979 ◽  
Vol 42 (12) ◽  
pp. 938-941 ◽  
Author(s):  
B. J. JUVEN ◽  
S. GORDIN ◽  
A. LAUFER
Keyword(s):  
Escherichia Coli ◽  
Enterobacter Cloacae ◽  
Raw Milk ◽  
Processing Plant ◽  
Citrobacter Freundii ◽  
Milk Processing ◽  
Milk Samples ◽  
Serratia Liquefaciens ◽  
Ph Reduction ◽  
Bulk Tank

Enterobacter cloacae, Citrobacter freundii, Serratia liquefaciens and Escherichia coli were the predominant Enterobacteriaceae species isolated from raw milk samples collected from refrigerated bulk tank trucks at the entry of a milk processing plant. About half of the 181 Enterobacteriaceae isolated were psychrotrophs and these included 80% of E. cloacae, 80% of Klebsiella ozaenae and 62% of S. liquefaciens. S. liquefaciens grew in raw and in pasteurized milk at refrigeration temperatures, causing significant pH reduction but only slight lipolytic changes. The significant proteolytic activity of S. liquefaciens in refrigerated milk samples is assumed to have been the cause of the unclean flavor detected.

scholarly journals DAIRY INDUSTRIAL HYGIENE: A REVIEW ON BIOFILM CHALLENGES AND CONTROL

2018 ◽  
Vol 6 (2) ◽  
pp. 268-273
Author(s):  
Ismail T. Kabwanga ◽  
Atila Yetişemiyen ◽  
Shakira Nankya
Keyword(s):  
Control Strategies ◽  
Dairy Industry ◽  
Raw Milk ◽  
Critical Issue ◽  
Modern Medicine ◽  
Production Equipment ◽  
Effective Control ◽  
Chemical Methods ◽  
Biofilm Growth ◽  
And Control

The development of biofilms and the microbial biofilm adherence into the production equipment and facilities used in the dairy industry is a critical issue that needs to be addressed. Biofilms lead to the contamination of food by pathogenic and spoilage m/os. The microbes cause both company loses due to unsafe spoilt products, equipment depreciation and death of consumers under severe pathogenic out breaks. Biofilms may also lead to a failure of anti- microbial therapy hence major threats to modern medicine. Biofilm formation however is a dynamic process with different mechanisms involved in the biofilm growth. Raw milk provides an ideal medium for the formation of a biofilm as it contains bacteria and is nutrient-rich. This paper gives highlights regarding microbial sources, challenges, biofilm control strategies that include but not limited to physical, mechanical, enzymatic and chemical methods for the effective control of formation and or eradicate biofilm in the dairy industry.

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