scholarly journals Effects of different moisture and temperature levels on Salmonella survival in poultry fat

2019 ◽  
Vol 3 (4) ◽  
pp. 1369-1374
Author(s):  
Valentina Trinetta ◽  
Austin McDaniel ◽  
Gabriela Magossi ◽  
Umut Yucel ◽  
Cassandra Jones
Keyword(s):  
Salmonella Spp ◽  
Inoculum Level ◽  
Residual Moisture ◽  
Growth And Survival ◽  
Poultry Fat ◽  
Low Levels ◽  
Temperature Levels ◽  
And Storage ◽  
Salmonella Survival ◽  
Storage Temperatures

Abstract Fat products have been historically thought to have too low water activity to harbor pathogens. However, it has been recently reported that high moisture levels in fats may lead to Salmonella presence and growth. Limited research on strategies to eliminate pathogens in these environments is available, and the mechanisms contributing to microbial presence and growth are not yet well understood. The purpose of this research was to evaluate the effects of moisture levels and storage temperatures on the growth and survival of Salmonella in poultry fat. Samples were stored for 7 d at 48°C or 76°C and remaining Salmonella was evaluated. When poultry fat was challenged with a wet high inoculum, more than a 4 log CFU/mL difference in Salmonella population was observed with 1% and 3% moisture levels at 48°C after 5 d (P < 0.05). No differences between moisture levels (P > 0.05) were observed when samples were tested with a wet low inoculum. Counts below detectable limits were observed after 24 h in samples challenged at 76°C, regardless of inoculum level. When poultry fat was stored at 48°C and inoculated with low levels of Salmonella spp., bacterial growth was influenced only by time (P < 0.05) and not affected (P > 0.05) by moisture level. However, when poultry fat was stored at 48°C and inoculated with high levels of Salmonella spp., bacterial decrease was easier (P < 0.05) in samples containing greater moisture. This research suggests that residual moisture in containers during transportation of poultry fat largely does not affect Salmonella spp. growth.

scholarly journals Effects of moisture and temperature on Salmonella survivability in beef tallow, white grease and chicken rendered fat

2021 ◽  
Author(s):  
A Molitor ◽  
U Yucel ◽  
J Vipham ◽  
C Jones ◽  
V Trinetta
Keyword(s):  
Beef Tallow ◽  
Weibull Model ◽  
Inoculum Level ◽  
Progressive Decline ◽  
Growth And Survival ◽  
White Grease ◽  
Challenge Study ◽  
Poultry Fat ◽  
Rendered Fat ◽  
And Storage

Abstract High moisture levels introduced to fats after the rendering process can lead to Salmonella presence and growth. Limited research on strategies to eliminate pathogens in these environments are available. Rendered fat characteristics, such as water activity and fatty acids composition, may contribute to Salmonella survivability. The purpose of this research was to evaluate the effects of moisture levels (0%, 0.5%, 1%, and 3%), storage temperatures (48˚C and 76˚C), and fat characteristics on the growth and survival of Salmonella in beef tallow, white grease and poultry fat samples. Samples were inoculated with a high (~10⁸ CFU/mL) and a low (~10⁵ CFU/mL) Salmonella cocktail (S. Sentfenberg, S. Newport, S. Thompson and S. Infantis). Samples were stored for up to 5 days at 48 and 76 ºC. Remaining population was evaluated daily with and without enrichment step. Death rates were calculated using Weibull model for each temperature and moisture level. Only temperature had an effect (P < 0.05) on Salmonella inactivation, while no effect between moisture and/or inoculum level were observed. When all products were challenged at 76 ˚C, counts were below detectable limits after 6 hours. At 48˚C a progressive decline in Salmonella population was observed within 3 days for both beef tallow and white grease when high inoculum was used for the challenge study. Salmonella was below detectable limit within 4 days for both fat types when a low inoculum was instead applied. This research identified the effect of moisture and temperature in rendered fat samples contaminated with Salmonella and underlined the need to use time-moisture-temperature data to minimize microbial growth during transportation and storage.

scholarly journals Survival of Selected Pathogenic Bacteria during PDO Pecorino Romano Cheese Ripening

Dairy ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 297-312
Author(s):  
Giacomo Lai ◽  
Rita Melillo ◽  
Massimo Pes ◽  
Margherita Addis ◽  
Antonio Fadda ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Salt Content ◽  
Raw Milk ◽  
Salmonella Spp ◽  
Growth And Survival ◽  
E Coli ◽  
Cheese Ripening ◽  
Protected Designation Of Origin ◽  
Low Levels ◽  
First Time

This study was conducted to assess, for the first time, the survival of the pathogenic bacteria Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus during the ripening of protected designation of origin (PDO) Pecorino Romano cheese. A total of twenty-four cheese-making trials (twelve from raw milk and twelve from thermized milk) were performed under the protocol specified by PDO requirements. Sheep cheese milk was first inoculated before processing with approximately 106 colony-forming unit (CFU) mL−1 of each considered pathogen and the experiment was repeated six times for each selected pathogen. Cheese composition and pathogens count were then evaluated in inoculated raw milk, thermized milk, and cheese after 1, 90, and 150 days of ripening. pH, moisture, water activity, and salt content of cheese were within the range of the commercial PDO Pecorino Romano cheese. All the cheeses made from raw and thermized milk were microbiologically safe after 90 days and 1 day from their production, respectively. In conclusion, when Pecorino Romano cheese is produced under PDO specifications, from raw or thermized milk, a combination of factors including the speed and extent of curd acidification in the first phase of the production, together with an intense salting and a long ripening time, preclude the possibility of growth and survival of L. monocytogenes, Salmonella spp., and E. coli O157:H7. Only S. aureus can be still detectable at such low levels that it does not pose a risk to consumers.

Growth and Survival of Foodborne Pathogens in Beer

2011 ◽  
Vol 74 (10) ◽  
pp. 1670-1675 ◽  
Author(s):  
GARRY MENZ ◽  
PETER ALDRED ◽  
FRANK VRIESEKOOP
Keyword(s):  
Salmonella Typhimurium ◽  
Foodborne Pathogens ◽  
Storage Temperature ◽  
Escherichia Coli O157 ◽  
Gram Negative ◽  
Growth And Survival ◽  
E Coli ◽  
And Storage ◽  
And Staphylococcus Aureus ◽  
Storage Temperatures

This work aimed to assess the growth and survival of four foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus) in beer. The effects of ethanol, pH, and storage temperature were investigated for the gram-negative pathogens (E. coli O157:H7 and Salmonella Typhimurium), whereas the presence of hops ensured that the gram-positive pathogens (L. monocytogenes and S. aureus) were rapidly inactivated in alcohol-free beer. The pathogens E. coli O157:H7 and Salmonella Typhimurium could not grow in the mid-strength or full-strength beers, although they could survive for more than 30 days in the mid-strength beer when held at 4°C. These pathogens grew rapidly in the alcohol-free beer; however, growth was prevented when the pH of the alcohol-free beer was lowered from the “as received” value of 4.3 to 4.0. Pathogen survival in all beers was prolonged at lowered storage temperatures.

Fate of Selected Pathogens in Vacuum-Packaged Dry-Cured (Country-Style) Ham Slices Stored at 2 and 25°C†

1997 ◽  
Vol 60 (12) ◽  
pp. 1541-1547 ◽  
Author(s):  
WOOI FANG NG ◽  
BRUCE E. LANGLOIS ◽  
WILLIAM G. MOODY
Keyword(s):  
Staphylococcus Aureus ◽  
Treatment Group ◽  
Salmonella Enteritidis ◽  
Storage Temperature ◽  
Salmonella Spp ◽  
Treatment Groups ◽  
E Coli ◽  
Dry Cured Ham ◽  
And Storage ◽  
Storage Temperatures

Whole dry-cured (country-style) hams from six manufacturers were sliced and the slices randomly allotted into five treatment groups per manufacturer. One treatment group served as a control and slices in the four other treatment groups were inoculated with approximately 105 CFU/g of ham of either Escherichia coli O157:H7, Listeria monocytogenes, a mixture of three Salmonella spp. (Salmonella typhimurium, Salmonella enteritidis and Salmonella choleraesuis), or Staphylococcus aureus. All ham slices were vacuum-packaged with half of the packages in each treatment group stored at 25°C and half stored at 2°C. Two packages from each manufacturer for each treatment and storage temperature were examined after storage for 0,7, 14,21, and 28 days. S. aureus was detected in 2 of 60 control slices, Salmonella in 2 of 120, L. monocytogenes in 4 of 120, and E. coli O157:H7 was not detected in any of the 120 control ham slices analyzed before or after storage. Aerobic (26 and 35°C) populations of the control vacuum-packaged hams slices increased (P < 0.05) with storage time and the increase in populations was greater (P < 0.05) in vacuum-packaged hams slices at 25 than at 2°C. The extent of the decreases in populations of the inoculated pathogens during storage of vacuum-packaged dry-cured ham slices varied with manufacturer (P < 0.05) and storage temperature (P < 0.05). Decreases in Salmonella spp. and E. coli O157:H7 populations were greater (P < 0.05) in slices stored at 25 than at 2°C, while decreases in L. monocytogenes were similar at both storage temperatures. Staphylococcus aureus enterotoxin was not detected in either S. aureus-inoculated or control ham slices after storage for 28 days. Survival of these pathogens in vacuum-packaged dry-cured ham slices suggests that contaminated hams may pose a safety risk to consumers if consumed without adequate cooking.

scholarly journals Influence of Different Filling, Cooling, and Storage Conditions on the Growth of Alicyclobacillus acidoterrestris CRA7152 in Orange Juice

2009 ◽  
Vol 75 (23) ◽  
pp. 7409-7416 ◽  
Author(s):  
Ana Cláudia N. F. Spinelli ◽  
Anderson S. Sant'Ana ◽  
Salatir Rodrigues-Junior ◽  
Pilar R. Massaguer
Keyword(s):  
Orange Juice ◽  
Storage Temperature ◽  
Growth Parameters ◽  
Storage Conditions ◽  
Inoculum Level ◽  
Alicyclobacillus Acidoterrestris ◽  
Time Required ◽  
Cold Point ◽  
And Storage ◽  
A Current

ABSTRACT The prevention of spoilage by Alicyclobacillus acidoterrestris is a current challenge for fruit juice and beverage industries worldwide due to the bacterium's acidothermophilic growth capability, heat resistance, and spoilage potential. This study examined the effect of storage temperature on A. acidoterrestris growth in hot-filled orange juice. The evolution of the A. acidoterrestris population was monitored under six different storage conditions after pasteurization (at 92°C for 10 s), maintenance at 85°C for 150 s, and cooling with water spray to 35°C in about 30 min and using two inoculum levels: <101 and 101 spores/ml. Final cooling and storage conditions were as follows: treatment 1, 30°C for the bottle cold point and storage at 35°C; treatment 2, 30°C for 48 h and storage at 35°C; treatment 3, 25°C for the bottle cold point and storage at 35°C; treatment 4, 25°C for 48 h and storage at 35°C; treatment 5, storage at 20°C (control); and treatment 6, filling and storage at 25°C. It was found that only in treatment 5 did the population remain inhibited during the 6 months of orange juice shelf life. By examining treatments 1 to 4, it was observed that A. acidoterrestris predicted growth parameters were significantly influenced (P < 0.05) either by inoculum level or cooling and storage conditions. The time required to reach a 104 CFU/ml population of A. acidoterrestris was considered to be an adequate parameter to indicate orange juice spoilage by A. acidoterrestris. Therefore, hot-filled orange juice should be stored at or below 20°C to avoid spoilage by this microorganism. This procedure can be considered a safe and inexpensive alternative to other treatments proposed earlier.

STORABILITY OF FARM-STORED HULLESS OATS IN MANITOBA

1979 ◽  
Vol 59 (4) ◽  
pp. 949-957 ◽  
Author(s):  
R. N. SINHA ◽  
H. A. H. WALLACE ◽  
J. T. MILLS ◽  
R. I. H. McKENZIE
Keyword(s):  
Storage Temperature ◽  
First Year ◽  
Aspergillus Versicolor ◽  
Cryptolestes Ferrugineus ◽  
Moisture Contents ◽  
Grain Moisture ◽  
Avena Nuda ◽  
Low Levels ◽  
Second Year ◽  
Temperature Levels

Storability of properly harvested, mature hulless oats (Avena nuda L. ’Terra’) of 9.7–10.5% moisture content was determined from a 24-mo field trial of two 11.5-t lots of oats stored in two wooden farm bins in Manitoba during 1976–78. Oats were stored safely with very low levels of infestation by preharvest fungi, mites and insects and negligible quality loss for up to about 20 mo. Afterwards the grain moisture contents at the bottom layers of both bins rose from about 10 to 13–16%; this led to heavy floor level infestations by the fungi Penicillium and Aspergillus versicolor, and mites Caloglyphus berlesei and Tarsonemus granarius. Fat acidity values rose from the first year levels of about 30 to 50–78 mg KOH/100 g of dry grain. Populations of Cryptolestes ferrugineus and Tribolium castaneum, introduced to one bin, did poorly during the first summer and failed to survive during the second year. A third beetle, Oryzaephilus surinamensis, continued to multiply in small numbers after 22 mo. Low storage temperature levels during most of the years seemed to have affected adversely the multiplication of insects and to a lesser extent mites in farm-stored oats.

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