Effect of Chelators, Organic Acid and Storage Temperature on Growth of Escherichia coli O157: H7 in Ground Beef Treated with Nisin, Using Response Surface Methodology

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
T.J. Fang ◽  
Y.-T. Hsueh
Keyword(s):  
Escherichia Coli ◽  
Response Surface Methodology ◽  
Organic Acid ◽  
Response Surface ◽  
Storage Temperature ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
And Storage

scholarly journals Investigation and Evaluation of Impact Bruising in Guava Using Image Processing and Response Surface Methodology

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 411
Author(s):  
Than Htike ◽  
Rattapon Saengrayap ◽  
Nattapol Aunsri ◽  
Khemapat Tontiwattanakul ◽  
Saowapa Chaiwong
Keyword(s):  
Response Surface Methodology ◽  
Image Analysis ◽  
Response Surface ◽  
Storage Temperature ◽  
Impact Damage ◽  
Color Difference ◽  
Guava Fruit ◽  
Fractal Image ◽  
And Storage

Simulated impact damage testing was investigated by fractal image analysis using response surface methodology (RSM) with a central composite design (CCF) on quality of ‘Glom Sali’ guava for drop heights (0.2, 0.4, and 0.6 m), number of drops (1, 3, and 5) and storage temperature conditions (10, 20, and 30 °C). After 48 h, impacted fruit were determined and analyzed for bruise area (BA), bruise volume (BV), browning index (BI), total color difference (∆E), image analysis for bruise area (BAI), and fractal dimension (FD) at the bruising region on peeled guava. Results showed that the correlation coefficient (r = −0.6055) between ∆E and FD value was higher than ∆E and either BA (r = 0.3132) or BV (r = 0.2095). The FD variable was determined as a better indicator than conventional measurement (BA or BV) for pulp browning and impact bruising susceptibility. The FD variable also exhibited highest R2adj value (81.69%) among the other five variables, as the highest precision model with high determination coefficient value (R2adj) (>0.8) for impact bruising prediction. Recommended condition of the FD variable to minimize impact bruising was drop height of 0.53 m for five drops under storage at 30 °C. FD variable assessed by image analysis was shown to be a highly capable measurement to determine impact bruising susceptibility in guava fruit.

Effects of Acetic-Lactic Acid Treatments Applied to Beef Trim on Populations of Escherichia coli O157:H7 and Listeria monocytogenes in Ground Beef†

1997 ◽  
Vol 60 (12) ◽  
pp. 1560-1563 ◽  
Author(s):  
D. E. CONNER ◽  
J. S. KOTROLA ◽  
W. B. MIKEL ◽  
K. C. TAMBLYN
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Ground Beef ◽  
Escherichia Coli O157 ◽  
Beef Production ◽  
E Coli ◽  
Production Scheme ◽  
And Storage ◽  
Lactic Acids ◽  
Acid Treatments

The efficacy of organic acid sprays for eliminating Escherichia coli O157:H7 and Listeria monocytogenes from beef trim used in a model ground beef production scheme was determined. Beef trim pieces with ca. 20% fat inoculated with E. coli O157:H7 or L. monocytogenes (ca. 3 log10 CFU/g) were utilized as controls or treated by spraying with 2 or 4% acetic and lactic acids. Propylene glycol (20%) was the carrier for each treatment. Following acid treatment, intact pieces were stored at 4°C for 12 or 24 h, ground, divided into 4 100-g retail packages and stored at 4°C for 0, 1, 2, or 4 days, at which time surviving populations of E. coli O157:H7 or L. monocytogenes were enumerated. High populations (>2.6 log10 CFU/g) of the pathogens persisted in all treatments. The 2% acid spray reduced (P < 0.01) the E. coli O157:H7 population by only 0.1 log10 CFU/g. The 2 and 4% acid sprays reduced (P < 0.001) the L. monocytogenes populations by 0.36 and 0.44 log10 CFU/g, respectively. Storing beef trim intact prior to grinding resulted in lower populations of E. coli O157:H7, and storage following grinding did not affect populations of either pathogen. The acid treatments tested were only slightly effective as sanitizers for beef trim destined for ground beef production.

Viability of Escherichia coli O157:H7 in Salami Following Conditioning of Batter, Fermentation and Drying of Sticks, and Storage of Slices

1998 ◽  
Vol 61 (4) ◽  
pp. 377-382 ◽  
Author(s):  
NANCY G. FAITH ◽  
NELLY PARNIERE ◽  
TRINA LARSON ◽  
TIMOTHY D. LORANG ◽  
CHARLES W. KASPAR ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Storage Temperature ◽  
Starter Culture ◽  
Escherichia Coli O157 ◽  
Protein Ratio ◽  
E Coli ◽  
Log10 Unit ◽  
Storage Atmosphere ◽  
Unit Reduction ◽  
And Storage

The fate of Escherichia coli O157:H7 was monitored in salami during conditioning of batter, fermentation and drying of sticks, and storage of slices. The raw batter (75% pork:25% beef, wt/wt, fat content about 20%) was inoculated with a pediococcal starter culture (about 108 CFU/g) and a five-strain cocktail of E. coli O157:H7 (≥2 × 107 CFU/g) and stuffed into 104-mm diameter fibrous casings. After being refrigerated at 4°C or being tempered at 13°C, frozen at −20°C, and thawed at 4°C, or being frozen at −20°C, and thawed at 4°C, the inoculated batter was fermented at 24°C and 90% relative humidity (RH) to pH ≤4.8, dried at 13°C and 65% RH to a moisture/protein ratio of ≤1.9:1, and then stored at 4 or 21°C under air or vacuum. For salami sticks sampled immediately after drying, appreciable differences were evident among the various batter-conditioning treatments; pathogen numbers were reduced from original levels by 2.1, 1.6, or 1.1 log10 units when batter was tempered, frozen, and thawed, frozen and thawed, or refrigerated, respectively. Similarly, regardless of storage temperature or atmosphere, within 7 days salami slices cut from sticks prepared from batter that was tempered, frozen, and thawed (2.7- to 4.9-log10-unit reduction) or frozen and thawed (2.3- to 4.8-log10-unit reduction) displayed a greater impact on pathogen numbers than slices cut from sticks prepared from batter that was refrigerated (1.6- to 3.1-log10-unit reduction). The effects of batter conditioning notwithstanding, a greater reduction in levels of E. coli O157:H7 was observed when slices were stored at 21°C compared to otherwise similar slices stored at 4°C. After storage for 60 days the pathogen was only detected by enrichment in slices stored at 21°C, whereas pathogen levels ranged from 1.4 to 4.5 log10 CFU/g in slices stored at 4°C. Differences related to storage atmosphere were first observed after slices were stored for 21 days. Such differences were more readily demonstrable after 60 and 90 days, with pathogen numbers for treatments that were statistically different ranging from 0.6- to 1.5-log10 units higher on slices stored under vacuum than in air. These data emphasize the need to implement multiple barriers to appreciably reduce numbers of E. coli O157:H7 in salami.

Death of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in Garlic Butter as Affected by Storage Temperature

2002 ◽  
Vol 65 (12) ◽  
pp. 1976-1980 ◽  
Author(s):  
BARBARA B. ADLER ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Storage Time ◽  
Storage Temperature ◽  
Rapid Decline ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Pathogen Populations ◽  
And Storage

Garlic is known to have antimicrobial activity against several spoilage and pathogenic bacteria. However, the fate of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in garlic butter has not been reported. This study was undertaken to determine the viability of these organisms in garlic butter as affected by the type of raw minced garlic added to the butter, storage temperature, and storage time. Unsalted butter at 40°C was combined with raw minced jumbo, elephant, or small-cloved garlic at a 4:1 butter/garlic ratio (wt/wt), inoculated with mixed-strain suspensions of Salmonella, E. coli O157:H7, or L. monocytogenes, and stored at 4.4, 21, or 37°C for up to 48 h. All pathogens retained their viability at 4.4°C, regardless of the presence of garlic. The addition of garlic to butter enhanced the rates of inactivation of all three pathogens at 21 and 37°C. The most rapid decline in pathogen populations was observed at 37°C. The inactivation of L. monocytogenes occurred more slowly than did that of Salmonella or E. coli O157:H7. The inactivation of Salmonella and L. monocytogenes was more rapid in jumbo garlic butter than in elephant or small-cloved garlic butter. It is concluded that Salmonella, E. coli O157:H7, and L. monocytogenes did not grow in unsalted butter, with or without garlic added (20%, wt/wt), when inoculated products were stored at 4.4, 21, and 37°C for up to 48 h.

Growth and survival of uninjured and sublethally heat-injured Escherichia coli O157:H7 on beef extract medium as influenced by package atmosphere and storage temperature

1999 ◽  
Vol 45 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Jeffrey J Semanchek ◽  
David A Golden ◽  
Robert C Williams
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Storage Temperature ◽  
Brain Heart Infusion ◽  
Escherichia Coli O157 ◽  
Phase Growth ◽  
Growth And Survival ◽  
E Coli ◽  
Beef Extract ◽  
And Storage

The effect of atmospheric composition and storage temperature on growth and survival of uninjured and sublethally heat-injured Escherichia coli O157:H7, inoculated onto brain heart infusion agar containing 0.3% beef extract (BEM), was determined. BEM plates were packaged in barrier bags in air, 100% CO2, 100% N2, 20% CO2 : 80% N2, and vacuum and were stored at 4, 10, and 37°C for up to 20 days. Package atmosphere and inoculum status (i.e., uninjured or heat-injured) influenced (P < 0.01) growth and survival of E. coli O157:H7 stored at all test temperatures. Growth of heat-injured E. coli O157:H7 was slower (P < 0.01) than uninjured E. coli O157:H7 stored at 37°C. At 37°C, uninjured E. coli O157:H7 reached stationary phase growth earlier than heat-injured populations. Uninjured E. coli O157:H7 grew during 10 days of storage at 10°C, while heat-injured populations declined during 20 days of storage at 10°C. Uninjured E. coli O157:H7 stored at 10°C reached stationary phase growth within approximately 10 days in all packaging atmospheres except CO2. Populations of uninjured and heat-injured E. coli O157:H7 declined throughout storage for 20 days at 4°C. Survival of uninjured populations stored at 4°C, as well as heat-injured populations stored at 4 and 10°C, was enhanced in CO2 atmosphere. Survival of heat-injured E. coli O157:H7 at 4 and 10°C was not different (P > 0.05). Uninjured and heat-injured E. coli O157:H7 are able to survive at low temperatures in the modified atmospheres used in this study.Key words: E. coli O157:H7, sublethal injury, modified atmosphere packaging.

Survival of Escherichia coli O157:H7 in Buttermilk as Affected by Contamination Point and Storage Temperature

2000 ◽  
Vol 63 (4) ◽  
pp. 441-444 ◽  
Author(s):  
S. C. McINGVALE ◽  
X. Q. CHEN ◽  
J. L. McKILLIP ◽  
M. A. DRAKE
Keyword(s):  
Escherichia Coli ◽  
Storage Temperature ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
D Values ◽  
And Storage ◽  
Storage Temperatures

The effects of contamination point (during fermentation versus postfermentation) and storage temperature (5 and 12°C) were determined for survival of Escherichia coli O157:H7 in fermented buttermilk. E. coli O157:H7 was recovered from buttermilk inoculated during fermentation for 22 days and in buttermilk inoculated postfermentation for 32 days. For storage temperatures of 5 and 12°C, D-values were lower for E. coli O157:H7 inoculated during fermentation (2.5, 2.2 days) than postfermentation (5.6, 4.8 days) (P &lt; 0.05). Developed acidity in inoculated buttermilks was not different from controls (P &gt; 0.05). The extended recovery of viable enterohemorhagic E. coli O157:H7 from both processing scenarios indicates that the presence of E. coli O157:H7 in buttermilk is not limited to postprocessing contamination.

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