Reduction of Microbial Pathogens during Apple Cider Production Using Sodium Hypochlorite, Copper Ion, and Sonication

2004 ◽  
Vol 67 (4) ◽  
pp. 766-771 ◽  
Author(s):  
STEPHANIE L. RODGERS ◽  
ELLIOT T. RYSER
Keyword(s):  
Sodium Hypochlorite ◽  
Copper Ion ◽  
Microbial Pathogens ◽  
Sodium Hypochlorite Solution ◽  
Escherichia Coli O157 ◽  
Hypochlorite Solution ◽  
Apple Cider ◽  
E Coli ◽  
Log Reduction ◽  
Pathogen Reduction

Sodium hypochlorite (100 ppm), copper ion water (1 ppm), and sonication (22 to 44 kHz and 44 to 48 kHz) were assessed individually and in combination for their ability to reduce populations of Escherichia coli O157:H7 and Listeria monocytogenes on apples and in apple cider. Commercial unpasteurized cider was inoculated to contain approximately 106 CFU/ml of either pathogen and then sonicated at 44 to 48 kHz, with aliquots removed at intervals of 30 to 60 s for up to 5 min and plated to determine numbers of survivors. Subsequently, whole apples were inoculated by dipping to contain approximately 106 CFU/g E. coli O157:H7 or L. monocytogenes, held overnight, and then submerged in 1 ppm copper ion water with or without 100 ppm sodium hypochlorite for 3 min with or without sonication at 22 to 44 kHz and examined for survivors. Treated apples were also juiced, with the resulting cider sonicated for 3 min. Populations of both pathogens decreased 1 to 2 log CFU/ml in inoculated cider following 3 min of sonication. Copper ion water alone did not significantly reduce populations of either pathogen on inoculated apples. However, when used in combination with sodium hypochlorite, pathogen levels decreased approximately 2.3 log CFU/g on apples. Sonication of this copper ion–sodium hypochlorite solution at 22 to 44 kHz did not further improve pathogen reduction on apples. Numbers of either pathogen in the juice fraction were approximately 1.2 log CFU/ml lower after being juiced, with sonication (44 to 48 kHz) of the expressed juice decreasing L. monocytogenes and E. coli O157:H7 populations an additional 2 log. Hence, a 5-log reduction was achievable for both pathogens with the use of copper ion water in combination with sodium hypochlorite followed by juicing and sonication at 44 to 48 kHz.

Efficacy of Ultraviolet Light for Reducing Escherichia coli O157:H7 in Unpasteurized Apple Cider

2000 ◽  
Vol 63 (5) ◽  
pp. 563-567 ◽  
Author(s):  
J. R. WRIGHT ◽  
S. S. SUMNER ◽  
C. R. HACKNEY ◽  
M. D. PIERSON ◽  
B. W. ZOECKLEIN
Keyword(s):  
Thin Film ◽  
Escherichia Coli ◽  
Uv Light ◽  
Uv Disinfection ◽  
Escherichia Coli O157 ◽  
Apple Cider ◽  
E Coli ◽  
Log Reduction ◽  
Disinfection Unit ◽  
Additional Reduction

This study examined the efficacy of UV light for reducing Escherichia coli O157:H7 in unpasteurized cider. Cider containing a mixture of acid-resistant E. coli O157:H7 (6.3 log CFU/ml) was treated using a thin-film UV disinfection unit at 254 nm. Dosages ranged from 9,402 to 61,005 μW-s/cm2. Treatment significantly reduced E. coli O157:H7 (P ≤ 0.0001). Mean reduction for all treated samples was 3.81 log CFU/ml. Reduction was also affected by the level of background microflora in cider. Results indicate that UV light is effective for reducing this pathogen in cider. However, with the dosages used in this experiment, additional reduction measures are necessary to achieve the required 5-log reduction.

scholarly journals Inactivation of Listeria monocytogenes ATCC 7644 on tomatoes using sodium dodecyl sulphate, levulinic acid and sodium hypochlorite solution

2015 ◽  
Author(s):  
◽  
Elizabeth Mnyandu
Keyword(s):  
Sodium Hypochlorite ◽  
Sodium Dodecyl Sulphate ◽  
Contact Time ◽  
Levulinic Acid ◽  
Fresh Produce ◽  
Sodium Dodecyl ◽  
Soluble Solids ◽  
Sodium Hypochlorite Solution ◽  
Hypochlorite Solution ◽  
Log Reduction

Listeria monocytogenes have been implicated as a public health concern worldwide. The study explored the survival of non-adapted, heat adapted and chlorine adapted L. monocytogenes on tomatoes; as well as the survival of non-adapted, heat adapted and chlorine adapted biofilms after exposure to sodium dodecyl sulphate (SDS), levulinc acid, sodium hypochlorite solution. Contact time of 1, 3 and 5 minutes was used. The survival of L. monocytogenes was monitored at 0, 24, 48 and 72 hours. The sanitizers were used individually or combined as follows; 1% sodium dodecyl sulphate individually; 0.5% levulinic acid individually; 200 ppm sodium hypochlorite solution individually and 0.5% levulinic acid/0.05% sodium dodecyl sulphate in combination (mixture). The samples were kept at 4 °C throughout the period of assessment. The effect of these sanitizers on pH, total soluble solids (TSS) and titratable acidity (TA) was also determined. Furthermore, the attachment of L. monocytogenes on tomatoes was investigated using a scanning electron microscope. Highest log reduction of non-adapted L. monocytogenes were observed on tomatoes treated with 1% SDS and least log reduction was achieved when tomatoes were treated with sodium hypochlorite solution. Though the log reduction achieved by 0.5% levulinic acid was higher that sodium hypochlorite solution, it was lower than log reduction achieved when 0.05% SDS / 0.5% levulinic acid mixture was used for all contact times. Using non-adapted L. monocytogenes, SDS was able to destroy all L. monocytogenes at 1, 3 and 5 minutes contact time. The trend was the same when heat adapted and chlorine adapted L. monocytogenes were used. There was no significant log reduction observed with biofilms. More favourable results were observed as contact time was increased from 1 to 5 minutes. Though there was a decrease in surviving bacteria from 1 to 3 minutes contact time, this decrease was not significant. The study investigated if exposure to sanitizer has an effect on pH, titratable acidity (TA) and total soluble solids (TSS) of the tomatoes. It was revealed that levulinic acid and mixture can have detrimental effect on pH, TA and TSS of tomatoes. The TA and TSS of samples treated with levulinic acid and mixture varied significantly (P ≤ 0.05) compared to the control sample. Although the TA and TSS of samples treated with SDS and sodium hypochlorite solution were different from the control, the differences were not significant. As much as sanitizers have the potential to reduce the bacterial population in fresh produce they may not completely destroy pathogens. Chlorine based sanitizers such as sodium hypochlorite though frequently used in the fresh produce industry, are not the best sanitizer to be used against food borne pathogens. Other sanitizers such as SDS used alone or in combination with another sanitizer can achieve better results than the widely used sodium hypochlorite solution as observed in this study. Stress adapted pathogens become less responsive to sanitizers during subsequent treatments. Through this research, it was established that biofilms are resistant to sanitizers. Though application of sanitizers in fresh produce is cheaper and simpler to apply, there is need to monitor varying concentrations of sanitizers, contact time and minimise contact with sub-surfaces as this could lead to sensory quality losses.

Validation of Apple Cider Pasteurization Treatments against Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes

2001 ◽  
Vol 64 (11) ◽  
pp. 1679-1689 ◽  
Author(s):  
PEGGY P. MAK ◽  
BARBARA H. INGHAM ◽  
STEVEN C. INGHAM
Keyword(s):  
Escherichia Coli ◽  
New York ◽  
Listeria Monocytogenes ◽  
Fluorescent Protein ◽  
Escherichia Coli O157 ◽  
Salmonella Spp ◽  
Apple Cider ◽  
E Coli ◽  
Log Reduction ◽  
Green Fluorescent

Time and temperature pasteurization conditions common in the Wisconsin cider industry were validated using a six-strain cocktail of Escherichia coli O157:H7 and acid-adapted E. coli O157:H7 in pH- and ∘Brix-adjusted apple cider. Strains employed were linked to outbreaks (ATCC 43894 and 43895, C7927, and USDA-FSIS-380–94) or strains engineered to contain the gene for green fluorescent protein (pGFP ATCC 43894 and pGFP ATCC 43889) for differential enumeration. Survival of Salmonella spp. (CDC 0778, CDC F2833, and CDC HO662) and Listeria monocytogenes (H0222, F8027, and F8369) was also evaluated. Inoculated cider of pH 3.3 or 4.1 and 11 or 14°Brix was heated under conditions ranging from 60°C for 14 s to 71.1°C for 14 s. A 5-log reduction of nonadapted and acid-adapted E. coli O157:H7 was obtained at 68.1°C for 14 s. Lower temperatures, or less time at 68.1°C, did not ensure a 5-log reduction in E. coli O157:H7. A 5-log reduction was obtained at 65.6°C for 14 s for Salmonella spp. L. monocytogenes survived 68.1°C for 14 s, but survivors died in cider within 24 h at 4°C. Laboratory results were validated with a surrogate E. coli using a bench-top plate heat-exchange pasteurizer. Results were further validated using fresh unpasteurized commercial ciders. Consumer acceptance of cider pasteurized at 68.1°C for 14 s (Wisconsin recommendations) and at 71.1°C for 6 s (New York recommendations) was not significantly different. Hence, we conclude that 68.1°C for 14 s is a validated treatment for ensuring adequate destruction of E. coli O157:H7, Salmonella spp., and L. monocytogenes in apple cider.

scholarly journals Inactivation of heat adapted and chlorine adapted Listeria monocytogenes ATCC 7644 on tomatoes using sodium dodecyl sulphate, levulinic acid and sodium hypochlorite solution

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Oluwatosin Ademola Ijabadeniyi ◽  
Elizabeth Mnyandu
Keyword(s):  
Listeria Monocytogenes ◽  
Sodium Hypochlorite ◽  
Sodium Dodecyl Sulphate ◽  
Levulinic Acid ◽  
Sodium Dodecyl ◽  
Storage Period ◽  
Sodium Hypochlorite Solution ◽  
Hypochlorite Solution ◽  
Log Reduction ◽  
Significant Difference

The effectiveness of sodium dodecyl sulphate (SDS), sodium hypochlorite solution and levulinic acid in reducing the survival of heat adapted and chlorine adapted <em>Listeria monocytogenes</em> ATCC 7644 was evaluated. The results against heat adapted <em>L. monocytognes</em> revealed that sodium hypochlorite solution was the least effective, achieving log reduction of 2.75, 2.94 and 3.97 log CFU/mL for 1, 3 and 5 minutes, respectively. SDS was able to achieve 8 log reduction for both heat adapted and chlorine adapted bacteria. When used against chlorine adapted <em>L. monocytogenes</em> sodium hypochlorite solution achieved log reduction of 2.76, 2.93 and 3.65 log CFU/mL for 1, 3 and 5 minutes, respectively. Using levulinic acid on heat adapted bacteria achieved log reduction of 3.07, 2.78 and 4.97 log CFU/mL for 1, 3, 5 minutes, respectively. On chlorine adapted bacteria levulinic acid achieved log reduction of 2.77, 3.07 and 5.21 log CFU/mL for 1, 3 and 5 minutes, respectively. Using a mixture of 0.05% SDS and 0.5% levulinic acid on heat adapted bacteria achieved log reduction of 3.13, 3.32 and 4.79 log CFU/mL for 1, 3 and 5 minutes while on chlorine adapted bacteria it achieved 3.20, 3.33 and 5.66 log CFU/mL, respectively. Increasing contact time also increased log reduction for both test pathogens. A storage period of up to 72 hours resulted in progressive log reduction for both test pathogens. Results also revealed that there was a significant difference (P ≤ 0.05) between contact times, storage times and sanitizers. Findings from this study can be used to select suitable sanitizers and contact times for heat adapted and chlorine adapted <em>L. monocytogenes</em> in the fresh produce industry.

Escherichia coli O157: H7 Acid Tolerance and Survival in Apple Cider

1994 ◽  
Vol 57 (6) ◽  
pp. 460-464 ◽  
Author(s):  
LESLIE GARLAND MILLER ◽  
CHARLES W. KASPAR
Keyword(s):  
Escherichia Coli ◽  
Sodium Benzoate ◽  
Acid Tolerance ◽  
Potassium Sorbate ◽  
Escherichia Coli O157 ◽  
Control Strain ◽  
High Ph ◽  
Apple Cider ◽  
E Coli ◽  
Log Reduction

The survival of two Escherichia coli O157:H7 (ATCC 43889 and 43895) and a control strain E. coli was compared in apple cider and in Trypticase soy broth (TSB) adjusted to low and high pH. The O157:H7 strains were detectable in apple cider after 14 to 21 days at 4°C, whereas the control strain could not be detected (&gt; 4-log reduction) after 5 to 7 days. During the first 14 days of storage at 4°C, the levels of strain 43889 decreased by ~3 logs, whereas levels of strain 43895 were unchanged. Survival of O157:H7 strains and the control strain were unaffected by the presence of potassium sorbate or sodium benzoate, except in one instance. Sodium benzoate caused a decrease of 57% in strain 43895 after 21 days, but ~104 CFU/ml still remained. In TSB adjusted to pH 2, 3, 4, 11 or 12, strain 43895 was again the more resistant of the O157:H7 strains, both of which were more durable than the control strain. The O157:H7 strains (especially strain 43895) withstood pH 2 with a minimal drop in CPU after 24 h, whereas no viable organisms were detectable after this time at pH 12. At these extremes of pH, survival was generally greater at 4°C than at 25°C. Despite differences between strains, these results show that E. coli O157:H7 is exceptionally tolerant of acid pH.

Efficiency of Sodium Hypochlorite, Fumaric Acid, and Mild Heat in Killing Native Microflora and Escherichia coli O157:H7, Salmonella Typhimurium DT104, and Staphylococcus aureus Attached to Fresh-Cut Lettuce

2006 ◽  
Vol 69 (2) ◽  
pp. 323-329 ◽  
Author(s):  
NOZOMI KONDO ◽  
MASATSUNE MURATA ◽  
KENJI ISSHIKI
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Sodium Hypochlorite ◽  
Fumaric Acid ◽  
Bacterial Flora ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Mild Heat ◽  
Log Reduction

The effect of the disinfectant sodium hypochlorite (NaClO), with or without mild heat (50°C) and fumaric acid, on native bacteria and the foodborne pathogens Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella Typhimurium DT104 attached to iceberg lettuce leaves was examined. The retail lettuce examined consistently harbored 6 to 7 log CFU/g of native bacteria throughout the study period. Inner leaves supported 1 to 2 log CFU/g fewer bacteria than outer leaves. About 70% of the native bacterial flora was removed by washing five times with 0.85% NaCl. S. aureus, E. coli, and Salmonella allowed to attach to lettuce leaves for 5 min were more easily removed by washing than when allowed to attach for 1 h or 2 days, with more S. aureus being removed than E. coli or Salmonella Typhimurium. An increase of time for attachment of pathogens from 5 min to 2 days leads to decreased efficiency of the washing and sanitizing treatment. Treatment with fumaric acid (50 mM for 10 min at room temperature) was the most effective, although it caused browning of the lettuce, with up to a 2-log reduction observed. The combination of 200 ppm of sodium hypochlorite and mild heat treatment at 50°C for 1 min reduced the pathogen populations by 94 to 98% (1.2- to 1.7-log reduction) without increasing browning.

Pathogen Reduction in Unpasteurized Apple Cider: Adding Cranberry Juice To Enhance the Lethality of Warm Hold and Freeze-Thaw Steps

2006 ◽  
Vol 69 (2) ◽  
pp. 293-298 ◽  
Author(s):  
STEVEN C. INGHAM ◽  
ERICA L. SCHOELLER ◽  
REBECCA A. ENGEL
Keyword(s):  
Uv Light ◽  
Cranberry Juice ◽  
Apple Cider ◽  
E Coli ◽  
Freeze Thaw ◽  
Injury Repair ◽  
Log Reduction ◽  
Positive Score ◽  
Pathogen Reduction ◽  
Hedonic Scale

U.S. Food and Drug Administration (FDA) regulations require processors of apple cider sold wholesale to use processing steps that ensure a 5-log reduction in numbers of the pertinent pathogen, generally considered to be Escherichia coli O157: H7. Current widely used validated pathogen-reduction steps are thermal pasteurization and UV light treatment. These techniques may be unaffordable or undesirable for some processors. This study investigated the cran-cider process, which is the addition of cranberry juice at a 15% (vol/vol) level, followed by warm hold (45°C for 2 h) and freeze-thaw steps (−20°C for 24 h, 5°C for 24 h). When enumeration procedures did not include injury repair, the cran-cider process achieved a ≥5-log reduction in numbers of E. coli O157:H7, Salmonella serovars, and Listeria monocytogenes. However, an injury-repair step was included in the pathogen enumeration procedure in confirmatory trials, and the resulting E. coli O157:H7 reductions of 3.5 to 4.2 log did not meet the FDA requirement. Consumer evaluation of apple cider subjected to the cran-cider process was favorable with a mean (n = 197) score of 5.8 on a seven-point hedonic scale (where 6 equals “like moderately”) and 89% of panelists giving the product a positive score of 5, 6, or 7. The cran-cider process provides a novel way to improve microbial safety of unpasteurized apple cider, but it does not meet FDA-mandated pathogen reductions for wholesalers. However, cider makers selling apple cider only at retail could use the process to improve the safety of their product, provided containers were labeled with the FDA-mandated consumer warning.

Antimicrobial Effects of Weak Acids on the Survival of Escherichia coli O157:H7 under Anaerobic Conditions†‡

2011 ◽  
Vol 74 (6) ◽  
pp. 893-898 ◽  
Author(s):  
HUIYING J. LU ◽  
FREDERICK BREIDT ◽  
ILENYS M. PÉREZ-DÍAZ ◽  
JASON A. OSBORNE
Keyword(s):  
Escherichia Coli ◽  
Food Products ◽  
Escherichia Coli O157 ◽  
Weak Acids ◽  
Anaerobic Conditions ◽  
Antimicrobial Effects ◽  
Apple Cider ◽  
E Coli ◽  
Log Reduction ◽  
Antimicrobial Effectiveness

Outbreaks of disease due to vegetative bacterial pathogens associated with acid foods (such as apple cider) have raised concerns about acidified vegetables and related products that have a similar pH (3.2 to 4.0). Escherichia coli O157:H7 and related strains of enterohemorrhagic E. coli (EHEC) have been identified as the most acid resistant vegetative pathogens in these products. Previous research has shown that the lack of dissolved oxygen in many hermetically sealed acid or acidified food products can enhance survival of EHEC compared with their survival under aerobic conditions. We compared the antimicrobial effects of several food acids (acetic, malic, lactic, fumaric, benzoic, and sorbic acids and sulfite) on a cocktail of EHEC strains under conditions representative of non–heat-processed acidified vegetables in hermetically sealed jars, holding the pH (3.2) and ionic strength (0.342) constant under anaerobic conditions. The overall antimicrobial effectiveness of weak acids used in this study was ranked, from most effective to least effective: sulfite &gt; benzoic acid &gt; sorbic acid &gt; fumaric acid &gt; l- and d-lactic acid &gt; acetic acid &gt; malic acid. These rankings were based on the estimated protonated concentrations required to achieve a 5-log reduction in EHEC after 24 h of incubation at 30°C. This study provides information that can be used to formulate safer acid and acidified food products and provides insights about the mode of action of weak acids against EHEC.

Efficacy of Electrolyzed Water in the Inactivation of Planktonic and Biofilm Listeria monocytogenes in the Presence of Organic Matter

2006 ◽  
Vol 69 (9) ◽  
pp. 2143-2150 ◽  
Author(s):  
BEATRICE AYEBAH ◽  
YEN-CON HUNG ◽  
CHYER KIM ◽  
JOSEPH F. FRANK
Keyword(s):  
Organic Matter ◽  
Listeria Monocytogenes ◽  
Serum Concentration ◽  
Sodium Hypochlorite ◽  
Bactericidal Effect ◽  
Sodium Hypochlorite Solution ◽  
Chicken Serum ◽  
Hypochlorite Solution ◽  
Log Reduction ◽  
Oxidation Reduction

The ability of electrolyzed (EO) water to inactivate Listeria monocytogenes in suspension and biofilms on stainless steel in the presence of organic matter (sterile filtered chicken serum) was investigated. A five-strain mixture of L. monocytogenes was treated with deionized, alkaline EO, and acidic EO water containing chicken serum (0, 5, and 10 ml/liter) for 1 and 5 min. Coupons containing L. monocytogenes biofilms were also overlaid with chicken serum (0, 2.5, 5.0, and 7.5 ml/liter) and then treated with deionized water, alkaline EO water, acidic EO water, alkaline EO water followed by acidic EO water, and a sodium hypochlorite solution for 30 and 60 s. Chicken serum decreased the oxidation-reduction potential and chlorine concentration of acidic EO water but did not significantly affect its pH. In the absence of serum, acidic EO water containing chlorine at a concentration of 44 mg/liter produced a &gt;6-log reduction in L. monocytogenes in suspension, but its bactericidal activity decreased with increasing serum concentration. Acidic EO water and acidified sodium hypochlorite solution inactivated L. monocytogenes biofilms to similar levels, and their bactericidal effect decreased with increasing serum concentration and increased with increasing time of exposure. The sequential 30-s treatment of alkaline EO water followed by acidic EO water produced 4- to 5-log reductions in L. monocytogenes biofilms, even in the presence of organic matter.

Addition of Fumaric Acid and Sodium Benzoate as an Alternative Method To Achieve a 5-log Reduction of Escherichia coli O157:H7 Populations in Apple Cider

2002 ◽  
Vol 65 (3) ◽  
pp. 476-483 ◽  
Author(s):  
JUSTIN E. COMES ◽  
ROBERT B. BEELMAN
Keyword(s):  
Escherichia Coli ◽  
Fumaric Acid ◽  
Sodium Benzoate ◽  
Bactericidal Effect ◽  
Escherichia Coli O157 ◽  
Refrigerated Storage ◽  
Apple Cider ◽  
E Coli ◽  
Log Reduction ◽  
Strong Linear Correlation

A study was conducted to develop a preservative treatment capable of the Food and Drug Administration–mandated 5-log reduction of Escherichia coli O157:H7 populations in apple cider. Unpreserved apple cider was treated with generally recognized as safe acidulants and preservatives before inoculation with E. coli O157:H7 in test tubes and subjected to mild heat treatments (25, 35, and 45°C) followed by refrigerated storage (4°C). Fumaric acid had significant (P &lt; 0.05) bactericidal effect when added to cider at 0.10% (wt/vol) and adjusted to pH 3.3, but citric and malic acid had no effect. Strong linear correlation (R2 = 0.96) between increasing undissociated fumaric acid concentrations and increasing log reductions of E. coli O157:H7 in apple cider indicated the undissociated acid to be the bactericidal form. The treatment that achieved the 5-log reduction in three commercial ciders was the addition of fumaric acid (0.15%, wt/vol) and sodium benzoate (0.05%, wt/vol) followed by holding at 25°C for 6 h before 24 h of refrigeration at 4°C. Subsequent experiments revealed that the same preservatives added to cider in flasks resulted in a more than 5-log reduction in less than 5 and 2 h when held at 25 and 35°C, respectively. The treatment also significantly (P &lt; 0.05) reduced total aerobic counts in commercial ciders to populations less than those of pasteurized and raw ciders from the same source (after 5 and 21 days of refrigerated storage at 4°C, respectively). Sensory evaluation of the same ciders revealed that consumers found the preservative-treated cider to be acceptable.

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