CONTROL OF FOODBORNE PATHOGENS IN MEAT PRODUCTS BY by roq91753

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									    CONTROL OF FOODBORNE
PATHOGENS IN MEAT PRODUCTS BY
    SANITATION, DRYING AND
       ANTIMICROBIALS


           John N. Sofos
      Colorado State University

      John.Sofos@colostate.edu
 SANITIZER INACTIVATION OF ACID-
ADAPTED AND NONADAPTED LISTERIA
    MONOCYTOGENES BIOFILMS

                     Objective
To evaluate the antimicrobial effects of sodium
hypochlorite (200 ppm, pH 10.4), pH-adjusted (pH
6.8) sodium hypochlorite (200 ppm), a quaternary
ammonium compound (200 ppm), and peroxyacetic
acid (150 ppm) on biofilms produced by previously
acid-adapted or nonadapted Listeria monocytogenes
inoculated in fresh beef decontamination washings.
                         10       Stainless steel attached cells; fresh beef washings (15oC, 2 days) inoculated
                                  with Listeria monocytogenes
log CFU/cm (TSAYE+Rif)



                          8                Adjusted sodium hypochlorite (200 ppm)    Adjusted sodium hypochlorite (200 ppm)
                                           Peroxyacetic acid (150 ppm)               Peroxyacetic acid (150 ppm)
                                           Quaternary ammonium compound (200 ppm)    Quaternary ammonium compound (200 ppm)
                          6                Sodium hypochlorite (200 ppm)             Sodium hypochlorite (200 ppm)
                                             Closed symbols = acid-adapted cells; open symbols = nonadapted cells


                          4
       2




                          2


                          0
                              0                             30                             120                            300
                                                                      Time (sec)
             10
                      Deattached cells; fresh beef washings (15oC, 2 days) inoculated with Listeria
                      monocytogenes
(TSAYE)



              8                Adjusted sodium hypochlorite (200 ppm)   Adjusted sodium hypochlorite (200 ppm)
                               Peroxyacetic acid (150 ppm)              Peroxyacetic acid (150 ppm)
                               Quaternary ammonium compound (200 ppm)   Quaternary ammonium compound (200 ppm)
                               Sodium hypochlorite (200 ppm)            Sodium hypochlorite (200 ppm)
              6
                                Closed symbols = acid-adapted cells; open symbols = nonadapted cells
log CFU/ml




              4


              2


              0
                  0                15                 30                60                120               300
                                                           Time (sec)
                         Conclusions
• Previous acid adaptation did not affect biofilm formation or
inactivation.
• Intact biofilms were more resistant to inactivation than biofilm
cells (deattached) removed into suspension.
• Peroxyacetic acid was more effective on the attached cells of
the natural flora than those of L. monocytogenes.
• Peroxyacetic acid was relatively less effective on biofilm cells
in suspension than on attached biofilm cells when compared with
the other sanitizers.
• Sodium hypochlorite adjusted to pH 6.8 was more effective than
when unadjusted (pH 10.4).
FATE OF LISTERIA MONOCYTOGENES IN
  FRESH MEAT DECONTAMINATION
       FLUIDS AT 4 AND 10oC

                   Objective

 To evaluate the potential for survival and growth
 of acid-adapted, partially acid-adapted or
 nonadapted Listeria monocytogenes in acid or
 nonacid (water) spray-washings of fresh beef at
 low temperatures to simulate conditions
 encountered in the meat industry.
                      Behavior of Listeria monocytogenes in meat washings
             10
                        AD (W)              AD (LA/W 1:99)       AD (AA/W 1:99)
                        NAD (W)             NAD (LA/W 1:99)      NAD (AA/W 1:99)
              8
log CFU/ml




              6



              4



              2



              0
                  0               2             4            o
                                                                 7                 14
                                      Days of storage (10 C)
                  Conclusions

• Limited survival of L. monocytogenes for at
  maximum 4 days may be expected in undiluted
  acidic (lactate or acetate) meat decontamination
  washings, or mixed with water washings, when
  the resulting pH is less than 4.0.
• Acid-containing washings with a pH above 4.0
  may support survival and potential growth for
  extended times, while in nonacid (water) washings
  the pathogen may increase to high numbers.
FRESH BEEF DECONTAMINATION AND
     POPULATIONS OF LISTERIA
 MONOCYTOGENES DURING VACUUM-
   PACKAGED STORAGE (4oC, 10oC)

TREATMENTS
• Control
• Water (pH 6.7, 55C)
• Water (pH 6.7, 75C)
• Lactic acid (2%, pH 2.3, 55C)
• Acetic acid (2%, pH 2.8, 55C)
                  Acid-adapted Listeria monocytogenes in vacuum packaged beef
                   Not-treated: , Water (55°C): , Water (75°C): , Lactic acid
                                (55°C): or Acetic acid (55°C):
              8

              7

              6
log CFU/cm2




              5       a
                      a              a                                           a
                                     a            a             a                a
              4                                   a             a                a
              3       b
                      b              b            b             b
                      b                           b
              2                      b            b             b                b
                                     b                          b                b
              1

              0
                  0              7               14            21               28
                                                       o
                                         Time (days at 4 C)
                   Acid-adapted Listeria monocytogenes in vacuum packaged beef
                    Not-treated: , Water (55°C): , Water (75°C): , Lactic acid
                                 (55°C): or Acetic acid (55°C):
               8

               7
                                                       a             a                a
                                      a                a             b
               6                      a
                                      a                                               b
                                                       b             c                b
log CFU/cm 2




               5       a
                       a
               4

               3       b                                                              c
                       b              b                              d
                                                       c             d
               2       c              b                c                              d

               1

               0
                   0              7               14            21               28
                                                           o
                                          Time (days at 10 C)
                   Conclusions
• Application of organic acids (acetic or lactic acid) to
  meat can reduce levels of contamination and then inhibit
  growth of L. monocytogenes during storage at 4 or
  10C.
• Although 75C water decreased the initial population of
  L. monocytogenes on meat, growth of the pathogen
  occurred during storage.
• Prior acid-adaptation of this strain did not enhance
  growth on meat treated with acid or water.
• This study emphasizes the importance of long-term
  residual effects of acid and water decontamination
  treatments and storage temperatures on meat safety.
 EVALUATION OF PROCESSES TO DESTROY
 ESCHERICHIA COLI O157:H7 AND LISTERIA
MONOCYTOGENES IN WHOLE MUSCLE HOME
          DRIED BEEF JERKY

                     Objectives

  To determine the survival of inoculated E. coli
  O157:H7 populations during preparation of whole
  muscle beef jerky with and without marinade and
  acids.
             10
                  Escherichia coli O157:H7        No marinade   No marinade    Marinade
                                                   62.5oC       62.5oC         62.5oC
                  Beef Jerky
                                                  Marinade      Marinade       Marinade
              8                                    62.5oC       68.3oC          68.3oC
                                                                Closed symbols = TSA
                                                                Open symbols = SMAC
log CFU/cm




              6
       2




              4


              2


              0
              INOC          0          4                6              8                 10
                                             Time (h)
             10
                      Escherichia coli O157:H7       No marinade         No marinade    Marinade
                                                      62.5oC             62.5oC         62.5oC
                      Beef Jerky
                                                     Marinade            Marinade       Marinade
              8                                       62.5oC             68.3oC          68.3oC
                                                                         Closed symbols = TSA;
                                                                         Open symbols = SMAC
log CFU/cm




              6
       2




              4


              2


              0
                  0                    30                           60                             90
                                                                o
                                        Storage time (days, 25 C)
             10   Escherichia coli O157:H7          Water/Marinate                         Water/Marinate
                  Beef Jerky (68.3oC)            Water =   94oC,   15 sec          Marinate/store at 4oC, 24 h
                                                    Seasoning/Hot brine                    Seasoning/Hot brine
                                                 Season/store at 4oC, 24 h           Hot brine = 78oC, 90 sec
              8
                                                    Acetic acid/Marinate                   Acetic acid/Marinate
                                                 Acetic acid (2.5%),     57.5oC   20 sec
log CFU/cm




                                                    Marinate/Acetic acid                   Marinate/Acetic acid
              6
        2




                                                                            Closed symbols = TSA
                                                                            Open symbols = SMAC


              4


              2


              0
              INOC       PD1       PD2          4                    6                     8                 10

                                             Time (h)
Water activity    1




                 0.5



                                                      Water/Marinate                    Seasoning/Hot brine
                                                    Water = 94oC, 15 sec           Marinate/store at 4oC, 24 h
                                                    Season/store at 4oC, 24 h      Hot brine = 78oC, 90 sec
                       Escherichia coli O157:H7
                                                      Acetic acid/Marinate              Marinate/Acetic acid
                       Beef Jerky (68.3oC)          Acetic acid (2.5%), 57.5oC 20 sec
                  0
                  INOC        PD1      PD2            4                 6                  8                   10
                                                  Time (h)
          7   Escherichia coli O157:H7
              Beef Jerky (62.5oC)
          6

                                  Control                         Marinade
          5
                                  Marinade+Ascorbic acid (7.7%)   Marinade+Citric acid (3.7%)
D-value




          4

          3

          2

          1

          0

                    TSA                SMAC-CT                           MEMB
                   Bacterial counts (TSA+0.1% pyruvate) on jerky (dried at 60.0oC)
                   inoculated with E. coli 0157:H7
              10

                                                                Control

              8                                                 Trad. Mar.

                                                                EtOH+Sod.Lact.+Trad. Mar.

              6                                                 Acetic Acid+Trad. Mar
log CFU/cm2




                                                                TW20+Acetic A.+Trad. Mar


              4



              2
                                                                                            5.0 log reduction


              0
                     After Inoc.    0           4           7                    10
                                             Time (h)
               Survival Of L. monocytogenes on beef jerky—(PALCAM)
              10



              8                                          Control

                                                         Trad. Mar.

                                                         EtOH +Sod. Lact.+Trad. Mar.
              6
log CFU/cm2




                                                         Acetic Acid +Trad. Mar

                                                         TW20+Acetic A. +Trad. Mar
              4



              2


                                                                                       5.0 log reduction
              0
                   After Inoc.   0          4           7                   10
                                         Time (h)
                    Conclusions

• The traditional marination procedure did not result in
  a 5 log reduction of either pathogen.
• In addition, the traditional marination procedure may
  provide protection/resistance of pathogens during
  drying.
• In general, application of pre-drying treatments or
  modified marination was more detrimental to either
  pathogen than the control or traditional procedures
  and more detrimental to Listeria monocytogenes than
  E. coli O157:H7.
• Bacterial injury may be occurring during drying.
  TREATMENTS TO CONTROL POST-
  PROCESSING CONTAMINATION BY
 LISTERIA MONOCYTOGENES ON PORK
FRANKFURTERS AND SLICED BOLOGNA
STORED AT 4oC IN VACUUM PACKAGES

                   Objective
 To evaluate antimicrobials or their combinations
 in the formulation of frankfurters, or as dipping
 solutions for bologna slices, against surface
 inoculated Listeria monocytogenes after
 peeling/slicing and before vacuum packaging.
                       10              Control                     Water                     Acetic Acid (2.5%)
                                       Acetic Acid (5%)            Lactic Acid (2.5%)        Lactic Acid (5%)


                        8
log CFU/cm2 (PALCAM)




                        6



                        4



                        2


                                Bologna slices inoculated with Listeria monocytogenes and then immersed (1 min)
                        0
                            0           10                20     35             50      70            90          120
                                                               Days of storage (4 oC)
                       10             Control                   Water                      Sodium Acetate (2.5%)
                                      Sodium Acetate (5%)       Sodium Diacetate (2.5%)    Sodium Diacetate (5%)


                        8
log CFU/cm2 (PALCAM)




                        6



                        4



                        2

                                Bologna slices inoculated with Listeria monocytogenes and then immersed (1 min)
                        0
                            0            10            20       35            50          70           90          120
                                                              Days of storage (4 oC)
                       10              Control                      Water                      Potassium Benzoate (5%)
                                       Potassium Sorbate (5%)       Sodium Lactate (5%)        Sodium Lactate (10%)
log CFU/cm2 (PALCAM)




                        8



                        6



                        4



                        2


                                Bologna slices inoculated with Listeria monocytogenes and then immersed (1 min)
                        0
                            0            10            20          35            50       70            90               120
                                                                                      o
                                                                Days of storage (4 C)
                        10       Control                               Water
                                 Lysozyme (0.01%)                      Lysozyme (0.1%)
                                 Nisin (0.5%)                          Lysozyme (0.01%)+Nisin (0.5%)
                                 Lysozyme (0.1%)+Nisin (0.5%)
                         8
log CFU/cm 2 (PALCAM)




                         6



                         4



                         2



                         0
                             0                  10                       20                      35    50
                                                                Days of storage (4 oC)
             10            Control                       Water                          N+Potassium Benzoate (3%)
                           N+Potassium Sorbate (3%)      N+Sodium Acetate (3%)          N+Sodium Acetate (5%)
                           N+Sodium Diacetate (3%)       N+Sodium Diacetate (5%)
 (PALCAM)


              8


              6
log CFU/cm




              4
        2




              2

                      Bologna slices inoculated with Listeria monocytogenes and then immersed (1 min)
              0
                  0            10             20        35            50           70           90            120
                                                      Days of storage (4oC)
                    Conclusions
• Listeria monocytogenes inoculated (2-3 log CFU/cm2)
  on bologna slices before vacuum packaging reached
  high populations (> 7 log CFU/cm2) in 10-20 days of
  storage at 4oC.
• Immersion of inoculated bologna slices in acetic acid
  (2.5 and 5%), lactic acid (5%), sodium diacetate (5%)
  or potassium benzoate (5%) inhibited Listeria
  monocytogenes for over 90 days at 4oC.
• Lower immersion concentrations of lactic acid (2.5%)
  and sodium diacetate (2.5%), or immersion in sodium
  acetate (2.5 and 5%), and sodium lactate (5 and 10%)
  exhibited lower levels of inhibition.
                      Conclusions
• Results of this study revealed that post-processing
  contamination with L. monocytogenes may be
  controlled in cured meat products by post-processing
  exposure to solutions of acetic, lactic, benzoic or sorbic
  acid or their salts.
• Sensory evaluation studies should be performed,
  however to refine the concentrations needed and to
  determine their effects in product shelf-life before the
  commercial application of any of the effective
  treatments of this study.
• Evaluation of antimicrobial effects at abusive
  temperature is also suggested and technological
  innovations are needed for commercial application of
  the treatments.
             10               Control                                   Sodium Acetate (0.25%)
                              Sodium Acetate (0.50%)                    Sodium Diacetate (0.25%)
                              Sodium Diacetate (0.50%)                  Sodium Lactate (3%)
                              Sodium Lactate (6%)
(PALCAM)



              8


              6
log CFU/cm




              4
       2




              2
                      Frankfurters with antimicrobials included in the formulation inoculated
                      with Listeria monocytogenes
              0
                  0           10           20              35           50            70           90   120
                                                         Days of storage (4oC)
             10          Control 1      Control 2      30s        30s         60s      60s        90s     90s
                      Inoculated frankfurters dipped in hot   (75oC)   water; open symbols = 1 frankfurter/bag;
                      closed symbols = 2 frankfurters/bag
(PALCAM)



              8


              6
log CFU/cm




              4
       2




              2


              0
                  0                    10                        20                          35                   50
                                                      Days of storage (4oC)
                             Control
             10              Sodium lactate (1.8%)
                             Sodium lactate (1.8%)+Sodium acetate (0.25%)
                             Sodium lactate (1.8%)+Sodium diacetate (0.25%)
(PALCAM)



              8              Sodium lactate (1.8%)+Glucono-delta-lactone (0.25%)


              6
log CFU/cm




              4
       2




              2
                      Frankfurters with antimicrobials included in the formulation inoculated
                      with Listeria monocytogenes
              0
                  0           10             20             35             50      70      90   120
                                                         Days of storage (4oC)
                    Conclusions
• Listeria monocytogenes inoculated (2-4 log
  CFU/cm2) on frankfurters after peeling exceed 7
  log CFU/cm2 after 20-35 day at 4oC in vacuum
  packages.
• Permissible concentrations of sodium acetate and
  sodium diacetate (both at 0.25% of the total
  formulation weight) were inhibitory to Listeria
  monocytogenes inoculated on frankfurters post-
  processing for up to 30 days at 4oC.
• The permissible concentration of sodium lactate
  (3% of the total formulation weight) inhibited
  growth of the pathogen for 50 to 70 days during
  storage at 4oC under the experimental conditions.
                   Conclusions
• Increase of the permissible concentrations of
  sodium acetate to 0.5% did not affect growth of L.
  monocytogenes for more than 20 days, while by
  doubling their permissible concentrations, sodium
  diacetate and sodium lactate exhibited complete
  control for 120 days at 4oC.
• As applied, post-packaging thermal pasteurization
  (75-80oC/30-90sec) had variable effects in
  reducing initial contamination and was not
  effective or reliable in controlling growth of L.
  monocytogenes during storage, especially when
  two frankfurters were included in a package.
                    Conclusions
• The increase in the permissible concentrations of
  antimicrobials in frankfurters could be avoided by
  combining a lower level of sodium lactate (1.8%) with
  sodium acetate (0.25%) or sodium diacetate (0.25%);
  these combinations inhibited growth of the pathogen for
  up to 120 days at 4oC.
• Post-packaging thermal treatment may enhance the
  inhibitory activity of the combined antimicrobials
  during storage at 4oC.
• Use of adequate levels of antimicrobials or their
  combinations, in the formulation of cooked meat
  products, needs to be evaluated for effects on product
  quality and shelf-life, and for antimicrobial effects at
  abusive temperatures.
               ACKNOWLEDGEMENTS
• Faculty                             • Graduate Students:
   –   K.E. Belk                           –    A. Abushelaibi
   –   P.A. Kendall                        –    S. Albright
   –   J.A. Scanga                         –    C. Anderson
   –   G.R. Schmidt                        –    T. Bacon
   –   G.C. Smith                          –    G. Bedie
• Post Docs:                               –    J. Burnham
   – J. Samelis                            –    E. Derrickson
   – J. Ikeda                              –    T. DiPersio
   – M. Calicioglu                         –    S. Lakkakula
• Research Associate                       –    J. Ransom
   – M.L. Kain                             –    K. Segomelo
                                           –    J. Stopforth
• Funding:
                                           –    Y. Yoon
   • USDA-CSREES
   • Colorado Agricultural Experiment Station
   • National Pork Producers Council

								
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