microbiology and haccp for surimi seafood. surimi seafood microbiology production and storage...
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Microbiology and HACCP For Surimi Seafood
Surimi Seafood Microbiology
• Production and storage• Microbial quality• Microbial safety • Pasteurization studies• Non-thermal processing
• HACCP• Microbial standards• Packaging• Fermented products• Rapid test kits
Microbiology of Surimi During Production and Storage
Microbial Quality and Safety of Surimi Seafood Depends On:
• Microbial load in the raw surimi• Microbial load in ingredients• Processing time/temperature abuse• Equipment sanitation• Employee hygiene
Figure 1. Aerobic Plate Count
01234567
a b c d e f g h
Processing step
Log
CF
U/g
Surimi Crab Leg
Flaked SurimiCrab MeatSurimi Scallops
a = surimib = surimi plus ingredientsc = first cook/rope formationd = color addition
e = second cookf = flaking or choppingg = packagingh = “pasteurization”
Figure 2. Coliform Counts
00,5
11,5
22,5
33,5
4
a b c d e f g h
Processing step
Log
Tot
al C
olif
orm
/g
Surimi Crab Leg
Flaked SurimiCrab MeatSurimi Scallops
a = surimib = surimi plus ingredientsc = first cook/rope formationd = color addition
e = second cookf = flaking or choppingg = packagingh = pasteurization
Figure 3. Fecal Coliform Counts
0
0,5
1
1,5
2
2,5
3
a b c d e f g h
Processing step
Log
Fec
al C
olif
orm
/g
Surimi Crab Leg
Flaked SurimiCrab MeatSurimi Scallops
a = surimib = surimi plus ingredientsc = first cook/rope formationd = color addition
e = second cookf = flaking or choppingg = packagingh = pasteurization
Equipment Sanitation
• Belt conveyor 1,800,000/cm2
• Container of mixed paste 25,000/cm2
• Inner wall of mixer 540/cm2
Surimi Seafood Shelf Life
Days at: 15oC 10oC 5oC 0oC59oF 50oF 41oF 32oF
Surimi crab legs 4 14 >28 >28Flaked surimi
crab meat <3 <4 <7 14
Figure 4. APC: Surimi Crab Legs
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0 10 20 30
Days of Storage
Log
CF
U/g 15C
10C5C0C
Figure 5. APC: Flaked Surimi Crab Meat
3456789
10
0 10 20 30
Days of Storage
Log
CF
U/g 15C
10C5C0C
Microbial Quality of Surimi Seafood: Bacillus Species and Other Gram-positive Bacteria
Pasteurization
• Has no effect on bacterial spores, i.e., Clostridium and Bacillus species
• Bacillus species are prime spoilers in air-packaged surimi seafood
Figure 6. Microbial Flora of Vacuum-Packed Flaked Surimi Crab Meat
0%
20%
40%
60%
80%
100%
0 4 8 13 19
Days at 22oC (71.6o F)
% C
omp
osit
ion
UnknownGram-NegativeGram-Positive
0%
20%
40%
60%
80%
100%
% C
ompo
siti
on
0 1 2 3 4 5 6
Days of Storage
Figure 7a. Microbial Isolates From
Surimi Crab Legs Stored at 15oC (59oF)
OtherPseudomonasBacillus
0%
20%
40%
60%
80%
100%
% C
ompo
siti
on
0 3 6 9 12 15 18
Days of Storage
Figure 7b. Microbial Isolates From
Surimi Crab Legs Stored at 5oC (41oF)
OtherPseudomonasBacillus
0%20%40%60%80%
100%
%
Com
posi
tion
0 7 14 21 28 35 42
Days of Storage
Figure 7c. Composition of Microbial Isolates From Surimi Crab Legs Stored
at 0oC
OtherPseudomonasBacillus
Microbial Safety of Surimi Seafood: Listeria
monocytogenes, Clostridium botulinum and Other Bacteria
L. monocytogenes
• 1988 surimi survey found 29% of samples positive
• 1988 U.S. Class I recall of imitation crab meat produced in Japan and distributed in three states
Table 1. Surimi Seafood Recalls Due to L. monocytogenes
• Imitation crab meat products 7/28/99 • Imitation crab spread 9/17/97• Imitation king crab legs 8/6/97• Imitation crab meat chunks 6/12/96• Imitation crab meat salad 9/30/92• Seafood salad 7/2/92
Clostridium botulinum
• Strict anaerobe• Grows above 38°F• No instances reported from surimi seafood• C. botulinum type E and nonproteolytic types
B and F are the target bacteria for FDA’s pasteurization processes– 6-D process = 90°C (194°F) for 10 minutes
Generation Times (Hours) for Pathogens in Surimi Seafood
15oC 10oC 5oC 0oC59oF 50oF 41oF 32oF
Aeromonas hydrophila 18 48 194 -Salmonella species 11 34 - -Staphylococcus aureus 29 46 - -Yersinia enterocolitica 11 26 77 166
Pasteurization Studies for Surimi Seafood
• Inoculated pack studies with Enterococcus faecium– 93°C (199.4°F) 5 minutes– 85°C (185°F) for 15 minutes– 75°C (167°F) for 15 minutes
• Yielded 6 log reduction of E. faecium– Process also effective against C. botulinum Type E (85 and
93°C), L. monocytogenes, enteropathogenic E. coli, Salmonella, Yersinia entercolitica, and Vibrio
• Ineffective against C. botulinum Type B
Pasteurization Studies for Surimi Seafood
Temperature Time D-Values(min.) L.m. C.b.(E) C.b.(B)
93°C (199.4°F) 5 16,200 52 0.785°C (185°F) 15 5,400 24 0.675°C (167°F) 15 350 2.2 0.1
Microbiological Implications of Novel Surimi Processing
Technologies• High pressure– 200-400 MPa– Effective against Vibrio, Listeria, Salmonella– Ineffective against pressure resistant species and spore
forming Bacillus and Clostridium species
• Electron beam– Untested
HACCP and Surimi Seafood
• Preventive system of food safety control• Based on – Identified hazards– Critical control points– Monitoring records
Metal Fragments
• Hard or sharp objects >7 mm in size are a potential hazard from laceration, perforation wound, and secondary infections
• Hard or sharp objects <7 mm in size are a possible hazard for high risk (e.g., infants, elderly) individuals
• Controls can include frequent inspections of cutting, portioning, blending, or other mechanical equipment for damage, or use of a metal detector
Pasteurization
• Eliminates targeted pathogenic bacteria and also extends product shelf life
• Pathogens in packaged products indicates inadequate pasteurization, or post pasteurization contamination, and time/temperature abuse
• Critical aspects: temperature of heating medium, length of pasteurization cycle, package thickness, package integrity, product formulation, and microbial quality of the cooling medium
Cooling
• Rapid cooling prevents growth from Bacillus and Clostridium
• 60°C (140°F) to 21.1°C (70°F) in 2 hours• To 4.4°C (40°F) within another 4 hours
Refrigerated Storage
• Refrigerated storage below 4.4°C (40°F) prevents growth of pathogens
Microbial Recommendations for Ready-to-eat Seafood
n c m MAerobic plate count 5 2 105 106
E. coli 5 1 11 500S. aureus 5 0 103 -V. parahaemolyticus 10 1 102 103
FDA Tolerance Levels: Vacuum Packaged Ready-to-eat Seafood
C. botulinum Presence of cells, Enteropathogenic E. coli 103/gL. monocytogenes PresenceSalmonella PresenceS. aureus 104/g or toxin positive V. cholerae PresenceV. parahaemolyticus 104/gV. vulnificus Presence
Microbiological Considerations in Packaging of Surimi Seafood
• Nitrogen and carbon dioxide packaging reduce fat and pigment oxidation and reduce spoilage bacterial growth
• Aseptic packaging requires a sterile product and may not be feasible
New Surimi Seafood Products Utilizing Fermentative Bacteria
• Fermented pollock kamaboko– pH 4.5– Sour tasting
• Fermented chum salmon surimi• Sensory studies have not been conducted
Reliability and Efficacy of Rapid Microbiological Procedures
• Traditional methods– APC with petri dishes or PetriFilm
• Rapid test kits for L. monocytogenes– 1-2 days instead of 5-7 days
Conclusion
• Surimi seafood Products are ready-to-eat– Safety and quality concerns remain– HACCP can help ensure a safe product
• The use of the term “pasteurization” should be discouraged or the process needs to be further studied