Microbiology and pasteurization of surimi seafood

What is surimi?Types of surimi. Major producing countries of surimi.Pasteurization of different kinds of surimi.Microbiology of surimi.

Edible paste made from processed seafood,Imitation crab meat made by mild white fish such as Cod and pollack.Low in fat and High in protein.Types of surimi Based seafood:Satsuma-age(fried)Chikuwa(Baked)Kamaboko(steamed)Flavored kamaboko(fish sausage)Hanpen/Naruto(boiled)Crab legs

South koreaThailandMalaysiaChina (Fish ball, Crab stick)

This is a process of heating food to a specific temperature for a predefined period of time and then Immediately cooling it after it is removed from the heat.This process slows spoilage caused by microbial growth in the food.It just reduce the number of viable pathogens not kill all types of pathogens like sterilization because sterilization change the texture, flavor and Quality of food.

Processing temperatureProcessing temperatureProcessing time ( oF ) ( oC ) ( Min )185 85 175192 88.8 85198 92.2 65

Surimi Seafood MicrobiologyProduction and storageMicrobial qualityMicrobial safety Pasteurization studiesNon-thermal processing

Microbial standardsPackagingFermented productsRapid test kits

Microbial load in the raw surimi.Microbial load in ingredients.Processing time/temperature abuse.Equipment sanitation.Employee hygiene.

a = surimib = surimi plus ingredientsc = first cook/rope formationd = color additione = second cookf = flaking or choppingg = packagingh = pasteurization

a = surimib = surimi plus ingredientsc = first cook/rope formationd = color additione = second cookf = flaking or choppingg = packagingh = pasteurization

PasteurizationHas no effect on bacterial spores, i.e., Clostridium and Bacillus speciesBacillus species are prime spoilers in air-packaged surimi seafood

Microbial Quality of Surimi Seafood: Bacillus Species and Other Gram-positive Bacteria

Microbial Safety of Surimi Seafood: Listeria monocytogenes, Clostridium botulinum and Other Bacteria

Generation Times (Hours) for Pathogens in Surimi Seafood15oC10oC5oC0oC59oF50oF41oF32oFAeromonas hydrophila1848194-Salmonella species1134--Staphylococcus aureus2946--Yersinia enterocolitica112677166

Pasteurization Studies for Surimi SeafoodInoculated pack studies with Enterococcus faecium93C (199.4F) 5 minutes85C (185F) for 15 minutes75C (167F) for 15 minutesIneffective against C. botulinum Type B

Microbiological Implications of Novel Surimi Processing TechnologiesHigh pressure200-400 MPaEffective against Vibrio, Listeria, SalmonellaIneffective against pressure resistant species and spore forming Bacillus and Clostridium speciesElectron beamUntested

Cooling and Refrigeration in food storageRapid cooling prevents growth from Bacillus and Clostridium60C (140F) to 21.1C (70F) in 2 hoursTo 4.4C (40F) within another 4 hoursRefrigerated storage below 4.4C (40F) prevents growth of pathogens

Microbiological Considerations in Packaging of Surimi SeafoodNitrogen and carbon dioxide packaging reduce fat and pigment oxidation and reduce spoilage bacterial growthAseptic packaging requires a sterile product and may not be feasible

ConclusionSurimi seafood Products are ready-to-eatSafety and quality concerns remainThe use of the term pasteurization should be discouraged or the process needs to be further studied

*Three CCPs*Microbiological data on surimi seafood production are variable.Changes in Aerobic Plate Count at processing steps in the production of surimi seafood.High initial counts from the raw surimi and ingredientsSome reduction in APC during the initial cookFurther reduction during second cookFlaking, chopping, packaging add bacteriaPasteurization reduces APC to low levels. Pasteurization does not kill all bacteria, e.g., spores of Bacillus and Clostridium.

2. JR Matches, E Raghubeer, IH Yoon, RE Martin. Microbiology of surimi-based products. In: DE Kramer, J Liston, ed. Seafood Quality Determination. Amsterdam: Elsevier Science Publ, 1987, pp 373-387. *Coliforms and fecal Coliforms, present in surimi and ingredients or contributed through handling, are generally low to absent in pasteurized surimi seafood.*Increasing storage temperature for surimi seafood, increases the rate of bacterial growth.*II. Microbial Quality of Surimi Seafood: Bacillus species and Other Gram-Positive Bacteria.

Bacillus can produce volatile fatty acids (lactic and acetic) and alcohols (butabediol and ethanol) from sucrose and sorbitol (cryoprotectants). Slime formation and sour odors are also theorized to occur from Bacillus growth on cryoprotectants.

A major source of Bacillus is starch, which may contain 10,000 spores/gram.*Vacuum packaged, surimi flaked crabmeat stored at 22C (71.6F) is predominated by Gram-positive bacteria.*Other pathogens have been shown to grow in surimi seafood, although no outbreaks have been reported.Psychrotrophic Aeromonas hydrophila and Yersinia enterocolitica grew slowly at 5C (41F) *IV. Pasteurization Studies for Surimi Seafood.

Inoculated pack studies with Enterococcus faecium93C (199.4F) initial temperatureReduced to 75C (167F) for 15 minutesYielded 6 log reduction of E. faeciumProcess also effective against L. monocytogenes, enteropathogenic E. coli, Salmonella, Yersinia entercolitica, and VibrioIneffective against C. botulinum

*V. Microbiological Implications of Novel Surimi Processing Technologies.High pressure200-300 MPaEffective against Vibrio, Listeria, SalmonellaLess effective against Moraxella, Acinetobacter, Enterococcus, and CorynebacteriumIneffective against Bacillus, ClostridiumElectron beamUntested

*Rapid cooling prevents growth from Bacillus and Clostridium60C (140F) to 21.1C (70F) in 2 hoursTo 4.4C (40F) within another 4 hours