Bangabandhu Sheikh Mujibur Rahman Agricultural University

Salna, Gazipur-1706

Fish is a highly perishable food which needs proper handling and preservation. The

central concern of fish processing is to prevent fish from deteriorating & microbial

contamination. We should maintain better quality of fish for Human Consumption. We

should ensure the supply of fresh fish (free from contaminants) in the market.

Microbial Contamination of Fish :

Attack on fish by undesirable microorganisms (Bacteria,

Yeast, Mold, Fungi, Virus or their toxins and by-products)

from external sources is called microbial contamination of

fish.

Fish Processing:

The processes associated with fish and fish products between the time fish are caught or

harvested, and the time the final product is delivered to the customer.

TYPES OF MICROBIAL CONTAMINANTS :

There is a broad range of microbiological pathogens, which can cause contamination

in fish processing industries.

Within these groups, several different types of pathogens exist:

1. Bacteria: Gram-positive and Gram-negative bacteria.

Commensal bacteria.

Pathogenic bacteria.

2. Virus: Subcellular biological objects with a size of 20-200 nm. They

exist with and without envelopes.

3. Prions: Infectious protein particle. Smallest pathogen below 5 nm in

size.

4. Different Fungi, yeasts and protozoa.

Contamination of fish in fish processing industry:

Contamination may occur from different fish

processing instruments. Eg. Knife .

Contaminants may come from fish collecting ship.

Contamination may occur from fish processing

table.

Using contaminated Auxiliary gutting device (

Used to clean fish and their Gut ), Filleting machine

etc.

Figure: Processing of Tuna Fish.

Using of different medicine in fish may contaminate fish.

Contaminated ice may contaminate fish at the time of freezing.

Microbial Contamination may come from the polluted environment of that processing

industry.

Contamination of fish in fish processing industry (Continued):

Lack of proper controlling of temperature treatment in fish processing.

Lack of proper controlling of water activity may contaminated fish.

Solid wastes include skin, viscera, fish heads and carcasses (fish bones) may

contain different microorganism. That can contaminate the fish. A very wide

range in microbial numbers has reported as shown below-

Skin- 102 to 107 /cm2

Gills- 103 to 109/cm2

Intestine- 103 to 109/cm2

Different Anaerobic bacteria may contaminate the fish in fish processing

industry.

Microbial contaminants may come from laborer. If they are not neat & clean.

Recommendation:

Controlling temperature; using ice, refrigeration or freezing.

Controlling water activity by drying, salting, smoking or freeze-drying.

Physical control of microbial loads through microwave heating or ionizing

irradiation

Chemical control of microbial loads by adding acids

Controlling Oxygen deprivation, such as vacuum packing.

Maintaining “Hazard Analysis and Critical Control Points.”

Using disinfectant to disinfect the fish processing materials used in industry.

Proper Handling of live fish.

Maintaining Pasteurization ( 62.80C for 30 minutes or 71.70C for 15 minutes in

milk) treatment.

Preservation techniques are needed to prevent fish contamination. They

are designed to inhibit the activity of spoilage bacteria and the metabolic

changes that result in the loss of fish quality.

Contaminating bacteria are the specific bacteria that produce the

unpleasant odours and flavours associated with spoiled fish.

We should maintain proper handling to prevent this Contamination in Fish

Processing Industry..

Conclusion: