6. Marinating fishery products | Quizlet

Purpose of marinating fish products

Preserves fish & shellfish in a mix of acetic acid + salt

Extends shelf life by slowing bacteria & enzymatic activity
Give characteristic flavour & tenderness

What is used to marinate fish

Acetic acid + salt

What is best raw material for marinating

Pelagic fish - with high flesh fat content i.e., herrings & sardines
Fat content gives characteristic flavor

Role of acetic acid in marinating

Due to proteolytic enzymes - breakdown proteins & release free amino acids & controls pH - selective autolysis action

Lows bacterial and enzyme activity
Provides characteristic tastes & tenderness

Role of Salt (NaCl) in marinating

Removes water
Coagulates protein
Controls hydrolytic action

Groups of marinated fish

1. Cold
2. Cooked
3. Fried

Describe cold marinated fish:

Raw fish preserved in acetic acid + salt - no heating
Ph4.5 salt 10% - most bacterial stopping
Limited shelf life bc autolytic & bacterial activity still occurs = off flavour
Chilled temp - months
Ambient - few weeks

What is optimal conditions of cold marinating fish to halt bacterial action

4.5pH 10% salt

Shelf life of cold marinated fish

Chilled - months
Ambient - weeks

Describe cooked marinated fish

Fish in hold soln (+85C) of acetic acid & salt
Most of bacteria are killed & enzymes denatured / inactivated

Steps of producing cooked marinated fish

1. Pre treatment: pre salting
2. Bleaching: immersed in 1-2% acetic acid + salt @85C for 10-15 mins
3. Cooling: cold water remove fat & protein foam
4. Packing: glass, procelin, lacquered cans can add spices or jelly - 1-2% acetic acid + 3% salt

What are parameters for cooked marinating fish

1-2% acetic acid + salt @85C for 10-15 mins

What is purpose of cooling & washing cooked marinated fish

Remove fat & protein foam

Conc of acetic acid in salt in final liquid / jelly of cooked martinated fish

1-2% acetic acid + 3% salt

Describe fired marinades

Fish fired or baked before packing in acetic acid + salt
Frying kills most of bacteria & denatures enzymes

Process of fired marinades

1. Pre treatment: cleaning, presalting, draining, breading
2.Frying: in fat 160-180C 5-12m, in deep drying is done when pieces rise
3. Packing: cans + brine 2-3.5% acetic acid + 3-5% salt + spices

Marinating parameters for cold, cooked & fried

Cold: pH 2.5 10% salt
Cooked: 1-2% acetic acid + 3% salt (85C for 10-15 mins)
Fired: 2-3.5% acetic acid + 3.55 salt (160-180C 5-12 mins)

What pH & temp will keep marinated products for months

Ph 4.5 4C

How does marinating affect bacteria

Prevents all food poising bacteria and most spoilage from growing

Some bacteria & enzymes will remain active
This may be desirable in semi-preserves product for typical flavor & texture

Storage of marinated fish according to PN-A-86 780: 1998

0-8C for 14 days from date or production