Pickle curing is a process for preserving fatty fish by immersing it in brine or packing it in barrels with brine. It allows the fish to be stored for longer periods of time by limiting oxygen exposure and slowing rancidity. There are different definitions of pickle curing depending on the country. The document discusses the process of pickle curing herring in Northern Europe, which involves catching, processing, packing in barrels, and storing the herring in brine for months to develop flavor. Key factors that influence the quality of pickled herring are storage temperature, the fish's body composition, and presence of gut.

1. Pickle Curing
Professor Dr. Md. Abul Mansur

2. Pickle Curing
Pickle curing has different meaning in different countries.
Definition
• In the UK and Europe Pickle curing refers to the technology of
fatty/oily fish preservation in which the fish is preserved in airtight
barrels in a strong pickle formed by dissolving in the body fluids of
fish. (Burgess et. al., 1965).
• Exam? Pickle curing is a process of fatty fish preservation for a longer
period of time by immersing in concentrated brine which restricts the
atmospheric oxygen and ultimately retards rancidity reactions,
although certain degree of rancidity is desirable in the development of
characteristic flavour (Horner, 1992).
• Exam? In the USA this term is used to mean the uncooked fish
products that have been preserved by first salt brining and finally by
acidifying in vinegar which usually contains a variety of spices (Jarvis,
1950). In the UK and Europe this type of processing and products are
called marinating and marinades respectively.

3. Pickle Curing
• Actually it is a method of fish salting:
Classification of fish salting methods
According to Burgess et. al. (1965) fish salting methods are-
1. Dry salting
(a) Heavy or Hard cure
(b) Light or Gaspe cure
2. Pickle curing
According to Horner (1992) fish salting methods are-
1. Brining
2. Pickle curing
3. Kench curing
4. Gaspe curing

4. Pickle Curing
Pickle curing (Northern Europe method): Exam?
● Usually the pre-spawning herring (Clupea harengus) is used for pickle
curing.
● In the north-east part of UK the herring is caught from piper field, 90-
110 miles north east from Peterhead, Scotland.
● Herring fish is caught by the drifters in that fishing ground.
● After capture the catch is pumped from the net through a de-watering
device into RSW tanks at -2⁰ C and the drifters return to the port within
24 hours.
● The catch is unloaded by an on-board winch-operated scoop net digging
the catch out of the RSW tanks and transfering them via a hopper to
polypropylene tanks of about 1 m3 capacity which are fork lifted to the
adjacent processing factory.
● At this stage the temperature of fish usually remain around 0⁰ C.

5. Pickle Curing
• FLOW CHART OF PICKLE CURING Exam?
Raw Fish
↓
Gibbing
↓
Rousing
↓
Packing in Barrel
↓
Filling the Barrel
↓
Closing the Barrel
↓
Storage for Ripening

6. Composition and Quality of Pickled herring Exam?
Sl. No. Parameter Result
1 Moisture (%) 53.19
2 Lipid (%) 17.80
3 Ash (%) 2.98
4 Protein (%) 20.15
5 TVBN (mg/100g) 74.87
6 TMAN mg/100g) 6.2
7 Histamine (mg/100g) 10.00
8 PO (meq/Kg lipid) 14.62
9 TBARS (meq MA/Kg lipid) 21.72
10 NaCl (%) 10.62
11 pH 6.05

7. Sensory property of Pickled herring
Sl. No. Parameter Result
1 Colour Golden
2 Texture Tender
3 Flavour Malty

8. Pickle Curing
Factors Influencing Pickle Curing: Exam?
1. Storage temperature
2. Body composition/condition e.g. pre-spawning or post-
spawning
3. Presence or absence of gut
Storage temperature: Elevated storage temperature reduces the
ripening time. At 250C the ripening time was 1.5 to 3 months as
compared to 12-15 months at 0-50C without giving rise to
unacceptably high histamine levels provided that the salt
equilibration is allowed to proceed at 0-50C before high storage
temperature exposure. But the sensory characteristics of the
products ripened at 40C and 250C were different.

9. Pickle Curing
Result of Scientific Research on Pickle curing: Exam?
1. Proteolysis
2. Lipid of the pickled herring remains in the induction phase of lipid
oxidation until the tenth month of ripening. Then proceed towards the
propagation phase between the tenth and fifteenth month of ripening.
3. Histamine level remains within MAL
4. TVBN and TMAN remains within MAL.
5. Inspite of initial toughening the texture become tender and loss
elasticity compared to the texture of original raw fish.
6. Colour formation on the fish skin is influenced by the body
composition, spawning season, gibbing. Fish skin attain golden colour
whereas the muscle attain brown colour.
7. Flavour compounds are formed as a result of oxidative changes in
lipid components. Major groups are aldehydes, volatile alcohol,
aromatic compounds, hydrocarbons, some acids and a sugar
derivative.

10. Pickle curing
Improvement suggestion: Exam?
1. Selection of correct raw fish
2. Correct storage of apparatus, equipment, barrels, lids, collar.
3. Washing of raw fish
4. Hygienic practice, cleaning, sanitizing processing environment
should comply with HACCP principles.
5. All steps of handling and processing, storage should comply
with HACCP principles and HACCP plan.
6. A standard ratio of fish to salt should be established.
7. Care should be taken to prevent autolytic spoilage, bacterial
spoilage and oxidative rancidity.
8. Pure salt preferably IMS (Industrially Manufactured Salt) may
be used considering the health safety of the consumers.