A continuous process for high-yield surimi processing0 pages

AlfaPlus™
A continuous process for high-yield surimi processing
AlfaPlus™ is a continuous, hygienic and automatically
controlled surimi processing line. The use of centrifugal
separation instead of the rotary screens and presses used in
conventional surimi processing increases yields substantially
as well as eliminating several process stages. AlfaPlus
handles all kinds of fish, in fillets or trimmings, and features
exceptional flexibility in handling capacity changes. AlfaPlus is
compact and easily modified to fit existing plants.
High yield – high quality – single grade of surimi
The AlfaPlus system produces surimi from butterfly cuts (with
or without the backbone attached), fillets or trimmings.
Protein losses from washing and dewatering are kept to a
minimum in the AlfaPlus system equipped with Alfa Laval
decanters specially designed and optimized for surimi
processing. The combination of the optimal decanter
configuration and process control allows seafood processors
to recover 70% of the incoming mince into high-quality
surimi. The surimi produced using AlfaPlus is of highly
consistent quality compared with conventional processing,
which produces two or three different grades.
Process description
To isolate the fish proteins from minced fish, the mince is first
mixed with conditioned water in a mixing tank. The washing
takes place continuously and the ratio of mince to water is
automatically monitored and precisely adjusted. This feature
ensures optimum conditions since the washed mince is then
pumped to the refining stage where the fish proteins are
effectively separated from non-muscle tissue such as bone,
skin, connective tissue and other impurities.
For whitefish, the refined slurry is continuously pumped to the
decanter centrifuge for separation of water and fish mince. If
dark-fleshed or fatty fish are being processed into surimi, a
second washing stage may be necessary before decanting.
All Alfa Laval surimi decanters are equipped with the unique
Alfa Laval Direct Drive System®, an automatic solid control
system that ensures a consistent moisture content of 82% or
less.
The dewatered mince from the decanter is pumped to a
blending system where it is mixed with sugars, sorbitol and
polyphosphates to prevent freeze denaturation. The mixer is
equipped with a cooling jacket, which keeps the temperature
as low as possible and maintains the high quality of the fish
protein.
The surimi enters an extruder, which forms the surimi into
blocks that are then frozen.
Sanitary production
The AlfaPlus line improves sanitary levels by using CIP
(Cleaning-in-Place) procedures that reduce the number of
man-hours necessary to complete cleaning of the process
line. Tanks, pumps and decanters can be automatically
cleaned on a daily basis by the attached CIP module. The
total cleaning cycle lasts about 212 hours, and during this time
the refiner, mixer and extruder can be manually cleaned. Daily
cleaning significantly reduces the bacterial count.
Flexible production planning
AlfaPlus not only makes existing production more flexible and
more efficient, but also adds more hours to the production
schedule. In an AlfaPlus plant, for example, different raw
materials such as lean and fatty fish species can be
processed in successive cycles. The production time is
reduced to about fifteen minutes compared with two hours in
a conventional surimi processing system.