Preserving Freshness

Whole Reef Fish

A Red Humback Snapper vacuumed packed and Blast Frozen and treated at -60 degree Celsius for at least 15 hours.

Yellowfin Tuna Portion

Our Yellowfin Tuna Belly is of sashimi grade. Vacuumed packed and Blast Frozen and treated at -60 degree Celsius for at least 15 hours.

Chilling is to quickly bring down the temperature of the fish from room conditions to close to zero degree Celsius so as to retard bacteria growth and spoilage.

Flash Freezing or more commonly known as Blast Freezing is used to preserve the integrity of the fish through a process of rapid cooling to below -35 degrees Celsius and keeping it for a period of time. This is to ensure all bacteria and parasites are killed by this treatment without compromising the quality of the meat. 

Vacuum Packing is a form of Modified Atmospheric Packaging technology to reduce oxidative degradation of the fish by preventing air from coming into contact with the meat.

In this blog we explore the the use of these technologies at Reelly Fresh.

Ice Chilling

In this process, the fish are kept under iced condition. Hence, the temperature of the fish is maintained at around 2 degree Celsius. 

Usually, fishermen keeps fishes covered with ice and this melts over time. Hence, it is difficult to maintain constant temperature around 2 degrees Celsius especially during long fishing trip up to a week. As such, the risk of  degradation of quality would be higher under such conditions and with time.  

While fish can be kept fresh under proper chilled condition, the technique is an art. There is a need for a correct mix of seawater to ice ratio besides the ice slurry composition. If the conditions can be fulfilled, chilled fish can be kept fresh for up to a week. 

Blast Freezing

In this process, the fish is subjected to ultra cold temperature of at least -35 degree Celsius. Within the freezer,  cold air are directed onto the fish, bringing down the temperature rapidly.

The most challenging part is to quickly remove the latent heat from the body of the fish so that freezing can take place in the shortest time. Using a blast freezer, the fluid freezes so quickly that the crystals formed are minute and will not puncture the cell wall of the flesh keeping the integrity of the meat.

If the fish is blast frozen when it is harvested, the freshness is frozen in time. Degradation of the meat drastically slows down and most fish treated in this way can keep the quality for up to 2 years. 

Vacuum Packing

In this process, the fish or portions of the fish is packed in a high quality polyurethane bags.  

The aim is to remove the oxygen which is the main culprit in the oxidative degradation process. Using a high performance vacuum machine, air is then sucked out to a level of less then 3% oxygen. At this level, oxidative spoilage of the fish is reduced drastically. 

If the fish is not kept in chilled condition, bacteria growth can still continue especially those that do not require oxygen, hence spoilage can still happen.  

Vacuum packing is a high cost option and may not be necessary if the fish is freshly caught and to be eaten within a day.

How we do it?

At Reelly Fresh, we adopt all 3 technologies to ensure the fish will be as fresh as when it was caught. 

After it has been caught, the fish is put in an ice slurry to quickly bring down the temperature of the fish to near zero degrees as the fishing boat would be out at sea. The catch will not be at sea for more than 12 hours. At freezing temperature, bacteria growth will be reduced.

Once at the processing factory, the fish is gutted to remove the internal organs which is a source of bacteria contamination. The fish is cleaned and vacuumed packed. In this way, the fish is maintained fresh as bacteria growth and oxidative degredation are minimised. All these while, the temperature is maintained at about 2 degree Celsius within the plant.

Next we treat the fish at ultra-low temperature of -60 degree Celsius. This will lock-in the freshness of the fish, similar concept to stem cell storage. Hence, if you were to taste the chilled fish and our ultra low temperature treated fish, you are unlikely to tell the difference! Also, you can keep in your freezer and be consumed at your own convenience. 

In Japan, the Bluefin tunas are Blast Frozen on the trawlers and then sold at the market. Similar for us, all our fishes including tunas are treated at such low temperature for food safety reasons besides keeping the fish fresh. If you want to make sashimi or sushi at home without having to spend your hard earned money at restaurants, this is a good option.

Normal freezer does not have a capability to freeze the fish quick enough to preserve the quality nor does it satisfy the ultra low temperature of -35 degrees Celsius for food safety. 

A quick video to show the effects of Blast Freezing and normal freezing. As evident, Blast Freezing does not puncture the cell wall of the meat, thus retaining the flavour and texture of the meat. 

Great advice in choosing fish for sashimi or sushi. Our fish are Blast Frozen down to -35 degree Celsius and below so that any parasites within are killed while retaining the fresh quality just like it has been caught from the ocean.

According to the Food & Agriculture Organisation, to kill all parasites the following conditions must be met:

a.  Freezing and storing at an ambient temperature of -20°C or below for 7 days (total time); or

b. Freezing at an ambient temperature of -35°C or below until solid and storing at an ambient temperature of -35°C or below for 15 hours; or

c. Freezing at an ambient temperature of -35°C or below until solid and storing at an ambient temperature of -20°C or below for 24 hours.