Quality ingredients are must-haves for any conscientious chef who understand its direct effect on the final dish, particularly when it comes to fish since it is considered to be highly perishable.
Any fish is highly susceptible to faster spoilage than meat, poultry or vegetables.
A commonly thought idea that is not true is that frozen fish is always quality fish. This is not true because although freezing does lock in the characteristics of the fish, it needs to be handled properly before freezing. What happens between harvesting and freezing plays a critical role in preserving a fish’s quality.
There are other factors affecting the freshness of the fish and prevent them from faster spoilage.
Here’s what you need to know :
Temperature
Temperature plays a critical role in altering the stability of any product. Highly perishable foods like fish are easily affected by ambient temperature. They are less stable because of their high moisture content and availability of nutrients for the growth of microorganisms.
Fish need to be kept in ice or salinised ice water or blast frozen immediately after harvesting to lock in freshness. It remains in almost the same natural conditions even after freezing, which is why freezing is effective for retaining a fish’s flavour, colour, and nutritional value. More importatly, freezing helps control the build-up of bacteria.
During freezing, the water in the fish muscle is crystallised into ice which will complete at -40 oC. For example, Sushi-grade tuna is typically frozen at sea and then thawed.
After freezing, the fish must be kept at a constant temperature at -18 C or below. Keeping fish at a consistent temperature ensures its quality for its maximum shelf life. Fluctuation in temperature will affect the aesthetic appeal of the fish itself. Dehydration or moisture loss in the fish’s skin results in a dull appearance and even discolouration when a temperature change happens. And then, recrystallisation occurs.
But as earlier mentioned, frozen doesn’t necessarily mean quality. Some scrupulous sellers freeze old fish to extend its shelf life, which may spoil shortly after the fish is thawed.
Some tips:
- Do not buy it if the package is torn, visibly open, or damaged on the edges.
- Do not buy packages with signs of frost or ice crystals (freezer burns), which means the fish has been stored a long time, not correctly packaged or has thawed and refrozen.
- Do not buy packages where the “frozen” fish flesh is not hard. The fish should not be bendable.
For more of this tips, check this related read link below.
RELATED READ: Sourcing Ingredients For Your Restaurant: fish
Handling
If fish isn’t correctly handled, the shelf life declines quickly. Rough handling damages the flesh, causing enzyme breakdown and bacterial spoilage.
Bacteria may be present in the surface slime, intestine and gills, which starts to attack the flesh as soon as the fish is dead, causing spoilage.
- Always be careful in handling fish to minimise physical damage such as bruising, which causes changes in texture and flavour. If the flesh is broken, bacteria can enter the fish further and cause spoilage.
- Observe practices that prevent cross-contamination between raw and food items, including utensils, containers, towels. Unless the fish is smoked or dried, rinse it under cold, running water before preparation.
- If not frozen, use the fish as soon as possible. Also, minimise the time between food preparation and thawing.
- Follow a first in, first out storage rotation system to ensure that the items stored will be used first.
Oil Content
Fish with high oil content are valued for their Omega-3 fatty acids, which have tremendous health benefits. Unfortunately, it is the same reason that shortens the fish the shelf life. And the typical cause is oxidative rancidity of these fats. Oxidative rancidity in foods refers to the reaction of oxygen to fats.
Be mindful that fish with more fatty oil content in their bodies tend to spoil faster. Therefore, consume them as soon as possible or freeze them properly to make the most of it.
In Summary:
Serving food with the slightest hint of spoilage is every chef’s nightmare. Chefs are trained to identify what to look for when buying, storing and preparing quality fish. Having one in your team will prevent potentially dangerous health concerns and affect the food business’s reputation.
Get in touch with us at Anytime Chefs, where we assist you in solving your chef and staffing needs and provide consultation services to support your business!
That’s it for this week.
As always, Professional Chefs on Call at Anytime!
Ciao for now,
Thomas
