The picture above shows salt-frozen shrimp, and the picture below shows water-frozen shrimp.
Extended material
Advantages and disadvantages of salt-frozen shrimp and water-frozen shrimp (also known as block frozen shrimp or plate frozen shrimp in China market) and their different markets;
Firstly, it is clear that salt freezing and water freezing are both freezing technologies, and their ultimate goal is to better preserve the taste, taste and nutrition of shrimp and facilitate the transportation of shrimp in international trade. It is precisely because of the different freezing techniques that there are obvious differences between salt-frozen shrimp and water-frozen shrimp in market price, appearance and taste.
First, the freezing process is different.
Saltwater quick-frozen shrimp can also be referred to as saltwater IQF shrimp for short, that is, salted frozen shrimp. Semi-independent frozen shrimp can also be abbreviated as semi-IQF shrimp, that is, water-frozen shrimp.
As can be known from the English name, salt-frozen shrimp is a separate frozen shrimp, which is scattered among individuals; Water-frozen shrimps are frozen together by the action of water freezing into ice. So in the market, some dealers will also call water-frozen shrimp frozen shrimp or frozen shrimp.
In the final analysis, the most essential difference between salt-frozen shrimp and water-frozen shrimp lies in the freezing process.
The basic technological process of water-frozen shrimp is: shrimp is collected in the shrimp pond, transported to the factory, manually sorted, mechanically sorted, boxed, frozen (about 7-8 hours), packaged and sold at the factory. The traditional cabinet freezer is used to freeze and stick the shrimps together through the water on the surface of the shrimps.
Workers in some factories will add a small amount of fresh water when packing shrimp boxes to make products with a net weight of about 1.4kg/ box and a gross weight of about 2kg/ box.
Compared with water-frozen shrimp, salt-frozen shrimp has more processes of low-temperature saltwater leaching.
The basic technological process of frozen shrimps with salt is: collecting shrimps in shrimp ponds, transporting them to factories, sorting them manually, sorting them by machines, bagging them, freezing them with ultra-low temperature salt water (about 10 minutes), packaging them and selling them at the factory.
The low-temperature salt water freeze-dryer is used to reduce the central temperature of shrimp to about-17 to 18 degrees Celsius in a short time, so that the shrimp can freeze quickly and form salt particles and frost on the shrimp surface. Among them, the brine is high-concentration brine, and each factory will adjust the brine composition and shower time according to the actual situation, which are the core secrets of the factory.
After the salt freezing is completed, some factories will put some crushed ice at the bottom of the shrimp box to meet the requirements of domestic customers, so that the gross weight of the whole box is about 2kg/ box and the net weight is about 1.8kg/ box.
Compared with the freezing process, the freezing time of salt-frozen shrimp is shorter than that of water-frozen shrimp, and the processing efficiency is higher. In China market, due to the relationship between supply and demand, the futures quotation of salt-frozen shrimp is always about 0.2-0.3 USD/kg more expensive than that of water-frozen shrimp.
Second, the freezing effect is different.
The surface of salt-frozen shrimp is white with salt particles, and the surface of shrimp is white with frost. After thawing, shrimp meat has high freshness, good elasticity, no shrinkage when cooked and perfect shape. The head, whiskers and feet of shrimp are intact, but the salt content is high and the taste is salty. Moreover, the protein of shrimp meat changed after salt exposure, and the taste of shrimp meat became firm.
The surface of water-frozen shrimp is the true color of shrimp, and the color is normal. You can eat the original flavor of shrimp, but it will shrink a little when cooked.
Third, eat differently.
The thawing time of salt-frozen shrimp is different from that of water-frozen shrimp. Salted and frozen shrimp thaws quickly, and the adhesion between shrimp is not strong, so it is easy to separate. Consumers can eat as much as they want.
However, the thawing time of water-frozen shrimp is different, which mainly depends on the form of shrimp icing and the packaging of products. Boxed frozen shrimps with natural ice coats are easier to thaw. The net weight 1.4kg/ box, and the shrimp box with gross weight of 2.0kg/ box contains more ice, which is the most difficult to thaw and takes a long time to thaw.
Frozen shrimp with salt is easy to thaw, but it tastes salty. Consumers need to soak shrimp in water or pure water to remove salt particles before eating. The frozen shrimp tastes just right. It only needs to be thawed normally and is easy to cook and taste.