The main reason for the fishy smell of food is that the amino acids in it decompose after heating, releasing volatile amino acids, nitrogen compounds and other substances. Therefore, the principle of removing fishy smell can be started from the following aspects:

1. Acidic seasonings to neutralize the fishy smell: adding acidic seasonings (such as lemon juice, vinegar, wine) can neutralize the volatile compounds released by amino acids, Reduce fishy smell.

2. Accumulating aroma: Soaking ingredients in liquids such as salt water, ginger juice, onion juice, etc. can help the ingredients emit a specific smell and neutralize or mask the fishy smell.

3. Steaming and cooking to remove fishy smell: High-temperature cooking methods such as steaming and boiling can evaporate the volatile odors in the ingredients and reduce the fishy smell.

4. Activated carbon removes fishy smell: Activated carbon can absorb odor molecules. Putting food into an activated carbon box or placing some activated carbon on top of the stove can remove the fishy smell of food.

5. Pickle ingredients with salt, vinegar, and sugar: The salt, vinegar, and sugar in seasonings can neutralize the fishy smell in the brine and remove the alkaline smell.

To sum up, the principle of fishy removal uses different methods to neutralize, cover, decompose or absorb the fishy smell in the food, thereby making the food more delicious.