Even if you sprinkle salt and wrap the tuna block with paper, the period during which it can be eaten raw does not significantly extend.
For sashimi-grade tuna purchased at supermarkets, always prioritize the indicated expiration date. If you process it at home and intend to eat it raw, plan primarily for consumption within the same day or by the next day under good conditions, and avoid eating it if there is any doubt.
When Using Salt and Paper
Salt draws moisture from the surface, and the paper absorbs the extracted moisture. After processing, rewrap with fresh paper and place the tuna in a sealed container for refrigeration.
If the paper remains wet, the surface condition deteriorates easily, so it should be replaced regularly. However, this is a treatment to improve quality, not one that changes or resets the expiration date.
Taste Changes Observed After Half a Day
In this case, tuna was sprinkled with salt, wrapped in paper, and refrigerated for half a day. Moisture was moderately removed, the flavor concentrated, umami increased, and the texture improved considerably as sushi ingredient.
It is important to note that this observation is about taste and texture changes, not safety for raw consumption. Always prioritize the raw consumption label, expiration date, time since purchase, and refrigeration temperature. If there is any concern about conditions, choose to not eat it raw.
Priorities for Storage
Do not leave the tuna at room temperature after purchase; refrigerate it as quickly as possible. Places with fewer refrigerator door openings, such as low-temperature compartments or chilled rooms, are better due to less temperature fluctuation.
You cannot determine safety solely by odor, color, or sliminess. Consider label information, condition at purchase, transport time, and storage history together when judging.
Summary
Using salt and paper is a method to improve flavor and texture. It does not guarantee the number of days the fish can be eaten raw.
Always prioritize the expiration date and low-temperature management, use the same day to next day as a rough guideline, and avoid forcing yourself to eat raw fish if there is any concern.
