according to the national standard QBT1394-217, the ph should not be higher than 4.5.

The acidity of canned tomatoes refers to the acid content in canned tomatoes. In food processing, acidity refers to the concentration of dissolved acid in food, which is usually expressed by pH value.

according to national regulations, the acidity of canned tomatoes should not exceed 4.5. This means that the pH value of canned tomatoes should not be higher than 4.5. Canned tomatoes with too high acidity may have adverse effects on human body, so manufacturers of canned tomatoes should strictly control the acidity of canned tomatoes.

In addition, the acidity of canned tomatoes is also related to the shelf life of canned tomatoes. Canned tomatoes with low acidity can be preserved for a longer time, because canned tomatoes with low acidity are more difficult to be attacked by microorganisms, thus prolonging the shelf life.