First, opacity
In addition to triggering a deterioration reaction in food, light can also cause changes in proteins and amino acids.
According to research analysis, the loss of vitamin C in transparent glass bottles of milk is 14 times higher than that of dark bottled milk, light will also cause milk to produce oxidative odor, and nuclide, methionine and other cleavage and loss of nutritional value, the opacity of tinplate cans makes the preservation rate of vitamin C the highest.
Second, good sealing
The barrier of packaging containers to air and other volatile gases is very important for the preservation of nutrients and sensory qualities.
Comparing various juice packaging containers shows that the oxygen transmittance of the container directly affects the browning of fruit juice and the preservation of vitamin C. Metal cans, glass bottles, aluminum foil laminates and cartons with low oxygen transmission rate have better preservation of vitamin C, among which iron cans are the best.
Third, the reducing effect of tin
The tin on the inner wall of tinplate will interact with the oxygen remaining in the container during filling, reducing the chance of oxidation of food ingredients.
The reduction effect of tin has a good preservation effect on the flavor and color of light fruits and juices, so the juice cans packed in unpainted iron cans are better nutritious than the juice cans packed in other packaging materials, the brown change is slight, the acceptance of flavor quality is better, and the storage period is extended.
