Opaque
In addition to the deterioration of food, light can also cause changes in protein and amino acids. Vitamin C is more likely to react with other food ingredients when exposed to light, resulting in a large amount of loss. According to research and analysis, the loss of vitamin C in transparent glass bottle milk is 14 times higher than that in dark bottle milk. Light will also cause the milk to produce oxidation odor, as well as the decomposition of nuclide and methionine, which will result in the loss of nutritional value. The opacity of tinplate makes the preservation rate of vitamin C the highest.
Good sealing
The barrier of packaging containers to air and other volatile gases is very important for the preservation of nutritional components and sensory quality. The comparison of various juice packaging containers shows that the oxygen permeability of the container directly affects the browning of juice and the preservation of vitamin C; the metal cans, glass bottles, aluminum foil laminations and cartons with low oxygen permeability have better preservation of vitamin C, among which the iron cans are the best.
Reduction of tin
Tin on the inner surface of tinplate will react with the oxygen remaining in the container during filling to reduce the chance of oxidation of food ingredients. The reduction effect of tin has a good preservation effect on the flavor and color of light fruit and fruit juice. Поэтому, the fruit juice can without painting iron can has better nutrition preservation than the fruit juice can with other packaging materials. The brown change is slight, the acceptability of flavor quality is good, and the storage period is extended.
