The barrier properties of packaging containers against air and other volatile gases are crucial for the preservation of nutrient composition and sensory quality. Comparing various fruit juice packaging containers proves that the oxygen permeability of the container directly affects the browning of fruit juice and the preservation of vitamin C; Metal cans, glass bottles, aluminum foil adhesive layers, and paper boxes with low oxygen permeability have better preservation of vitamin C, and iron cans are preferred among them. The reduction effect of tin on the inner wall of tinplate will reduce the opportunity for food ingredients to be oxidized by the residual oxygen in the container during filling. The reducing effect of tin has a good preservation effect on the flavor and color of light colored fruits and juices. Therefore, juice cans packaged in unpainted iron cans have better nutrient preservation than juice cans packaged in other materials, with subtle brown changes and better tolerance for flavor quality. As a result, the storage period is extended.

Food packaged in tin cans, except for a few light colored fruit and juice cans, mostly use empty cans with internal paint to improve the corrosion resistance of the container; Due to the electrochemical effect of metals, a small amount of iron will dissolve from painted canned foods during storage, existing in the form of divalent iron in sealed canned foods, which is easily absorbed by the human body, with a content of approximately 1 to 10 ppm. In terms of fruit and vegetable products, the raw materials themselves do not contain a lot of iron. For iron can products, with a beverage can of 350 ml per can and an iron content of 5 ppm, each can can can provide 1.75 mg of iron, which is about one tenth of the daily intake of 18 mg for the human body. If the above-mentioned fruit and vegetable juice beverage cans contain abundant vitamin C, iron is more easily absorbed. Therefore, iron canned food and beverages are a good source of iron, and their significance in providing nutrients to iron canned food is even more profound.  

Due to these properties, tin cans provide a closed system that completely blocks environmental factors in addition to heat. They prevent colored foods from deteriorating due to light, oxygen, and moisture, and do not fade due to fragrance or become contaminated by environmental odors. The stability of food storage is better than other packaging materials, and the retention rate of vitamin C and nutrients is also good.