In addition to the deterioration of food, light can also cause changes in proteins and amino acids. Vitamin C is more easily exposed to light
Make it interact with other food ingredients, so that a lot of it is lost. According to research analysis, the loss of vitamin C in transparent glass bottle is 14 times higher than that of dark bottled milk. Light also causes milk to produce oxidative odors, and the nucleus, methionine and other lysates will lose nutritional value. The opacity of tinplate makes vitamin C the highest preservation rate.
The barrier properties of packaging containers to air and other volatile gases are very important for the preservation of nutritional content and sensory quality. Comparison of various juice packaging containers proves that the oxygen transmission rate of the container directly affects the browning of the juice and the preservation of vitamin C; the preservation of vitamin C in metal cans, glass bottles, aluminum foil laminates, and cartons with low oxygen transmission rates Better, of which tin cans are the best.
Reduction of tin
The tin on the inner wall of tinplate interacts with the oxygen remaining in the container during filling, reducing the chance of food ingredients being oxidized. The reduction of tin has a good preservation effect on the flavor and color of light-colored fruits and juices. Therefore, the use of unpainted iron cans has better nutrition preservation than other packaging cans, and the brown changes are slight. The acceptability of flavor quality is good, and the shelf life is extended accordingly.
Provide a source of effective iron
Tinplate canned foods, except for a few light-colored fruits and canned juices, are mostly empty painted cans to improve the corrosion resistance of the container. Due to the electrochemical action of metals, painted canned foods will have a small amount in storage Of iron dissolves in the form of divalent iron in sealed canned foods and is easily absorbed by the body at levels of about 1 to 10 ppm. For fruit and vegetable products, the raw material itself does not contain much iron. Iron can products are based on a 350 ml beverage can with an iron content of 5 ppm. Each can can provide 1.75 mg of iron, which is about 18 mg per day One-tenth. If the above-mentioned fruit and vegetable juice beverage cans are rich in vitamin C, iron can be absorbed more easily. Therefore, iron canned food and beverages can be a good source of iron, and the significance of providing nutrition to iron canned food is far-reaching.
With these attributes, tinplate tins provide a closed system that completely isolates environmental factors, in addition to heat, avoiding color foods that are degraded by light, oxygen, and moisture, and that do not fade due to aroma transmission or are subject to environmental odors. Pollution and taste change, food storage stability is better than other packaging materials, vitamin C has the highest preservation rate, and the best preservation of nutrients.