Bone marrow contains more iron. When bone soup is cooked, iron ions in bone marrow will become ferrous ions and be dispersed in the soup. Ferrous ions are grass green. However, ferrous ions are easily oxidized. Continue to make soup. After a while, the grass-green ferrous ions will be oxidized. The grass green will disappear.
In addition, the beef bone soup is green after boiling, and it is also possible that the meat bone is polluted by copper sulfate. Slaughtering workshops are often disinfected with copper sulfate, if the meat and bones will stick to copper sulfate during this process. When copper sulfate is dissolved in water, the boiled soup will turn blue-green. Just rinse it several times before cooking.
Extended data:
Cow bone is richer in calcium phosphate, calcium carbonate and collagen than beef. Bovine bone has the effects of tonifying kidney and strengthening bone, warming middle warmer and stopping diarrhea.
Beef is rich in protein and amino acids, which can improve human disease resistance, especially suitable for growth and tissue repair. Beef also has the functions of nourishing the middle energizer, strengthening the spleen and stomach, strengthening bones and muscles, resolving phlegm and calming wind, and quenching thirst.
Matters needing attention in boiling bone soup:
1, avoid adding cold water in the middle, because the meat being heated will shrink when it meets cold water, and the protein will not dissolve easily, so the soup will lose its original flavor.
2, don't put salt too early, put salt too early, salt will make the protein of meat solidify, not easy to dissolve, so the soup is dark in color, not enough in concentration, and its appearance is not delicious enough.
3, avoid putting too much seasoning, avoid putting too much seasoning such as onion, ginger, garlic, cooking wine and so on. , so as not to affect the original flavor of the soup. If you put too much seasoning, the flavor of the seasoning masks the original flavor of the meat.
Baidu encyclopedia-Shannon beef bone soup