Fish skin is rich in protein and various trace elements, and its protein is mainly composed of macromolecular collagen and mucopolysaccharide, which is a good product for ladies' beauty and health care. Medical research has found that leucine, the white blood cell in "fish skin", has anti-cancer effect. Fish skin is rich in collagen. Every 100g of dry shark skin contains protein 67. 1g, fat 0.5g, and its protein is collagen.

It is good for beauty and calcium supplementation. An acid-soluble fish skin collagen is prepared by chopping marine fish skin, soaking in NaCl solution to remove impurities, and degreasing with ethanol and acetone. Then soaking and extracting with a mixture of citric acid and acetic acid, centrifuging and separating to obtain an acid-soluble fish skin collagen solution, and salting out with NaCl solid to obtain an acid-soluble fish skin collagen precipitate.

Finally, the acid-soluble fish skin collagen precipitate was dissolved in acetic acid solution, and then dialyzed in Na2HPO4 (pH 8.6), or ultrafiltered with acetic acid hollow fiber membrane with molecular weight greater than 60000, and the dialyzed product obtained by ultrafiltration or solid vacuum freeze-drying was obtained.

The product is white, tasteless and spongy after freeze-drying. The purity of collagen products is ≥97%. Collagen is rich in glycine, proline and hydroxyproline, and its hydrolysate also contains physiologically active peptides. The molecular weight of collagen is above 60,000.

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Nutrition of other parts of fish:

1, fish head.

Fish head contains a certain amount of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), belonging to ω-3 polyunsaturated fatty acids, which is beneficial to the nervous system and brain development of infants. Compared with fish, fish heads are more likely to be rich in harmful substances. In order to be nutritious and safe, it is suggested to avoid some fish with high mercury content, such as tuna, swordfish and swordfish.

2, fisheye.

Fisheye has always been regarded as a good eyesight-improving product, which does contain omega-3 polyunsaturated fatty acids beneficial to retinal health, but the content is not outstanding, which can not achieve the eyesight-improving effect. Fisheye is completely edible, but don't expect it to improve your eyesight.

3. Fish gills.

Fish gill is an important respiratory organ of fish, which is rich in iron. This part is also very easy to be polluted by harmful substances. If you want to eat, you should also avoid fish with high mercury content such as tuna and swordfish.

4, fishbone.

Fishbone is rich in trace elements such as calcium, but if eaten directly, the amount that the human body can absorb and utilize is particularly small. If you want to get nutrition from fishbone, you can add vinegar to the soup and stew it for 2~4 hours.

5. Fish roe.

Fish roe contains quite a lot of lecithin, which is helpful for the development of nervous system. But lecithin is also a kind of fat, and it is easy to get fat if you eat too much. It is recommended that you control the amount when eating, so as not to increase the risk of obesity.

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