Abstract:

Red slate fish gelatin was used as the raw material, and collagen was extracted by acid enzyme method. Physicochemical properties were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis （SDS-PAGE） and amino acid composition analysis. A senescent mice model was established with D-galactose to investigate its effects on the water content, hydroxyproline content, skin pathological morphology, and antioxidant activity of the mice. The results show that the collagen consists of two α-chains and one β-chain, which is a typical type Ⅰ collagen. Collagen contains characteristic amino acids such as glycine, alanine, glutamic acid and proline, which account for 13.890%, 8.601%, 7.650% and 7.124% of the total amino acid content, respectively, and does not contain tryptophan. After being modeled by D-galactose, the results of moisturising and skin-care experiments show that the model group compared with the control group, the skin of mice is rough and loose, the number of wrinkles and antioxidant capacity decrease, the moisture content of the skin and the content of hydroxyproline decrease by 13.52% and 26.2%, respectively, and the content of collagen fibres and elastin fibres reduced, some of which are obviously disconnected. After the intervention of red slate fish gelatin collagen, it can significantly improve the water loss of mouse back skin caused by D-galactose stimulation, enhance the resistance to oxidative stress of mouse skin tissues, and basically restore the skin structure of the collagen group, with the content of collagen fibres and elastic fibres of the skin elevated, and the proportion of type Ⅰ/Ⅲ collagen elevated by 9.79%. In conclusion, collagen prepared from red slate fish gelatin can delay the skin aging caused by D-galactose, which can provide a basis for the high value utilisation of collagen in the field of cosmetics.

Key words: gelatin collagen, electrophoresis, amino acid composition, D-galactose, anti-aging