Extraction And Applicatiom Of Ictalurus Punctatus Skin Collagen

Derived from the animals fibrous protein, collagen is the principal constituent of animals connective tissue,skin,bones,cartilage and so on,which played a supporting and protecting the body function. Collagen molecules are composed of three intertwined in the so-called collagen triple-helix, some 27 different types of collagen have been identified recently.Because of its unique functional and technological properties,collagen is widely used in biomedical materials, food, cosmetic, health care and other areas. Currently the collagen mainly comes from mammal leather and bone, but its usage scope were limited by the religious belief and "cow" factors.On the other hand, the range of fish processing waste reached 730 million tons every year, causing serious pollution of environment and resources waste. Therefore, this paper actively explore the extraction and application of collagen from the cutfish processing waste,which will create the important economic benefit and social benefit.Based on the Ictalurus Punctatus skin as raw materials, the basic ingredients was determined by use of the national standard method,the results show:Ictalurus Punctatus skin water contented 68.9%,total protein contented 28.25%, crude fat contented 2.14%, total sugar contented 0.3136%, ash contented 1.3%. Using the spectral determination,the intrinsic collagen amino acids-hydroxyproline contented 2.19%,estimation of collagen content 24.31%, which contented about 86.05% in total cutfish skin protein. Results showed that cutfish skin is rich in collagen and can be considered as collagenous raw materials.This paper examined the acid-extraction collagen from Ictalurus Punctatus skin and compared collagen yield of various acids,we found acetic yield was 24.6%.Based on the single factor experiment,the orthogonal experiment was adopted in collagen processing for acetic extracting optimization,the results showed that:extracting temperature=5℃,acid concentration= 1.0 mol/L, the liquid-solid ratio=1:30, extracting time=72h, the highest collagen yield was 33.79%.After the purification of ultraviolet (UV) and detecting of infrared spectroscopy (FTIR) scanning,the results show that original UV maximum absorption of acid soluble collagen in 236nm peak, accord with representative collagen absorption peaks. In the 3450 cm-1,1652 cm-1,1263 cm-1 and other aeras also have infrared absorption peaks,which confirmed the vibration of the region N-H,C=O,C-H in collagen and spiral structure of collagen.This paper examined the protease-extraction collagen from Ictalurus Punctatus skin and compared collagen yield of pepsin, trypsin, alkali protease and acid protease,the results showed:yield of pepsin-extraction collagen was 26.08%.Using Box-Behnken design of pepsin, temperature, fluid extraction time and more than four factors, we found the best respectively of them:pepsin=2.21%, temperature=11.66℃, liquid ratio=1:32.55, extracting time=42.86h.Theoretical experimental results showed that the collagen yield was34.41%,which was similar to the actual value 34.92%. By detecting of the ultraviolet and infrared scanning,the results of protease soluble collagen showed:the maximum peaks of protease ultraviolet absorption was 235nm as similar to absorption with acid soluble, infrared scanning results showed N-H, C= O andC-H telescopic vibration absorption peaks respectively 3450 cm-1,1637cm-1 and 1267cm-1,Which explained the existence of protease spiral structure of collagen.This paper prepared collagen/chitosan composite film based on the cutfish skin collagen and chitosan mixture. Single factor experiment results indicated:temperature=70℃, collagen:chitosan=1:1,added 1% glutaraldehyde, the maximum tensile strength of the compound film was 0.82 N/mm2By analysis of scanning electron microscope (SEM) and infrared scanning, results showed that composite film under the preparation conditions was uniform, collagen and chitosan had good compatibility. Film function research results showed:When the film in 60℃, bibulous rate and the swelling ratio reached the maximum 21.2% and 1.2%;transparency declined overall with temperature, in 40℃light transmittance reached maximum 68.6%.