Study On Preparation Of Tilapia Fish Scale Gelatin By Enzyme Method

Gelatin is the degradating product of collagen and losses the biological activity,the molecular weight is between the collagen and collagen hydrolysate.The gelatin has a viscosity?gel strength and other properties.Because the transparency?viscosity and gel strength is high relative to the gelatin of other animal hide,so the work selected the scale to process gelatin.The traditional method for producing gelatin with alkaline?acid?saline and alkaline?acid and saline,since the traditional methods processing cycle is long,The quality of the gelatin is not better and a lot of acid and alkali residue in the waste water,which result in environment pollution,so the paper studied the preparation and character of gelatin with enzyme.Because the scale is contained of 33.94%inorganic salt,consequently,the gelatin is not easilly distilled,it is necessary to remove the ashes before extracting,the optimal technological parameters were optimized by orthogonal test,as followings:the dosage of hydrochloric acid 3.5%,the liquid ratio 1:10,the total time 1.5h.The paper researched the optimization process of preparating gelatin from fish scale by As1398 neutral protease?trypinasa?Acid protease and trypinasa.The optimization process of As1398 neutral protease is as follows:(1)As1398 neutral protease concentration 0.4%,pH 7,temperature 35? for 1h;(2)The optimization process of Acid protease is as follows:Acid protease concentration 0.3%,pH 3,temperature 35? for lh;(3)The optimization process of trypinasa is as follows:trypinasa concentration 0.3%,pH 6,temperature 40? for 1.5h;(4)The optimization process of trypinasa is as follows:trypinasa concentration 0.4%,pH 2,temperature 40? for 1.5h;By the comparation of the four kinds enzymes for the affect of the properties and yield of gelatin,trypinasa is selected for distilling gelatin and researched the optimization parameters of destroying enzyme and extracting gelatin.In order to prevent the collagen degradated into small molecules and affect the characters of the gelatin,the enzyme is destroyed with 7min on the temperature of 90? by single factors.At the same time,the single-factor analysis is done with temperature?time?pH and ultrasonic,the result is:original pH value 5;50? distilling gelatin for 2h,55?distilling gelatin for 2.5h,60? distilling gelatin for 2.5h;ultrasonic distilling gelatin with 50w,unite the three times percolate,then concentrate and dry.The yield of the gelatin from processing optimization can reach to 28.03%,Viscosity reach to 6.64mPa.s,gel strength reach to 271 Bloom g,ashes 0.37%,The measured indexes reach the national standard GB6783-94 edible gelatin.