The Studies On Enrichment Of PUFA In Crayfish Yolk Fat

In this paper, crayfish yolk were studied as material, firstly, its components were measured, analyzed and evaluated. Secondly, extraction of fats from crayfish yolk was optimized. Thirdly, crayfish yolk oil catalyzed by lipase has been investigated and finally, the study on the enrichment technology of crayfish yolk fat through urea complexation method was optimized. The main results are as follows:(1) The ingredients of crayfish yolk were measured and analysed, the results showed that the fat and protein content of crayfish yolk were14.36%and4.16%, phospholipid content was6.36mg/g. It Contains8kinds of minerals,8kinds of essential amino acids, and5kinds of flavor amino acids, meanwhile, it containing26kinds of fatty acids,among them there were16kinds unsaturated fatty acids, representing59.40%,9polyunsaturated fatty acids, representing27.92%, palmitic acid (14.88%), oleic acid (16.42%), linoleic acid (15.76%), α-linolenic acid (6.68%), EPA (2.63%) with higher levels. The test results showed that crayfish yolk is a good development of aquatic resources.(2) The ultrasonic-assisted enzymatic hydrolysis extraction of fats from crayfish yolk was optimized in this artical.Meanwhile, GC was used to analyze the fatty acids of crayfish yolk fats. The results showed that the optimum extraction technique parameters were:water-material ratio of3:1, adding0.6%protemax, ultrasonic enzymatic temperature, ultrasonic power and time were152℃,150W and125min respectively. Under these conditions, the extraction rate of fats can reach77.86%.(3) The enzymatic hydrolysis of crayfish yolk oil catalyzed by lipase has been investigated. The optimal reaction conditions were found to be:ratio of oil to water of1:3, a lipase amount of1.5%(mass fraction to oil), and a reaction temperature of50℃for10h. Under this condition a hydrolysis degree of81.66%was obtained.(4) The study on the enrichment technology of crayfish yolk fat through urea complexation method was optimized.the optimum process parameters was determined: reflow temperature55℃, the ratio of urea to fat and solvent to fat was4:1and5:1perspectively, crystallization temperature of-15℃, and crystallization time10h.in this condition,the percentage of PUFA was82.74%.Through compared to the original crayfish oil,urea complexation resulted in dramatic reduction in SFA(39.03% decrease to5.8%) and MUFAs(33.09%decrease to11.04%). n-3series fatty acids were increased from3.59%to33.18%by the inclusion ago, which DHA and EPA levels were increased from8.25%to16.95%.