Nutrition And Functional Component Research Of Oceans-duck Eggs From Guangxi Province

the sea-duck is trained Jinyun Sheldrake which is feeding outdoors in the north gulfof Guangxi province. The major food of it is the shrimps and sandworms.The currentstudy is take the sea-duck＇s eggs as the material, take a trophic analysis of it，especiallyon the lipid solubility component as lecithin，cholesterol, carotenoids and fatty acids. Bycomparing the differences in component content between the sea-ducks and the commons,to give a objective appraisal to the edibility and the functionality of the sea-ducks.This paper comprehensively analyzes the sea duck egg nutrients. Take yolk oilextraction ratio as the evaluation index, establish models of ultrasonic assisted extractionmethod and conventional ethanol extraction method. Then, using gas chromatographywith autosampler and external standard method, established a method for determine DHAcontent from eggs; Through GC and GC-MS instrument analysed the sea-duck yolk oilon composition of fatty acid, and the distribution of ω-3PUFA component inphospholipid and glycerides. Got the conclution of we Can’t purify ω-3PUFA by theseparation of phospholipids and glycerides; To establish a method of ultrasonic assistedyolk oil esterification, and through the response surface model to get the best reactionconditions. Specific as follows:1、according to the national standard method，the nutrients of sea duck egg areanalyzed.Through measurement, get the protein content of sea duck egg edible part is16%or so, lecithin content of about1.4%, cholesterol content of fresh egg liquid isabout429mg/100g. that the lipid exist in sea duck egg on cholesterol is less. Itrelate to the varieties and diet of the ducks. In addition, the RYCF value of sea duckegg is more than13, and total carotenoids significantly higher than ordinary duck egg.The fatty acid composition, sea duck egg and ordinary duck egg have significantdifferences, and they have different food, poly-unsaturated fatty acids has morepotential research value. That would be the study of the main parts of the follow-upstudy.2、According to the experimental result, we get the best solvents to extract lipidcomponent of sea-duck yolk is CM mixed solvent. but considering the later organicsolvent recovery, and the test personnel damage, using more safe ethanol as workingsolvent. A single factor experiment and L9（34） orthogonal test were carried out againstextracting time, extracting temperature and ratio of material to liquid. Obtained thetwo significant factors were ratio of material to liquid and extracting temperature; twooptimal level were1:25as ratio of material to liquid and50oC as the temperature; thebest optimal combination was1:25as ratio of material to liquid,50oC as thetemperature and the3hour as the extracting time. Then we take the uniform design to the ultrasonic assisted extraction yolk oil test, get the regression equation,Y=-3.55X₁+1.37X₂-0.564X₃+62.05. Regression equation is significant, and has agood linear relationship, The result analysis reflects that they affect the extractionyield in the order of ultrasound time> ultrasound power> ratio of material to liquid.Acid value of the yolk oil is40.34mgKOH/g, saponification value is174.49mgKOH/g, average molecular weight is about1225.3、Get the test method of DHA in yolk oil, that is, using the external standard method byGC combined with automatic sampler to determine the sea duck yolk of DHA content.Through the screening, get the most suitable GC operated conditions, this method fordetection of DHA is accurate, reproducible and detection limit low characteristic.Established the standard working curve of DHA, got the equation of linear regression,y=1802.1x+3.4093,R=0.998,had good linear relationship of the range from0.005mg/mL to0.05mg/mL.4、This chapter shows that the ratio of ω-3PUFA in the yolk oil is2.81%, the ratio ofω-6PUFA is5.15%,the ratio of ω-9PUFA is59.38%, and ω-3PUFA/ω-6PUFA is0.545. lecithin in yolk oil is37.576mg/g, the standard deviation is0.107.the fattyacid composition are similar in lecithin and triglyceride, but different in theproportion, especially the fatty acid18:1（ω-9）.Based on the classification of thefatty acid, establish the research foundation for ensuring the existence form ofω-3PUFA. And get the conclusion, enrichment of ω-3PUFA, esterification is difficultto avoid.5、By contrast, for calculating of esterification rate, it is more accurate by the ratio ofgas chromatographic peak area than the acid value. The rate of yolk oil esterificationis significantly higher through ultrasonic assisted method. By analysis of the primaryand secondary factors, we know that the ratio of Alcohol and oil, the entire time, onceultrasonic time, Amount of alkali and the interaction between Amount of alkali andthe ratio of Alcohol and oil have significance influence to the esterification rate,P=0.05. the ultrasonic power and the kind of alkali do not have influence to theesterification rate. Using response surface design method, construct a model ofultrasonic assisted of engineering,Y=0.544-0.03X₁-0.003X₂-0.036X₃0.008X₁X₂-0.047X₁X₃0.019X₂X₃-0.020X₁²-0.054X₂²-0.041X₃²Optimize the best parameters of ultrasonic assisted esterification, amount of alkali1.27ml, ultrasonic time9.82min, entire time4.96min, yolk oil esterification rate isthe highest,54.87%.