Lipid Changes Of Blue Peafowl Eggs During Storage And Processing

Blue peafowl(Pavo cristatus)is originally belonged to a kind of rare birds,which has been raised in most countries in recent years,and the blue peafowl eggs are also become a special egg for consumer to taste.However,the quality and its change of blue peafowl eggs have not been reported.Thus,the analysis and identification of blue peafowl egg lipids and its change under storage and processing have been investigatin in the paper.The main contents are as follows:Lipid analyses of eggs from blue peafowl and Jinbai hen were compared using HPLC method.The results showed the contents of the total lipid(TL),polar lipid(PL)and phosphatidyl choline(PC)of blue peafowl eggs were higher but cholesterol was lower compared to those of Jingbai eggs.The differences were not significant(P > 0.05).The lipid content of blue peafowl eggs was 1.16 times than that of Jingbai eggs.The proportions of the neutral lipid(NL)vs the total lipids were 62.61% and 65.81%,but for polar lipid,they were 38.19% and 34.20% in egg yolks of blue peafowl and Jingbai hen,respectively.The proportions of the phosphatidyl choline(PC),phosphatidyl ethanolamine(PE)and phosphatidyl inositol(PI)vs the total lipid were separately 31.2%?2.79% and 1.60% in blue peafowl eggs,and they were 27.77%?2.88% and 2.13% in Jingbai eggs.The contents of the cholesterol were 32.07 and 35.32 ?g/mg in blue peafowl and Jingbai eggs.Fatty acid profiles of egg yolks from blue peafowl and Jinbai hen were compared using GC-MS.A total of the same types of 22 fatty acids were identified in two kinds of egg samples,but their contents were found different.The highest level of fatty acid was oleic acid(C18:1?-9)in two kinds of egg,followed by saturated palmitic acid(C16:0).The contents of C18:1?-9 in both eggs were 253.48 and 199.61?g/mg,respectively(P < 0.01),and the contents of C16:0 were 183.28 and 166.85?g/mg,respectively(P < 0.01).The contents of docosahexaenoic acid(DHA,C22:6?-3)),eicosapentenoic acid(EPA,C20:5?-3)in blue peafowl and Jingbai eggs were invidually 19.73? and 15.32?g/mg(P < 0.05),29.91 and 18.78?g/mg(P < 0.01).The content of the monounsaturated fatty acids(MUFA)and polyunsaturated fatty acids(PUFA)in blue peafowl yolks were significantly higher than that of the saturated fatty acids(SFA)(P < 0.05),while the content of the SFA in Jingbai hen yolks was significantly higher than those of MUFA and PUFA(P < 0.05).The proportions of ?-6/?-3 of blue peafowl and Jingbai hen yolks were 4.41 and 4.10,respectively,which were in the recommended optimal ratio range.The indexes of AI and TI in blue peafowl eggs were both lower than those of Jingbai eggs.The content changes of lipid and fatty acid of blue peafowl eggs were investigated before and after having been stored in 4±2 ? and 22±2 ?.The lipid and PL contents decreased while FFA content increased during storage.Among them,the lipid contents decreased 5.47% in 4±2 ? and 31.96% in 22±2?,and the content of PL decreased 14.95% in 4±2 ? and 20.79% in 22±2? after 8-week storage,respectively.The SFA content increased while UFA and cholesterol decreased,of which the content of SFA increased 0.91% in 4±2? and 1.84% in 22±2? after 8-week storage.The MUFA content decreased 0.35% in 4±2? and 2.08% in 22±2? after 8-week storage.After 8-week storage the PUFA content decreased 1.28% in 4±2? and 3.03% in 22±2?,and the cholesterol content decreased 6.94% and 4.88% in 4±2? and 22±2?,respectively.The content changes of lipid and fatty acid of blue peafowl eggs were investigated before and after boling heating and microwave heating.The contents of NL and FFA showed increasing trend(P < 0.05)while the PL content decreased(P > 0.05)during heating processing.The SFA content was increasing(P < 0.05)while most of the UFA content was decreasing(P > 0.05)during heat processing.The decending range of the UFA content was below 3% after blue peafowl eggs were boiling heating for 5 min.The contents of the C18:1 and C18:3 were decreased 35.50% and 33.72% after blue peafowl eggs were microwave heating for 5 min,respectively.The contents of the C20:4 and C22:6 were slightly decreased.The cholesterol contents were slightly going up during heating,and they were increased 0.94% and 3.13% during boliling heating and microwave heating.All in all,the effect of boiling heating on lipid content was smaller than that of microwave heating.The content changes of lipid and fatty acid of blue peafowl eggs were investigated before and after vacuum freeze-drying.The contents of NL and FFA respectively increased up to 1.27% and 5.36%,while the content of PL decreased down to 1.92% after vacuum freeze-drying.Compared to fresh blue peafowl eggs,the contents of PC,PE and PL decreased 6.13%,3.75% and 13.69%,respectively.The SFA content increased while most of UFA content decreased after vacuum freeze-drying.Among SFA,the contents of C16:0,C18:0,C20:0 and C24:0 individually increased 1.68%,4.97%,0.23% and 3.25% in comparison with those of fresh blue peafowl eggs.For UFA,the contents of C16:1,C18:2,C20:2,C20:3,C20:4,C20:5 and C22:6 individually decreased 0.97%,1.18%,0.42%,0.02%,1.37%,5.61% and 3.85%,while the contents of C18:1,C18:3 and C20:2 individually increased 0.29%,0.13% and 0.02% compare to those of fresh blue peafowl eggs.The effect of vacuum freeze-drying on cholesterol content was not significant,and it was only going down to 1.68% after processing.