【作者】 徐晓霞；

【导师】 杨富民；

【作者基本信息】 甘肃农业大学 ， 动物性食品营养与工程， 2017， 博士

【摘要】 蓝孔雀(Pavo cristatus)原属观赏珍禽,现已在世界各国普遍饲养,蓝孔雀蛋也已作为特色禽蛋品种供消费者食用。然而,目前对蓝孔雀蛋的品质及其变化规律等的研究尚未见报道。为此,本论文对蓝孔雀蛋的脂质及其在贮藏、加工过程中的变化规律进行了系列研究。主要研究结果如下:(1)采用HPLC分析了蓝孔雀蛋和京白鸡蛋的脂质。相对于京白鸡蛋,蓝孔雀蛋的总脂质、极性脂和磷脂酰胆碱含量较高,胆固醇含量较低,但差异不显著(P>0.05)。蓝孔雀蛋的总脂质含量是京白鸡蛋的1.16倍。蓝孔雀蛋和京白鸡蛋蛋黄中的中性脂质占总脂质的比例分别为62.61%和65.81%,而极性脂质占总脂质的比例分别为38.19%和34.20%。磷脂组分中,蓝孔雀蛋中的磷脂酰胆碱(PC)、磷脂酰乙醇胺(PE)、磷脂酰肌醇(PI)的比例分别占总脂质含量的31.2%、2.79%和1.60%;而京白鸡蛋中PC、PE、PI的含量分别占总脂质含量的27.77%、2.88%和2.13%。蓝孔雀蛋和京白鸡蛋的胆固醇酯含量分别为32.07μg/mg和35.32μg/mg。(2)采用GC-MS分析了蓝孔雀蛋和京白鸡蛋中的脂肪酸。两种禽蛋中均含有相同类型的22种脂肪酸,但含量存在差异。两种禽蛋中油酸的含量最高(C18:1ω-9),其次为饱和棕榈酸(C16:0)。其中,蓝孔雀蛋和京白鸡蛋中的C18:1ω-9含量分别为253.48μg/mg和199.61μg/mg(P<0.01),C16:0含量分别为183.28μg/mg和166.85μg/mg(P<0.01)。蓝孔雀蛋和京白鸡蛋中的DHA(C22:6ω-3)的含量分别为19.73μg/mg和15.32μg/mg(P<0.05),EPA(C20:5ω-3)的含量分别为29.91μg/mg和18.78μg/mg(P<0.01)。在蛋黄脂质中,蓝孔雀蛋的多不饱和脂肪酸(PUFA)和单不饱和脂肪酸(MUFA)显著高于饱和脂肪酸(SFA)(P<0.05),而京白鸡蛋的多不饱和脂肪酸(PUFA)和单不饱和脂肪酸(MUFA)显著低于饱和脂肪酸(SFA)(P<0.05)。蓝孔雀蛋和京白鸡蛋的ω-6/ω-3脂肪酸的比例分别为4.41和4.10,均在推荐的最佳比例范围内。蓝孔雀蛋的AI指数和TI指数均低于京白鸡蛋。(3)考察了4±2℃和22±2℃两种温度保藏的过程中蓝孔雀蛋脂质和脂肪酸含量的变化。结果显示两种温度贮藏过程中蓝孔雀蛋的中性脂质(NL)和磷脂(PL)含量降低而游离脂肪酸(FFA)含量增加。贮藏8周后,4±2℃和22±2℃贮藏样品的NL含量分别下降5.47%和31.96%,PL则分别下降了14.95%和20.79%。两种温度贮藏过程中蓝孔雀蛋脂肪酸均表现为SFA含量升高而UFA和胆固醇含量降低。贮藏8周后,4±2℃和22±2℃贮藏样品的SFA含量分别上升了0.91%和1.84%,MUFA含量分别下降了0.35%和2.08%,而PUFA含量分别下降了1.28%和3.03%,胆固醇含量则分别下降6.94%和4.88%。(4)考察了蓝孔雀蛋在蒸煮加热和微波加热过程中脂质和脂肪酸含量的变化。两种方式加热过程中,蓝孔雀蛋黄主要脂质组分中的中性脂质(NL)和游离脂肪酸(FFA)含量呈现上升趋势(P<0.05),而磷脂(PL)含量呈现下降趋势(P>0.05)。加热过程中蓝孔雀蛋蛋黄饱和脂肪酸的含量呈现显著上升趋势(P<0.05),大多数不饱和脂肪酸的含量呈现下降趋势(P>0.05)。蒸煮加热5min,不饱和脂肪酸的含量下降幅度均在3%以下。微波加热5min时,C18:1、C18:3的含量分别下降35.50%和33.72%,而C20:4和C22:6含量下降幅度较小。胆固醇含量呈现轻微上升趋势,加热5min时,蒸煮加热和微波加热的蓝孔雀蛋胆固醇含量分别上升了0.94%和3.13%。整体而言,蒸煮加热对蓝孔雀蛋中的脂质影响小于微波加热。(5)考察了蓝孔雀蛋在真空冷冻干燥前后脂质和脂肪酸含量的变化。真空冷冻干燥后,蓝孔雀蛋黄中性脂质组分上升了1.27%,游离脂肪酸上升了5.36%,磷脂则下降了1.92%。与新鲜蓝孔雀蛋黄相比,真空冻干蓝孔雀蛋黄粉中的磷脂酰胆碱下降了6.13%,磷脂酰乙醇胺下降了3.75%,磷脂则下降了13.69%。真空冷冻干燥使蛋黄脂质中的饱和脂肪酸升高而不饱和脂肪酸降低。相对于新鲜蓝孔雀蛋黄脂质中的饱和脂肪酸,C16:0、C18:0、C20:0、C24:0在真空冷冻干燥以后分别升高了1.68%、4.97%、0.23%和3.25%。真空冷冻干燥使蛋黄脂质中的大多数不饱和脂肪酸降低,而使少量不饱和脂肪酸升高。蛋黄粉中的C16:1、C18:2、C20:2、C20:3、C20:4、C20:5、C22:6相对于新鲜蓝孔雀蛋黄脂质分别降低了0.97%、1.18%、0.42%、0.02%、1.37%、5.61%和3.85%。真空冷冻干燥使蛋黄脂质中的不饱和脂肪酸C18:1、C18:3、C20:2含量分别升高了0.29%、0.13%和0.02%。真空冷冻干燥对胆固醇的影响较小,蛋黄粉中胆固醇含量相对于新鲜蛋黄仅下降了1.68%。更多还原

【Abstract】 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 μg/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(C18:1ω-9)in two kinds of egg,followed by saturated palmitic acid(C16:0).The contents of C18:1ω-9 in both eggs were 253.48 and 199.61μg/mg,respectively(P < 0.01),and the contents of C16:0 were 183.28 and 166.85μg/mg,respectively(P < 0.01).The contents of docosahexaenoic acid(DHA,C22:6ω-3)),eicosapentenoic acid(EPA,C20:5ω-3)in blue peafowl and Jingbai eggs were invidually 19.73μ and 15.32μg/mg(P < 0.05),29.91 and 18.78μg/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 ω-6/ω-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.更多还原