本文選題：蛋黃　切入點：卵磷脂　出處：《河北農(nóng)業(yè)大學》2015年碩士論文

【摘要】：在飼料中添加卵磷脂可提高動物的生產(chǎn)性能,但卵磷脂的價格過高會增加養(yǎng)殖成本,減少經(jīng)濟效益。蛋黃是工業(yè)制備卵磷脂的重要來源,我國雞蛋產(chǎn)量位居世界首位,鮮雞蛋蛋黃中含有豐富的卵磷脂,其含量約為蛋黃總重量的9.76%,且蛋黃卵磷脂中磷脂酰膽堿(PC)的含量約是大豆卵磷脂的三倍。但相較大豆卵磷脂,蛋黃卵磷脂含有較多的膽固醇,機體攝入過多的膽固醇會影響健康。一些卵磷脂的制備工藝引入丙酮、乙醚等有毒溶劑也有一定的安全隱患。本試驗主要探討了蛋黃卵磷脂的制備方法,以建立低成本、無有毒溶劑殘留、無膽固醇、簡單、高效、經(jīng)濟、適合規(guī)�；a(chǎn)蛋黃卵磷脂工藝流程為目的,從蛋黃卵磷脂的粗提、甘油三脂的去除、膽固醇的去除以及蛋黃卵磷脂的精制四個方面進行了研究。首先,根據(jù)卵磷脂易溶于乙醇的特性,將卵磷脂從蛋黃液中提取出來。乙醇提取蛋黃卵磷脂的工藝受提取溫度、提取時間、乙醇濃度以及料液比的影響,本試驗通過單因素實驗考察了四種因素對蛋黃卵磷脂提取率的影響,并通過正交試驗確定了提取時間和提取溫度是影響蛋黃卵磷脂粗提的主要因素,且最佳的工藝條件為提取時間60 min、提取溫度35℃、乙醇濃度95%、料液比1:12,蛋黃卵磷脂粗制品的得率為25.18%。其次,通過低溫冷結(jié)晶法去除蛋黃卵磷脂中大部分的甘油三脂。將蛋黃卵磷脂的乙醇溶液在4℃下靜置過夜,溶液中的甘油三脂在低溫下會結(jié)晶沉淀出來,離心后可將大部分甘油三酯去除,檢測前后蛋黃卵磷脂中甘油三脂的含量,可計算出甘油三酯的去除率為58.96%。之后,對應用β-環(huán)糊精脫除蛋黃卵磷脂中膽固醇的工藝條件進行了研究。先配制β-環(huán)糊精的飽和溶液再與蛋黃卵磷脂的乙醇溶液混勻,利用β-環(huán)糊精的包埋吸附作用去除膽固醇,并研究吸附劑劑量、吸附溫度以及吸附時間等因素對膽固醇去除效果的影響,采用薄層色譜法和皂化比色法定性和定量檢測膽固醇。結(jié)果發(fā)現(xiàn)β-環(huán)糊精對膽固醇有良好的去除效果,操作簡單、適合工業(yè)化生產(chǎn),10 g鮮蛋黃液可使用1.6 gβ-環(huán)糊精將其中含有的膽固醇去除,去除率為99.00%。最后,將去除大部分甘油三酯和脫膽固醇后的蛋黃卵磷脂進一步精制。蛋黃卵磷脂的等電點為p H=6.7,在其等電點可發(fā)生沉淀,因此可利用緩沖液對蛋黃卵磷脂進行精制,通過對三種緩沖液的選擇,確定了使用1/15 mol/L的磷酸緩沖液,配制成p H=6.7的溶液與蛋黃卵磷脂的乙醇溶液以1:2的比例混合,可得到純度為81.32%的蛋黃卵磷脂,其中PC含量為56.14%,PE含量為25.18%。
[Abstract]:Adding lecithin to feed can improve the performance of animals, but the high price of lecithin will increase the breeding cost and reduce the economic benefit.Egg yolk is an important source of lecithin in industry. The egg production in China ranks first in the world. The egg yolk of fresh eggs is rich in lecithin.The content of phosphatidylcholine in egg yolk lecithin was about three times that of soybean lecithin.However, egg yolk lecithin contains more cholesterol than soybean lecithin.Some lecithin preparation technology introduced acetone, ether and other toxic solvents also have some safety risks.The preparation of egg yolk lecithin was studied in order to establish a low cost, no toxic solvent residue, no cholesterol, simple, efficient, economical and suitable for large-scale production of egg yolk lecithin.The extraction of egg yolk lecithin, the removal of triglyceride, the removal of cholesterol and the purification of egg yolk lecithin were studied.Firstly, lecithin was extracted from egg yolk fluid according to the characteristic of lecithin soluble in ethanol.The extraction process of egg yolk lecithin by ethanol was influenced by the extraction temperature, extraction time, ethanol concentration and the ratio of material to liquid. The effects of four factors on the extraction rate of egg yolk lecithin were investigated by single factor experiment.The extraction time and temperature are the main factors affecting the crude extraction of egg yolk lecithin, and the optimum technological conditions are as follows: extraction time 60 min, extraction temperature 35 鈩，

本文編號：1713079