鸡蛋蛋黄比例研究综述

蛋黄是鸡蛋的精华部分,蛋黄比例是衡量鸡蛋营养价值的一项重要指标,市场中不同消费群对鸡蛋中蛋黄的含量需求有所不同。掌握蛋黄比例的变化规律及其影响因素对产品质量和市场销售有重要的作用。本文从蛋黄比例的相关概念、研究意义及其影响因素等方面,对蛋黄比例近几年相关研究结果进行了总结和概述,并提出对蛋黄比例研究和育种的思考,为今后相关的研究工作提供参考。     

鸡蛋蛋黄比例研究综述

蛋黄是鸡蛋的精华部分,蛋黄比例是衡量鸡蛋营养价值的一项重要指标,市场中不同消费群对鸡蛋中蛋黄的含量需求有所不同。掌握蛋黄比例的变化规律及其影响因素对产品质量和市场销售有重要的作用。本文从蛋黄比例的相关概念、研究意义及其影响因素等方面,对蛋黄比例近几年相关研究结果进行了综述,并提出对蛋黄比例研究和育种的思考,为今后相关的研究工作提供参考。     

鸡蛋蛋黄生物活性成分的开发现状

简述了鸡蛋的结构以及蛋黄成分组成.同时综述了蛋黄中磷脂类、活性蛋白质类以及涎酸类化合物等活性成分的生理功能以及制备方法进展,包括有蛋黄油、蛋黄卵磷脂、卵黄高磷蛋白、低密度脂蛋白、卵黄球蛋白、涎酸、涎酸低聚糖以及涎酸糖肽等.     

蛋黄营养多 吃鸡蛋不可扔掉蛋黄

现在有许多人吃鸡蛋时会将鸡蛋黄扔掉，因为他们认为，鸡蛋黄中含胆固醇量很高。医学专家今天发出提醒，称鸡蛋黄中含有丰富的营养成分。     

鸡蛋蛋黄中主要蛋白质及蛋黄肽的生物活性研究进展

蛋黄富含蛋白质和脂质,也是维生素和矿物质良好的供给源,其所含的营养成分全面且丰富,是人类重要的营养来源。在对蛋黄相关文献进行统计分析的基础上,综述了蛋黄中主要的蛋白质,介绍了蛋黄源活性肽的功能活性,以期为后续深入的基础研究和功能性保健食品的开发提供参考。     

胆固醇氧化酶转化蛋黄胆固醇工艺的优化

研究了用响应面分析法(RSM)优化酶法转化蛋黄胆固醇的工艺,发现胆固醇氧化酶(COD)添加量及蛋黄粉的稀释率是影响蛋黄胆固醇转化率最重要的因素.在模拟优化的条件下反应时间为14.15h,蛋黄粉稀释率为3.54,COD为5.39U/g时,胆固醇转化率达85.61%.对氧化产物进行分析发现仅有单一产物胆甾烯酮,该产物具有降血脂、减肥等功效.     

鸡蛋蛋黄蛋白脱磷方法的比较

为保证慢性肾脏病患者蛋白营养供给充足的同时控制磷的摄入,采用一种新的脱磷方法即蛋白酶辅助碱性脱磷制备低磷蛋黄蛋白粉。同时分析比较了碱性蛋白酶辅助脱磷和碱法脱磷的效率、蛋白质溶解度、结构及氨基酸组成的差异。结果表明碱法脱磷对蛋白质氨基酸有破坏作用影响蛋白质品质;碱性蛋白酶辅助脱磷方法的脱磷率达45.17%左右,蛋白质质量分数高达74.74%,蛋白水解度高,脱磷效率高于碱法脱磷,表明脱磷率与水解度呈正相关;同时脱磷后蛋黄蛋白呈疏松片状结构,无规则卷曲蛋白质质量分数为90%左右;碱性蛋白酶辅助脱磷的蛋黄蛋白中可溶蛋白质质量分数18.92%,溶解稳定性高达98.62%,优于碱法脱磷。另外,采用此脱磷方法的氨基酸FAO/WHO模式贴近度0.958,明显优于碱法脱磷。因此,所制备的低磷蛋白粉可作为慢性肾脏病患者的优质蛋白补充。     

热处理对鸡蛋蛋黄性质的影响

研究了不同强度的热处理(处理温度59、62、65、68℃,处理时间0～9 min)对鸡蛋蛋黄上清和颗粒的蛋白质组成、溶解性、乳化性和游离巯基含量的影响。结果表明:蛋黄上清中的γ-卵黄蛋白和蛋黄颗粒中的部分高密度脂蛋白在加热处理过程中发生变性形成大分子聚集体,加热处理对蛋黄上清蛋白质溶解度的影响大于对蛋黄颗粒的影响,温和的热处理对蛋黄上清与颗粒的乳化性质均没有显著影响,68℃处理较长时间会使蛋黄上清与颗粒的乳化活力下降,乳化稳定性提高。热处理过程中蛋黄上清和颗粒的游离巯基含量变化均未表现出明显的规律性。     

储藏温度对鸡蛋蛋黄乳化性的影响

本研究通过测定鸡蛋在不同温度(4℃、25℃和37℃)储藏15 d后蛋黄的表面疏水性(H0)、乳化活性(EA)和乳化稳定性(ES)、Zeta电位、粒径分布、蛋白质溶解度、圆二色谱(CD)等指标变化,评估储藏温度对蛋黄蛋白质结构和乳化性的影响。结果表明,随着储藏温度的降低,H0、Zeta电位绝对值和EA均显著降低(p0.05),粒径显著升高(p0.05),相比对照组(3.22±0.03),在4℃储藏15 d后的蛋黄H0下降至1.09±0.04;ES的变化受温度的影响不显著,而蛋白质溶解度仅在低温条件下显著下降(p0.05);CD的结果显示随着储藏温度的升高,α-螺旋和β-折叠含量逐渐降低,无规卷曲含量逐渐升高。本研究发现储藏温度显著影响着蛋黄的乳化性(p0.05),虽然高温储藏会加速鸡蛋品质劣化,高温储藏蛋黄乳化活性(0.63±0.01)优于低温储藏蛋黄乳化活性(0.42±0.02),这为鸡蛋在不同温度储藏条件下蛋黄产品的开发提供理论参考。     

鸡蛋蛋黄活性成分的生理功能及开发

介绍了鸡蛋蛋黄成分中的活性成分,以及相应的制备方法和生理功能.     

蛋黄甘油三酸酯的脂肪酸组成分析

采用毛细管气相色谱法分析酶法制备的蛋黄甘油三酸酯的脂肪改组成及相对含量，结果表明：其主要合有棕榈酸、油酸、硬脂酸、亚油酸、棕榈油酸，此外还含有微量的亚麻酸、花生四烯酸和二十二碳六烯酸。不饱和脂肪酸超过60％，是一种极具开发价值的营养保健油脂。     

Chemical Compositions of Egg Yolks and Egg Quality of Laying Hens Fed Prebiotic,Probiotic, and Synbiotic Diets

A 16‐wk feeding experiment was conducted to investigate the effects of a prebiotic, isomaltooligosaccharide (IMO), a probiotic, PrimaLac®, and their combination as a synbiotic on the chemical compositions of egg yolks and the egg quality of laying hens. One hundred and sixty 16‐wk‐old Hisex Brown pullets were randomly assigned to 4 dietary treatments: (i) basal diet (control), (ii) basal diet + 1% IMO (PRE), (iii) basal diet + 0.1% PrimaLac® (PRO), and (iv) basal diet + 1% IMO + 0.1% PrimaLac® (SYN). PRE, PRO, or SYN supplementation not only significantly (P < 0.05) decreased the egg yolk cholesterol (24‐ and 28‐wk‐old) and total saturated fatty acids (SFA; 28‐, 32‐, and 36‐wk‐old), but also significantly (P < 0.05) increased total unsaturated fatty acids (UFA; 28‐, 32‐, and 36‐wk‐old), total omega 6 and polyunsaturated fatty acids (PUFA), including linoleic and alpha‐linolenic acid levels in the eggs (28‐wk‐old). However, the total lipids, carotenoids, and tocopherols in the egg yolks were similar among all dietary treatments in the 24‐, 28‐, 32‐, and 36‐wk‐old hens. Egg quality (Haugh unit, relative weights of the albumen and yolk, specific gravity, shell thickness, and yolk color) was not affected by PRE, PRO, or SYN supplementation. The results indicate that supplementations with IMO and PrimaLac® alone or in combination as a synbiotic might be useful for improving the cholesterol content and modifying the fatty acid compositions of egg yolk without affecting the quality of eggs from laying hens between 24 and 36 wk of age.     

低温乙醇除脂法纯化鸡卵黄中免疫球蛋白

采用低温乙醇除脂法提取鸡卵黄免疫球蛋白 (immunoglobulinyolk,IgY)。通过低温乙醇沉淀、透析和葡聚糖凝胶等不同方法逐步纯化免疫球蛋白。研究了卵黄稀释倍数、乙醇浓度、NaCl浓度以及离心转速对纯化效果的影响。分离纯化后所得的冷冻干燥制品 ,经SDS PAGE和抑菌试验检测可知 :可溶性蛋白质得率为每毫升蛋黄 1 2 6mg ,可溶性蛋白质含量占总蛋白质量的 97% ,且保持了免疫球蛋白的活性     

功能性不饱和脂肪酸研究进展

随着对脂肪研究的深入,人们认识到脂肪酸与机体的健康有着密不可分的关系。而对于功能性的不饱和脂肪酸的研究更是国内外的研究热点。本文着重对功能性不饱和脂肪酸的分类、来源、合成途径及生物学功能的研究进展进行了阐述。     

微波辅助提取林蛙卵油的工艺优化及脂肪酸组成分析

以林蛙卵为原料,以无水乙醇为提取剂,研究微波法对林蛙卵油提取率的影响。在单因素试验的基础上,进行响应面优化试验,研究料液比、浸泡时间、微波功率对林蛙卵油提取的影响。结果表明,提取最佳工艺条件为料液比1∶9.82(g/mL)、浸泡时间3.33 h、微波时间30 min、微波功率600 W;林蛙卵油的提取率可达到(20±0.67)%。与其他林蛙卵油提取方法比较,微波法辅助提取林蛙卵油具有得率高的优点。对得到的林蛙卵油采用气相色谱-质谱分析检测出27种脂肪酸,不饱和脂肪酸质量分数54.98%,其中以亚油酸、二十碳二烯酸、二十碳三烯酸、二十碳四烯酸、亚麻酸、棕榈反油酸、二十二碳五烯酸含量较高。     

泌乳期母乳脂肪酸变化及其多不饱和脂肪酸影响因素

采用气相色谱-质谱联用技术测定不同泌乳期母乳中脂肪酸的动态变化,并分析乳母血型、生育年龄、孕周、孕前身体质量指数（body mass index,BMI）、分娩方式和婴儿性别、胎次对成熟母乳中与婴儿生长发育直接相关的重要多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）,亚油酸（linoleic acid,LA）、α-亚麻酸（α-linolenic acid,ALA）、花生四烯酸（arachidonic acid,AA）,二十碳五烯酸（eicosapentaenoic acid,EPA）、二十二碳六烯酸（docosahexaenoic acid,DHA）相对含量的影响。结果显示,饱和脂肪酸（saturated fatty acid,SFA）含量在初乳和成熟乳间差异显著（P＜0.05）,单不饱和脂肪酸（monounsaturated fatty acid,MUFA）含量随着泌乳期的延长逐渐降低,但差异不显著（P＞0.05）,PUFA含量在各泌乳期无显著差异（P＞0.05）,AA、DHA含量随着泌乳期的延长逐渐降低,在初乳、过渡乳中含量差异均不显著（P＞0.05）,但均显著高于成熟乳中含量（P＜0.05）;母乳中LA含量与婴儿性别有关,ALA含量与乳母孕前BMI有关,母乳中AA、EPA含量与乳母血型有关,DHA含量与乳母孕前BMI、乳母血型有关,均具有统计学意义（P＜0.05）。     

Cholesterol Reduction in Liquid Egg Yolk using β-Cyclodextrin

A process to reduce cholesterol in liquid egg yolk using β-cyclodextrin (CD) was optimized by response surface methodology, based on cholesterol reduction and yield. The most important factors influencing cholesterol reduction were dilution of egg yolk to a defined water:solid ratio and CD concentration. In the final process, egg yolk was adjusted to pH 10.5, diluted to a water:solid ratio of 2.9, heated to 50°C, and CD added at a CD:cholesterol molar ratio of 4.0. The slurry was mixed for 6.5 min at 1800 rpm, cooled to 4°C and centrifuged. Cholesterol in the supernatant was reduced by 89.2%. The yield, cholesterol and CD in the final product were adjusted by varying centrifugal force and CD concentration.     

蛋黄蛋白-植酸静电复合物对蛋黄乳液物理稳定性的影响

为改善蛋黄（egg yolk,EY）在酸性乳液体系的物理稳定性,采用EY蛋白与植酸（phytic acid,PA）形成静电复合物稳定EY乳液。研究酸性条件下PA质量分数（0%～0.8%）对EY蛋白及EY乳液物理稳定性的影响。结果表明,pH 3.0时,EY与0.012 5%～0.8% PA形成不溶性的静电复合物EY-PA;最优质量分数（0.2%）PA与含1%蛋白的EY形成复合物制备乳液较对照组的乳液黏度升高,粒径及乳析指数显著降低（P＜0.05）,界面蛋白质吸附量显著提高（P＜0.05）,乳滴分布更均匀,乳液的抗聚结效果提高。因此,EY蛋白与PA形成的静电复合物可调控EY乳液的理化特性,提高EY在酸性乳液体系的物理稳定性。     

Isolation of Egg Yolk Granules as Low‐Cholesterol Emulsifying Agent in Mayonnaise

Egg yolk is an essential ingredient for many food products due to its excellent functional properties such as emulsification. However, the consumers’ concern of its cholesterol level has led food industry to seek solutions for its replacement. Utilization of low‐fat egg yolk granules as emulsifier can be an alternative strategy. In this study, granules with low cholesterol content were separated from egg yolk by a simple method under easily scalable centrifugal conditions. The egg yolk granules isolated within 0.17 M NaCl solution achieved a 22.5% yield that was similar to that using higher centrifugation speeds and longer time. The yield of egg yolk granules increased from 25% to 32% when the yolk:water ratio was changed from 1:1 to 1:2. Mayonnaise was prepared to evaluate the emulsifying capacity of the egg yolk granules. It was found that egg yolk granules exhibited similar emulsifying activity as that of whole egg yolk, but a better emulsion stabilizing property that is evidenced by the higher viscosity of mayonnaise prepared with the granules. In addition, the viscosities of mayonnaise prepared by spray dried yolk and granules were slightly higher than the liquid counterpart, showing a further improvement by spray drying on the emulsion stabilizing properties. The mechanical spectra of mayonnaise samples by frequency sweep also suggested that granules favored the formation of stronger 3‐dimensional arrangements of oil droplets and therefore a more stable emulsion. Results suggest that granules isolated within 0.17 M NaCl solution present best emulsifying properties and can be applied as whole yolk replacer in food emulsions.