topic11 eggs Flashcards
free run vs free range
free fun: They are not confined to cages, but they may not have access to the outdoors. Instead, they have space to roam and exhibit natural behaviors within a sheltered environment.它们不会被关在笼子里，但它们可能无法进入户外。相反，他们有空间漫游，在一个庇护的环境中表现出自然的行为
Free range:While they may spend part of their time indoors, they are granted outdoor access, and the idea is to provide a more natural environment for the chickens to express their natural behaviors.它们可能会在室内度过一部分时间，但它们被允许到室外活动，这样做的目的是为鸡提供一个更自然的环境来表达它们的自然行为。
nutrition value of eggs
1.Eggs have highest PER (protein efficiency ratio: measure of protein quality)
2.13 essential vitamins and minerals E.gRiboflavin, selenium
3.Fat (yolk)
in yolk: iron, vitamin A, cholesterol, choline, lutein叶黄素, zeaxanthin玉米黄质
Egg formation
26 hours —> 1 egg
brown or white egg?
same in nutritional value
egg composition for different nutritional values
75% water
12% protein
10% fat
1% carbohydrate
1% minerals
egg weight
~57g with shell, ~50g without shell, 2/3 albumen, 1/3 yolk
different proteins in albumen
- ovalbumin
2.ovomucin
3.lysozyme
pH of albumen
fresh pH of 7-8.5, increase due to loss of CO2 during storage
characters of ovalbumin
- contributes to foaming
2.denatured by heat
characteristics of ovomucin
viscous(粘稠的) gel properties
2. contributes to foam stability
properties of lysoenzyme
Antimicrobial enzyme; part of the innate immune system
Thermally stable (up to 72°C)
Large pH range of 6-9
protein in egg yolk
lipoproteins: emulsifying proterties
lipids in egg
Triglycerides
Phospholipids
Cholesterol
1/3rd of the weight of the yolk
Taste
Question: eggs and heart health?
omega-3 fatty acids lower risk of CVD, normal people do not need to limit egg yolk consumption
what is vitelline
yolk
what is albumen?
egg white
what is chalazae
twisted cordlike strands to anchor the yolk
