bi3mw > 26-12-2021, 10:05 PM
Quote:Benecke (1994: 370-372)[1] proves that chickens definitely became larger as well as more different in shape and color from the late Middle Ages on. From about the 15th century, there are first indications of incipient breeding. In the Middle Ages, the animals can be divided according to the construction of the skeleton into small chickens similar to today's bantams and heavier chickens such as Leghorn or Italian. Chicken breeds or different types of chickens that emerged in the late Middle Ages are the origin of some breeds still living today ....
Linda > 26-12-2021, 11:11 PM
Bernd > 27-12-2021, 02:44 AM
bi3mw > 27-12-2021, 02:05 PM
(27-12-2021, 02:44 AM)Bernd Wrote: You are not allowed to view links. Register or Login to view.The albumen of an egg does not contain cell nuclei and thus only traces of DNA from the hen's oviduct.
(27-12-2021, 02:44 AM)Bernd Wrote: You are not allowed to view links. Register or Login to view.It is possible to identify some albumen traits associated with chicken breeds though but you'd likely need a proteome database from other contemporary paintings containing egg white of known origin.
You are not allowed to view links. Register or Login to view.
MichelleL11 > 27-12-2021, 05:05 PM
(27-12-2021, 02:05 PM)bi3mw Wrote: You are not allowed to view links. Register or Login to view.Unfortunately, the effect of being able to get comparison material (bones) quickly and easily is eliminated. Building such a database is notoriously difficult and lengthy.
As for the durability of egg white, it should be noted that it was used, among other things, for gilding with real gold leaf. Quote: "These gildings are characterized by special luster and durability, their durability can be calculated after centuries." ( Wikipedia, section "Use in bookbinding" )
bi3mw > 27-12-2021, 07:21 PM
Aga Tentakulus > 27-12-2021, 08:55 PM
bi3mw > 27-12-2021, 10:08 PM
(27-12-2021, 08:55 PM)Aga Tentakulus Wrote: You are not allowed to view links. Register or Login to view.Today's farm animals are crossbreeds of different breeds.
How can an exact pedigree be recorded here.
(27-12-2021, 02:44 AM)Bernd Wrote: You are not allowed to view links. Register or Login to view.It is possible to identify some albumen traits associated with chicken breeds though but you'd likely need a proteome database from other contemporary paintings containing egg white of known origin.
(27-12-2021, 05:05 PM)MichelleL11 Wrote: You are not allowed to view links. Register or Login to view.I agree that building the database for ovalbumin (protein) for particular strains of chickens is going to take some time.
bi3mw > 28-12-2021, 03:26 PM
Quote:.... until the later Middle Ages manuscript miniatures were mainly painted using glair. Glair was made from the egg white, presumably the ones that were left over from painting wood panels with egg yolk. The proteins of egg white must be broken down by beating to make a runny substance for mixing paint.
Quote:If egg whites are beaten until they are stiff, they are fully denatured and have no elasticity; they lose their original properties and aren't able to return to their former state. If egg whites are beaten only until they form soft peaks, the proteins are only partially denatured and retain some of their elasticity.
MichelleL11 > 28-12-2021, 07:35 PM
(28-12-2021, 03:26 PM)bi3mw Wrote: You are not allowed to view links. Register or Login to view.I was wondering what exactly of the egg is actually used to make glair. It is not the beaten egg white but the liquid egg white that forms on the bottom of the container after a few hours. As I understand it, beating the egg white breaks down the proteins ( denaturation ). That probably has a negative impact on any analysis although the primary biochemical structure remains unchanged.