Hello, avidin is a protein present in hen egg white and tissues of birds. In hens, it is synthesized in the oviduct and then deposited in the albumin where it protects chicken embryos from disease-causing organisms that require biotin (vitamin H) to grow.

With its remarkably high affinity for biotin, avidin tightly binds and sequesters biotin, depriving bacteria and other microbes of an essential growth factor.

Thanks so much @Karen

Your welcome!

Egg is the only source of avidin