Between the first and second half of the 20th c., Egyptian food habits changed drastically. Frozen foods, mechanised bakeries, and foreign foodstuffs became easily accessible and ushered in new techniques and staples that quickly replaced traditional foods and preservation techniques.
Change occurred at a dizzying pace, and instead of gradually evolving, local traditions were hastily replaced, making it imperative to study, document, and perhaps try to save the many disappearing age-old traditions.
For more, see the full story Seven Thousand Years of Food (link in details).