Eggs in Shells: The liquid inside eggs expands when frozen, which can cause the shells to crack and risk bacterial contamination. It's better to crack the eggs and beat them before freezing.
Mayonnaise and Emulsified Sauces: Mayo, hollandaise, and similar emulsified sauces can separate and become oily when frozen and thawed, ruining their texture.
Cream-Based Products: Cream-based soups, sauces, and custards can separate and curdle when frozen due to their high dairy content.
Salad Dressings and Vinaigrettes: Many salad dressings, especially those that are oil-based or contain dairy, can separate and become grainy or congeal when frozen and thawed.