Codex-ing DuraPro Natamycin 50L bears a plain O/K Kosher symbol on the packaging instead of the required O/KD (dairy). This product is certified Kosher by the O/K and is Dairy.

Kosher Food Additives
Ingredients & Additives — What “Natural Flavoring” May Be Hiding Many ingredients are hidden by manufacturers through legal loopholes. “Natural flavoring” may simply mean a