Utilization of Oak (genus Quercus) tree parts in food industry: a review

Acorns, the fruit of the oak tree, as well as oak leaves have been for a long time an important source of food in various cultures throughout history. However, over the time they have disappeared from the diet and their usage in the food industry was minimal, especially due to the high tannin content and astringency. Despite that, several products have begun to appear on the market in the recent years such as an acorn flour or acorn coffee substitute and some studies were focused on the possibilities of using oak leaves extracts as a natural antioxidant against protein and lipid oxidation in the meat industry as well as for the beverage production.