Losses of phenolic compounds during drying processes may be mainly attributed to
oxidative reactions. While during oven drying one might expect
both non-enzymatic and enzymatic oxidative reactions to take
place, during freeze drying enzymatic oxidation by polyphenol oxidase and peroxidase is more likely to occur, due to the lower exposure to oxygen (Gümüs ay et al., 2015; Wojdyło et al., 2014) and to
cell structure injury caused by ice crystals formation