Enzymatic Browning

Enzymatic browning refers to the natural oxidation process in cannabis plant material where polyphenol oxidase (PPO) and other oxidative enzymes convert phenolic compounds into brown melanin-like pigments. This occurs during drying, curing, and storage, and is distinct from chlorophyll degradation. Enzymatic browning is commonly observed in slower-dried or improperly stored flower, and breeders occasionally select for cultivars with lower PPO activity or higher antioxidant profiles to maintain visual quality. The degree of browning can affect aesthetic grading but does not necessarily indicate potency or chemical composition. Understanding enzymatic browning is relevant to post-harvest handling, breeding for storage stability, and preservation techniques.

Breeders working on storage stability and visual retention sometimes select parent plants with naturally lower polyphenol oxidase activity or higher endogenous antioxidant levels. Cultivars bred for extended shelf life or particular preservation methods may show resistance to rapid enzymatic browning under standard conditions.