Characterization of flavonoids and pectins from bergamot (Citrus bergamia Risso) peel, a major byproduct of essential oil extraction

Bergamot peel is an underutilized byproduct of the essential oil and juice-processing industry. As with other Citrus peels, it still contains exploitable components, such as pectins and flavonoids. Commercial glycoside hydrolases, specifically a combination of pectolytic and cellulolytic enzymes, solubilized a high percentage of the material (81.94%). The flavonoid profile of the peel consisted of characteristic Citrus species flavanone rutinosides and neohesperosides derived from naringenin, eriodictyol, and hesperetin. In addition, a number of minor flavanone and flavone glycosides, not found in orange and lemon peels, were identified. The majority of flavonoids were extracted in the two 70% v/v EtOH extractions. Processing this material clearly has economic potential leading to low environmental impact.