Chemical composition and antioxidant capacity of black pepper pericarp

Piper nigrum L. is a widely used spice because of its flavour and health effects. It is prepared as black and white pepper, according to the harvest time and inclusion of the outer skin. Pepper pericarp is usually considered waste when making white pepper. In this study, bioactive and flavour compounds and minerals in the pericarp of black pepper were determined to identify its applications. The pericarp contained total phenol, total flavonoid and piperine contents of 1421.95 ± 22.35 mg GAE/100 g, 983.82 ± 8.19 mg CE/100 g and 2352.19 ± 68.88 mg/100 g, respectively. There were higher levels of total phenols and total flavonoids in the pericarp compared with black pepper and white pepper. Piperine content was lower in the pericarp than in black pepper. The principal monoterpene compounds in the pericarp were α-pinene (9.2%), 2-β-pinene (14.3%), δ-3-carene (21.5%) and dl-limonene (18.8%), and the primary sesquiterpenes were α-copaene (5.1%) and caryophyllene (17.2%). The higher percentages of flavour compounds found in the pericarp would impart a more potent odour, and the pericarp exhibited higher minor and tiny differences based on electronic nose analysis. It had more minerals than black pepper and peeled black pepper.