Investigation of the formation mechanism of the pepper starch-piperine complex

In this study, a new carrier for loading piperine was prepared using pepper starch, and its interaction mechanism was investigated. The porous pepper starch-piperine complex (PPS-PIP) showed higher loading efficiency (76.15 %) compared to the porous corn starch-piperine complex (PCS-PIP (52.34 %)). This may be ascribed to the hemispherical shell structure of porous pepper starch (PPS) compared to the porous structure of porous corn starch (PCS) based on the SEM result. PPS-PIP had smaller particle size (10.53 μm), higher relative crystallinity (38.95 %), and better thermal stability (87.45 °C) than PCS-PIP (17.37 μm, 32.17 %, 74.35 °C). Fourier transform infrared spectroscopy (FTIR) results implied that piperine not only forms a complex with amylose but may also be physically present in porous starch. This was demonstrated by the short-range order and X-ray type. Molecular dynamics simulations confirmed that hydrogen bonding is the primary interaction between amylose and piperine. Besides the formation of the amylose-piperine complex, some of the piperine is also present in physical form.