Non-destructive determination of the oil content in peach palm (Bactris gasipaes) flour using NMR and NIR spectroscopies

Abstract

The oil from the fruit of peach palm or Pupunha (Bactris gasipaes) is an example of a material with low-cost and good antioxidant capacity. However, Conventional methods for measuring oil content are time-consuming, labor-intensive and use toxic chemicals. In this sense, the aim of this study was evaluated fast and non-destructive spectroscopy methods, such as Near Infrared (NIR) and Time-Domain Nuclear Magnetic Resonance (TD-NMR) (CPMG and ROSE pulse sequences), to quantify the oil content in pupunha flours collected in the amazon forest. For this, 93 samples were used and the results showed three distinct levels of oil in the samples: high, medium and low oil content. Furthermore, the determination coefficient (R 2 ) reached values of 0.92, 0.92 and 0.70 for NIR, TD-NMR (ROSE) and TD-NMR (CPMG), respectively. Therefore, the NIR and TD-NMR (ROSE) methods demonstrate a higher prediction efficiency, with the NIR achieving 100% classification of the samples.