Innovatively identifying naringin and hesperidin by using terahertz spectroscopy and evaluating flavonoids extracts from waste orange peels by coupling with multivariate analysis

Fourier transform far-infrared (FT-FIR) was exploited to evaluate the flavonoids content of orange extracts using Soxhlet extraction. The absorbance fingerprint spectra hesperidin and naringin were identified in range 0.5–7 THz. absorption peaks obtained at 1.53, 1.85, 2.46, 3.36, 4.51, 5.35, 6.51, 7.55 THz, respectively. For naringin, observed 0.75, 1.50, 2.29, 3.76, 5.18, 6.48, 8.36 perceptible 4.40, 5.18 THz can be from whilst those cannot detected spectrum. noticeable 8.19 whereas they are indiscernible Pre-treatments such as normalization, standard normal variate (SNV), multiplicative scatter correction (MSC), 1st 2nd derivation employed enhance robustness model performance. Partial least squares regression performed well explain relationship between concentrations with determination coefficients prediction up 0.99 (pre-treated by deviation) for 0.97 This study addressed detection terahertz spectroscopy, which could potentially simplify procedures detect waste peels. • (HES) (NAR) identified. HES NAR innovatively distinct, compared HPLC. PLSR developed data pretreated deviation got R p 2 raw spectral achieved high Orange peel extracts' showed a similar pure hesperidin.