Structural characterization of cellulose obtained from extraction wastes of graviola (annona muricata) leaf

Cellulose is one of the most common functional ingredients in food products and has been widely used as fat replacers and stabilizers. In the present study, the structural properties of cellulose obtained from extraction wastes of graviola (Annona muricata.) leaf (CWG) were characterized via scanning electron microscope (SEM), X-ray diffraction (XRD), fourier transform-infrared (FTIR), and ¹³C nuclear magnetic resonance (NMR) analyses. Extraction and purification of CWG were accomplished by alkali treatment and bleaching processes. An elongated, fibrous structure of CWG was observed in SEM analysis. The XRD, FTIR, and ¹³C NMR spectra of CWG were compared with microcrystalline cellulose (control cellulose) and it was found that CWG exhibited similar structural characteristics to the control. XRD diffractogram of CWG showed typical peaks (2θ=15^o and 22.6^o) of cellulose I. According to the specific peaks (898, 1,057, and 1,430 cm⁻¹) and chemical shifts (104.5, 88.5, 72∼75, and 64.6 ppm) obtained by FTIR and NMR analyses, respectively, it was cofirmed that cellulose was successfully extracted from CWG.