X-ray diffractograms, optic and electronic microscopy were used to study the structural changes on extruded orange pulp using a Brabender<span style="white-space:nowrap;">®</span> laborat...X-ray diffractograms, optic and electronic microscopy were used to study the structural changes on extruded orange pulp using a Brabender<span style="white-space:nowrap;">®</span> laboratory single-screw extruder (GNF 1014/2, 20:1, L/D). The results showed that most of the cellulose would be in the amorphous state, with small crystalline areas in the angular region of 2<em>θ</em> = 14.5<span style="white-space:nowrap;">°</span>. The evaluated extrusion conditions did not affect the crystallinity of the raw cellulose, maintaining the size of the crystalline regions in the angular region of 2<em>θ</em> = 22.5<span style="white-space:nowrap;">°</span>. Neutral detergent solubilized the crystalline areas of potassium citrate and cellulose, formed during the extrusion process. However, these conditions did not affect the crystallinity of the raw cellulose. In addition, no change was observed in the crystallinity of pectin. The electron microphotographs allowed for the estimation of the heterogeneity of orange pulp and assessment of the difference of resistance between the walls of the buds and juice vesicles. Thus, it was demonstrated that during the extrusion process most of the porosity and the cellular structure of the endocarp remained unaltered.展开更多
文摘X-ray diffractograms, optic and electronic microscopy were used to study the structural changes on extruded orange pulp using a Brabender<span style="white-space:nowrap;">®</span> laboratory single-screw extruder (GNF 1014/2, 20:1, L/D). The results showed that most of the cellulose would be in the amorphous state, with small crystalline areas in the angular region of 2<em>θ</em> = 14.5<span style="white-space:nowrap;">°</span>. The evaluated extrusion conditions did not affect the crystallinity of the raw cellulose, maintaining the size of the crystalline regions in the angular region of 2<em>θ</em> = 22.5<span style="white-space:nowrap;">°</span>. Neutral detergent solubilized the crystalline areas of potassium citrate and cellulose, formed during the extrusion process. However, these conditions did not affect the crystallinity of the raw cellulose. In addition, no change was observed in the crystallinity of pectin. The electron microphotographs allowed for the estimation of the heterogeneity of orange pulp and assessment of the difference of resistance between the walls of the buds and juice vesicles. Thus, it was demonstrated that during the extrusion process most of the porosity and the cellular structure of the endocarp remained unaltered.
