Structural Analysis of Extruded Fiber Components of Orange Pulp

X-ray diffractograms, optic and electronic microscopy were used to study the structural changes on extruded orange pulp using a Brabender® 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 2θ = 14.5°. 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 2θ = 22.5°. 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.

Physiological Quality of Soybean Seeds Treated with Carboxymethyl Cellulose and Fungicide

Soybean is the most produced oil crop in the world, with great increase in its annual production as well as great generation of waste from its industrialization. The soybean hulls can be used for the elaboration of products such as carboxymethyl cellulose (CMC), adding high value to this residue and it can be used as a coating polymer in seeds. The objective of this work was to analyze the physiological quality of soybean seeds treated with CMC and fungicide, recording images to verify the effectiveness of the coating in the seeds. The experiment was randomized into factorial scheme 2 × 4 with four replicates, two soybean cultivars M-7110 and M-7739 and four types of coating: without (control), CMC, fungicide and fungicide/CMC. The variables analyzed were: vigor (first count), germination test, accelerated aging, length and dry mass of the radicle and hypocotyl length. The images were made with a scanning electron microscope (SEM) with zoom of 50 and 200 times. The CMC used alone or with fungicide, provided good physiological quality of soybean seeds. In some analyzes there was difference between the cultivars M 7110 and M 7739. The combination of CMC and fungicide provided a better coating on the seeds.

Extraction and Characterization of Starch Fractions of Five Phenotypes <i>Pachyrhizus tuberosus</i>(Lam.) Spreng

Pachyrhizus tuberosus is a native plant of short life cycle found in South America riverside, which provides easy starch extraction from its tuberous roots. The aim of this study was to determine the physicochemical, rheological and functionality of the starch granules extracted from the roots of five phenotypes identified as V2, V3, V4, V6 and V7. Protein and ash content of all phenotypes were considerable high when compared to other root sources such as cassava varying from 4.35% to 7.43% and 1.58% to 2.49%, respectively, whereas lipid content was lower, between 0.29 and 0.49%. The starch granules were mostly circular and polygonal with varied sizes. The starch granules structural conformation showed cristallinity A type, normally for cereals. The maximum pasting viscosity at 95℃ ranged from 1644 cP (V7) to 2232 cP (V2). The initial temperature of pasting formation occurred at 69.4℃ for V2, 71.5℃ for V3, 87.9℃ for V4, 69.5℃ for V6 and 71.5℃ for V7. These values showed high variability within the phenotypes and generally high for roots and tubers starches. The maximum viscosity at 95℃ for V2, V3, V4, V6 and V7 were 2232, 2150, 1995, 2214 and 1644 cP, respectively. The viscosity curves showed low tendency to retrogradation. The thermal properties showed that the enthalpy of gelatinization varied from 8.91 J/g (V3) to 11.78 J/g (V2). The initial gelatinization temperature varied from 63.19℃ (V6) to 65.14℃ (V4). The swelling power at 90℃ ranged from 14.7% to 20.1% p/p and solubility from 10.3% (V2) to 27.2% (V7). It is concluded that Pachyrhizus tuberosus starch showed low retrogradation (1320 - 1560 cP) comparable to non-common native waxy starches, a feature which indicates the capability of using this natural and easy extraction starch source as gelling agent in certain manufactured food of undesirable retrogradation.