Ariá (Goeppertia allouia) Brazilian Amazon tuber as a non-conventional starch source for foods

Dual cross-linked starch hydrogel for eugenol encapsulation and the formation of hydrogen bonds on textural hydrogel

Physical and chemical cross-linked hydrogels combining N, N'-Methylenebisacrylamide (MBA)-grafted starch (MBAS) and sorbitol were successfully prepared and encapsulated with eugenol in this work. The dense porous structure with diameter of 10-15 μm and strong skeleton after restructuring inside the hydrogel was confirmed by SEM. The band shifts between 3258 cm^-1 and 3264 cm^-1 clarified the presence of a large number of hydrogen bonds in physical and chemical cross-linked hydrogels. The robust structure of the hydrogel was confirmed by mechanical and thermal property measurements. Molecular docking techniques were used to help understand the bridging pattern between three raw materials and to assess the advantageous conformation, which demonstrate sorbitol is beneficial to improve the characteristics of textural hydrogel by the formation of hydrogen bonds, creating a denser network, structural recombination and new intermolecular hydrogen bonds between starch and sorbitol afforded considerably junction zones. Compared to ordinary starch-based hydrogels, eugenol-loaded starch-sorbitol hydrogels (ESSG) exhibited a more attractive internal structure, swelling properties, viscoelasticity. Moreover, the ESSG showed excellent antimicrobial activity for typical undesired microorganisms in foods.

Crosslinked starch-coated cellulosic papers as alternative food-packaging materials

In general, during the production of cellulosic materials for food-packaging applications, lignin and other amorphous components are usually removed via the pulping and multilevel bleaching process to entirely separate them from the fiber.

Novelties from the herbaceous stratum in a key region for the conservation of the Southern Amazon

Abstract The contribution of the herbaceous stratum to tropical plant diversity is considerable, however this component remains undersampled. We investigated floristic, structural, ecological and conservation issues concerning the herbaceous component of a seasonal deciduous forest associated with granitic rock outcrops in the Cristalino Region, a key area for biodiversity conservation in the Brazilian Amazon. We installed a permanent plot of 1 ha, allocating 10 transect-lines of 20 m each. We identified the sampled individuals, measured height and projection, and verified cover and frequency per species, genera and family. We recorded 86 species, 62 genera and 25 families, with Orchidaceae being the family with the highest species richness. Among the 26 new species added to Cristalino Flora, we included Philodendron deflexum Poepp. ex Schott and Griffinia nocturna Ravenna, the latter ‘Critically Endangered’. Furthermore, the occurrence of G. nocturna in an Amazonian forest matrix is a novelty in this study. The estimate of species diversity according to Shannon-Wiener (H’) was 2.43 nats.ind.-1 (equivalent to 11.37 ± 0.90 IC95% equally common species), and according to Simpson (1/D), 6.82 (± 0.648 IC95%). The rarefaction and extrapolation curves for the diversity estimates tended to stabilize. Although the vegetation on rock outcrops usually presents a high number of endemic species, this pattern was not found in our study area, which can be explained by its continuous occurrence in the forest matrix. The understory of our study area consists in a mixture of floras, being composed mainly of species from the Amazon and/or Cerrado biomes. In view of the current anthropic pressure faced by the southern Amazon, we reinforce the importance of carrying out inventories of its herbaceous communities, since the risk of species loss is even more alarming when considering present undersampling of this component.

Dielectric barrier atmospheric cold plasma applied to the modification of Ariá (Goeppertia allouia) starch: Effect of plasma generation voltage

The goal of this paper was to evaluate the influence of a range of plasma generation voltages on the physicochemical, structural, and technological properties of Aria (Goeppertia allouia) starch. Untreated (0 kV) and high voltages of cold plasma generation (7, 10, 14, and 20 kV) treated samples were evaluated according to their amylose content, pH, groups carbonyl/carboxyl, molecular size distribution, structure and technological properties (empirical viscosity, hydration properties, thermal analysis and gel strength). The applied voltage of 14 kV resulted in the greatest depolymerization of the starch chains, while 20 kV allowed the formation of oxidized complexes, promoting crosslinking of the starches chain. The cold plasma technique did not affect the levels of resistant starches, but increased the starch digestibility. The increased carbonyl and carboxyl groups also influenced the paste viscosity, improved hydration properties. This study suggests that the cold plasma technique can be useful in the controlled modification of starches, producing starches with different technological properties.