The intrinsic growth rate as a predictor of population viability under climate warming

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A DFT Study of Structural and Electronic Properties of ZnS Polymorphs and its Pressure-Induced Phase Transitions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of ball milling on the physicochemical characteristics of Peruvian carrot and cassava starches

Peruvian carrot and cassava starches were ground in a ball mill for 4, 8, 16, and 32 h and their structural and physicochemical characteristics were determined. Results obtained from HPAEC-PAD, GPC, and amylose content indicated a breaking of hydrogen bounds and α-(1 [RIGHTWARDS ARROW] 6) linkages of the starch molecules after treatment. X-ray diffractograms showed that the milling provided a reduction in the crystalline area of the starch granules. Most of the starch granules displayed agglomeration after 4 h of milling, when observed under a scanning electron microscope, and after 16 h a shapeless mass was observed for Peruvian carrot starch. Solubility and water absorption capacity of the starches increased with an increase in the milling time, while RVA profiles showed a progressive reduction of peak, breakdown, and final viscosities, as well as the development of initial viscosity. Gelatinization temperatures and enthalpies were reduced. Prolonged ball milling accelerated the enthalpy relaxation in both starches. These results confirmed a partial gelatinization of the starches, which was 82.6% for Peruvian carrot and 65.4% for cassava starches after 32 h of milling. The Peruvian carrot starch was more affected by the ball milling because of both its lower amylose content and the defects in its crystalline structure

Behavior of Peruvian carrot (Arracacia xanthorrhiza) and cassava (Manihot esculenta) starches subjected to the heat-moisture treatment

Peruvian carrot and cassava starches were isolated, adjusted to 30 and 35% moisture, and heatedat 90°C for 8 h. Structural and physicochemical characteristics of the treated starches wereevaluated and compared. High performance anion exchange chromatography with pulsedamperometric detector (HPAEC-PAD), gel permeation chromatography (GPC), and amylosecontent, revealed that the HMT did not change the chemical structures of the starches. A largeagglomeration of granules was observed from SEM, particularly in the Peruvian carrot starch.Crystalline patterns in Peruvian carrot and cassava starches changed from B to C and CAto A,respectively. Relative crystallinity decreased from 30 to 25% in Peruvian Carrot starch, andincreased from 35 to 37% in cassava starch adjusted to 30% moisture. SF and peak viscositydecreased, breakdown was almost completely eliminated (particularly in the Peruvian carrotstarch), and final viscosity increased. WAI and WSI increased as moisture levels of bothstarches increased. Gelatinization temperatures increased and enthalpy decreased. Degrees ofgelatinization increased as the moisture level increased, reaching 33 and 72% in the cassavaand Peruvian carrot starches, respectively. HMT strengthened the intra- and intermolecularinteractions of starches and increased their stability during heating and shearing, but also causeda partial gelatinization in the starches, particularly in Peruvian carrot starch.

Study of thermodynamic water properties and moisture sorption hysteresis of mango skin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of glycerol monostearate on the gelatinization behavior of maize starches with different amylose contents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effects of heat-moisture treatment on avocado starch granules: thermoanalytical and structural analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of heat-moisture treatment on the structural, physicochemical, and rheological characteristics of arrowroot starch

The effect of heat-moisture treatment on structural, physicochemical, and rheological characteristics of arrowroot starch was investigated. Heat-moisture treatment was performed with starch samples conditioned to 28% moisture at 100℃ for 2, 4, 8, and 16 h. Structural and physicochemical characterization of native and modified starches, as well as rheological assays with gels of native and 4 h modified starches subjected to acid and sterilization stresses were performed. Arrowroot starch had 23.1% of amylose and a CA-type crystalline pattern that changed over the treatment time to A-type. Modified starches had higher pasting temperature and lower peak viscosity while breakdown viscosity practically disappeared, independently of the treatment time. Gelatinization temperature and crystallinity increased, while enthalpy, swelling power, and solubility decreased with the treatment. Gels from modified starches, independently of the stress conditions, were found to have more stable apparent viscosities and higher G' and G″ than gels from native starch. Heat-moisture treatment caused a reorganization of starch chains that increased molecular interactions. This increase resulted in higher paste stability and strengthened gels that showed higher resistance to shearing and heat, even after acid or sterilization conditions. A treatment time of 4 h was enough to deeply changing the physicochemical properties of starch.

Thermoanalytical study of cassava starch native and treated with hydrogen peroxide

Starch is one of the most important sources of reserve of carbohydrate in plants and the main source in the human diet due to its abundance in the nature. There no other food ingredient that can be compared with starch in terms of sheer versatility of application in the food industry. Unprocessed native starches are structurally too weak and functionally too restricted for application in today’s advanced food and industrial technologies. The main objective of this study was to compare the thermal behavior of native cassava starch and those treated with hydrogen peroxide, as well as those treated with hydrogen peroxide and ferrous sulfate. The cassava starch was extracted from cassava roots (Manihot esculenta, Crantz) and treated by standardized hydrogen peroxide (H2 O2 ) solutions at 1, 2 and 3% (with or without FeSO4 ). Investigated by using they are thermoanalytical techniques: thermogravimetry - TG, differential thermal analysis – DTA and differential scanning calorimetry - DSC, as well as optical microscopy and X-ray powder diffractometry. The results showed the steps of thermal decomposition, changes in temperatures and in gelatinization enthalpy and small changes in crystallinity of the granules.

Modificação química de amido de mandioca e aplicação em emulsão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)