RESUMO

This study investigates the equilibrium state diagram of maltodextrins with varying dextrose equivalents (DE 10 and 30) for quercetin microencapsulation. Using XRD, SEM, and optical microscopy, three transition regions were identified: amorphous (aw 0.07-0.437), semicrystalline (aw 0.437-0.739), and crystalline (aw > 0.739). In the amorphous region, microparticles exhibit a spherical morphology and a fluffy, pale-yellow appearance, with Tg values ranging from 44 to -7 °C. The semicrystalline region shows low-intensity diffraction peaks, merged spherical particles, and agglomerated, intense yellow appearance, with Tg values below 2 °C. The crystalline region is characterized by fully collapsed microstructures and a continuous, solid material with intense yellow color. Optimal storage conditions are within the amorphous region at 25 °C, aw 0.437, and a water content of 1.98 g H2O per g of dry powder. Strict moisture control is required at higher storage temperatures (up to 50 °C) to prevent microstructural changes. This research enhances understanding of maltodextrin behavior across diverse dextrose equivalents, aiding the development of stable microencapsulated products.

RESUMO

Research background: Enzymatically resistant maltodextrins (ERM) are a resistant starch type 4, synthesized from native starch. They are obtained by the sequential application of two processes: pyrodextrinization, which produces pyrodextrins, and enzymatic hydrolysis, which produces ERM. In these processes atypical bonds are formed that confer pyrodextrins and ERM similar properties to dietary fiber, such as resistance to digestion. The aim of this work is to determine and evaluate some physicochemical properties of pyrodextrins and ERM obtained from native starch isolated from makal (Xanthosoma yucatanense) tubers. Experimental approach: Pyrodextrinization and complementary hydrolysis were conducted using factorial designs. For pyrodextrinization, factors and their levels were (m(starch):V(HCl))=80:1 and 160:1 (c(HCl)=2.2 M), temperature 90 and 110 °C and reaction time 1 and 3 h, and for CH, α-amylase per pyrodextrin volume fractions 0.5 and 1 µL/mL and reaction time 10 and 30 min. The physicochemical profile included determination of resistant starch content, estimation of color change (ΔE), microscopy and determination of dextrose equivalents (DE). Results and conclusions: According to the factorial design, the best treatment conditions for pyrodextrinization were: (m(starch):V(HCl))=160:1, 90 °C and 3 h, since they resulted in the highest resistant starch content (84.73 %) and the lowest ΔE (3.742). Due to the low DE (13.89 %), increased amount of resistant starch (90.73 %) and low ΔE (4.24) in the resulting ERM, complementary hydrolysis with α-amylase per pyrodextrin volume fraction 0.5 µL/mL and hydrolysis time 10 min was selected as the best treatment. Novelty and scientific contribution: The results show that the pyrodextrins and ERM obtained from makal can be used as ingredients for the development of functional foods, due to their high content of indigestible material and low degree of browning.

RESUMO

Resveratrol is an antioxidant abundant in red fruits, and one of the most powerful inhibiting reactive oxygen species (ROS) and oxidative stress (OS) produced by human metabolism. The effect of the spray drying processing conditions of blueberry juice (BJ) and maltodextrin (MX) mixtures was studied on content and retention of resveratrol. Quantitatively, analysis of variance (ANOVA) showed that concentration of MX was the main variable influencing content of resveratrol. Response surface plots (RSP) confirmed the application limits of maltodextrins based on their molecular weight, where low molecular weight MXs showed a better performance as carrying agents. After qualitatively comparing results for resveratrol against those reported for a larger antioxidant molecule (quercetin 3-D-galactoside), it was observed a higher influence of the number of active sites available for the chemical interactions, instead of stearic hindrance effects.

RESUMO

Maltodextrin (MX) is an ingredient in high demand in the food industry, mainly for its useful physical properties which depend on the dextrose equivalent (DE). The DE has however been shown to be an inaccurate parameter for predicting the performance of the MXs in technological applications, hence commercial MXs were characterized by mass spectrometry (MS) to determine their molecular weight distribution (MWD) and degree of polymerization (DP). Samples were subjected to different water activities (aw). Water adsorption was similar at low aw, but radically increased with the DP at higher aw. The decomposition temperature (Td) showed some variations attributed to the thermal hydrolysis induced by the large amount of adsorbed water and the supplied heat. The glass transition temperature (Tg) linearly decreased with both, aw and DP. The microstructural analysis by X-ray diffraction showed that MXs did not crystallize with the adsorption of water, preserving their amorphous structure. The optical micrographs showed radical changes in the overall appearance of the MXs, indicating a transition from a glassy to a rubbery state. Based on these characterizations, different technological applications for the MXs were suggested.

Assuntos

RESUMO

Entre marzo y agosto de 1987 se estudiaron 86 ninos con edades comprendidas entre 1 y 24 meses, quienes habian ingresado al Servicio de Lactantes del Hospital Infantil de Medellin, con deshidratacion secundaria a enfermedad diarreica aguda, prolongada o cronica. Una vez hidratados se inicio la alimentacion con dieta que contenia lactosa. Mediante la prueba de Clinitest se hizo el diagnostico de intolerancia a la lactosa y a las maltodextrinas; la primera estaba presente en el 78% de los pacientes y la segunda en el 10%. No hubo diferencias significativas en la frecuencia de malabsorcion en cuanto al tiempo de evolucion de la riarres ni al estado nutricional de los pacientes. La intolerancia a las maltodextrinas fue significativamente mayor en los menores de seis meses. Los resultado con la prueba de Benedict fueron similares a los encontrado con el Clinitest. Aun cuando en general el ph fecal es mas bajo en los casos de intolerancia, se concluye que su sola medcicion no confirma tal entidad.

Between March and August 1987 we studied 86 children aged 1 to 24 months, who had been admitted to the Lactant Service at Hospital lnfantil, Medellín, Colombia. They were dehydratedas a result of acute, chronic or prolonged diarrhea. Once rehydration was obtained they were put on a lactose-containing diet. Lactose and maltodextrine intolerance were diagnosed employing Clinitest and were found to be present in 78 and 10% respectively. The frequency of malabsortion was not significantly different in regards to duration of diarrhea or nutritional status of patients. Maltodextrine intolerance was significantly more common in those under six months of age. Benedict test and Clinitest ylelded similar results. Fecal pH was generally lower in children with intolerance but this finding was not confirmatory of the presence of this entity

Assuntos