Determination of the minimum integral entropy, water sorption and glass transition temperature to establishing critical storage conditions of beetroot juice microcapsules by spray drying

The aim of this work was to microencapsulate beetroot juice (BJ) (Beta vulgaris L.) by spray-drying using as protective colloid gum Arabic. The adsorption isotherms of the microcapsules and the minimum integral entropy (∆S int)T were determined at 25, 35 and 40 ◦C. The glass transition temperature (Tg) was measured by differential scanning calorimetry and modeled by GordonTaylor equation. The water contents-water activity (M-aW ) sets obtained from (∆S int)T , and critical water content (CWC) and critical water activity (CWA) from the Tg were similar, being in the range of water content of 5.11-7.5 kg H2O/100 kg d.s. and in the water activity range of 0.532-0.590. These critical storage conditions were considered as the best conditions for increase the stability of the microcapsules, where the percentage of retention Betanin in the microcapsules was higher compared with other storage conditions in the temperature and aw range studied. Keywords: beetroot juice, microcapsules, minimum integral entropy, glass transition temperature, critical water content, critical water activity

Effect of new generation enzymes addition on the physical, viscoelastic and textural properties of traditional Mexican sweet bread

Se estudio el efecto de la adición de enzimas en las propiedades viscosas y texturales de un pan tradicional mexicano.The effect of adding new generation enzymes (0.25, 0.5, 0.75, and 1.0% w/w) on traditional Mexican sweet bread physical, viscoelastic (elastic and plastic work) and textural properties was studied. Physical properties as weight lost, pore uniformity, color, etc., improved with enzyme addition. Viscoelasticity properties were analyzed by uniaxial compression test under small strain, showing that the use of small enzyme fractions (~0.25-0.5% w/w) are enough to enhance mechanical behavior (higher elastic work) and cohesiveness and resilience parameters after four storage days. This trend suggests a mechanism related to pore distribution and an equilibrium crust-crumb that lead to improved bread freshness over storage period. Overall, results indicated that relatively low enzyme concentrations can led to important improvements in the fabrication process of traditional Mexican sweet bread. The proposed enzyme concentrations are as small as 0.25-0.3% w/w, corresponding to approximately half the percentage of the amount frequently used in industrial bread production

Interrelationship between the structural features and rehydration properties of spray dried manzano chilli sauce microcapsules

Manzano chilli sauce microcapsules (MCHS) were obtained by spray drying using Gum Arabic (GA100%), whey protein concentrate (WPC100%) and a blend of these biopolymers (GA50%-WPC50%) as wall materials in 2:1 and 4:1 wall to core material ratios (WCMR). Water vapor adsorption isotherms data of microcapsules were obtained at 35 °C and fitted to GAB's model. The monolayer water content values of the microcapsules varied from 9.97 to 14.32 kg H2O/100 kg dry solids, and were used for determining the surface fractal dimension (Ds). Ds values ranged between 2.04 to 2.30 for the 2:1 WCMR and 2.17 to 2.43 for the 4:1 WCMR, respectively. Microcapsules topology was determined by Scanning Electronic Microscopy (SEM). Microcapsules with WPC100% exhibited smoother and more regular shaped topology than those with GA100% which tended to exhibit surface flaws and dents, while those made with the biopolymers blend exhibited an intermediate morphology. Rehydration times of the microcapsules were function of water activity (aw) and WCMR. The higher the WCMR, the higher the rehydration time required

Efectos de las variables de proceso en la microencapsulación del aceite de ajonjolí (Sesamum indica L.) mediante secado por aspersión

Artículo científico en revista indizada en SCOPUS, JCR, CONACyTThe aim of this study was to investigate the effects of the process variables of microencapsulation sesame oil (SO) by spray drying to generate the desired powder quality with the highest efficiency encapsulation and maximum linoleic acid content microencapsulated using a full factorial design of experiments. Thirty two tests were made, and five replicates were conducted on the central points. Independent variables were volumetric dispersed phase (O/W) (0.05, 0.10 and 0.15), wall material to core ratios (Wa:Co) (1:1, 2:1 and 3:1) and drying air inlet temperature (Ti) (120, 140 and160 °C). Surface oil (SOM%), encapsulation efficiency (EE%), linoleic acid content (LAC%), and moisture content (MC%) were analyzed as responses. Under maximum process conditions Wa:Co=2.59:1, O/W=0.05 and Ti=154.04 °C, the response variables including, EE and LAC were predicted as 88.20% and 50.02% respectively. It was concluded that these microcapsules containing high content of linoleic acid can be used as functional food.CONACy

Influence of the wall material on the moisture sorption properties and conditions of stability of sesame oil hydrogel beads by ionic gelation

Artículo científico publicado en la Revista LWT-Food Science and Technology, la cual se encuentra indizada en el JCR, SCOPUS, pertenece al cuartil Q1 con un factor de impacto de 4.0Sesame oil was encapsulated by ionic gelation using matrices of sodium alginate and nopal mucilage as wall material. Moisture sorption isotherms of three different types of hydrogels beads formed by SA-NM (1:0 w/w), SA-NM (1:1 w/w) and SA-NM (1:1.5 w/w) were performed at 25, 35 and 45 °C. Experimental isotherms were described by means of the GAB model, showing sigmoidal shape. Pore radius values of beads ranged from 0.81 to 7.59 nm, corresponding to micropores and mesopores classification. The integral thermodynamic properties were estimated to define conditions of maximum stability of the hydrogel beads. The point of maximum stability, linked to minimum integral entropy, was in the range 3.31-5.59 kg H2O/100 kg d.s. (corresponding to water activity, aW, of 0.23-0.59) in the studied temperature range. Enthalpy-entropy compensation for the beads exhibited the presence of two isokinetic temperatures; one at low moisture contents (0-5.95 kg H2O/100 kg d.s.) controlled by variations of the water entropy, and a second given by enthalpy-driven mechanisms. Overall, the results showed that the hydrogel beads exhibited features of micro- and meso-porous biomaterials. Besides, the composition of the wall material has central implications for the characteristics of the sorption process.Universidad Autónoma del Estado de México mediante el proyecto con clave 4738/2019/CI

Moisture sorption properties and storage stability conditions of a nutraceutical system microencapsulated by spray drying

The adsorption isotherms of a nutraceutical system microencapsulated by spray drying were determined at 20, 35 and 40 °C. Experimental data of the isotherms were fitted using the GAB and Caurie models and the integral thermodynamic functions (enthalpy and entropy) were estimated by the Clausius-Clapeyron equation. The Kelvin and Halsey equations were adequate for calculation of pore radius which varied from 0.67 to 8.15 nm. The point of maximum stability (minimum integral entropy) was found between 3.61 and 3.81 kg H2O/100 kg d.s. (corresponding to water activity, aW, of 0.19-0.37). Enthalpy-entropy compensation for the microcapsules showed two isokinetic temperatures. The first isokinetic temperature was observed at low moisture contents (< 3.81 kg H2O/100 kg d.s.) and was controlled by changes in the entropy of water, whereas the second isokinetic temperature was considered to be enthalpy-driven (3.81-20 kg H2O/100 kg d.s.). Keywords: sorption isotherms, pore radius, minimum integral entropy, enthalphy-entropy compensation, water activity

Rheological and thermal properties of dough and textural and microstructural features of bread obtained from nixtamalized corn/ wheat flour blends

Bread made with corn flour has a rich tradition in several countries. On the other hand, nixtamalization is a process conferring malleability and functionality to corn flour via calcium incorporation. The aim of this work was to study the rheological and thermal properties of dough, and the textural and microstructural features of bread obtained from nixtamalized corn (NCF)/wheat flour (WF) blends. Thermal analysis indicated that NCF promoted the interaction between starch molecules and lipids. The incorporation of NCF improved the viscoelasticity of dough, indicative that the participation of lower amounts of gluten (protein) due to WF substitution by NCF might be compensated by the cross-linking capacity of calcium ions. Morphological analysis via SEM showed that as NCF was incorporated, a more compact and porous microstructure arose that caused breads to exhibit increasing hardness, but a decrease in the rest of the textural characteristics. Increasing amounts of NCF led to more homogeneous bread crust color, characterized by a more subdued lightness and yellow hue. Overall, NCF offers a mean to improve dough viscoelasticity and granular microstructure of wheat-based bread

Propiedades reológicas y térmicas de masa y características texturales y microestructurales de pan obtenido de mezclas de harina nixtamalizada y harina de trigo

Bread made with corn flour has a rich tradition in several countries. On the other hand, nixtamalization is a process conferring malleability and functionality to corn flour via calcium incorporation. The aim of this work was to study the rheological and thermal properties of dough, and the textural and microstructural features of bread obtained from nixtamalized corn (NCF)/wheat flour (WF) blends. Thermal analysis indicated that NCF promoted the interaction between starch molecules and lipids. The incorporation of NCF improved the viscoelasticity of dough, indicative that the participation of lower amounts of gluten (protein) due to WF substitution by NCF might be compensated by the cross-linking capacity of calcium ions. Morphological analysis via SEM showed that as NCF was incorporated, a more compact and porous microstructure arose that caused breads to exhibit increasing hardness, but a decrease in the rest of the textural characteristics. Increasing amounts of NCF led to more homogeneous bread crust color, characterized by a more subdued lightness and yellow hue. Overall, NCF offers a mean to improve dough viscoelasticity and granular microstructure of wheat-based bread

Propiedades térmicas y reológicas de batidos para panqué tipo esponja elaborados con almidón nativo de maíz, con el reemplazamiento total o parcial de harina de trigo

The effect of substituting wheat flour by native corn starch on the rheological and thermal properties of sponge cake batter formulations, and on the texture and microstructural characteristics of sponge cake were evaluated. Thermal analysis showed that starch granules underwent only incipient swelling due to the limited availability of water in the batter matrix. Increasing replacement of wheat flour by native corn starch endowed increasing order to the batter matrix, but produced a decrease in the apparent viscosity, and a drop in the storage and loss moduli. Creep-recovery tests showed that the retardation time was only slightly affected by native corn starch content, indicating that a consolidated 3D network was formed by interaction of starch granules with other components of the batter formulations, with bonds restoration and fracture taking place at similar rates. The textural characteristics of the sponge cake decreased monotonously as the native corn starch content increased. In brief, the use of native corn starch enabled the modulation of the textural properties of wheat-based breads without sacrificing dough viscoelasticity

Thermal and rheological properties of sponge cake batters and texture and microstructural characteristics of sponge cake made with native corn starch in partial or total replacement of wheat flour

The effect of substituting wheat flour by native corn starch on the rheological and thermal properties of sponge cake batter formulations, and on the texture and microstructural characteristics of sponge cake were evaluated. Thermal analysis showed that starch granules underwent only incipient swelling due to the limited availability of water in the batter matrix. Increasing replacement of wheat flour by native corn starch endowed increasing order to the batter matrix, but produced a decrease in the apparent viscosity, and a drop in the storage and loss moduli. Creep-recovery tests showed that the retardation time was only slightly affected by native corn starch content, indicating that a consolidated 3D network was formed by interaction of starch granules with other components of the batter formulations, with bonds restoration and fracture taking place at similar rates. The textural characteristics of the sponge cake decreased monotonously as the native corn starch content increased. In brief, the use of native corn starch enabled the modulation of the textural properties of wheat-based breads without sacrificing dough viscoelasticity