Maria Helena Rocha Leão

Ascorbic acid retaining using a new calcium alginate-Capsul based edible film

This work aimed to produce a new calcium alginate-Capsul edible film with antioxidant incorporated in matrix. The vitaminic stability was evaluated in the films during their storage under different conditions for 140 days. The films were characterized with respect to their mechanical properties and surface morphology. The results indicated a 25.6% of vitamin C incorporation in matrix during the film preparation. The films stored under refrigeration in the dark did not show a decrease in the vitaminic retention. The films stored under room temperature in the dark and in the bright/dark cycles exhibited significant decreases in the vitamin retaining from the 84th and 70th days, respectively. The vitamin C addition significantly decreased the tensile strength in the new pellicle. The results of the microscopy revealed a cohesive matrix in the new edible films. These results support the utilization of the new pellicle to protect ingredients, although more studies are necessary.This work aimed to produce a new calcium alginate-Capsul edible film with antioxidant incorporated in matrix. The vitaminic stability was evaluated in the films during their storage under different conditions for 140 days. The films were characterized with respect to their mechanical properties and surface morphology. The results indicated a 25.6% of vitamin C incorporation in matrix during the film preparation. The films stored under refrigeration in the dark did not show a decrease in the vitaminic retention. The films stored under room temperature in the dark and in the bright/dark cycles exhibited significant decreases in the vitamin retaining from the 84th and 70th days, respectively. The vitamin C addition significantly decreased the tensile strength in the new pellicle. The results of the microscopy revealed a cohesive matrix in the new edible films. These results support the utilization of the new pellicle to protect ingredients, although more studies are necessary.

Encapsulation of the alpha-tocopherol in a glassy food model matrix

a-tocopherol was encapsulated in a glassy food model based on solution of maltodextrin (DE 20) and gelatin, through the use of quick freeze and freeze-drying procedures. The ratio of the maltodextrin, a-tocopherol and gelatin was 3:2:1 respectively. The morphology of the glassy food model was observed by scanning electron microscopy, whose analyses showed a slightly smooth surface and a rather fragile and porous structure due to cavities formed by ice crystals during freezing, and the absence of crystalline structure. It was observed by x ray diffraction that the material is an amorphous state. The samples stored in a specific plastic vessel isolated from gas and light held its amorphous state with no variations that concern to morphology and keeping 100% of the encapsulated a-tocopherol up to 90 days at 25 and 35 °C.

Removal of skim milk lactose by fermentation using free and immobilized Kluyveromyces marxianus cells

Kluyveromyces marxianus CBS 6164 cells, free or immobilized in Ca-alginate (2%) beads, are able to consume more than 99% of the skim milk lactose in anaerobic conditions. In batches at 30 °C, the lactose consumption after 3.5 h of skim milk fermentation by 30 and 50 g free K. marxianus cells per liter was around 99 and 99.6% respectively, with an approximate conversion of lactose to ethanol and CO2 of 80%. The immobilized cells, easy to handle and showing a faster and easier separation from the fermented medium compared to the free ones, were used in more than 23 batches (cycles of re-use) without losing their activity.Kluyveromyces marxianus CBS 6164 cells, free or immobilized in Ca-alginate (2%) beads, are able to consume more than 99% of the skim milk lactose in anaerobic conditions. In batches at 30 °C, the lactose consumption after 3.5 h of skim milk fermentation by 30 and 50 g free K. marxianus cells per liter was around 99 and 99.6% respectively, with an approximate conversion of lactose to ethanol and CO2 of 80%. The immobilized cells, easy to handle and showing a faster and easier separation from the fermented medium compared to the free ones, were used in more than 23 batches (cycles of re-use) without losing their activity.

Avaliação da porosidade de microcápsulas contendo proteína bioativa por porosimetria de mercúrio e adsorção de nitrogênio

Microcapsules containing lactoferrin were produced by spray drying using dextrin:octenylsuccinate starch, as wall materials. Porosity characteristics of spray-dried microcapsules were investigated by mercury intrusion porosimetry and nitrogen adsorption. The outer and inner structures of microcapsules were studied by Scanning Electron Microscopy and sizes were determined by Laser Diffraction. Results indicate that all microcapsules presents adsorption isotherm of type II and that micropores on the microcapsules surface will be very few or none. Our results show that microstructure, surface area and size of microcapsules are affected by dextrin: octenylsuccinate starch proportion. Pore characteristics for various microcapsules are found to be different.

Microencapsulation of Passion Fruit (Passiflora) Juice in Capsul

Food microencapsulation has been an efficient way of raising food shelf life during storage. Passion fruit juice was encapsulated in Capsul® and stored at different temperatures. The shelf life of vitamin C was analyzed and X-ray diffraction, scanning electronic microscopy, and laser diffraction analyses were performed. Samples stored at 7, 25, and 37°C retained 91.4, 81.1, and 36.2%, respectively, of vitamin C after storage. Capsules had an average size of 205.7 ± 0.09 μm and were presented in an amorphous form. Capsul® was shown to be an interesting material for the encapsulation of passion fruit juice.

Linhaça marrom e dourada: propriedades químicas e funcionais das sementes e dos óleos prensados a frio

The aim of the study was to compare the chemical composition and antioxidant capacity of the brown and golden flaxseed and their cold-pressed oils, and evaluate the oxidative stability of oils. We determined the chemical composition, total antioxidant capacity and total phenolic compounds of the seeds. In the oils we determined acid and peroxide value, unsaponifiable matter, composition of fatty acids and tocopherols, phenolic compounds, antioxidant capacity and oxidative stability in four storage conditions up to one year. There were no significant differences between the flaxseed types in the analyzed properties and between the oils in terms of yield after pressing, composition of unsaturated fatty acids, acid value, unsaponifiables and phenolic compounds. The oxidative stability of both oils decreased with storage time, however the brown flaxseed oil and the oils stored under refrigeration were more stable. The peroxide value was higher in the golden flaxseed oil. The total tocopherol content and antioxidant capacity were higher in brown flaxseed oil. It was observed equality between the brown and golden flaxseed and a superiority of brown flaxseed oil.

Extraction, chemical modification by octenyl succinic and characterization of cyperus esculentus starch

The purpose of this study was to characterize, isolate and chemically modify tiger nut (Cyperus sculentus L.) starch with octenyl succinic anhydride. The efficiency of the chemical modification was 0.04. Chemical composition, particle morphology (SEM), particle size, X-ray diffraction, infrared analysis, thermogravimetric analysis, differential scanning calorimetry and swelling and solubility power were determined for characterization of the native and modified starch. Both showed similar chemical composition and amylose and amylopectin contents, as well as absorption spectra in the infrared region without modification of the molecular structure and A-type crystalline pattern. The particles of both had an oval and spherical shape. The modified starch was more resistant to temperature and the gelatinization process occurred at 67.52 °C. These results suggest that tiger nut starch has a great industrial potential.

pH Effect on the Dissolution Behavior of the Microspheres Containing Strontium Ranelate

Strontium is known for efficient actions on bone formation and resorption. Strontium ranelate (SrR) is a commercial drug which maintains this balance during bone turnover, reducing the risks of vertebral fractures in the patients. Calcium phosphate bioceramics associated with alginate matrices containing strontium (Sr) could improve bone regeneration due to gradual Sr release. In this report, the strontium ranelate was incorporated on microspheres of alginate (ALG)/β-tricalcium phosphate in a single route of the production. Energy dispersive spectroscopy showed that strontium was incorporated on the surface of the microspheres produced. Thedissolution behaviour into a buffer solution at pH 4.0 and at 7.4 was evaluated, measuring Sr content on the microspheres after in vitro assays by atomic absorption spectrometry. Dissolution tests showed a rapid strontium release in both assays, however, it was more pronounced at pH 4.0. Fourier transform infrared spectra indicated the presence of a new precipitated phase at pH 7.4 up after 14 days. Scanning electron microscopy of the microspheres submitted to in vitro revealed that the microspheres at pH 4.0 buffer underwent erosion up to 7 days, while the ones in pH 7.4 buffer, eroded in 48h. This behaviour is due to the high swelling rate of the microspheres in neutral pH. The solubility of the microspheres favors its use as a great material for a local strontium release and remodeling bone.