Gelatin-based films containing soy lecithin or Yucca schidigera extract and glycerol as plasticizer were produced by casting and characterized for their mechanical properties, water vapor permeability (WVP), water solubility, opacity and morphology. The addition of glycerol reduced the tensile strength, with a difference of ~ 68% between the values for the minimum and maximum concentrations evaluated, both for the plasticizer and the surfactant. Elongation values reached 52% and 40%, for films containing yucca extract and lecithin, respectively, when higher amounts of plasticizer and surfactant were added. Lower values of WVP were obtained when the intermediate concentration of glycerol (20 g plasticizer/100 g protein) was used, reaching 0.14 and 0.15 g mm/m² h kPa, respectively, for films containing yucca extract and lecithin. The solubility was not affected by adding plasticizer and / or surfactants. The morphologies of the inner sections of the films, regardless of type of surfactant used, were compact, without pores or phase separation, indicating efficient incorporation of the compounds added to the protein matrix.

As amoras-pretas apresentam coloração atrativa devido à presença de antocianinas, porém a utilização destes pigmentos como corante natural é difícil, pois alguns fatores, especialmente pH>3, provocam sua descoloração. Por outro lado, a microencapsulação tem sido utilizada na indústria para proteger ingredientes ativos. Os objetivos deste estudo foram estabelecer as condições de encapsulação de antocianinas de amora-preta, avaliar as características das cápsulas, bem como a liberação de antocianinas. Três polissacarídeos (curdlana, pectina e alginato de sódio) foram avaliados como material de parede para obter cápsulas por gelificação. A curdlana foi escolhida, pois foi a única goma capaz de formar um gel firme sob baixo pH. As cápsulas apresentaram forma esférica e multinucleada, e a eficiência de encapsulação variou entre 80,3 e 96,7%. As curvas de liberação apresentaram comportamento cinético de primeira ordem, com forte efeito "burst" com 80 a 100% das antocianinas liberadas em solução pH 1 após 20 min.

Blackberry shows an attractive color due to the presence of anthocyanins; however the use of these pigments as natural colorant is difficult since some external agents, specially pH>3, cause their discoloration. On the other hand, encapsulation techniques have been widely used in the industry to protect active ingredients. The aims of this study were to establish the encapsulation conditions of anthocyanins from blackberry, to evaluate the capsules characteristics, as well as the anthocyanins release. Three polysaccharides (curdlan, pectin and sodium alginate) were evaluated as wall material to obtain capsules by gelation. Curdlan was chosen since it was the only gum capable to form hard gel under low pH value. The capsules showed spherical form and multinucleated appearance, and encapsulation efficiency ranged from 80.3 to 96.7%. The release curves followed first order kinetics, with a strong burst effect, 80 to 100% of the anthocyanins released in solution at pH 1 after 20 min.

Os objetivos deste trabalho foram desenvolver filmes à base de pectina de baixo teor de esterificação, amidada, com adição dos ácidos graxos láurico (AL), palmítico (AP) e esteárico (AE) e caracterizá-los quanto às propriedades de permeabilidade ao vapor de água (PVA) e ao oxigênio, propriedades mecânicas (tensão de ruptura e elongação), solubilidade em água e opacidade, além de observar a morfologia da superfície dos filmes utilizando microscopia eletrônica de varredura (MEV). A adição de 12 e 18% dos ácidos promoveu aumento da PVA e da elongação e redução da tensão de ruptura, em relação aos filmes com 6% de ácido graxo. Todos os filmes apresentaram-se 100% solúveis em água e mais opacos quando os ácidos graxos foram adicionados. A partir da MEV, foi observado que os ácidos graxos não se incorporaram à matriz filmogênica.

The purposes of this research were to develop and characterize composite biofilms produced with low methoxyl amidated pectin plus lauric, palmitic and stearic acids. Water vapor permeability, oxigen permeability, mechanical properties (tensile strength and elongation), water solubility, opacity and, surface morphology were evaluated. The increase of fatty acids addition to 12 and 18% resulted in an increase in water vapor permeability and elongation and a decrease in tensile strength compared to the level of 6% of fatty acids. All formulations produced films showing 100% water solubility. As observed by scanning electronic microscopy the fatty acids were not homogeneously incorporated on the filmogenic matrices.