Navegando por Palavras-chave "Complex Coacervation"

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    Microcápsulas por coacervação complexa: avaliação do polissacarídeo de chia e proteínas vegetais como materiais de parede
    (Universidade Federal de São Paulo (UNIFESP), 2020-02-20) Silva, Leticia Ascendino [UNIFESP]; Bonsanto, Fabiana Perrechil [UNIFESP]; Universidade Federal de São Paulo
    The complex coacervates formed from biopolymers such as proteins and polysaccharides have received increasing attention due to their characteristics of biodegradability, biocompatibility, non-toxicity and low cost. The present work developed and evaluated microcapsules with hydrophobic core, obtained by complex coacervation, from the interaction of emulsions that were stabilized by rice protein (RP) or pea protein (PP) with chia polysaccharide (CP). These pairs are unpublished on the literature and emerge as an alternative to materials from animal sources, once they can be used by vegan and vegetarian consumers. The use of gelatin (GE) and arabic gum (AG) as model compounds was also evaluated. CP are not found commercially, therefore this extraction was necessary. It was extracted at room temperature, without using organic solvents. Different conditions of extraction were evaluated. The yield (Y) varied around 3% with a maximum of 4,8% for a 6 h extraction. The majority centesimal composition was carbohydrates (75%) and proteins (19%). About 85% of the analyzed monosaccharides were arabinose and xylose. The degradation of the polysaccharides occurs at temperatures above 250 ° C and the application of ultrasound increases the thermal stability of the extracted product. FTIR analyzes indicate that there was no change in the functional groups of the obtained polysaccharides. The net charge of the extracts is negative in the highest studied pH range, with pKa around 1.7. The samples showed a weak gel behavior with pseudoplastic characteristics. The polysaccharide sample with the highest Y was chosen for the microencapsulation stage. Zeta potential, turbidity and macroscopic appearance analyzes were used to determine the best ratio and the best pH of interaction between each pair of biopolymers. The ratios 01:01 and pH 2.5 for RP:AG, 01:02 for PP:AG and pH 2.5, 03:01 and pH 2.0 for RP:CP, 03:01 and pH 2.5 for PP:CP and 03:01 and pH 4.0 for GE:CP were evaluated. In all tested conditions, microparticles were formed with the average diameter varied from 22 to 53 µm. The Y for microparticles containing CP were higher (Y> 74%) than those containing AG (Y <40%) indicating that CP interacts better than AG with the proteins studied under the analyzed conditions. For the PP: AG system, the encapsulation efficiency was 9%, for the other studied systems it varied from 55% to 99%, showing a high potential for oil incorporation. The RP:CP system has lower R and EE, but higher when compared to PP:CP and GE:CP . PP:CP behaves similarly to GE:CP, which can replace GE on systems that contain CP.