Potencialidades da succinil quitosana como emulsificante e substituto de fração lipídica em massa de bolo / Potentialities of succinyl chitosan as emulsifier and lipid fraction substitute on cake batter

A necessidade da criação de produtos inovadores com características funcionais está relacionada com a demanda de consumidores que priorizam o bem-estar vinculado a uma alimentação saudável e equilibrado. Nesse sentido, o objetivo deste estudo foi avaliar os efeitos da adição de succinil quitosana (SQ) como um substituto da fração lipídica e agente emulsificante sobre a qualidade de bolos. Para tanto, no capítulo 1 foi realizado um levantamento conciso da literatura para a compreensão dos temas abordados. No capítulo 2, o estudo da SQ se baseou na sua obtenção e caracterização para aplicaçãoem bolos. A análise de infravermelho e difração de raio X validaram as reações de desacetilação e succinilação, sendo que os estudos térmicos demonstraram estabilidade térmica (acima de 300 °C) viabilizando a utilização da SQ em produtos de panificação. A aplicação da suspensão de SQ (2,0 g/100 g) em massas de bolos com níveis reduzidos de gordura (0 % (controle), 25 %, 50 %, 75 % e 100 % (ausência total de gordura)) com ajustes na quantidade de água, para adaptação das consistências das massas, resultou em massas de bolos com parâmetros de viscosidade semelhantes. A redução de gordura até um nível de 50 % e presença de SQ contribuiu para o aumento da área 2D (de 13, 83 para 19,05 mm2) e razão largura/altura, além da umidade e atividade de água. A SQ influenciou significativamente (p < 0,05) na vida de prateleira, visto que a taxa de endurecimento foi de 27,8 (N/dia) para os bolos controle, e em bolos com nível de 25 % apresentou o valor de 26,1 (N/dia) e 49,2 (N/dia) para àqueles com presença total de SQ. Os teores de lipídeos diminuíram significativamente (p < 0,05), embora o conteúdo total de minerais e proteínas tenham apresentado ligeiras variações. Em relação à análise sensorial, foram atribuídas aos bolos com redução de até 50 % de gordura notas entre 6 e 7, e àqueles com 75 % de redução, nota inferior para os atributos de textura, sabor e aspecto geral. Dos provadores, 35 % "provavelmente comprariam" os bolos com 50 % de gordura. Nesse sentido, a SQ pode ser considerada um potencial substituto de gordura em bolos, podendo-se reduzir à metade a quantidade deste ingrediente em sua formulação original, agregando qualidades tecnológicas, sensoriais e nutricionais a esses produtos

The need to create innovative products with functional characteristics is related to the demand of consumers which prioritize the well-being combined to a healthy and balanced diet. In this sense, the objective of this study was to evaluate the effects of the addition of succinyl chitosan (SQ) as an emulsifying agent and lipid fraction substitute on the qualities of cakes. Therefore, in chapter 1 a concise survey of the literature was carried out to understand the themes covered. In chapter 2, the SQ study was based on its obtaining and characterization for application in cakes. Infrared analysis and X-ray diffraction validated the deacetylation and succinylation reactions, and the thermal studies demonstrated thermal stability (above 300 °C), allowing the use of SQ in bakery products. The application of SQ suspension (2.0 g / 100 g) with reduced levels of fat (0 % (control), 25 %, 50 %, 75 % and 100 %) adjusting the amount of water, to adapt the batter's consistencies, resulted in cakes with similar viscosity parameters. The reduction of fat up to 50 % and presence of SQ contributed to the increase of the 2D area (from 13,83 to 19,05 mm2) and width / height ratio, as well as moisture and water activity. SQ significantly influenced (p <0.05) shelf life, since the hardening rate was 27,8 (N / day) for control cakes, and in cakes with a 25% level the value was 26,1 (N / day) and 49.2 (N / day) for those with total presence of SQ. The lipid contents decreased significantly (p <0.05), although the total content of minerals and proteins showed slight variations. Regarding sensory analysis, scores between 6 and 7 were attributed to cakes with a fat reduction of up to 50%, and those with a 75% reduction were attributed a lower score, according to the attributes of texture, taste and overall appearance. From consumers, 35% "I would probably purchase" the cakes with 50% fat. In this sense, SQ may be considered a potential substitute for fat in cakes, and it can reduce the amount of this ingredient by half in its original formulation, adding technological, sensorial and nutritional qualities to these products

Research Progress in the Chemical Modification of Chitosan and the Antioxidant Activity of Its Derivatives / 中国药师

Chitosan (CS) is a natural,non-toxic biopolymer mainly made from the deacetylation of chitin. Chitosan has good bio-compatibility with unique antioxidant and biodegradable properties. Due to the poor solubility of chitosan in neutral or alkalinized media,the application of chitosan is restricted. Thus,numerous chitosan derivatives have been developed through chemical modifica-tions to broaden the application scope and improve its value. Chitosan and its derivatives with antioxidant activity have shown superior medical value in recent years. In this paper,several modification methods of chitosan were reviewed. In addition,the research progress in chitosan and its derivatives as antioxidants was introduced.

Preparation and in vitro studies of polysaccharide modified compound liposomes loaded with paclitaxel and doxorubicin / 中国药科大学学报

The objectives of this study were to prepare polysaccharide modified compound liposomes loaded with paclitaxel (PTX) and doxorubicin (DOX) and characterize their phyisicochemical properties,stability and in vitro release profiles.Both PTX-DOX-Lipo and N-lauryl-O-glycol chitosan (LGC) modified liposomes (PTX-DOX-Lipo-LGC) were successfully prepared,and the morphology of the liposomes was observed by transmission electron microscope (TEM),and particle size and zeta potential were analyzed by dynamic light scattering (DLS).pH and osmotic pressure were also determined.The drug loading and encapsulation efficiency,stability and in vitro release were assayed using high-performance liquid phase.Both PTX-DOX-Lipo and PTX-DOX-Lipo-LGC exhibited spherical shape with smooth surface.The average diameter was about 150 nm.pH value and osmotic pressure were in the range of 5.3-6.1 and 820-870 mOsm/kg,respectively.Both PTX and DOX could be encapsulated in liposomes with high encapsulation efficiency (greater than 90％).Compared with PTX-DOX-Lipo,PTX-DOX-Lipo-LGC exhibited lower leakage,higher stability in serum and more sustained release profiles.Moreover,a quicker release rate was observed in pH 5.8 PBS compared with pH 7.4 PBS.PTX-DOX-Lipo-LGC with high drug loading,good stability and sustained drug release profiles has a wide prospect in future clinical application.

Progress in research of chitosan derivatives in bioadhesive drug delivery system / 中国药学杂志

OBJECTIVE: To review the applications and progress in research of chitosan derivatives in bioadhesive drug delivery system.