RESUMO

Hibiscus extract exhibits considerable antioxidant activity and a high anthocyanin content, which suggesting potential health benefits. However, these compounds are highly susceptible to environmental factors. The aim of this study was to establish the optimal conditions for the encapsulation of Hibiscus sabdariffa extract (HSE) using mixed porous maize starch-gum Arabic to enhance the stability of bioactive compounds under accelerated aging conditions. Response surface methodology (RSM) was used to optimize microencapsulation conditions through spray drying. The optimal conditions for microencapsulation of HSE by RSM were determined to be 126 °C at the inlet temperature (IT) and 8.5 % at the total solid content (TSC). Using these conditions, the amount of bioactive compounds in optimized microcapsules (OMs) was 2368 mg GAE/100 g, 694 mg QE/100 g, and 930 mg EC3G/100 g, of phenolic compounds, flavonoids, and anthocyanin, respectively. The release rate of anthocyanins during in vitro digestion was more effectively regulated in the OM sample, which retained up to 40 % of anthocyanins compared with 10 % in the HSE. The experimental values in this study exhibit high assertiveness, which renders the optimization model technologically and financially viable for the encapsulation of bioactive compounds with potential use in the food and pharmaceutical industries.

Assuntos

Antocianinas , Composição de Medicamentos , Goma Arábica , Hibiscus , Extratos Vegetais , Amido , Hibiscus/química , Amido/química , Goma Arábica/química , Extratos Vegetais/química , Porosidade , Antocianinas/química , Cápsulas , Antioxidantes/química , Antioxidantes/farmacologia , Trato Gastrointestinal/metabolismo , Estabilidade de Medicamentos

RESUMO

Native corn starch and pretreated corn starch were treated with α-amylase, glucoamylase and mixtures of both to generate starches with high porosity with conserved granular structure. Porous starches were characterized; particle size distribution analysis, nitrogen adsorption-desorption analysis, scanning electron microscopy, water and oil adsorption capacity, differential scanning calorimeter, X-ray diffraction and damaged starch techniques were used. The α-amylase/glucoamylase mixture at the highest dose was the best treatment to generate porous starches with interesting adsorption capacity and granular structure conservation. Selected starches were impregnated with chia oil using a vacuum. Pretreated corn starch modified with the α-amylase/glucoamylase mixture showed no significant differences on impregnation capacity compared with native starch with a similar enzyme treatment. The highest oxidative stability was achieved with pretreated porous starch impregnated with 10 to 25% chia oil, compared with the bulk oil (5.37 to 4.72 and 2.58 h, respectively). Results have demonstrated that vacuum impregnation could be a potential technique for the incorporation of oil in porous structures based on starch and porous starches obtained by enzymatic hydrolysis are a promising material for the incorporation and protection of oils susceptible to oxidation.