A mixture design approach for developing ginger extract encapsulation by spray drying method: in vitro digestion and release behavior in a model product

Ginger (Zingiber officinale) extract was encapsulated in maltodextrin/modified starch with spray drying. Composition of maltodextrin and composition of modified starch were chosen as mixture components (0%, 5%, 10%, 15%, and 20% (w/v)), while process factor was inlet air temperature (135 ?, 150 ?, and 165?). I-optimal design under combined study type was selected for design of the experiments, modeling, and optimization. The optimum conditions were achieved by pure modified starch with 20% (w/v) in the mixture of wall material and active material under 140.5 ? to achieve 400.09 mg/100 g total phenolics, 65.29% product yield, 98.32% solubility, and 25.84% Carr index. The temperature was found significant for only Carr index, while the mixture components were effective for the remaining responses at p < 0.05. Characterization studies under particle size, particle morphology, and glass transition temperature measurements were applied to the microparticles obtained under optimum conditions. Release of bioactive content from the microparticles was evaluated depending on in vitro digestion system. The release was higher in the intestinal system than in the gastric system. Last but not the least, sunflower oil was selected as the model food product for the application of microcapsules as additive. The oxidative stability of the oil was increased by almost 16%, while total phenolic content and antioxidant activity of the oil were enhanced by approximately twice and four times, respectively.

Automated summary

Ginger extract was encapsulated in maltodextrin/modified starch microcapsules using spray drying. The optimal conditions were achieved with 20% (w/v) modified starch in the mixture, an inlet air temperature of 140.5?, and resulted in 400.09 mg/100 g total phenolics, 65.29% product yield, 98.32% solubility, and 25.84% Carr index. The release of bioactive content from the microcapsules was higher in the intestinal system than in the gastric system. Sunflower oil, when used as a model food product, showed increased oxidative stability, total phenolic content, and antioxidant activity when the microcapsules were added.