Search

Microencapsulation protects core materials from deteriorating due to environmental conditions, such as moisture or oxidation, and improves the bioavailability of active compounds, allowing one to make solid formulations from oils and increase their solubility. Wall and core material properties determine the microencapsulation efficiency and the best results are achieved when a wall material mixture is used to prepare the microcapsules. In this work, we optimized the wall material composition (gelatin supplemented with gum Arabic, Tween 20, and β-cyclodextrin) of Turkish oregano microcapsules prepared by spray-drying technology to increase the product yield, the encapsulation efficiency, and to achieve narrower particle size distribution. When the wall material solution contained 10 g of gelatin, 7.5 g of gum Arabic, 1.99 g of Tween 20, 1.98 g of β-cyclodextrin, and 20 g of ethanolic oregano extract, the encapsulation efficiency of oregano's active compounds, rosmarinic acid and carvacrol, were 96.7% and 99.8%, respectively, and the product yield was 85.63%. The physicochemical properties, microscopic morphology, and in vitro release of the prepared microcapsules were characterized in the study. The use of gelatin as the main coating material, in supplementation with gum Arabic, Tween 20, and β-cyclodextrin, not only improved the encapsulation efficiency, but also increased the in vitro release of both main active compounds of Turkish oregano extract—rosmarinic acid and carvacrol. [ABSTRACT FROM AUTHOR]

The microencapsulation of maqui juice by spray-drying and freeze-drying was studied as a strategy to protect anthocyanins in new food formulations in order to improve the anthocyanin retention before consumption and the bioaccessibility. It is well known that the encapsulation method affects both the shape and size of powders, being assumed that undefined forms of freeze-drying powders might affect their stability due to the high permeability to oxygen. The objective of this study was to compare the microencapsulation of maqui juice by spray-drying and freeze-drying, evaluating the stability of specific anthocyanins in yogurt and after in vitro digestion. Results indicated that most relevant differences between spray-drying and freeze-drying powders were the morphology and particle size that affect their solubility (70.4–59.5%) when they were reconstituted in water. Nevertheless these differences did not affect the stability of anthocyanins as other research have proposed. Both encapsulation methods generated powders with a high stability of 3-O-monoglycosylated anthocyanins in yogurt (half-life values of 75–69 days for delphinidin-3-sambubioside). Furthermore, no significant differences in the bioaccessibility of anthocyanins between maqui juice powders (44.1–43.8%) were found. In conclusion, the microencapsulation of maqui juice by freeze-drying is as effective as spray-drying to produce new value-added food formulations with stable anthocyanins. [ABSTRACT FROM AUTHOR]