Evaluation of the addition of artichoke by-products to O/W emulsions for oil microencapsulation by spray drying

This study aimed to evaluate the use of artichoke bracts in oil microencapsulation by spray drying. Thus, 1% and 2% w/w of this material was added to sunflower O/W emulsions to partially replace maltodextrin and substitute Tween (R) 20. Emulsions were compared with a control containing only maltodextrin as wall material and Tween (R) 20 as emulsifier. The emulsion containing 2% of artichoke exhibited higher (p < 0.05) viscosity and stability against coalescence and flocculation (24 h) and 20% higher encapsulation efficiency after spray drying, compared with control. The three microcapsules showed similar microstructure, density, porosity, flow properties, and Tg. Microcapsules containing artichoke exhibited, on average, 15% larger particles, 19% lower moisture content, and 9% lower solubility, besides perceptible colour changes. Microcapsules containing artichoke (2%) showed lower oxidation indicators content (37%) after spray drying and over 2 months of controlled storage (35 degrees C, 50% relative humidity) than control. After 90 days, decreases in linoleic acid were observed in all the samples (up to 24%), with increases of oleic and saturated fatty acids. The control showed the highest increase in saturated fatty acids (73%). Hence, artichoke bracts can be exploited for their application in lipid microencapsulation because of their emulsifier properties and the oxidative protection they provide.

Automated summary

This study demonstrates that adding artichoke bracts in oil microencapsulation can improve the stability and encapsulation efficiency of emulsions, while reducing the content of oxidation indicators. Artichoke bract microcapsules have larger particles, lower moisture content, lower solubility, and better antioxidant properties under controlled storage conditions.